|
I3BUILETI
of the
FLORIDA
MUSEUM OF
NATURAL HISTORY
WILDLIFE IN SOUTHERN EVERGLADES
WETLANDS INVADED BY MELALEUCA
(Melaleuca quinquenervia)
Nancy K. O'Hare and George H. Dalrymple
Volume 41 No. 1. Dp. 1-68
1997
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WILDLIFE IN SOUTHERN EVERGLADES WETLANDS
INVADED BY MELALEUCA (Melaleuca quinquenervia)
Nancy K. O'Hare and George H. Dalrymple'
ABSTRACT
In the Everglades region of southeastern Florida, invasion of graminoid/herbaceous wetlands by
the invasive, non-native tree melaleuca (Melaleuca quinquenervia) results in a closed-canopy forested
wetland, with a sparse understory. Intermediate stages in this transformation include a savannah with
scattered mature melaleuca trees, and mature dense melaleuca heads surrounded by areas with moderate to
low levels of melaleuca. Intermediate levels of melaleuca invasion have not received any attention and were
the rationale for our study. Wildlife was surveyed monthly for two years to determine species richness and
abundance in wetlands with different melaleuca coverages. Wildlife included all vertebrate classes, as well
as selected macro-invertebrates such as crayfish (Procambarus alleni) and grass shrimp (Paleomonetus
paludosus).
Species richness was highest in areas with moderate melaleuca coverage. Higher species richness
is typical of sites with greater vegetative structural diversity, i.e., as in the savannah stage of invasion, as well
as areas in an early stage of disturbance. The higher species richness was primarily the result of an increased
number of migratory, upland birds. Many of these transient and winter-resident birds occurred at much
lower abundances than in native forested habitats such as cypress swamps (Taxodium distichum), tropical
hardwood hammocks, and pine (Pinus elliottii var. densa) rocklands.
In contrast to the birds, number of species and the abundance of herpetofauna varied little across
the melaleuca gradient. There was no shift in species composition from wetland to upland species as the
melaleuca coverage increased. The number of fish species was similar across the melaleuca gradient
Unlike the herptiles, fishes were less abundant in the closed-canopy melaleuca forests, indicating poorer
habitat quality. Complex patterns of hydrology and gapping in the forest canopy due to wind storms and
fires permitted light penetration and the persistence of productive pockets of aquatic life even within dense
stands of melaleuca.
The mosaic of areas with low to moderate infestations of melaleuca surrounding mature dense
melaleuca stands allowed higher numbers of individuals and species to persist in or seasonally use mature
dense melaleuca stands. This interspersion of habitats resulted in stands of melaleuca with ecotonal edges
that provided marginal habitat for species characteristic of natural communities. Higher degree of
interspersion (more edge) may also mean that the natural areas experience higher exposure to melaleuca seed
source, which may result in a faster rate of spread of melaleuca.
The results demonstrated that animal populations persisted in areas with disturbed vegetation, as
long as critical abiotic factors (in this case hydrology) remained in operation. Areas with moderate levels of
melaleuca retained species composition and productivity typical of the natural wetland community. The
dominant characteristic of the faunal shifts along the gradient of increasing melaleuca coverage was
increased numbers of upland, arboreal, and/or forest species, not the loss of wetland species. Regional
'Current address: Everglades Research Group. Inc., 35250 SW 212 Avenue, Florida City, Florida 33034-4016
O'Hare, N. K, and G. H. Dalrymple. 1997. Wildlife in southern Everglades wetlands invaded by
melaleuca (Melaleuca quinquenervia). Bull. Florida Mus. Nat. Hist. 41(1):1-68.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
permitting and natural resource agencies should recognize that lands with moderate levels of melaleuca may
retain significant habitat quality. Restoration of such lands will demonstrate higher levels of success if the
method used for melaleuca removal allows for retention of the in situ wildlife community.
RESUME
La invasion de los humedales graminoides/herbaceos en la region de los Everglades del sureste
de la Florida por el irbol no native melaleuca (Melaleuca quinquenervia) result en un humedal forestado de
dosel cerrado y de sotobosque ralo. Los estados intermedios de esta transforaci6n incluyen una savana con
melaleucas maduras y dispersas y bosquetes maduros y densos de melaleuca rodeados de areas con
moderados a bajos n6meros de melaleucas. Estos estados intermedios han sido poco estudiados, y por esto,
fueron el foco de nuestro studio. Con el objeto de determinar el n6mero de species y su abundancia en
humedales con diferentes coberturas de melaleuca, se realizaron reconocimientos mensuales de vida silvestre
durante dos aflos. La vida silvestre estudiada incluy6 todas las classes de vertebrados, asi como algunos
invertebrados tales como dos species de camar6n (Procambanis alleni y Paleomonetus paludosus).
El mayor numero de species se encontr6 en areas con una cubierta moderada de melaleuca. Un
mayor numero de species es tipico de ireas con una mayor diversidad structural vegetal, como por
ejemplo, en el estado de invasion tipo savana, asi como tambi6n en areas con un estadio de perturbaci6n mis
temprana. El mayor n6mero de species fue primariamente el resultado de un mayor n6mero de aves
migratorias de tierras mis altas. Muchas de estas epecies de aves en trinsito o residents invemales se
encontraron en abundancias much menores que en bosques natives, como pantanos de cipr6s (Taxodium
distichum), bosquetes de madera dura y bosques de pino (Pinus elliottii var. densa). En contrast a las aves,
el nfmero de species y la abundancia de anfibios y reptiles vari6 poco a traves del gradiente de melaleuca.
No hubo cambio en la composici6n de species a media que la cobertura de melaleuca aument6. El nimero
de species de peces tambi6n fu6 similar a media que la cobertura de melaleuca aument6. A diferencia de
los anfibios y reptiles, los pieces fueron menos abundantes en bosques de melaleuca de dosel cerrado,
indicando una calidad de habitat mis pobre. La presencia de clams en el bosque producidos por tormentas
de viento y fuegos, asi como la compleja hidrologia, permitieron la penetraci6n de luz y la persistencia de
bolsones de productividad de vida acuitica, incluso dentro bosques densos de melaleuca.
El mosaico de ireas con infestaciones de melaleuca moderada a baja rodeando bosquetes
maduros y densos de melaleuca permitieron la persistencia o uso estacional en 6stos 61timos de un n6mero
mayor de individuos y species. El entrelazamiento de habitats result en bosquetes de melaleuca con bordes
ecotonales, los cuales proveyeron habitats marginales para species caracteristicas de comunidades naturales.
Un mayor nivel de entrelazamiento (m6s bordes) tambi6n significa que las areas naturales tienen una mayor
exposici6n a las fientes de semillas de melaleuca, lo cual puede resultar en una tasa de advance mayor para la
melaleuca.
Los resultados demostraron que las poblaciones animals persistieron n areas con vegetaci6n
alterada, siempre y cuando factors abi6ticos critics (en este caso hidrologia) continden operando. Las
areas con una cobertura moderada de melaleuca mantuvieron la composici6n de species y la productividad
tipica de la comunidad natural del humedal. La caracteristica dominate de los cambios faunisticos a lo
largo del gradiente de melaleuca fue el incremento del n6mero de species de tierras altas, arb6reas, o de
species del bosque; no la p6rdida de species de humedal. Las agencies que administran recursos naturales
deben reconocer que areas con niveles moderados de melaleuca pueden retener niveles significtivos de
calidad de habitat La restauraci6n de estas areas puede resultar mas exitosa si el m6todo usado para
remover melaleuca permit la retenci6n de la comunidad silvestre present en dicha irea.
TABLE OF CONTENTS
Introduction ....................................................................................................... .................................. 3
A know ledgm ents...................................................................................................................................... 4
Description of Study Area and Cover Types....................................................... ....................... 4
Sam pling M ethods.................................................................................................. ............................. 6
Hydrological Assessm ent................................. ....................................... ..................................... 8
Statistical M ethods............................................................................................. ................................. 8
Results and D iscussion.................................................................................. ...................................... 11
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
Literature C ited ............................................................................................... ................................. 23
Figures......................................................... ...................................................................................... 26
Tables ............................................................. ....... 48
A appendix ..................................................................................................................... ................ ...... 61
INTRODUCTION
In the Everglades region of southern Florida, invasion of an open canopy,
graminoid/herbaceous wetland by the non-native pest tree melaleuca (Melaleuca
quinquenervia) results in a closed-canopy forested wetland, with a sparse
understory. Intermediate stages in this transformation may include a savannah
with scattered mature melaleuca trees and mature dense melaleuca heads
surrounded by areas with moderate to low levels of melaleuca. Previous surveys of
wildlife in melaleuca-infested areas have focused on either a few species of
mammals (Mazzotti et al. 1981; Sowder and Woodall 1985) or surveyed only dense
melaleuca stands (Schortemeyer et al. 1981; Repenning 1986). Each of these
studies was of short duration (few months). Therefore, relatively little is known
regarding the use of melaleuca-invaded wetlands by native wildlife.
Disturbance of natural communities typically results in an increase in
species richness as "weed" species, non-native, migratory and/or species
uncommon to the natural community increase in numbers (Odum 1983).
Furthermore, areas with higher vegetative structural diversity, such as the
intermediate stages of melaleuca invasion of graminoid wetlands, are likely to have
higher species diversity compared to areas with lower vegetative structural
diversity (c.f. Cody 1985a). Therefore, the number of species (species richness)
and the number of individuals (species abundance) are not, by themselves, a good
measure of the environmental value of a habitat (Van Home 1983). Which species
are using a habitat and the manner in which they use the habitat (foraging,
breeding) are more important to final evaluation of habitat quality (Stauffer and
Best 1980; Keller et al. 1993). A fair analysis of habitat quality of disturbed areas
should evaluate the types of species (e.g., wetland versus upland animals, native
versus non-native), as well as their abundances.
Our goal in this study was to determine species richness and relative
abundance along the single gradient of melaleuca coverage, without presuming to
explain between-taxa differences, or variation within a single cover type. Wildlife
was broadly defined to include selected macro-invertebrates and all vertebrates.
Some of these groups are not traditionally included in wildlife assessments.
However, they were included in this study since the abundance of these animals
indicates the ability of a habitat to support higher trophic level animals, such as
wading birds, alligators, snakes, and mammals.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
ACKNOWLEDGMENTS
We thank Kenneth L Knyko for his dedication to the field work for two wet years. Joseph A.
Wasilewski, Carlos Pages, and Doug Barker also assisted in the field during various times. We also thank
Sue M. Alspach, Frank S. Bernardino, and Jean Evoy of the Dade County Department of Environmental
Resources Management and the members of the South Florida Limestone Mining Coalition. Funding was
provided by South Florida Limestone Mining Coalition, U. S. Army Corps of Engineers, South Florida
Water Management District, and Metro-Dade Water and Sewer Department. Project management, technical
support, and publication costs were provided by Dade County Department of Environmental Resources
Management
DESCRIPTION OF STUDY AREA AND COVER TYPES
The study was performed in northwest Dade County in a 19,400 ha region
known as the Lake Belt Study Area (LBSA). The area is bounded by the Dade-
Broward County line on the north, the Homestead Extension of Florida's Turnpike
on the east, Tamiami Trail (US 41) on the south, and Krome Avenue on the west
(Fig. 1). The area is the single, largest tract of land in the South Florida Water
Management District's proposed East Coast Buffer/Water Preserve Areas between
the urban areas and the remaining Everglades. The western one-third of the study
(between the Dade-Broward Levee and Krome Avenue) is commonly referred to as
the Pennsuco wetlands or Pennsuco Everglades.
The classic vegetation survey by Davis (1943) characterized most of the
area as "saw-grass marshes (medium dense to sparse)," with the southeastern
corner characterized as "saw-grass marshes (with wax myrtle thickets)."
Reconstruction of pre-drainage conditions by Everglades National Park, the Army
Corps of Engineers, and the South Florida Water Management District include
most of the LBSA as part of the long hydro-period marsh of northeastern Shark
River Slough (also see Fennema et al. 1994). Recent hydrological records
demonstrate that the Pennsuco wetlands (west of the Dade-Broward Levee) are still
flooded for more than six months a year under "normal rainfall" (e.g., 1986; Davis
et al. 1994). Soils in the region are classified as muck or peat soils, with depths up
to 1 m (EAS Engineering, Inc. 1995).
A map of existing cover types in the LBSA was generated from 1992
1:300 aerial photographs (Fig. 2; EAS Engineering, Inc. 1995). The region
included approximately 3000 ha of sawgrass marshes with little to no invasion by
melaleuca, 3300 ha of low to moderate coverage by melaleuca (10% to 75%
melaleuca) and 7000 ha with greater than 75% coverage by melaleuca. The
remaining 6100 ha were composed of lakes, littoral zones, agricultural lands,
canals, levees, correctional facilities, electrical power facilities, and power line
right-of-way (EAS Engineering, Inc. 1995).
There was a geographical gradient in the density of melaleuca within the
study area. Areas with the highest coverage by melaleuca tended to be located in
the eastern two-thirds of the region, while areas with lower melaleuca coverage
were located in the western one-third (Pennsuco Everglades). Many of the areas
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
with highest melaleuca coverage were adjacent to developed lands or near
structures that alter local hydrology. In the eastern one-third of the study area,
land uses included a municipal well field and rock-mining. Both of these uses
affected adjacent lands by altering hydro-period, albeit the type of effects differed.
The municipal well field had little effect on the ground surface topography.
However, associated canals and the effect of ground water pumping altered local
hydrology. The manner in which hydrology was altered was not predictable based
upon seasonal weather patterns, but rather was determined by water supply needs.
Therefore, the region may have standing water during the traditional "dry" season
of southern Florida. In contrast, rock-mining substantially altered surface
topography, creating permanent aquatic habitats up to 20 m deep. While the lakes
draw water from surrounding areas, shortening their hydro-period, annual
hydrological patterns fluctuated with normal seasonality of wet-dry periods.
Five cover types were designated for sampling based upon percent
coverage by melaleuca. The following abbreviations were used in the text, tables,
and figures.
