Characterization of Southern Florida Marsh Vegetation Using a Landscape Scale Random Sample: R-EMAP Phase III Vegetation Sampling. Jennifer H. Richards 1 Tom Philippi 1 P. Kalla 2 and D. Scheidt 3 1 Dept. of Biological Sciences, Florida International University, Miami, FL 2 U.S Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA 3 U.S. Environmental Protection Agency, Region 4, Water Management Division, Athens, GA
R-EMAP Sampling Design Sampled 111 sites in spring 25, 119 sites in fall 25, 23 total Parameters sampled at each site, where possible: Biogeochemical (soil, surface and pore-water nutrients/mercury/physical parameters) Plant species presence and vegetation mapping Fish (fall only) Invertebrates (fall only) Periphyton (fall only)
Plant Species Sampling Plant Community Analysis Exotic Plant Species Surveys Survey on fly-in Survey from helicopter pontoons
Plant Community Analysis: Species presence in 2 (¼ m 2 ) quadrats distributed along 1 m N-S transect 5 m west of sampling point Additional transect to reflect additional diversity within 5m radius at site Sawgrass density counted and l x w of longest leaf measured in 3rd m 2
Transect 1 Transect 2 2 (.25) m 2 quadrats S N Sawgrass density
Plant Community Analysis 23 sites visited (111 spring, 119 fall) 114 sites had transect 2 187 species encountered (including 4 unknowns) 173 on transect 1 16 on transect 2 14 species present on transect 2 but not on transect 1
Species Occurrence, Transect 1 173 taxa distributed among 23 sites (111 spring, 119 fall).9.8.7 Sawgrss (Cladium jamaicense) Frequency.6.5.4.3.2.1 Two species of Utricularia These 133 species (77%) occurred at 1 or fewer sites. 1 8 15 22 29 36 43 5 57 64 71 78 85 92 99 16 113 12 127 134 141 148 155 162 169 Species
Agglomerative hierarchical clustering of primary transect data: 5 groups recognized Information Remaining (%) 1 75 5 25 s128 s4 s143 s16 s138 s257 s15 s2 s13 s132 s142 s153 s131 s258 s136 s137 s14 s154 s11 s1 s18 s2 s13 s15 s3 s36 s41 s5 s135 s18 s165 s16 s253 s174 s15 s217 s229 s87 s93 s181 s182 s81 s56 s187 s185 s157 s1 s7 s7 s162 s166 s171 s367 s25 s14 s112 s163 s47 s17 s59 s189 s26 s216 s51 s195 s227 s254 s183 s24 s75 s252 s37 s177 s43 s219 s228 s16 s224 s95 s12 s67 s94 s226 s66 s23 s1 s239 s244 s176 s234 s9 s186 s191 s2 s197 s28 s223 s233 s11 s89 s145 s123 s22 s65 s24 s85 s48 s18 s249 s119 s364 s147 s178 s148 s152 s192 s118 s199 s194 s251 s193 s211 s215 s221 s238 s73 s8 s83 s68 s77 s156 s97 s218 s231 s82 s99 s179 s86 s84 s21 s22 s235 s19 s121 s236 s488 s115 s23 s12 s141 s124 s214 s37 s169 s27 s64 s14 s11 s151 s31 s222 s91 s155 s35 s351 s19 s17 s161 s21 s144 s23 s158 s32 s167 s17 s26 s27 s149 s39 s24 s29 s38 s12 s122 s146 s159 s213 s255 s198 s88 s3 s33 s4 s172 s28 s55 s49 s69 s76 s53 s57 s173 s188 s54 s368 s175 s237 s184 s242 s245 s374 s117 s114 s19 s96 s35 s225 s25 s212 s61 s72 s74 s365 s45 s63 s46 s52 s62 s58 s366 Muhlenbergia Cladium Typha Eleocharis Nymphaea (muhly) (sawgrass) (cattail) (spikerush) (water lily)
Muhly group is most species rich: 28 sites, 47 species, 41 significant indicator species; But note, also, sawgrass is present at 1% of these sites Species IV % p Muhly group Muhlenbergia capillaris 89.1 89.2 Panicum tenerum 59.1 75.2 Centella asiatica 52.4 54.2 Symphyotrichum bracei 48.5 5.2 Pluchea rosea 44.6 54.2 Rhynchospora microcarpa 36.7 57.2 Solidago stricta 35.7 36.2 Cassytha filiformis 35.6 36.2 Schizachyrium rhizomatum 35.3 36.2 Polygala grandiflora 32.1 32.2
Sawgrass group is most common but is species poor: 12 sites, 7 species, 2 significant indicator species; Species IV % p Sawgrass group Cladium jamaicense 34.8 1.2 Cephalanthus occidentalis 13.3 19.26
Spikerush group is next most abundant and diverse: 52 sites, 18 species, 8 significant indicator species; Species IV % p Spikerush group Eleocharis cellulosa 68.8 92.2 Bacopa caroliniana 6.9 75.2 Rhynchospora tracyi 35.8 44.2 Panicum hemitomon 34.3 6.2 Sagittaria lancifolia 2.4 48.94 Paspalidium geminatum 15. 37.194 Rhynchospora inundata 1.8 13.24 Justicia angusta 13.5 27.344
Water lily group has floating-leaved and submerged or free-floating aquatics 29 sites, 1 species, 6 significant indicator species, including 3 rootless, aquatic bladderwort species Species IV % p Water lily group Nymphaea odorata 74. 1.2 Utricularia purpurea 55. 9.2 Utricularia gibba 43.7 79.2 Eleocharis elongata 35.6 41.2 Nymphoides aquatica 25.4 34.2 Utricularia foliosa 31.3 72.4
