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The cascading impacts of vegetation on peat soil properties and crayfish survival in the Florida evergladesUnknown Date (has links)
Changes in vegetation may influence the quality and quantity of the underlying
organic peat soils and have impacts on faunal populations. My goal was to determine
whether shifts from native slough communities to invasive cattail in the Florida
Everglades could affect peat characteristics that could cascade to impact the dry season
survival of crayfish (Procambarus fallax). I contrasted peat soils from native slough and
cattail-invaded sites as alternative dry-season burrowing substrates for crayfish. Cattail
peat had higher average bulk density and inorganic content within the first ten
centimeters of the soil profile. Crayfish showed marginally greater initial burrowing
success in slough peat than in cattail peat but survival was equivalent in both peat soils
and high overall. Understanding these indirect linkages between vegetation and crayfish
populations in the Everglades can provide insight on the consequences of plant invasion
on ecosystem trophic dynamics. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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A comparison of pixel based and object based vegetation community classification in the Arthur R. Marshall Loxahatchee National Wildlife RefugeUnknown Date (has links)
Pixel based and object based vegetation community classification methods were performed using 30 meter spatial resolution Landsat satellite imagery of the Arthur R. Marshall Loxahatchee National Wildlife Refuge (Refuge), a remnant of the northern Everglades. Supervised classification procedures using maximum likelihood and parallelepiped algorithms were used to produce thematic maps with the following vegetation communities : wet prairie, sawgrass, cattail, tree island, brush, aquatic/open water. Spectral data, as well as NDVI, texture and principal component data were used to produce vegetation community classification maps. The accuracy levels of the thematic maps produced were calculated and compared to one another. The pixel based approach using the parallelepiped classification algorithm on the spectral and NDVI dataset had the highest accuracy level. A generalized form of this classification using only three vegetation communities (all wet prairie, tree island/brush and aquatic/open water) was compared to a previously published classification which used 1987 SPOT imagery in order to extract information on possible vegetation community transitions that are occurring within the Refuge. Results of the study indicate that 30 meter spatial resolution may be useful for understanding broad vegetation community trends but not species level trends. Pixel based procedures provide a more accurate classification than object based procedures for this landscape when using 30 meter imagery. Lastly, since 1987 there may be a trend of tree island/brush communities replacing wet prairie communities in the northern part of the Refuge and a transition to wet prairie communities in place of tree island/brush communities in the southern portion of the Refuge. / by Dorianne M. Barone. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, FL : 2008 Mode of access: World Wide Web.
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