1) DMM: 75-100% mature dense melaleuca coverage; DBH of trees>8
cm; stem density of 5000/ha (Hofstetter, unpubl. as cited by Hofstetter
1991)
2) SDM: 75-100% sapling dense melaleuca coverage; DBH of trees<8
cm; stem density of 250,000/ha (Alexander and Hofstetter 1975)
3) P75: 50-75% melaleuca coverage
4) P50: 10-50% melaleuca coverage
5) MAR (Marsh): 0-10% melaleuca coverage
The detailed vegetation map referenced above was not available when site
selection for the Wildlife Studies began. Potential study sites were identified from
the vegetation map in Larsen (1992) and 1992 aerial photographs. Actual site
selection was determined by ground-truthing. Cover types with intermediate
levels of melaleuca coverage (100/%50% and 50%-75%) were the most difficult to
delineate on the ground and also occurred in smaller, less discrete parcels relative
to the other three cover types. The spatial distribution of melaleuca in these areas
usually consisted of a heterogenous mix of melaleuca heads, and savannahs. Since
the minimum extent for cover type designation in the vegetation mapping was 0.40
ha (one acre), sites selected for wildlife sampling, were a minimum of 0.40 ha of
homogenous melaleuca coverage, embedded in a matrix that we judged to be of the
same cover type based upon ground-truthing. For each of the five cover types, ten
sites were selected (50 sites total).
Each site selected for sampling had to be readily accessible on foot from
an existing grade (e.g., up to 1 km from a levee, or right of way). Areas with
melaleuca seemed to be related to developed areas or areas with altered hydrology.
Approximately 75% of the area available for sampling (excluding cover types not
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
sampled, such as lakes or agriculture areas) was within 1 km of some type of
human disturbance (e.g., a primary or secondary road, existing grade, building,
canal or lake). Approximately 20% of the available area that was greater than 1
km from a grade was MAR. Thus only 5% of available area was more than 1 km
from a disturbance, and it was distributed unequally among four cover types.
Primary and secondary roads were located only on the boundaries of the study area.
Vehicular travel within the study area was confined to narrow gravel grades.
Access to these grades was restricted by locked gates at all entry points. The major
north-south grade was the Florida Power & Light (FPL) powerline right-of-way.
Portions of the FPL right-of-way were flooded during the wet season.
SAMPLING METHODS
Drift Fence Arrays
Drift fence sampling required intensive site preparation and permanent
installation of the trapping arrays (see below). Therefore, three sites for each cover
type were repeatedly sampled each month from January 1994 through December
1995. Preliminary surveys of the entire region indicated that a hydrological
gradient might exist from north-south. Hydrological data to either support or
refute these field observations were unavailable. Since sample sizes were low
(three sites per cover type), these sites were located in the northern one-third of the
study area to minimize variation in factors other than melaleuca coverage (e.g.,
hydrology) as a precautionary measure.
Drift fence arrays were checked four days per month, generally, every
other day over an eight day period, beginning the second week of each month. All
15 arrays were checked on the same days.
In studies of the amphibians and reptiles of the Everglades National Park,
drift fences designed to trap amphibians and reptiles also regularly trapped high
numbers of aquatic macro-invertebrates (e.g., crayfish, Procambarus alleni; grass
shrimp, Paleomonetus paludosus; and fishes (Dalrymple 1988; G.H. Dalrymple
and F.S. Bernardino, unpubl. data; Dalrymple 1994). Therefore, drift fence
trapping in this study was used as a sampling method for all aquatic, semi-aquatic
and terrestrial vertebrate animals (including fishes), as well as selected aquatic
macro-invertebrates.
Drift fences were constructed of shade or ground cloth. Each array had
four 15-m-long by 1-m-high arms arranged as a cross [+], with a total of four
funnel traps per array. Traps and funnels were constructed of 1/8" gauge
(approximately 3 mm) galvanized hardware cloth, with two funnels at one end of
each trap. One trap was placed at the end of each arm of the array, so that one
funnel rested on each side of the fence (as done by Dalrymple 1988). Pitfall traps
were not feasible since most sites were flooded six to nine months each year.
Arrays were maintained so that the fencing remained upright and no gaps
developed between the fencing material and the ground. Funnel traps were
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
repaired or replaced as needed. When the traps were not being checked, they were
removed from the end of the fence and the funnels were blocked to prevent animals
from entering the traps.
Standing water did not preclude trapping. However, when traps were
completely underwater, the time period between trap-check days was modified to
minimize mortality of amphibians and reptiles, i.e., traps were checked four
consecutive days rather than every other day for eight days. The number of check
days remained the same (4 days per month). Trap rates were calculated using the
number of days the arrays were open (array days), not the number of times the
traps were checked.
Bird Strip Transects
Bird transects did not require site preparation and, therefore, allowed
sampling to occur in a random subset of 3 of the 10 sites in each cover type each
month. This procedure permitted a wider range of sites to be sampled. Transects
were a fixed length of 100 m. The width of each transect was determined by the
farthest distance to a bird observed during the transect. If the bird was flying
overhead or could not be positively identified, it was not recorded. Sampling of the
15 sites occurred over a 2 -3 day period during the third week of each month. All
data were collected between sunrise and 11 a.m. The order in which cover type
sites were sampled was randomly chosen each month. Sites were sampled
regardless of standing water conditions.
Strip transects for birds in this study were designed to focus on the birds
that have limited daily cruising radii and, therefore, were most likely to reflect
habitat preferences based on vegetative cover rather than hydrology. Perching
birds (blackbirds, shrikes, warblers, cardinals), other land birds (doves,
woodpeckers), some smaller wading birds (snipe, rails), and some birds of prey
usually are studied to evaluate between habitat differences in vegetative cover
(Stauffer and Best 1980). Such surveys also allow assessment of habitat use by
migratory and/or transient birds versus resident breeders (Keller et al. 1993).
Mammal Surveys
Mammals were surveyed using Sherman live traps and scent and bait
stations on a quarterly basis, with one replicate per cover type. Oats were used to
bait 30 Sherman live traps, 15 Sigmodon-, and 15 Peromyscus-sized traps, laid out
in a grid, and checked for three consecutive nights. In addition, one scent
(mammal urine) and one bait station (oily tuna pet food) were also checked the
same three consecutive nights. Sampling generally occurred the first week of the
second month in each quarter (February, May, August, and October). In some
quarters, sampling was either delayed until later in the quarter or simply not
feasible due to high standing water levels.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Incidental Observations
To generate a complete species list for the LBSA, incidental observations
of species within the five defined cover types as well as species noted along
roadways were recorded. This information is presented in Appendix I.
HYDROLOGICAL ASSESSMENT
As a general rule, hydro-pattern (timing, depth, and duration) is a strong
determinant of wetland species diversity and abundance (Mitsch and Gosselink
1986; Campbell and Christman 1982; Dalrymple 1988). Therefore, evaluation of
biological resources in wetlands must consider hydrological conditions. As a
preliminary assessment of gross hydrological patterns, two data sets were gathered
through the Water Resources Section ofDERM. The first data set was the I -year
period (1985 to 1995) of ground water levels measured at USGS wells in the
LBSA. Two gages were randomly selected for more detailed analyses. One gage
was located west of the Dade-Broward Levee (G-975) and the other east of the
Dade-Broward Levee (G-972; see Fig. 2). The second data set was the 1994 and
1995 average monthly ground water levels of the seven USGS gages located in the
LBSA (G-594, G-968, G-972, G-975, G-976, G-1488, and G-3253).
STATISTICAL METHODS
Statistical analyses followed standard procedures outlined in Zar (1996),
Sokal and Rohlf (1995), Gauche (1982), and Krebs (1989). All analyses were
performed using STATISTICA 5.1 (StatSoft, 1995).
Drift Fences and Bird Transects
For the drift fencing data on macro-invertebrates, fishes, and amphibians
and reptiles the two year cumulative numbers (e.g., Sokal and Rohlf 1995; Zar
1996) from each of the 15 sites (3 replicates in the 5 cover types) were analyzed by
ANOVA. Some of the raw data sets did not follow a normal distribution and
neither log nor square root transformations (Krebs 1989) resulted in a normal
distribution. Therefore, in all cases, the data were analyzed by non-parametric
Kruskal-Wallis ANOVA.
For the bird transects, the two year cumulative numbers for each cover
type were analyzed. Cumulative data generated by this sampling protocol could
not be analyzed by ANOVA, because site-specific cumulative measures were not
available. While ANOVA of each of the 24 monthly samples for each method was
possible, most had such low sample sizes as to be or little or no value, and did not
address the larger issue of general patterns of habitat use.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
The above limitations are not critical to statistical analyses in ecological
sciences. "In general, the framework of hypothesis testing has been largely
overused by scientists..., especially in the context of environmental decision
making" (Steidl et al., 1997: 278). Simple statistical tests for average differences
between cover types in numbers of individuals, or numbers of species reveal a
limited amount about the ecological nature of cover type differences (Krebs 1989).
They are useful for recognizing gross differences in species richness or diversity,
but say little about the species composition of the cover types. Therefore,
multivariate techniques that simultaneously consider each species' contributions to
cover type differences (and vice versa) were used (Gauche 1982).
Data sets collected at standard sites, such as drift fence data for fishes,
amphibians and reptiles, or macro-invertebrates, were analyzed using the
multivariate techniques of cluster analysis, factor analysis and/or multidimensional
scaling. These analyses have the same three replicates for each cover type sampled
each month, permit the monthly data to be accumulated for tests of total numbers,
averages, or medians (e.g., see Sokal and Rohlf 1995, Box 9.8), and allow us to see
more of the variation among sites within the same cover type. The plots of these
analyses in the figures have three replicates for the five cover types, entered
separately and plotted separately. These data sets had enough replicates to permit
factor analyses as well as cluster analyses and multidimensional scaling. For
example, the herptile drift fence data has a matrix of 34 rows (species) by 15
columns (locations), i.e., 34 x 15 matrix. All multivariate matrices were derived
from the raw data sets to include the effects of differences in absolute sample sizes.
Cluster analyses were done using the unweighted pair-group average
(UPGMA) amalgamation method of joining groups (Krebs 1989). The joining was
done on a distance matrix generated as the subtraction of each Pearson's product
moment correlation coefficient from unity (1.0, i.e., 1-r), to generate the distances.
If for example two cover type sites or species had a correlation coefficient of 0.91,
then their distance is 1.0-0.91, or 0.09 (i.e., they cluster close together). The factor
analysis method used was the unrotated matrix of principal components based on
the same matrices of correlation coefficients. These methods are standard
procedures, and incorporate the least manipulation of the original data (unlike,
e.g., varimax rotations, etc.). Additionally, multidimensional scaling was used to
corroborate the results of the factor analyses.
Data sets that were collected using randomly located sites do not have the
same geographic locations in each sampling period. In these cases the data for
each cover type were lumped together to represent the overall pattern for the cover
type. For example the bird transect data had a matrix of 46 rows (species) by 5
columns (cover types), i.e., a 46 x 5 matrix. With only five columns, these
matrices were analyzable by cluster analysis but not by factor analysis (the latter
method requires more than five rows and/or columns).
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Tests for Diversity, Evenness, and Patterns of Dispersion
Species diversity was calculated using the Shannon H diversity index (Zar
1996). Species' patterns of dispersion among cover types were characterized as
uniform, random, or clumped (also called contagious or aggregated) using the
Index of Dispersion. The Index of Dispersion (I) was calculated as the variance
divided by the mean, of a sample of locations, where a species was recorded (Krebs
1989; I = variance/mean). The test statistic for this index was chi square (X 2),
where df (degrees of freedom) = number of locations minus 1. Interpretations were
based upon a two way test, in which the null hypothesis that the distribution was
random was accepted if:
X o.R7s < Observed X > X2 0.025
Significant differences less than 0.025 were interpreted as clumped, and greater
than 0.975 were uniform.
Habitat Quality and Species Composition
Habitat requirements for all life history stages of each species were
determined based on the literature and personal experience. Each species was then
assigned to one of two categories based upon these life history traits. For the
purpose of the analysis, species whose respiration, feeding mechanisms, diet,
reproduction, or larval development require 1 to 12 months of standing water each
year were termed "wetland dependent." Species whose respiration, feeding
mechanism, diet, reproduction, or larval development are independent of standing
water were termed "non-wetland." Animals described as "wetland dependent" use
upland habitats, but a population could not persist without suitable wetland habitat.
Conversely, animals described as "non-wetland" use wetland habitats, but their life
history traits allow them to survive and successfully breed outside of wetlands.
Within this group, some species may be highly tolerant of wetland conditions,
while others are intolerant.
Species assigned to the same category may have different preferences with
regard to timing, depth, and duration of flooding.
Some species designations were difficult due to insufficient information.
Others, mainly birds, required consideration of the relationship between hydrology
and vegetation. For example, most woodpeckers use forested wetlands, such as
cypress swamps. However, use of cypress swamps is due to the presence of trees,
not hydrological conditions, since woodpeckers also successfully live and
reproduce in upland forested areas such as pinelands and hardwood forests.
Therefore, all woodpeckers were categorized as non-wetland. In contrast, breeding
common yellowthroats (Geothlypis trichas) are strongly associated with dense,
graminoid vegetation. In this region, this habitat type is dependent upon
hydrological conditions of standing water approximately six to nine months per
year. Therefore, this species was categorized as wetland dependent. The current
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
assigned wetland association of each species of amphibian, reptile, and bird is
listed in Appendix I. Fishes were excluded because they are all, obviously wetland
dependent and were trapped in very high numbers. Therefore, they would
artificially bias the results toward the wetland dependent categorization in the
evaluation of cover types.
Hydrological Assessment
Pearson product moment correlation coefficients (r) were calculated for
each taxa group with water levels measured at USGS gages G972 and G975. In
graphical analyses, the height of the water column and the number of individuals
or species were plotted for each month.
RESULTS AND DISCUSSION
Macro-invertebrates from Drift fencing
During the 24 months of the study, macro-invertebrates were captured at
each of the 15 sites over 160 array days. A cumulative number of 9490 individuals
of 10 species of selected macro-invertebrates were trapped. At any one site, the
number of species of macro-invertebrates trapped ranged from 6 to 10, and the
number of individuals ranged from 199 to 2112 (Table 1). Overall, the most
abundant species were Procambarus alleni and Paleomonetus paludosus (Table 2).