Cattail group is least abundant 19 sites, 1 species, 6 significant indicator species, including exotics, shrubs and vines Species IV % p Cattail group Typha domingensis 88.8 95.2 Polygonum hydropiperoides 43.3 47.2 Salix caroliniana 25.1 26.2 Sarcostemma clausum 12.6 16.56 Salvinia minima 9. 11.172 Pontederia cordata 16.1 26.2
NMS Ordination of Sites: 3Dimensions with 8% of information; groups separate but with overlap Muhly group Sawgrass group Cattail group Spikerush group Water Lily group
Muhly group is very distinct; 8 Cattail group is dispersed; Axis 2 Sawgrass, spikerush and water lily groups overlap but occupy different sectors of ordination space. 4 4 8 Axis 1 8 8 Muhly group Sawgrass group Cattail group Spikerush group Water Lily group Axis 3 4 Axis 3 4 4 8 4 8 Axis 2 Axis 1
Species distributions among clusters reflect both overlap and distinctions among groups Muhly group Sawgrass group Cattail group Spikerush group Water Lily group Axis 3 8 4 Axis 3 8 4 Cladium 4 8 Axis 1 4 8 Axis 1 Nymphaea 8 8 Axis 3 4 Axis 3 4 Muhlenbergia Eleocharis 4 8 Axis 1 4 8 Axis 1
Four environmental variables, r 2 >.2, correlate most strongly to a single axis 8 DSDTN WSD Soil Variables Thickness ph Bulk Density* Ash Free Dry Weight* Total P Total N* Total C* Axis 3 4 BD Hydrology Variables Wet Season Water Depth* Dry Season Water Depth* Average Hydroperiod No. Week-long Drydowns 4 8 Axis 1 Muhly group Sawgrass group Cattail group Spikerush group Water Lily group
(Scheidt and Kalla 27) (Scheidt & Kalla 27)
But Total P in soil correlates to another axis, r 2 =.39 8 Soil Variables Thickness ph Bulk Density Ash Free Dry Weight Total P* Total N Total C Axis 2 4 TP Hydrology Variables Wet Season Water Depth Dry Season Water Depth Average Hydroperiod No. Week-long Drydowns 4 8 Axis 1 Muhly group Sawgrass group Cattail group Spikerush group Water Lily group
Combined correlations for the environmental variables are seen in the third dimension 8 DSD TN WSD Soil Variables Thickness ph Bulk Density* Ash Free Dry Weight Total P* Total N* Total C* Axis 3 4 TP Hydrology Variables Wet Season Water Depth* Dry Season Water Depth* Average Hydroperiod No. Week-long Drydowns BD 4 8 Axis 2 Muhly group Sawgrass group Cattail group Spikerush group Water Lily group
Removing outliers removes TP as a significant correlate, reduces axes to 2D, changes species composition of the cattail group and classifies more sites in the water lily group Axis 2 8 4 BD TC AFDW WSDSD TN Soil Variables Thickness ph Bulk Density* Ash Free Dry Weight* Total P Total N* Total C* Hydrology Variables Wet Season Water Depth* Dry Season Water Depth* Average Hydroperiod Maximum Hyrdroperiod No. Week-long Drydowns 4 8 Axis 1 Muhly group Sawgrass group Cattail group Spikerush group Water Lily group
Species Distributions Across the Landscape
The Everglades is the River of (Saw)Grass
Sawgrass morphology and culm density have unimodal (not bimodal) distributions; morphology but not density varies across the landscape Sawgrass Leaf Length vs. Density by Region Sawgrass Leaf Length by Region Length of Longest Leaf (cm) 3 25 2 15 1 5 y =.929x + 186.78 R 2 =.13 y =.6973x + 17.15 R 2 =.359 Sawgrass, ENP Sawgrass, north 1 2 3 4 5 6 7 8 Culms per m 2 Length of Longest Leaf (cm) 3 25 2 15 1 5 a b ENP LOX WCA2, 3 b
Other common species are unevenly distributed
White water lily is sparse in ENP 1999 25
Conclusions Everglades marsh plant associations can be broadly delimited into 5 communities that separate out along a hydrologic gradient The muhly and water lily groups are distinct and form the end-points of this environmental gradient; muhly and water lily make good indicator species for these groups. The other species associations show lots of overlap and grade into each other along the hydrologic gradient 8 DSDTN WSD Axis 3 4 BD 4 8 Axis 1
Conclusions A cattail association varies along a separate environmental gradient that correlates with soil TP; this association has sites that are both natural and nutrient impacted. Axis 3 8 4 TP DSD TN WSD BD Sawgrass shows broad tolerances of hydrological and biogeochemical conditions and is present and abundant throughout the entire Everglades, whereas other species have more restricted distributions. 4 8 Axis 2 Both water lily distribution and sawgrass morphology reflect on a landscape scale the drier, shallower environment in ENP as compared to the WCAs; these conditions should change with restoration.
Acknowledgements Paul Groff, Diana Van Dillewijn, Ana Castellanos, Walter Zagarra, Marlene Dow Morris Flexner, Chris Decker, and the rest of the EPA plant sampling team The Institute for Regional Conservation