There were no significant differences in the number of individuals
(Kruskal-Wallis H (df = 4, n=15) = 7.6, p=0.11), number of species (H (df = 4, n =
15) = 2.33, p=0.68), or diversity indices (H (df = 4, n = 15) = 2.73, p=6.03) of
macro-invertebrates between cover types (Fig. 3).
In tests of dispersion using the Index of Dispersion, all macro-
invertebrates showed random distributions among cover types (Table 2). This
indicated that cover type, defined by melaleuca cover, was not as important in the
dispersion of the species as were other variables, including standing water.
Cluster analyses revealed two main groupings of macro-invertebrates by
cover types: Paleomonetus paludosus, Pomacea paludosa, Romalea microptera ,
Odonate larvae and Stagnicola sp were predominantly found in MAR and some
of the intermediate cover type sites (P50, P75; Fig. 4). Procambarus alleni,
dytiscid beetles (Dytiscidae), gyrinid beetles (Gyrinidae), Biomphalaria
havanensis, and Lethocerus americanus were predominant in DMM, SDM and
other intermediate sites.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Fishes from Drift fencing
During the 24 months of the study, fishes were captured at each of the 15
sites over 160 array days. A cumulative number of 27 species and 8428 individuals
of fishes were trapped. At any one site, the number of species of fishes trapped
ranged from 10 (DMM site) to 18 (MAR site), and the number of individuals
ranged from 156 (SDM site) to 1111 (P50 site; Table 1). Overall, the most
abundant species were Gambusia holbrooki (3803 fishes), Hemichromis
letourneauxi (1059 fishes) and Fundulus confluentus (1038 fishes; Table 2).
Rarefaction curves for fishes indicated that, after 24 months, sampling
approached maximum species richness in some cover types (Fig. 5). The
rarefaction curves for MAR and DMM indicated that new species could be
expected with additional sampling. MAR had the highest species richness, with
the greatest number of species trapped even though a higher number of individuals
were trapped in other cover types. During the last quarter of trapping, two new
species of fishes were trapped in three of the five cover types. The non-native
cichlids Astronotus ocellatus and Tilapia mariae were trapped in DMM. Lepomis
punctatus and Clarias batrachus were trapped in SDM, and L. punctatus and T.
mariae were trapped in P50. No new species were trapped in P75 or MAR.
Kruskal-Wallis ANOVA was used to compare the average number of
species and the average number of individuals trapped between cover types (Table
1). There were no differences between cover types in the average number of
species trapped (H (df = 4, n = 15) = 4.03, p=0.40). However, there were higher
average numbers of individuals captured in MAR, P50, and P75, than in SDM, and
DMM (H (df = 4, n = 15) = 10.5, p=0.03; Fig. 6). This pattern of abundance of
fishes helped to explain why the intermediate cover types were commonly used by
foraging wading birds, and many fish-eating amphibians and reptiles (see below).
The Shannon Index was not significantly different between cover types (H (df = 4,
n = 15) = 2.27, p=0.69). There were no significant differences in the number of
individuals, or species of non-native fishes found among the cover types (p's>0.05;
Fig. 7).
Of the 27 species of fishes, 16 showed clumped distributions. However,
only seven species showed this clumping within a single cover type (Table 2).
Lucania goodei, Lepomis punctatus and A. ocellatus clumped in MAR.
Lepisosteus platyrhinchus and T. mariae clumped in P75. Belonesox belizanus
and Etheostoma fusiforme clumped in SDM. Each of the other taxa that showed
clumped distributions, 9 of 16 (or 56%), were clumped in locations in more than
one cover type. Since only 7 of 27 species (26%) showed clumped distribution
within a single cover type, variables other than melaleuca density were equally
important in determining species abundance. These variables would include
variations in historical patterns of distribution, hydropattern, and access to deep
water refugia.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
Cluster analyses of the data for fishes showed the three MAR replicates
tightly grouped together, but joined by a range of replicates from intermediate
cover types, and even DMM. Four of the six dense melaleuca sites (DMM and
SDM) clustered together with one P75 site (Fig. 8). This result demonstrated the
wide overlap in fish community structure along the melaleuca gradient. In other
words, most species of fish were found wherever there was standing water.
Seven species of non-native fishes were trapped or observed in the LBSA.
These species were Hemichromis letourneauxi (1059 individuals), Cichlasoma
bimaculatum (656 individuals), B. belizanus (106 individuals), Cichlasoma
managuense (62 individuals), A. ocellatus (21 individuals), Clarias batrachus (12
individuals), and T. mariae (5 individuals). The 19 A. ocellatus trapped in MAR
cover type were all juveniles, trapped on the same day in the same trap. Juveniles
of five species were trapped (H. letourneauxi, C. bimaculatum, A. ocellatus, C.
managuense, T. mariae). Belonesox belizanus, C. managuense, and H.
letourneauxi are predaceous on small forage size fishes. These small to moderate
size predators may have an impact on the natural recruitment of many forage fish
species in the area. However, it is likely that they are preyed upon by higher level
consumers (snakes, wading birds).
As was the case for the macro-invertebrates, the distribution of many
fishes was not strongly related to the gradient of melaleuca coverage. However,
their abundances were lower in dense melaleuca coverages. This translated into a
lower forage base for many higher-level consumers (e.g., many amphibians and
reptiles, wading birds, some mammals).
Amphibians and Reptiles from drift fencing
During the 24 months of the study, amphibians and reptiles were captured
at each of the 15 sites over 160 array days. A cumulative number of 1265
individuals of 34 species of amphibians and reptiles were captured. At any one
site, the number of species of herptile trapped ranged from 10 (DMM site) to 22
(two P75 sites). The cumulative number of individuals ranged from 33 (MAR site;
trap rate of 0.21 amphibians and reptiles per array day) to 175 (SDM site; trap rate
of 1.09 amphibians and reptiles per array day; Table 1). Overall, the most
abundant amphibians were Rana sphenocephala (218 individuals),
Eleutherodactylus planirostris (167 individuals), and Bufo quercicus (94
individuals; Table 2). The most abundant reptiles were Nerodia floridana (89
individuals), Anolis sagrei (83 individuals) and Nerodiafasciata (46 individuals).
Rarefaction indicated that the number of species trapped was near or at
maximum levels (Fig. 9). During the last quarter of trapping, no new species of
amphibians and reptiles were trapped in any of the cover types. Rarefaction curves
were similar for all cover types. Furthermore, rarefaction curves for melaleuca
invaded wetlands exceeded the short-hydroperiod prairies in Everglades National
Park (Dalrymple 1988).
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Kruskal-Wallis ANOVA was used to compare the average number of
species and the average number of individuals trapped between cover types. There
were no significant differences between cover types in the average number of
species (H (df= 4, n = 15) = 7.68, p=0.11), average number of individuals (H (df=
4, n = 15) = 4.87, p=0.30), or Shannon diversity (H (df = 4, n = 15) = 3.77,
p=0.44; Fig. 10).
Of the 34 species of amphibians and reptiles, 18 (54%) showed clumped
distributions. However, only six species showed this clumping within a single
cover type (Table 2). Kinosternon bauri and Bufo terretris clumped in MAR.
Thamnophis sirtalis and Eumeces inexpectatus clumped in P75. Anolis sagrei and
Hyla cinerea clumped in DMM. The other 12 taxa with clumped distributions
were clumped in locations in more than one cover type. Since only 6 of 34 species
(18%) showed clumped distributions within a single cover type, this indicated that
variables other than melaleuca density were also important in determining species
abundance. These variables may include variations in historical patterns of
distribution, hydro-pattern, and access to either deep water refugia or high ground
refugia (c.f. Campbell and Christman 1982).
When the numbers of individuals of each species were placed in a
correlation matrix by cover types for cluster analyses, the sites that shared similar
species composition were easily identified. In the cluster analysis by cover types, all
three MAR sites separated out with one of the P50. The other two P50 grouped
with the P75. The SDM and DMM separated as a third distinct group (Fig. 11).
When the same matrix was analyzed by species composition, Rana grylio, K.
bauri, N. floridana, Regina alleni, and Acris gryllus all clustered together as good
indicators of MAR. The majority of snakes, lizards, frogs, and toads used the wide
range of intermediate cover types (P50 and P75). This included fully aquatic
species such as Farancia abacura, Amphiuma means, and N. fasciata. The non-
native Osteopilus septentrionalis, Eleutherodactylus planirostris, and Anolis
sagrei, together with the native Gastrophryne carolinensis, Bufo quercicus, and
Siren lacertina grouped together in DMM and SDM. Factor analyses of the
loadings of the taxon on the first two principal components showed a broad
scattering (Fig. 12). Taxa at one extreme (left side of graph) were typical of MAR
and P50. Taxa at the other extreme (right side of graph) were typical of DMM and
SDM. The taxa with significant clumped distributions were shaded (I index
p's<0.025; Table 2).
The presence of so many S. lacertina in DMM and SDM habitats was
unexpected (Table 2). This salamander is fully aquatic, and, is unable to feed out
of the water (Bishop 1962; personal observation). It quickly dies from desiccation
on dry land and does not disperse over dry areas. It was trapped at 11 of the 15
drift fence sites. Of the 60 S. lacertina trapped by drift fencing, 22 were trapped in
one DMM site which was isolated from areas of lower melaleuca density. This
species has a rather limited home range and individuals were trapped as soon as
standing water levels existed. Four individuals were trapped at this site two days
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
after heavy rain resulted in flooding of this site. A fifth, large individual was
trapped on the third day following flooding. These short intervals indicated
subterranean refugia near the trapping sites. Another 11 S. lacertina were trapped
at one SDM site. Refugia for this species are known to be subterranean moist soils,
where they aestivate in a mucus covering (Bishop 1962). The substrate of porous
limestone overlain with up to 1 m of muck soil was readily accessible via numerous
crayfish burrows and natural crevices. A similar pattern of rapid exploitation of
surface water was found forA. means by Machovina (1994).
Two species of non-native amphibians and one species of non-native
reptile were trapped. All three species were typical of drier, ruderal or edificarian
habitats (Duellman and Schwartz 1958; Dalrymple 1988). Osteopilus
septentrionalis (10 individuals) was trapped in P75, DMM and SDM. This
treefrog requires standing water for its egg/tadpole stage, yet these stages are of
short duration (less than two months). Eleutherodactylus planirostris (167 frogs)
was trapped in 8 separate sites representing DMM, SDM, and P75 habitats.
However, 90% of these frogs were trapped at just two sites (109 frogs at a SDM site
and 41 frogs at a DMM site). This frog has no aquatic egg/tadpole stage. Anolis
sagrei is highly tolerant of disturbed settings (Wilson and Porras 1983). It was
most abundant in DMM (52 lizards from 3 sites), although it was trapped in all
cover types (83 lizards total across all habitats).
Birds from strip transects
When the strip transect data were analyzed as twenty-four month
cumulative data, 518 individuals of 46 species were observed across all five cover
types (Table 3). P75 had the highest number of species (29) and the highest
number of individuals (146; Fig. 13). DMM had the lowest number of species (9)
and individuals (39). Marsh had the second highest number of individuals (137)
yet had a lower number of species (15) than SDM, P75 and P50 (22, 29, and 27
species, respectively). Species in P75 were a peculiar mix of typical
wetland/prairie species and upland species. Species observed in DMM were
characteristic forest/edge species. Species observed in Marsh were typical of
Everglades wetlands (herons, egrets, red-winged blackbird (Agelaius phoeniceus),
eastern meadowlark (Sturnella magna), and common yellowthroat (Geothlypis
trichas); Robertson and Kushlan 1984). The Shannon Index was highest in SDM
and lowest in Marsh (Fig. 13). Lower diversity indicated that a fewer number of
species accounted for most of the individuals. Evenness was also highest in SDM.
It was lowest in P75. Lower evenness indicated that some species were dominant,
while others were rare (Odum 1983).
The rarefaction curves of all cover types still showed an upward trend,
indicating that the maximum species richness was not sampled after 24 months
(Fig. 14). The numbers of new species recorded in each cover type during the
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
eighth quarter were: DMM, 0 species; SDM, 1 species; P75, 1 species; P50, 1
species; MAR, 1 species.
Of 46 species of birds observed during transects, 15 showed clumped
distributions. Unlike the patterns seen in macro-invertebrates, fishes and
amphibians and reptiles, most species (11 of 15 or 73%) clumped in a single cover
type (Table 3). Geothlypis trichas, Capella gallinago and A. phoeniceus clumped
in MAR. Sayornis phoebe and Quiscalus major clumped in P50. Colaptes
auratus, Mimus polyglottos, Dendroica coronata, and Dendroica discolor clumped
in P75. Setophaga ruticilla and Pipilo erythrophthalmus clumped in SDM. The
remaining species clumped in adjacent seral stages. The 15 species (33% of total
species) that had clumped distributions accounted for 76% of all individuals
observed in transects (395 of 518). Many species did not show a clumped
distribution simply because they occurred only a few times (e.g., Troglodytes
aedon, Melospiza georgiana). These results indicated that cover type defined by
degree of melaleuca density was very important in the distribution of the many bird
species.
Cluster analysis demonstrated that the species composition of the cover
types was dramatically different (Fig. 15).Geothlypis trichas (57 individuals), and
A. phoeniceus (47) were characteristic of MAR. These two species are resident
breeding species, typical of long-hydroperiod, marsh habitats. They accounted for
76% of all individuals seen in MAR sites during transects. The DMM sites were
characterized by the presence of Carolina wren (Thyrothorus ludovicianus) and
bluejay (Cyanocitta cristata). The majority of herons, egrets, perching birds,
raptors, and woodpeckers used P50, P75, and SDM. These cover types had the
most species represented, but no more individuals than MAR.
Of the 46 species observed during transect surveys, 29 were resident
species and 17 were wintering species (designations based upon Robertson 1955,
Robertson and Kushlan 1984, and Louhglin et al. 1990; see Appendix I). The
percentage of individuals that were resident species was highest in MAR (93%)
and lowest in SDM (49%; Fig. 16). Most migratory species were warblers, which
prefer thickets or forested areas (Morse 1985).
The strip transect method used in this study targeted bird species with
small daily cruising radii, which selected habitat based primarily upon vegetative
cover (e.g., passerines, some raptors), not standing water conditions (e.g., many
wading birds). Yet wading birds are frequently given high profile in wetland
assessments in southern Florida. Again, sampling methods in this study were
intended to provide gross information on all species. Wading birds observed
during transects were generally solitary, foraging individuals.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
Mammals
Cumulative results of small mammal live trapping and use of scent and
bait stations are presented in Table 4. Since the data sets were small, only general
statements on the distributions of each species within each cover type are presented
below.
Dasypus novemcinctus sign was common in DMM. Didelphis virginiana
and Procyon lotor tracks were noted in all cover types. Each of these species are
abundant and common throughout their geographic ranges. Sylvilagus palustris
tracks and scats were observed in all cover types. On two separate occasions, its
scat was found on top of a drift fence funnel trap when sites had standing water.
Felis rufus tracks were noted in P50, P75, SDM and DMM. Urocyon
cinereoargenteus tracks were observed in P75, SDM and DMM. Lutra canadensis
tracks were noted in MAR, and scat occasionally were found along a levee adjacent
to MAR habitat. Odocoileus virginianus tracks were seen in each of the five cover
types during the dry season. All of the above species were directly observed on one
or more occasions.
Live-trapping captured Sigmodon hispidus in P50, P75, and SDM,
Oryzomys palustris in all cover types, and Peromyscus gossypinus in SDM and
DMM (Table 5). The cover type/habitat preferences of these three rodents
observed in this study were similar to trapping results in mature dense melaleuca
versus "mixed melaleuca-graminoid" (Mazzotti et al. 1981) and tree islands
surrounded by sawgrass marsh (Smith and Vriese 1979).
Percent similarity in species composition
The species composition of the MAR cover type was used as a standard to
evaluate species composition of the other four cover types. The number of species
that occurred in both MAR and the comparison cover type was divided by the total
number of species found in the two cover types combined. Separate comparisons
were made for each major vertebrate group, in each cover type. For fishes and
amphibians and reptiles, species composition of each of the four cover types
overlapped between 50 and 70 percent with MAR. The mammals showed
similarities in species overlap with MAR from 40 to 65 percent. The birds showed
the greatest difference in species composition, with between 20 and 30 percent
overlap in species composition to MAR (Fig. 17).
In general, as melaleuca invasion progressed, fishes and amphibians and
reptiles retained a high degree of constancy in community composition. These
faunal groups appeared to move in and out of local areas as water levels seasonally
shifted, regardless of melaleuca density. The birds showed the most dramatic shift
from typical marsh inhabitants to progressively greater numbers of forest dwelling
species. The mammals showed a progressive change from wetland to upland
species as forest cover increased.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
The percent of taxa that occurred in all of the five cover types varied
widely between faunal groups (Fig. 18). Eighty percent of the 10 invertebrate taxa
trapped by drift fencing were found in all cover types. Only 2 of the 46 birds
observed in strip transects were found in all cover types (Geothlypis trichas and
Dendroica palmarum).
Changes in species composition
There were two principal physical gradients in the Lake Belt Study Area
environment: tree density and water levels. Tree density was a geographic
gradient, with density varying primarily from east to west. Water level was
primarily a temporal gradient, varying with seasonal rainfall.
While it has been anecdotally noted in the literature that melaleuca
invasion causes secondary increase in ground surface elevation, we observed little
evidence of this in the study area. Most sites in the study area were flooded
regularly according to existing patterns of rainfall, topography, and water
management.
The dominant characteristic of the faunal shifts along the gradient of
increasing melaleuca coverage was increased numbers of upland, arboreal, and, or
forest species, not the loss of wetland species. As melaleuca coverage increased,
the habitat became suitable to non-wetland species at a faster rate than it became
unsuitable to wetland species. The result was a pattern of increasing species
diversity and abundance in the intermediate cover types. Increased use of areas by
savannah and forest birds, and mammals played a significant role in creating this
gradient.
The dominant characteristic of the faunal shifts along the gradient of
water level was seasonal variation in abundance of wetland species. The majority
of fully aquatic species (the aquatic macro-invertebrates, all the fishes, and some
amphibians and reptiles, birds, and mammals) did use habitat with increased
canopy cover, primarily as an effect of standing water. The existence of this prey
base (invertebrates and forage sized fishes, in particular) permitted higher
consumers to use these habitats.
Canopy closure occurred when melaleuca cover increased beyond 75%,
reducing sunlight penetration and primary productivity of the periphyton,
submerged and emergent vegetation. This had a dramatic effect on the primary
consumers and detritovore macro-invertebrates (e.g., Pomacea, Procambarus),
resulting in overall lower abundance and productivity in the understory. However,
complex patterns of hydrology, and gapping in forest canopy due to wind storms
and fires permitted light penetration and the persistence of productive pockets of
aquatic life even within dense stands of melaleuca.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
Habitat preference and species composition
Gross comparisons of the numbers of species or numbers of individuals
found in each cover type did not yield significant differences among the cover
types. However, multivariate analyses, which considered the contribution of each
species to overall community composition, demonstrated differences between cover
types. Indices of dispersion indicated that many faunal groups were distributed
along a gradient other than melaleuca density. To assist in evaluating community
composition in terms of hydrology, each species of herpetofauna and bird was
categorized based upon their requirement for a particular, gross hydrologic pattern
(see Methods).
Kruskal-Wallis ANOVA was used to compare the 24 month cumulative
number of species and individuals of wetland and non-wetland amphibians and
reptiles trapped at the 15 drift fence sites. There was no significant difference
between cover types in the number species of wetland and non-wetland amphibians
and reptiles (Kruskal-Wallis H (df = 4, 15) = 6.489 and 6.210, p=0.1655 and
0.184, respectively; Table 5). There were also no differences in the number of
individuals of wetland and non-wetland amphibians and reptiles (Kruskal-Wallis H
(df = 4, 15) = 5.510 and 8.610, p=0.239 and 0.072, respectively). The one SDM
and the one DMM site with a low percentage of wetland-dependent individuals
were the two sites where the non-native Eleuthrodactylus planirostris was
abundant (Table 2). As noted earlier, this species does not have a tadpole stage,
does not require standing water during any life history stage, and therefore, is a
non-wetland species.
In contrast to the amphibians and reptiles, when the 24 month cumulative
strip transect data for birds were considered, the occurrence of wetland-dependent
species of birds demonstrated a more dramatic shift. In MAR, wetland associated
species accounted for 80% of the species and 97% of the individuals. DMM had
the lowest percentage of wetland associated species (11%) and individuals (5%;
Table 6).
It is important to recognize that species categorized as "wetland
dependent" may require wetlands only during specific life history stages. Most
anuran amphibians have an egg/tadpole stage that is dependent upon standing
water, yet adults of some species preferentially use upland areas, only returning to
water to breed. Many aquatic snakes and turtles are unable to feed out of water, yet
require dry areas to lay eggs. Additionally, most species will have a preference for
the timing, depth and duration of flooding. Both Geothlypis trichas and Sturnella
magna generally have higher breeding densities when climatic conditions indicate
low standing water levels during the breeding season (Cody 1985b). Most wetland
vertebrates are adapted to using water depths of less than 25 cm (Fredrickson and
Laubhan 1994). Fredrickson and Laubhan state (1994:645): "No single wetland
or wetland type will provide all the resources needed by a single vertebrate during
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
all of its life-history stages or for all vertebrates adapted to wetlands. Thus,
wetland complexes are essential for successful management...".
Grons Hydrological Assessment
Animals experience interannual variation in abundances. These
variations may be partly determined by climatic conditions, such as rainfall (Cody
1985b; Morrow et al. 1997). The South Florida Water Management District has
described the 1994-1995 period of rainfall as a "25-year" high rainfall event
throughout Dade County. While the timing, depth, and duration of standing water
conditions are correlated with rainfall, this relationship may be altered in managed
wetlands by regional patterns of water management. Pumpage for drinking water
well fields, and/or water releases from basin to basin may affect the actual standing
water levels in an unnatural manner. Therefore, we considered ground water
levels as measured at USGS gages located within the study area as an indicator of
hydrological conditions throughout the study area.
To determine if there were significant differences in the average monthly
ground water levels in different regions (sub-basins) of the LBSA 1994 and 1995
data for seven gages were compared. There were significant differences among the
mean monthly water levels of the seven gages (ANOVA: F = 46.72, df = 152,
p<0.0001), with the lowest mean value at G3253; Fig. 19). Pearson Product-
moment correlation coefficients of variation in monthly mean values of all seven
gages were highly significant ( all r's>0.79, and all p's<0.05), indicating that all
gages followed the same pattern of timing and duration of seasonal water level
fluctuation. However, surface water depth cannot be extrapolated since ground
elevation data were not available.
Two wells were selected for more detailed analyses based upon their
proximity to the majority of sampling sites. Ground water levels during the two
years of the study were compared to the previous nine years for two USGS wells
located within the study area (USGS G972 and G975). This 11 year period
included years described as "low" (1989-1991), "average" (1986-1988), and "high"
rainfall (1994-1995). Average annual water levels at G972 and G975 for the 11
year period showed significant differences (ANOVA; G972: F = 10.586, df = 10,
114, p<0.0001; G975: F = 9.891, df = 10, 115, p<0.0001; Fig. 20). For each well,
Tukey's Honest Significant Difference Tests were done to determine which years
were significantly different from 1994 and 1995. At G972, the average monthly
water level in 1994 was only significantly higher than 1989-1991. In 1995 at
G972, it was higher than 1989-1991, plus 1985 (Tukey's Honest Significant
Difference Tests). At G975, the average monthly water level in 1994 was only
significantly higher than 1989-1990, and 1985. In 1995 at G975, water level was
only significantly higher than the three drought years, and 1985 (Tukey's Honest
Significant Difference Tests). In summary, even though annual rainfall in 1994
and 1995 was "high," average annual ground water levels measured at two wells in
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
the study area were not significantly higher than in years of "average" rainfall.
However, there was less variation in water level during 1994 and 1995 (i.e., it was
wet longer).
Correlations of Gauge Ground Water Level with Trap Rates
Major peaks in capture of macro-invertebrates, fishes, and amphibians
and reptiles by drift fences were generally associated with changing water levels
(either rising or falling; Fig. 21). When standing water existed over large areas,
aquatic and semi-aquatic animals were more dispersed, and capture rates were
generally lower.
Successional changes in vegetative structure and faunal implications
Melaleuca invasion of native graminoid/herbaceous wetlands changes the
vegetational structure of the landscape. It is unclear to what extent melaleuca
invasion also changes the hydrological characteristics of an area because variation
and shifts in water management and human disturbance are so strongly correlated
with the distribution of melaleuca. This study was designed to address only the
impact of melaleuca coverage on wildlife species richness and abundance. Prior to
the current study, the only information available was based upon either dense
melaleuca stands only (Schortemeyer et al. 1981) or were short-term studies that
considered only a few species (Mazzotti et al. 1981; Sowder and Woodall 1985;
Repenning 1986).
As melaleuca coverage increases, a graminoid wetland with low structural
diversity becomes a savannah (mix of open prairie/marsh and trees) with increased
structural diversity. As melaleuca coverage continues to increase, the savannah
becomes a closed canopy forest with sparse understory. Since little understory
persists in the forest and most of the trees are of similar size, structural diversity of
the forest is lower than existed in the savannah stage of melaleuca invasion. Some
animals (e.g., many birds, c.f. Cody 1985a) select habitat based upon subtle
differences in vegetational structure. However, other animals (e.g., amphibians
and reptiles) are less sensitive to vegetative structure but select habitats based upon
other characteristics (e.g., soil or hydrological characteristics; Campbell and
Christman 1982).
The results of this study demonstrated a higher species richness and
abundance of birds in the cover types that have moderate levels of melaleuca
coverage. As discussed above, these were the cover types with the greatest
structural diversity. Notably absent from these areas, though, were resident bird
species that are selective about the types of trees they use (e.g., pine warbler
(Dendroica pinus)). Many of the transient and winter-resident birds occurred at
much lower abundances than in cypress swamps of the Big Cypress National
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Preserve or the uplands of Long Pine Key, Everglades National Park (personal
observations).
In contrast to the birds, a similar diversity of herpetofauna was found
across all cover types. However, their abundances generally decreased in the
closed-canopy melaleuca forest (DMM cover type). The lower abundances
indicated poorer habitat quality. This was probably the result of the closed-canopy
of the forest limiting the amount of sunlight reaching the water surface. With
reduced sunlight, the algae forming the structure of the periphyton mat does not
develop. Many species of amphibians and reptiles consume crayfish, grass shrimp,
and smaller forage fishes which depend upon a well-developed periphyton mat.
However, complex patterns of hydrology, and gapping in forest canopy due to wind
storms and fires permit light penetration and the persistence of productive pockets
of aquatic life even within dense stands of melaleuca. Changes in both structural
and wildlife diversity are summarized in Figure 22.
Landscape effects
Habitat interspersion and melaleuca patch size were not explicitly
considered in sampling designs because detailed maps of the area were unavailable
at the start of the project. The only variable considered was melaleuca coverage.
Random sampling of three replicates of each cover type per month did not permit
testing of any variable other than melaleuca coverage. However, the mosaic of
areas with low to moderate infestations of melaleuca surrounding mature dense
melaleuca stands may allow higher numbers of individuals and species to persist
in, or seasonally use, mature dense melaleuca stands. A single stand of melaleuca
surrounded by prairie has less habitat interspersion than several, smaller stands of
melaleuca which have the same total area as the single large, stand. The smaller
stands have more "edge" habitat which is likely to provide at least marginal habitat
for species characteristic of the prairie. However, higher degree of interspersion
(more edge) may also expose surrounding natural areas to higher seedfall, since
seedfall is generally limited to a distance less than 1.5 times tree height (Meskimen
1962).
Factors affecting the rate of spread of melaleuca have not been examined.
The most widely cited paper on melaleuca expansion rate by Laroche and Ferriter
(1992) did not explore causal relationships between melaleuca invasion and biotic
or abiotic factors. In calculating expansion rate Laroche and Ferriter only
considered land sections that had attained 100% melaleuca coverage. This
approach was explicitly recognized by the authors as a constraint on the
application of their results, yet their results have been widely cited as the single
possible melaleuca expansion rate. Exclusion of sections that had some melaleuca
coverage yet had resisted heavy infestation may have led to the calculation of the
fastest possible expansion rate. Moreover, "invasion" was interpreted as the
presence of one or more melaleuca trees in an acre. This has unfortunately been
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
improperly interpreted as 100% dense melaleuca coverage, which was not the
intended use of the authors. Additional studies should examine land sections that
are exposed to melaleuca yet have resisted heavy infestation. Factors influencing
the rate of melaleuca expansion, such as habitat interspersion, melaleuca patch
size, soil, plant cover, human disturbance and hydrology, should also be
considered.
While the interspersion of areas of varying melaleuca coverage may
contribute to the abundance of animals (particularly fishes and semi-aquatic
amphibians and reptiles) in dense melaleuca sites, it is unlikely that the Pennsuco
marshes on the western edge of the area were the sole source of fishes and some
fully aquatic amphibians and reptiles in the study area. High levees subdivide the
LBSA along north-south (Dade-Broward Levee) and east-west axes (levees
associated with Wellfield and Pennsuco Canals). These levees were dispersion
barriers to fishes, and some fully aquatic amphibians and reptiles. Therefore, some
species were confined to isolated sub-basins, which sustain local populations. The
abundance of Siren lacertina (a fully aquatic salamander) in a DMM site isolated
from areas with lower melaleuca coverages was a good example of this. The rapid
rate at which fully aquatic amphibians and reptiles and fishes exploited standing
water in many sites indicated that deep water or subterranean refugia were
available even within areas of dense melaleuca. Likewise, the highly vagile
mammals and birds were readily capable of exploiting small patches of suitable
habitat throughout the entire region.
The numerous, recent reviews of the relationships between habitat quality,
demographics, dispersal, and metapopulations that are being derived from
landscape ecology are all relevant to future research on the impact of melaleuca
(c.f. Hansson 1995). For example, to what extent do melaleuca invaded habitats
function as marginal habitat?, and what effect does the ratio of optimal to marginal
patch area (ROMPA hypothesis; see Hansson 1995) play in the dynamics of the
various populations in the areas of melaleuca invasion?
Melaleuca continues to aggressively invade wetland habitats in southern
Florida as well as upland habitats in southwestern Florida and parts of Broward
and Palm Beach County. While the replacement of native vegetation with a
monoculture of non-native species is undesirable, it is important to recognize that
animal populations will persist in areas with disturbed vegetation. Therefore, these
areas still retain some habitat value. Successful restorations must re-establish
native animal communities as well as the native plant communities. Since many
native animals may persist in areas with melaleuca, preference should be given to
restoration methods that are sensitive to the existing on-site animal populations.
LITERATURE CITED
Alexander, T. R., and R. H. Hofstetter. 1975. Some current ecological aspects ofMelaleuca quinquenervia
(Cav.) Blake in southern Florida. Presented at the Florida Acad. Sci., 41st Ann. Mtg.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Bishop, S. C. 1962. Handbook of Salamanders The Salamanders of the United States, of Canada, and of
Lower California. Hafer Publishing Co., New York.
Campbell, H. W., and S. P. Christman. 1982. The herpetological components of Florida sandhill and sand
pine scrub associations. Pp. 163-171 in Norman J. Scott, ed. U.S. Fish and Wildlife Service Wildlife
Research Report 13, Washington, D.C.
Cody, M.L. 1985a. Habitat Selection in Birds. Academic Press.
S1985b. Habitat selection in grassland and open-country birds. Pp. 191-226 in M. L Cody, ed.
Habitat Selection in Birds. Academic Press.
Dalrymple, G. H. 1988. The herpetofauna of Long Pine Key, Everglades National Park, in relation to
vegetation and hydrology. Pp. 72-86 in R. Szaro, KE. Severson, and D.R. Patton, technical
coordinators. Management of Amphibians, Reptiles, and Small Mammals in North America. U. S.
D. A. Forest Service, Gen. Tech. Rept RM-166, Fort Collins, CO.
Dalrymple, 0. H. 1994. In-faunal Study of Wetland Restoration in the Hole-in-the-donut, Everglades
National Park 1990-1992. Final reportto South Florida Research Center, Everglades National Park.
Davis, J. H., Jr. 1943. The Natural Features of Southern Florida, Especially the Vegetation, and the
Everglades. Florida Geol. Surv., Tallahassee.
Davis, S. M., L H. Gunderson, W. A. Park, J. R. Richardson, and J. E. Mattson. 1994. Landscape
dimension, composition, and function in a changing Everglades ecosystem. Pp. 419-444 in S. M.
Davis and J. C. Ogden, eds. Everglades. The Ecosystem and its Restoration. St Lucie Press, Delray
Beach, FL
Duellman, W. E., and A. Schwartz. 1958. Amphibians and reptiles of southern Florida. Bull. Florida State
Museum, Biol. Sci. 3(5):181-324.
EAS Engineering, Inc. 1995. Year One Report on Vegetation of the Lake Belt Study Area. Report
submitted to Dade County, Dept Environ. Res. Mgmt, April 1995. .
Fenema,, R. J., C. J. Neidrauer, R. A. Johnson, T. K. MacVicar, and W. A. Perkins. 1994. A computer
model to simulate natural Everglades hydrology. Pp. 249-289 in S. M. Davis and J. C. Ogden, eds.
Everglades. The Ecosystem and its Restoration. St. Lucie Press, Delray Beach, FL.
Fredrickson, L H., and M. K. Laubhan. 1994. Managing wetlands for wildlife. Pp. 623-647 in T. A.
Bookhout, ed. Research and Management Techniques for Wildlife and Habitats. Fifth Ed. The
Wildlife Society, Bethesda, MD.
Gauche, H. G., Jr. 1982. Multivariate analysis in community ecology. Cambridge Univ. Press.
Hansson, L 1995. Development and applicaiton of landscape approaches in mammalian ecology. Pp. 20-
39 in W. Z. Lidicker, Jr., ed. Landscape Approaches in Mammalian Ecology. Univ. Minnesota
Press, Minneapolis and London.
Hofstetter, H. 1991. The current status ofMelaleuca quinquenervia in southern Florida. Pp. 159-176
In T. D. Center, R. F. Doren, R. H. Hofatetter, R. L Myers, and L D. Whiteaker, eds. Proceedings
of the Symposium on Exotic Pest Plants. Tech. Rept. NPS/NREVER/NRTR-91/06.
Keller, C. M. E., C. S. Robbins, and J. S. Hatfield. 1993. Avian communities in riparian forests of different
widths in Maryland and Delaware. Wetlands 13:137-144.
Krebs, C. J. 1989. Ecological Methodology. Harper and Row, Publ. New York.
Laroche, F. B., and A. P. Ferriter. 1992. The rate of expansion ofmelaleuca in South Florida. J. Aquat
Plant Mgmt. 30:62-65.
Larsen P. W. 1992. South Florida Limestone Mining Coalition Year 2050 Fresh Water Lake Belt Plan.
Larsen and Associates, Miami, FL
Loughlin, M. H., J. C. Ogden, W. B. Robertson, Jr., K. Russell, and R. W. March. 1990. Everglades
National Park Bird Check List Florida National Parks and Monuments Association, Inc.,
Homestead, FL. 18pp.
Machovina, B. L 1994. Ecology and life history ofAmphiuma means in Everglades National Park. M. S.
thesis, Florida International Univ., Miami, FL
Mazzotti, F. J., W. Ostreko, and A. T. Smith. 1981. Effects of the exotic plantsMelaleuca quinqueneria
and Casuarina equisetifolia on small mammal populations in the eastern Florida Everglades. Florida
Sci. 44:65-71
Meskimen, G. 1962. A silvical study of the melaleuca tree in South Florida. M. S. thesis, Univ. Florida,
Gainesville. 177 pp.
Mitsch,W.J., andJ. Goselink. 1986. Wetlands Van Nostrand Reinhold, New York.
Morse, D. H. 1985. Habitat selection in North American parulid warblers. Pp. 131-157 in M. L Cody, ed.
Habitat Selection in Birds. Academic Press.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
Odum, E. P. 1983. Basic Ecology. Saunders College Publishing.
Repenning. R. W. 1986 Mitigation of Fish and Wildlife Values in Rock-mined Areas of South Florida,
Pat li: Wildlife. Coop. Fish Wildlife Res. Unit Report, Univ. Florida, Gainesville.
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Robertson, W. B., Jr., and J. A. Kushlan. 1984. The southern Florida avifauna. Pp. 219-257 in P. J.
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FL
Runde, D. E., J. A. Gore, J. A. Hovis, M. S. Robson, and P. E. Southall. 1991. Florida Atlas of Breeding
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Schortemeyer, J. L, R. E. Johnson, and J. D. West 1981. A preliminary report on wildlife occurrence in
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Proceedings of Melaleuca Symposium, held September 23-24, 1980, Edison Community College, Ft
Myers. Florida Dept Agric. Consumer Serv. Div. Forestry, Tallahassee.
Smith A. T., and J. M. Vrieze. 1979. Population structure of Everglades rodents: Responses to a patchy
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Sokal R. R., and F. J. Rohlf. 1995. Biometry. W. H. Freeman and Co. New York.
Sowder, A., and S. Woodall. 1985. Small mammals of Melaleuca stands and adjacent environments in
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Stauffer, D. F., and. B. Best 1980. Habitat selection by birds of riparian communities: Evaluating effects
of habitat alterations. J. Wildly. Mgmt 44:1-15.
Steidl, R. J., J. P. Hayes, and E. Schauber. 1997. Statistical power analysis in wildlife research. J. Wild.
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Wilson, L D., and Porras. 1983. The Ecological Impact of Man on the South Florida Herpetofauna. Univ.
Kansas, Lawrence.
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Florida Game Fresh Water Fish Comm., Tallahassee.
Van Home, B. 1983. Density as a misleading indicator of habitat quality. J. Wild. Mgmt 47:893-901.
Zar, J. H. 1996. Biostatistical Analysis. Prentice Hall, Inc., Upper Saddle River, NJ.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Dade-Broward County Line
Approximate Scale
0 5 10
Tamiami Trail kilometers
Figure 1. Location of study area in southern Florida.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS 27
Figure 2. Map of vegetative cover types and man-made features within the study area, interpreted from 1992
1:300 aerial photographs.
ggTgv. m go
V l0 -nd (M
Mmnh (MAR)
pI,* lm. Amudu)
I 5 16%-1s9%.W -o DPM)
", .meiam w (OMM)
'AWig gh'W (A -)
i Mt Ub.Sld((D M
1_1
2870
2m
O~h~O~Cnvh I~LOUI1~ara*ll~ I(YI
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
I4UU
2000 A. -- in-Max
Median value
1600
1200
800 I i
400
0
MAR P50 P75 SDM DMM
B.
T
MAR P50 P75 SDM DMM
10
P5013
)0 C.
)0
)0
P75/1 MAR2
)0 SDM3 & AR3
P50/2 P75/2 SDM1
10 SDM2 MA 1 D1 D
SDMM2 DMM3
0 P75/3
0,-
0
I 8 9 10 11
SPECIES
Figure 3. Box-whisker plot of cumulative number of individuals of macroinvertebrates trapped by drift
fencing for each cover type. 3B. Box-whisker plot of cumulative number of species of macroinvertebrates
trapped by drift fencing for each cover type. Kruskal-Wallis H (4, 15) = 6.6, p = 1.16. 3C. Plot of number of
species versus number of individuals trapped for each cover type. Kruskal-Wallis H (4, 15) = 2.33, p = 1.68.
Cover type abbreviations: MAR = <10% melaleuca coverage; P50 = 10% to 50% melaleuca coverage; P75
= 50% to 75% melaleuca coverage; SDM = >75% melaleuca coverage, sapling trees; DMM = >75%
melaleuca coverage, mature trees.
rT
DMM1
SDM1
P50/1
MAR1
MAR2
MAR3
DMM2
DMM3
P75/1
P50/2
SDM2
SDM3
P50/3
P75/2
P75/3
A.
0.0 0.2 0.4 0.6
Linkage Distance
Pomacea paludosa
Paleo. paludosus
Romalea microptera
Stagnicola spp
Dragonfly larvae
Procambarus alleni
Dytiscidae
Leth. americanus
Biom. havanensis
Gyrinidae
0.0 0.2 0.4 0.6 0.8 1.0 1 2 1.4
Linkage Distance
Figure 4. Cluster analyses by individual replicates and by taxa for macroinvertebrates. Based upon 24 month cumulative drift fence data from the 15 replicates
(3 replicates per cover type). Cover type abbreviations as in Fig. 3.
24
20 _
Lu
o ;O ''/u -MAR
U 12 -P50
0 C "/s P75
"'. SDM
8 : DMM
0 400 800 1200 1600 2000 2400 2800 3200 z
INDIVIDUALS
Figure 5. Rarefaction curves for fishes trapped in each cover type. Curves based upon 24 month cumulative data from drift fencing. Cover type abbreviations
as in Fig. 3.
0
7'
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
I
I Min-Max
Median value
II
MAR P50 P75 SDM DMM
9 10 11 12 13 14 15 16 17 18 19 20
SPECIES
Figure 6A. Box-whisker plot of cumulative number of individuals of fishes trapped by drift fencing for each
cover type. Krusal-Wallis H (4, 15) = 10.5, p = 0.03. 6B. Box-whisker plot of cumulative number of
species of fishes trapped by drift fencing for each cover type. Kruskal-Wallis H (4, 15) = 4.03, p = 0.40.
6C. Plot of number of species versus number of individuals trapped for each of the 15 replicates (3 per cover
type). Cover type abbreviations as in Fig. 3.
MAR P50 P75 SDM DMM
9
7 B.I
5
3
1
Q _D.
1
1
Lu
UJI
. 1
C,
1
140
0
1200
1000
800
600
400
200
0
8
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
MAR P50 P75 SDM DMM
Figure 7A. Box-whisker plots of number of species of non-native fishes trapped in each cover type. Krukal-
Wallis H (4, 15) = 4.76, p = 0.31. 7B. Box-whisker plots of number of individuals of non-native fishes
trapped in each cover type. Krukal-Wallis H (4,15) = 5.10, p = 0.28. Cover type abbreviations as in Fig. 3.
A. Z- Min-Max
Median value
II
MAR P50 P75 SDM DMM
DMM1
DMM3
P50/2
P50/3
MAR1
MAR2
MAR3
P75/3
P75/1
P50/1
SDM1
SDM3
P75/2
SDM2
DMM2
0.0 0.2 0.4 0.6 0.8
Linkage Distance
Lepid platyrhinchus
Tilapia maria
Ameiurus nebulosus
Gambusia holbrooki
Poecilia latipinna
Fundulus confluentus
Hemi letoumeauxt
Lepomis gulosus
Cichla. bimaculatum
Ameturus natalis
Cyprin vanegatus
Clanas batrachus
Fundulus chrysotus
Ennea. gloriosus
Micro salmoides
Jordanella floridae
Lepomis marginatus
Lucania gooder
Lepomis macrochirus
Cichla managuense
Heterandria formosa
Lepomis punctatus
Astronotus ocellatus
Labidesthes sicculus
Lepomis microlophus
Belonesox belizanus
Etheostoma fusiforme
0.0 0.2
0.4 0.6 0.8 1.0 1.2
Linkage Distance
Figure 8. Cluster analyses by individual replicates and by taxa for fishes. Based upon 24 month cumulative drift fence data from the 15 replicates (3 replicates
per cover type). Cover type abbreviations as in Fig. 3.
35 .
2 5 ... ... .. ................ .. ....
uJ 20 .. .. ..
u 151
... 1 0 "--. .. .s.. .5......
5 1 0 ... .... .. ........ .......... .......................................................... .-D ...... "
SDM
0 50 100 150 200 250 300 350 400 450 500
INDIVIDUALS
Figure 9. Rarefaction curves (number of species versus number of individuals sampled) for herptiles based upon drift fence data for each cover type; 24 month
cumulative data collection. Cover type abbreviations as in Fig. 3.
.5.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS 35
200
180 A. I Min-Max
160 Median value
S140
D 120
-100
o 80 I~
24
22 B. -
20
18
16 _
14
12
10
8
6
MAR P50 P75 SDM DMM
100
80 C. SDW1
60
40
20 P75/2
0 DMM/1 M SD P75
100 ,PI,3 s
DMM/2
80 pS'oMM/3 P75/3
P50/2
SDM/2.
60 MAR2
40 MAt3
20
6 8 10 12 14 16
SPECIES
18 20 22 24
Figure 10A. Box-whisker plot of cumulative number of individuals of herptiles trapped by drift fencing for
each cover type. Kruskal-Wallis H (4, 15) = 4.87, p = 0.30. 10B. Box-whisker plot of cumulative number
of species of herptiles trapped by drift fencing for each cover type. Kruskal-Wallis H (4, 15) = 7.58, p =
0.11. 10C. Plot of number of species versus number of individuals trapped for each of the 15 replicates (3
per cover type). Cover type abbreviations as in Fig. 3.
DMM1 A
SDM1
DMM2
DMM3
SDM2
SDM3
P75/2
P75/1
P50/2
P75/3
P50/3
P50/1
MAR1
MAR2
MAR3
0.0 0.2 0.4 0.6 0.8 1.0
Linkage Distance
Acns gryllus
Elaphe guttata
Thamnophis sirlalis
Lampropeltis getula
Pseudacris nigrata
Bufo quercicus
Eumeces inexpectatus
Thamnophis sauritus
Coluber constrictor
Nerodia fasciata
Agkis. piscivorous
Farancia abacurai
Ophi compressus
Amphiuma means
Rana giylio
Rana sphenocephala
Anolis sagrei
Eleuth. planrostns
Gastro carolinensis
Hyla squirella
Diadophus punctatus
Notoph. vindescens
Siren lacertina
Hyla cinerea
Os. septentnonalis
Terrapene carolina
Anolis carolinensis
Chelydra serpentina
Pseudo. stratus
Bufo terrestis
Nerodia flondana
Regina allenis
Kinostemon baur
Limnaoedus oculars
0.0 0.2 0.4 0.6 0.8 1.0 1.2
Linkage Distance
Figure 11. Cluster analyses by individual replicates and by taxa for heptiles. Based upon 24 month cumulative drift fence data from the 15 replicates (3
replicates per cover type). Cover type abbreviations as in Fig. 3.
0.8
0.6
Acris gryllus *
Nerodia flondana Chelydra serpentina
Anolis carol.
SKnostemon baun
Bufoleneslris
* Psuedacris nigrata
Terrapene carolina
* Pseudo. striatus
Limn. ocularis Siren lacertina
0 nata
Notopth. *
escens Hyla cinere
Diadophis *
punctatus
0.2
0
Tham. sauritus
Hyla squirella
0
0.4
Q0 0.2
0
O
- 0.0
S-0.2
LL -0.2
0.6
1.0
FACTOR 1
DENSE MELALEUCA
Figure 12. Plot of the first two factor loadings for herptiles. Based upon 24 month cumulative drift fence data from the 15 replicates (3 replicates per cover
type). Taxa with significant clumped distributions are outlined (I index p 's > 0.025).
Regina .ale
Ophisaurus compressus &
Farancia abaclra
Amphiuma means
0
Ranagrylio Neodiafasciata Tham. sirtalis
Rana grylio Nerodia fasaa Ag. piscivorous T s Bufo quercicus
Lampro. getula Rana spheno. Coluber constrictor. &
e I Elaphe guttata Eumeces inexpectatus
Gastrophryne carol.
* Osteopilus septen.
a Eleuthro. plani. I
Anolis sagrei
Anolis sagrei
-0.6-
-1.0
viride
-0.6
MARSH
-0.2
-0.4
38 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
32 160
2 NO. SPP.
28 NO. INDS. 140
24 120
20 100 I
16 80 I
u) 12 60
z
8 40
4 20
0 0
MAR P50 P75 SDM DMM
4.2 0.95
S DIVERSITY
CL EVENNESS 0.90
3.8 .8
0.80
3.4 . 0.80
3.4 cI
0.75 z
z
w 0.70 z
> 3.0 WU
S0.65 m
MAR P50 P75 SDM DMM
Figure 13. Abundance, species richness, and diversity of birds observed during strip transects in the five
defined cover types. Cover type abbreviations as in Fig. 3.
32
3 2 . . .. . . .... . . . . .... . . . .. .. . . .. . . .
2 8 - .............. ....... ... ..................... . .
28 -
2 4 2 ........... ............^. ........... i .. .." . .. .. ... .. .. ..
LU
1 6 .................. .... : ..... ...... ............ ............ ........... ............
S16
12 >
U| / MAR
. . .... ... . . ... . . . . . .... .
8 .... ........................ 5 .. .
/ P75
4 .- i ............ ........... ........... ........... -......... ... ..... S D M ....
S".DMM
O . . . ..-.-. . . . . -. .. ... .-,-,-,1.. . . . ,
0 20 40 60 80 100 120 140 160
INDIVIDUALS
Figure 14. Rarefaction curves (number of species versus number of individuals sampled) for birds based upon strip transect data for each cover type; 24 month
cumulative data collection. Cover type abbreviations as in Fig. 3.
Phalacro. auritus
Circus cyaneus
Gallinula chloropus
Melospiza georiana
Capella galifago
Geothlypis trichas
Agelaius phoeniceus
Butondes striatus
Chordeiles minor
Ardea herodias
Lanius ludovicianus
Hydranassa tricolor
Megacetyle alcyon
Icteria virens
Stumella magna
Mycteria amencana
Buteo lineatus
Colaptes auratus
Troglodytes aedon
Mimus polyglottos
Dendroica coronet
Dendroica discolor
Picoides ubescens
Poliopta caerulea
Cardinalis cardinals
Dendroica palmarum
Florida caerulea
Sayonrs phoebe
Zenaida macrura
Columbina passerina
Tyrannus tyrannus
Quiscalus major
Casmerodius album
Quiscalus quiscula
Falco sparvenus
Seto phaga ruticilla
Mylarchus crinitus
Vireo giseus
Pipio erythro.
Dumetella carol
Parula americana
Melanerpes carol.
Cyano. cristata
Sphyr various
Thryo ludovicianus
Mniolilta vana
MAR
P50 & P75
--1 DMM & SDM
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Linkage Distance
Figure 15. Cluster analyses by cover type and by taxa for the strip transect data for birds. Based upon 24 month cumulative strip transect data from the five
cover types (data from the three replicates per cover type combined). Cover type abbreviations as in Fig. 3.
o s
0 0
0
MAR P50 P75 SDM DMM MAR P50 P75 SDM DMM60
U-
z- z
z 40 w 40
WINTERING a .l WINTERING
20 RESIDENT 20 RESIDENT
MAR P50 P75 SDM DMM MAR P50 P75 SDM DMM
Ul
Figure 16. Plot of the percentage of individuals and species of resident and wintering bird species. Based upon 24 month cumulative strip transect data from
the five cover types (data from the three replicates per cover type combined). Cover type abbreviations as in Fig. 3.
80
ir
< 70
i 60
i-
; 50
z
o 40
S30
0
-' 20
z
i10
0
70 D. MAMMALS
- 60
S50
0 40
2 30
o 20
z
a 10
01O
P50 P75 SDM DMM
Figure 17. Percent of species in common between Marsh and each other cover type for fishes, herptiles, birds, and mammals. Cover type abbreviations as in Fig.
3.
A. FISHES
P50 P75 SDM DMM
INVTS FISHES HERPES BIRDS MAMMALS
INVTS. FISHES HERPS BIRDS MAMMALS
Figure 18. Total taxa for each faunal group and percent of taxa found in all of the five defined cover types.
2.8
2.6 G968
2.4 '--G594 '
2.2
,. 2 G972 '
2.2.
E
U 1.2 G970
1.0G3253
0.8
0.6 z
0.4' 1994 1995
0.2
0 J FMAMJ JASONDJ FMAMJ JASOND
Figure 19. Plot of the average monthly water level for the seven USGS gages located within the Lake Belt Study area for 1994-1995.
DALRYMPLE & DALRYMPLE: MELALEUCA IN EVERGLADES WETLANDS
2.0
A. USGS G-972 -I l 96Std Err
r C 11 OOStd Err
> 1.8 Mean
z
1.6
I 14
z
< 1.2
z A
S *A B "B *B
1.0
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995
2.0
B. USGS G-975
1.8
S16
1 4- 1 96* Std Err
1 .- 1 00"Std Err
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995
Figure 20A. Plot of monthly average water level at G-972 for the period 1985-1995. 20B. Plot of the
monthly average water level at G-975 for the period 1985-1995. Each plot is intended to demonstrate the
range of conditions for the 11 year period, rather than to compare specific years. **A = Year significantly
different from 1995 only. **B = Year significantly different from both 1994 and 1995.
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
q1uu 1 .u
1000 O P50(L)
SP75(L) 1.7
800 SDM (L)
DMM (L) 1.6
600 G972(R) 1 5
400
200 1.4
0 1.3
JFMAMJJASONDJFMAMJJASOND
700 1.9
600 1
60 MAR(L) 1.
500 P50 (L)
o P75 (L) 1.7
400 a SDM (L)
DMM(L) I 16
300 G972(R) ', 0
200
100o -' /- ; 1.4
90 1.9
J FMAMJ JASONDJ FMAMJ JASOND
901 il----- . 1.9
-e- MAR(L)
aP50(L)
SP75 (L)
-- SDM(L)
DMM(L) | /
- G972(R),, \
1.4
" F -M A M J 'AF M, 1.3
J J J F 1.2
J FMAMJ JASONDJ FMAMJ J ASOND
Figure 21. Plot of the monthly number of individuals ofmacroinvertebrates, fishes, and herptiles trapped in
each cover type by drift fencing (Jan, 1994 thru Dec, 1995). Also plotted is the average monthly water level
at USGS gage G-972 for the same period. The horizontal line represents the LSD elevation for the gage (1.5
m, NGVD). Actual ground surface elevation is likely to be lower. Cover type abbreviations as in Fig. 3.
/--,\
Low levels of Melaleuca
No to little tree canopy
Moderate levels of Melaleuca High levels of Melaleuca
Open tree canopy
Closed tree canopy
Diversity of understory plants
Well developed periphyton mat
High abundance of crayfish & grass shrimp
High abundance of fishes
Mainly wetland herptiles
Mainly wetland birds
Mainly wetland mammals
Diversity of understory plants
Well developed periphyton mat
High abundance of crayfish & grass shrimp
High abundance of fishes
Mainly wetland with some upland herptiles
Mix of wetland & upland birds
Mix of wetland and upland mammals
Loss of understory plants
Poorly developed periphyton mat
Fewer crayfish & grass shrimp
Fewer fishes
Mainly wetland with some upland herptiles
Mainly upland birds
Mix of welland and upland mammals
Figure 22. Summary of changes in vegetation structural diversity and wildlife diversity in native graminoid wetland habitats with increasing coverage by
melaleuca.
Table 1. Summary of drift fence trapping results for each site (15 sites total), 24-month cumulative numbers. Cover type abbreviations: MAR=<10% melaleuca
coverage, P50=10% to 50% melaleuca coverage; P75=50% to 75% melaleuca coverage; SDM=>75% melaleuca coverage, sapling trees; DMM=>75%
melaleuca coverage, mature trees.
MAR P50 P75 SDM DMM
Site: 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Invertebrates
Odonate larvae 12 6 2
Romalea microptera 4 14 1
Lethocerus americanus 6 9 15
Dytiscid beetles 7 25 7
Gyrinid beetles -
Biomphalaria havanensis 1 5
Stagnicola sp 6 -
Pomacea paludosa 2 11 4
Paleomonetuspaludosus 295 748 690
Procambarus alleni 68 67 50
Fishes
Lepisosteusplatyrhinchus -
Ameiurus natalis -
Ameiurus nebulosus -
Clarias batrachus -
Cyprinodon variagatus 1 -
Fundulus chrysotus 30 29 34
Fundulus confluentus 32 43 16
Jordanellafloridae 79 43 40
Lucania goodei 18 11 10
- 1 8
3 -
1 66 87
7 84 86
- 4 14
- 1 1
1 1
459 3 19
104 626 1896
1 3
76 29 35
99 62 80
99 55 53
7 4 2
66 40 39
78 68 52
- 4 -
3 1 6
1 1 3
3 2
4 5 10
763 352 94
- 2
1 1
33 16 14
85 164 132
6 17 75
1 12
1 3 -
15 3 5
9 17 39
17 12 45
2 1
1 1
319 9 17
136 243 669
4 34
37 118 121
1 7 11
1 1 2
1 1
4 4 4
4 1 17
5 5 14
- 1 1
5 1
1 6 6
130 19 1
124 292 153
- I -
- 2 3
- 1 -
- 3
26 11 12
25 13
1 9
Table 1 Continued.
Belenosox belizanus* -
Gambusia holbrooki 296 264 281
Heterandriaformosa 3 12 2
Poecilia latipinna 16 46 50
Labidesthes sicculus 1
Enneacanthus glorious 1 2 2
Lepomis gulosus 1 1 -
Lepomis macrochirus 2 1 1
Lepomis marginatus 1 -
Lepomis microlophus 11 3 10
Lepomispunctatus 3 5 1
Micropterus salmoides 1
Etheostomafiusiforme 1 -
Astronotus ocellatus* 19 -
Hemichromis letourneauxi* 6 19 7
Cichlasoma bimaculatum* 5 5 13
Cichlasoma managuense* 8 2 2
Tilapia maria* -
Amphibians
Pseudobranchus striatus -
Siren lacertina 2 1 2
Amphiuma means 2 1
Notophthalmus viridescens 2 1
Bufo terrestris 7 2 -
Bufo quercicus 2 -
Gastrophryne carolinensis 1 1 -
Eleutherodactylus planirostris*- -
Pseudacris nigrita -
- -
264 598 556
4 2 -
39 82 62
3 1 -
1 2 5
I -
11 6 5
3 -
15 132 148
12 135 80
- 2 2
5 2
1 4 10
6 9
3 -
- 12 -
344 130 429
- 5 10
38 24 113
- 2 2
1 1
33 3 5
150 234 96
41 42 36
1 3
3
3 3
4 3 3
6 24 5
5 6
1 2 1
43 3 31
35 17 98
1 1 -
1 1 5
1 1
- 1 8
3 -
18 18 133
10 5 105
1 2 34
2 7 11
3 6 8
- 1 3
15 10 12
14 3
109 1
10 7
81 10 400
- 3 -
2 1 30
- 2 2
1 4 6
- 2 -
7 35 41
42 102 23
3 1 1
- 22 -
- 1 4
- 3 -
- 4
2 3
8 1 -
41 10 2
Table 1. Continued.
Limnaoedus ocularis -
Acris gryllus 4
Hyla cinerea 1
Hyla squirella -
Osteopilus septentrionalis -
Rana sphenocephala 13 9
Rana grylio 5 4
Reptiles
Kinosternon bauri 7 5
Terrapene carolina -
Chelydra serpentina -
Anolis sagrei* 1 -
Anolis carolinensis 5 1
Ophisaurus compressus -
Eumeces inexpectatus -
Nerodiafasciata 6 2
Nerodiafloridana 19 8
Regina alleni 10 4
Thamnophis sirtalis 2 -
Thamnophis sauritus 1
Diadophispunctatus 1
Farancia abacura -
Coluber constrictor -
Elaphe guttata -
Lampropeltis getulafloridana -
Agkistrodonpiscivorous 1
Mammals
Blarina carolinensis
- -
- 2
1 -
15 16
12 8
2 1
1 -
6 -
5 -
1 4
2 1
15 4
2 4
- 5
1 1
2 1
- 2
- 2
1 1
3 -
1 -
15 15
2 7
1 1 3
1 1
1 -
1 7 -
- 2 3
1 1 -
- 12 -
3 8 4
2 1 6
1 1 2
8 6 3
3 5 3
1 1 2
4 6 1
- 2 -
2 1
2 2 8
2 -
1 -
2 1 -
9 6 19
- 1 6
- 1 -
6 4 6
- 1
- 3 -
2 2 5
1 5 7
- 1 2
4 2 3
3 4 2
1 -
1 4 7
- 1
- 3
1 -
2 5
2 3
13 19
- 7
1 1 1
- 1 1
25 10 17
- 1 -
1 1 2
- 3 -
- 1 -
- 6 1
4 2 1
1 2 1
- 1 -
- 4
- 1 -
Table 1 Continued.
Sigmodon hispidus
Oryzomys palustris
All animals
Number of species
Number of individuals
Trap rate
Invertebrates only
Number of species
Number of individuals
Trap rate
Fishes only
Number of species
Number of individuals
Trap rate
Amphibians & Reptiles only
Number of species
Number of individuals
Trap rate
- 1
40 40 37 39 39 36 41 42 45 38 35 40
991 1,438 1,278 1,284 1,962 3,229 1,748 1,232 1,220 832 521 1,463
6.19 8.99 7.99 8.03 12.26 20.18 10.93 7.70 7.63 5.20 3.26 9.14
7 9 8 6 7 8 7 8 7 9 6 8
394 887 774 575 785 2,112 918 472 206 501 287 778
2.46 5.54 4.84 3.59 4.91 13.20 5.74 2.95 1.29 3.13 1.79 4.86
18 16 16 16 14 12 12 12 17 13 12 13
514 505 471 636 1,111 1,031 734 650 935 156 175 584
3.21 3.16 2.94 3.98 6.94 6.44 4.59 4.06 5.84 0.98 1.09 3.65
15 15 13 17 18 16 22 22 20 16 16 18
83 46 33 73 66 86 96 110 78 175 58 100
0.52 0.29 0.21 0.46 0.41 0.54 0.60 0.69 0.49 1.09 0.36 0.63
1
28 45 39
573 598 818
3.58 3.74 5.11
8 7 10
274 328 199
0.93 1.34 0.83
10 17 12
198 185 543
0.91 1.16 0.59
10 21 16
101 85 75
0.63 0.53 0.47
Table 2. Results of drift fencing trapping, summarized for each species by cover type (3 replicates in each cover type) 24 month cumulative numbers. Also
indicated, for each species, are the Index of Dispersion (I), Chi-square value (x2), and whether distribution was dumped in any cover type. Cover type abbreviations
as in Tab. 1.
MAR P50 P75 SDM DMM I Index x2 Cover types
Invertebrates
Odonate larvae 20
Romalea microptera 19
Lethocerus americanus 30
Dytiscid beetles 39
Gyrinid beetles
Biomphalaria havanensis 6
Stagnicola sp 6
Pomacea paludosa 17
Paleomonetus paludosus 1733
Procambarus alleni 185
Fishes
Lepisosteus platyrhinchus
Ameiurus natalis
Ameiurus nebulosus
Clarias batrachus
Cyprinodon variagatus 1
Fundulus chrysotus 93
Fundulus confluentus 91
Jordanellafloridae 162
2 5.49 76.86
12 5.65 79.069
22 26.80 375.18
24 29.01 406.16
2 2.10 29.33
1 5.94 83.17
6 2.43 34.00
13 3.77 52.79
150 375.90 5262.55
569 618.64 8660.99
2.00 28.00 Clumped P75
1 1.00 14.00
1 0.93 13.00
5 1.46 20.50
1 0.93 13.00
3 18.73 262.15 Clumped MAR P50
49 34.85 487.93 Clumped P75 SDM
38 28.49 398.90 Clumped MAR P50
Table 2 Continued.
Lucania goodei 39 13 13 4
Belenosox belizanus 12 77
Gambusia holbrooki 841 1418 903 150
Heterandriaformosa 17 6 15
Poecilia latipinna 112 183 175 2
Labidesthes sicculus 1 -
Enneacanthus glorious 5 4
Lepomis gulosus 2 8 4 7
Lepomis macrochirus 4 2 2
Lepomis marginatus 1 1 -
Lepomis microlophus 24 22 41 9
Lepomispunctatus 9 3 -
Micropterus salmoides 1 1 -
Etheostomafusiforme 1 1 3
Astronotus ocellatus* 19
Hemichromis letourneauxi* 32 295 480 169
Cichlasoma bimaculatum* 23 227 119 150
Cichlasoma managuense* 12 4 4 7
Tilapia mariae* 1 3 -
Amphibians
Pseudobranchus striatus -
Siren lacertina 5
Amphiuma means 3
Notophthalmus viridescens 3
Bufo terrestris 9
Bufo quercicus 2
10 5.84 81.82 Clumped MAR
17 23.88 334.38 Clumped SDM
491 142.44 1994.13 Clumped MAR P50 P75
3 5.20 72.78 Clumped MAR P75
33 33.22 465.01 Clumped MAR P50 P75
1.00 14.00
S 1.62 22.67
4 1.43 20.00
0.77 10.75
0.93 13.00
11 8.91 124.73 Clumped MAR P50 P75
1 2.52 35.29 Clumped MAR
0.93 13.00
2.00 28.00 Clumped SDM
2 17.12 239.71 Clumped MAR
83 73.85 1033.96 Clumped P50 P75 SDM
167 45.92 642.92 Clumped P50 SDM DMM
5 1.80 25.19
1 2.00 28.00 Clumped P75
S 1.00 14.00
22 9.43 132.04 Clumped SDM DMM
5 2.47 34.60 Clumped P50 SDM
3 1.80 25.14
4 3.77 52.71 Clumped MAR
5 7.42 103.87 Clumped P75 SDM
Table 2 Continued.
Gastrophryne carolinensis 2
Eleutherodactylus planirostris* -
Pseudacris nigrita
Limnaoedus ocularis 1
Acris gryllus 5
Hyla cinerea 1
Hyla squirella
Osteopilus septentrionalis
Rana sphenocephala 25
Rana grylio 11
Reptiles
Kinosternon bauri 20
Terrapene carolina
Chelydra serpentina 1
Anolis sagrei* 1
Anolis carolinensis 6
Ophisaurus compressus
Eumeces inexpectatus
Nerodia fasciata 12
Nerodiafloridana 34
Regina alleni 14
Thamnophis sirtalis 2
Thamnophis sauritus 2
Diadophis punctatus 1
Farancia abacura
Coluber constrictor 1
9 5.72
53 75.79
1.00
1.00
1 1.76
7 2.62
1 0.86
5 1.64
49 3.44
7 3.74
3 2.99
2 0.17
0.86
52 9.42
2.82
S 1.80
1 8.56
4 1.48
3 5.21
1 3.99
7 2.24
7 0.92
1 0.86
1.80
4 2.31
80.14 Clumped SDM DMM
1061.11 Clumped SDM DMM
14.00
14.00
24.57
36.73 Clumped DMM
12.00
23.00
48.15 Clumped P50 P75
52.40 Clumped P50 P75
41.88 Clumped MAR
10.00
12.00
131.88 Clumped DMM
40.35 Clumped MAR P50
25.14
119.77 Clumped P75
20.67
72.97 Clumped MAR P50
55.84 Clumped MAR P50
31.30 Clumped P75
12.91
12.00
25.14
32.39 Clumped P75 SDM
Table 2 Continued.
Elaphe guttata
Lampropeltis geulafloridana -
Agkistrodon piscivorous 1
Mammals
Blarina carolinensis
Sigmodon hispidus
Oryzomys palustris
1 1.36 19.00
1.57 22.00
4 2.89 40.40 Clumped P50 P75
- 1
- 1
All animals
Number of species 53 53 57 52 57
Number of individuals 3707 6475 4200 2816 1989
Trap rate 7.72 13.49 8.75 5.87 4.14
Macroinvertebrates only
Number of species 9 9 9 10 10
Number of individuals 2055 3472 1596 1566 801
Trap rate 4.28 7.23 3.33 3.26 1.67
Fishes only
Number of species 21 18 19 16 20
Number ofindividuals 1490 2778 2319 915 926
Trap rate 3.10 5.79 4.83 1.91 1.93
Amphibians and Reptiles only
Number of species 23 26 28 24 26
Number of individuals 162 225 284 333 261
Trap rate 0.34 0.47 0.59 0.69 0.54
Table 3. Results of bird strip transects summarized by cover type, 24-month cumulative numbers. Within each cover type, there were three replicates. Also
indicated for each species are the Index of Dispersion, Chi-square value, and whether distribution was clumped in any cover type. Cover type abbreviations as in
Table 1.
MAR P50 P75 SDM DMM I Index 2 Cover types
Phalacrocorax auritus
Ardea herodias
Butorides striatus
Florida caerulea
Casmerodius albus
Hydranassa tricolor
Mycteria americana
Buteo lineatus
Circus cyaneus
Falco sparverius
Gallinula chloropus
Capella gallinago
Zenaida macroura
Columbina passerina
Chordeiles minor
Megaceryle alcyon
Colaptes auratus
Melanerpes carolinus
Sphyrapicus various
Picoidespubescens
Tyrannus verticalis
Mylarchus crinitus
Sayornis phoebe
4.00
3.50
4.00
5.33
16.00 Clumped MAR P50
3.00
4.00
8.00
4.00
4.00
4.00
12.29 Clumped MAR
4.00
4.00
5.33
6.00
16.00 Clumped P75
4.50
8.00
2.00
4.00
8.00
12.00 Clumped P50
Table 3 Continued.
Cyanocitta cristata
Troglodytes aedon
Thryothorus ludovicianus
Mimuspolyglottos
Dumetella carolinensis
Polioptila caerulea
Lanius ludovicianus 1
Vireo griseus
Mniotilta varia
Parula americana
Dendroica coronata
Dendroica discolor
Dendroica palmarum 2
Geothlypis trichas 57
Icteria virens
Setophaga ruticilla
Sturnella magna 8
Agelaius phoeniceus 47
Quiscalus major 4
Quiscalus quiscula
Cardinalis cardinalis
Pipilo erythrophthalmus
Melospiza georgiana 1
Number of species 15
Number of individuals 137
Num
Num
1 5 5
1 -
1 4
1 5
2 3
3 7 7
3 6 1
1
1
1 2
2 18 4
10 4
11 22 13
20 12 4
1 1
3
26 28
11 1
21
2 1
1 5 4
1 1 5
27 29 22
127 146 69
Across all five cover types
ber of species 46
ber of individuals 518
1.94 7.75
1.00 4.00
8.42 33.67 Clumped SDM DMM
3.92 15.67 Clumped P75
2.00 8.00
2.55 10.21
2.59 10.36
1.00 4.00
1.33 5.33
1.33 5.33
11.92 47.67 Clumped P75
6.86 27.43 Clumped P75
4.59 18.35 Clumped P75 SDM
26.42 105.68 Clumped MAR
0.75 3.00
3.00 12.00 Clumped SDM
15.23 60.90 Clumped P50 P75
34.64 138.54 Clumped MAR
16.60 66.40 Clumped P50
1.33 5.33
2.14 8.55
3.07 12.29 Clumped SDM
1.00 4.00
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Table 4. Scent and bait stations and small mammal live trapping results by cover type, 24-month cumulative
numbers. Cover type abbreviations as in Table 1.
MAR P50 P75 SDM DMM
Bait stations
Didelphis virginiana + + + + +
Sigmodon hispidus +
Procyon lotor + + + + +
Urocyon cinereoargenteus + +
Canisfamiliaris + + +
Felis rufus + +
Number of species 3 2 3 5 5
Scent stations
Didelphis virginiana -- + +
Sigmodon hispidus +
Procyon lotor + + + + +
Canisfamiliaris + + +
Felis rufis + +
Odocoileus virginianus + +
Number of species 2 2 3 3 5
Sherman live traps
Sigmodon hispidus 7 4 1
Oryzomys palustris 3 4 2 2 1
Peromyscus gossypinus 3 2
Mus musculus 1
Rattus rattus 1
Number of species 1 3 2 3 5
Number of individuals 3 11 6 6 5
All three methods combined
Number of species 5 5 6 7 10
Across all five cover types
Number of species 11
Table 5. Habitat association and species composition of amphibian and reptiles in each cover type based upon the cumulative totals of number of species and
number of individuals trapped by drift fencing. Cover type abbreviations as in Table 1.
MAR P50 P75 SDM DMM
Site 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
Number of species
Wetland dependent 12 14 12 13 15 14 18 15 17 12 13 13 7 15 13
Non-wetland 3 1 1 4 3 2 4 7 3 4 3 5 3 6 3
% Wetland dependent 80 93 92 76 83 88 82 68 85 75 81 72 70 71 81
Number of individuals
Wetland dependent 76 45 32 59 59 83 89 78 73 58 47 84 34 60 55
Non-wetland 7 1 1 14 7 3 7 32 5 117 11 16 67 25 20
% Wetland dependent 92 98 97 81 89 97 93 71 94 33 81 84 34 71 73
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 41(1)
Table 6. Habitat association and species composition of birds in each cover type based upon the cumulative
totals of number of species and number of individuals observed during strip transects. Cover type
abbreviations as in Table 1.
MAR P50 P75 SDM DMM
Number of species
Wetland dependent 12 11 10 4 1
Non-wetland 3 16 19 18 8
% Wetland dependent 80% 41% 34% 18% 11%
Number of individuals
Wetland dependent 132 92 59 10 2
Non-wetland 5 35 87 59 37
% Wetland dependent 96% 72% 40% 14% 5%
APPENDIX I
Glossary of the scientific and common names of each vertebrate species found during the 24 months of the surveys in the
Lake Belt Study Area, including areas otehr than the five defined cover types (e.g. canals, levees). Within each class,
species are listed alphabetically by scientific name. The Status column indicates whether a species is considered non-native
in southern Florida. The GFC column indicates whether a species is listed as Endangered (E), Threatened (T) or Species of
Special Concern (SSC) by the State of Florida Department of Game and Freshwater Fish Commission. The FWS column
indicates whether a species is listed as Endangered (E), Threatened (T) or Candidate for Listing (Cl or C2) by the United
States Fish and Wildlife Service. For amphibians, reptiles, birds, and mammals only, the Habitat Assoc. column lists
whether the species requires wetland habitats at some point in its life history for either reproduction, respiration, feeding
mechanism or diet. For birds only, it is also indicated whether the species occurs in southern Florida all year (Resident),
only during certain seasons (Winter or Summer), or passes through during spring and/or fall migration (Transient). In
general, species designated "Resident" or "Summer" breed in southern Florida, although exceptions do exist.
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Fishes
Ameiurus natalis
Ameiurus nebulosus
Amia calva
Astronotus ocellatus
Belonesox belizanus
Cichla ocellaris
Cichlasoma bimaculatum
Cichlasoma managuense
Clarias batrachus
Cyprinodon variegatus
Enneacanthus glorious
Etheostomaifusiforme
Fundulus chrysotus
Fundulus confluentus
Gambusia holbrooki
Hemichromis letourneauxi
Heterandriaformosa
Jordanella floridae
Labidesthes sicculus
Lepisosteusplatyrhinchus
Lepomis gulosus
Lepomis macrochirus
Lepomis marginatus
Lepomis microlophus
Lepomis punctatus
Lucania goodei
Yellow bullhead catfish
Brown bullhead catfish
Bowfin
Oscar
Pike killifish
Peacock bass
Black acara
Nicaraguan cichlid
Walking catfish
Sheepshead minnow
Bluespotted sunfish
Swamp darter
Golden topminnow
Marsh killifish
Mosquito fish
Jewelfish
Least killifish
Flagfish
Brook silverside
Florida gar
Warmouth
Bluegill
Dollar sunfish
Redear sunfish
Spotted sunfish
Bluefin killifish
Non-native
Non-native
Non-native
Non-native
Non-native
Non-native
Non-native
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Micropterus salmoides Large mouth bass
Mugil cephalus Striped mullet
Poecilia latipinna Sailfin molly
Tilapia mariae Spotted tilapia
Amphibians
Acris gryllus Southern cricket frog
Amphiuma means Two-toed amphiuma
Bufo quercicus Oak toad
Bufo terrestris Southern toad
Eleutherodactylus planirostris Greenhouse frog
Gastrophryne carolinensis Eastern narrowmouth toad
Hyla cinerea Green treefrog
Hyla squirella Squirrel treefrog
Limnaoedus ocularus Little grass frog
Notophthalmus viridescens Peninsula newt
Osteopilus septentrionalis Cuban treefrog
Pseudacris nigrita Florida chorus frog
Pseudobranchus striatus Dwarf siren
Rana grylio Pig frog
Rana sphenocephala Southern leopard frog
Siren lacertina Greater siren
Reptiles
Agkistrodonpiscivorous
Alligator mississippiensis
Anolis carolinensis
Anolis sagrei
Apaloneferox
Cottonmouth
American alligator
Green anole
Brown anole
Florida softshell turtle
Non-native
Non-native
Non-native
SSC T
Non-native
Wetland
Wetland
Wetland
Wetland
Non-wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Non-wetland
Non-wetland
Wetland
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Chelydra serpentina
Coluber constrictor
Deirochelys reticularia
Diadophis punctatus
Elaphe guttata
Elaphe obsoleta
Eumeces inexpectatus
Farancia abacura
Gopherus polyphemus
Kinosternon baurii
Lampropeltis getulafloridana
Nerodiafasciata
Nerodiafloridana
Nerodia taxispilota
Opheodrys aetivus
Ophisaurus compressus
Pseudemysfloridana
Pseudemys nelsoni
Regina alleni
Terrapene carolina bauri
Thamnophis sauritus
Thamnophis sirtalis
Birds
Agelaiusphoeniceus
Ajaia ajaia
Anasfulvigula
Anhinga anhinga
Florida snapping turtle
Black racer
Chicken turtle
Southern ringneck snake
Red rat snake
Yellow rat snake
Southeastern five-lined skink
Mud snake
Gopher tortoise
Striped mud turtle
Florida kingsnake
Florida water snake
Florida green water snake
Brown water snake
Rough green snake
Island glass lizard
Peninsula cooter
Florida redbelly turtle
Striped crayfish snake
Florida box turtle
Peninsula ribbon snake
Eastern garter snake
Red-winged blackbird
Roseate spoonbill
Mottled duck
Anhinga
Wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
SSC C2 Non-wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Non-wetland
C2 Non-wetland
Wetland
Wetland
Wetland
Wetland
Wetland
Wetland
SSC
Wetland
Wetland
Wetland
Wetland
Resident
Resident
Resident
Resident
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Archilochus colubris
Ardea herodias
Bubulcus ibis
Buteojamaicensis
Buteo lineatus
Buteo regalis
Butorndes striatus
Cairina moschata
Capella gallinago
Cardinalis cardinalis
Casmerodius albus
Cathartes aura
Catharus guttatus
Catoptrophorus semipalmatus
Charadrius vociferus
Chordeiles minor
Circus cyaneus
Cistothorus palustris
Colaptes auratus
Colinus virginianus
Columbina passerina
Coragyps atratus
Cyanocitta cristata
Dendroica coronata
Dendroica nigrescens
Dendroica caerulescens
Dendroica discolor
Rubythroated hummingbird
Great blue heron
Cattle egret
Red-tailed hawk
Red-shouldered hawk
Swainson's hawk
Green heron
Muscovy
Common snipe
Northern cardinal
Great egret
Turkey vulture
Hermit thrush
Willet
Killdeer
Common nighthawk
Northern harrier
Marsh wren
Northern flicker
Bobwhite quail
Ground dove
Black vulture
Bluejay
Yellow rumped warbler
Black throated green warbler
Black throated blue warbler
Prairie warbler
Non-native
Non-wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
Wetland
Wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
Winter
Resident
Resident
Resident
Resident
Winter
Resident
Resident
Winter
Resident
Resident
Resident
Winter
Winter
Resident
Resident
Winter
Winter
Resident
Resident
Resident
Resident
Resident
Winter
Winter
Winter
Resident
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Dendroica palmarum
Dendroica striata
Dendroica tigrina
Dryocopuspileatus
Dumetella carolinensis
Egretta thula
Eudocimus albus
Falco columbarius
Falco sparverius
Florida caerulea
Fulica americana
Gallinula chloropus
Geothlypis trichas
Himantopus mexicanus
Hirundo rustica
Hydranassa tricolor
Icteria virens
Lanius ludovicianus
Lophodytes cucullatus
Megaceryle alcyon
Melanerpes carolinus
Melosdittacus undulatus
Melospiza georgiana
Mimus polyglottos
Mniotilta varia
Mycteria americana
Myiarchus crinitus
Palm warbler
Blackpoll warbler
Cape may warbler
Pileated woodpecker
Gray catbird
Snowy egret
White ibis
Merlin
American kestrel
Little blue heron
American coot
Common moorhen
Common yellowthroat
Black necked stilt
Barn swallow
Tricolor heron
Yellowbreasted chat
Loggerhead shrike
Hooded merganser
Belted kingfisher
Red-bellied woodpecker
Budgegriar
Swamp sparrow
Northern mockingbird
Black white warbler
Wood stork
Great crested flycatcher
Non-native
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
SSC Wetland
SSC Wetland
Independent
Non-wetland
SSC Wetland
Wetland
Wetland
Wetland
Wetland
Non-wetland
SSC Wetland
Non-wetland
C2 Non-wetland
Wetland
Wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
E E Wetland
Non-wetland
Winter
Transient
Winter
Resident
Winter
Resident
Resident
Winter
Winter
Resident
Resident
Resident
Resident
Resident
Transient
Resident
Resident
Winter
Winter
Winter
Resident
Resident
Winter
Resident
Winter
Resident
Resident
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Nyctanassa violacea
Nycticorax nycticorax
Pandion haliaetus
Parula americana
Passerculus sandwichensis
Phalacrocorax auritus
Picoides pubescens
Piranga rubra
Pipilo erythrophthalmus
Plegadisfalcinellus
Podilymbus podiceps
Polioptila caerulea
Prothonotaria citrea
Quiscalus major
Quiscalus quiscula
Rallus elegans
Sayornis phoebe
Seiurus aurocapillus
Setophaga ruticilla
Sphyrapicus various
Sterna albifrons
Streptopelia decaocto
Sturnella magna
Sturnus vulgaris
Thryothorus ludovicianus
Tringa flavipes
Tringa melanoleuca
Yellow crowned night heron
Black crowned night heron
Osprey
Northern parula warbler
Savannah sparrow
Double crested cormorant
Downy woodpecker
Summer tanager
Rufous-sided towhee
Glossy ibis
Pied billed grebe
Blue-gray gnatcatcher
Prothonotary warbler
Boat tailed grackle
Common grackle
King rail
Eastern phoebe
Ovenbird
American redstart
Yellow-bellied sapsucker
Least tern
Eurasian collared-dove
Eastern meadowlark
European starling
Carolina wren
Lesser yellowlegs
Greater yellowlegs
Non-native
Non-native
Wetland
Wetland
Wetland
Non-wetland
Wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
Wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
T Wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Wetland
Wetland
Resident
Resident
Resident
Winter
Winter
Resident
Resident
Transient
Resident
Resident
Resident
Winter
Transient
Resident
Resident
Resident
Winter
Winter
Winter
Winter
Summer
Resident
Resident
Resident
Resident
Winter
Winter
Habitat
Scientific Name Common Name Status GFC FWS Association Season
Troglodytes aedon
Turdus migratorius
Tyrannus tyrannus
Tyrannus verticalis
Vireogriseus
Vireophiladelphicus
Zenaida macroura
Mammals
Blarina carolinensis
Canisfamiliaris
Dasypus novemcinctus
Didelphis virginiana
Felis domesticus
Felis rufus
Lutra canadensis
Mus musculus
Odocoileus virginianus
Oryzomys palustris
Peromyscus gossypinus
Procyon lotor
Rattus rattus
Sigmodon hispidus
Sylvilagus palustris
Urocyon cinereoargenteus
House wren
American robin
Eastern kingbird
Western kingbird
White eye vireo
Philadelphia vireo
Mourning dove
Southern short-tailed shrew
Domestic dog
Nine-banded armadillo
Virginia opossum
Domestic cat
Bobcat
River otter
House mouse
White-tailed deer
Marsh rice rat
Cotton mouse
Raccoon
Black rat
Hispid cotton rat
Marsh rabbit
Gray fox
Winter
Winter
Resident
Winter
Resident
Transient
Resident
Non-native
Non-native
Non-native
Non-native
Non-native
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Non-wetland
Non-wetland
Non-wetland
Wetland
Non-wetland
Contributions to the BULLETIN OF THE FLORIDA MUSEUM OF NATURAL HISTORY may
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