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Description:
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Rapid development and urbanization of the Lower Florida Keys in the last 30
years has fragmented the habitat of the Lower Keys marsh rabbit (Sylvilagus palustris
hefneri ) and threatened it with extinction . Current threats exist at multiple
spatiotemporal scales and include threats due to development , invasive species , and
global climate change . On Boca Chica Key , the Lower Keys marsh rabbit (LKMR )
exists as a metapopulation on Naval Air Station -Key West (NASKW ) . I conducted a
population viability analysis to determine the metapopulation's risk of extinction under
multiple management scenarios by developing a spatially -explicit , stage -structured ,
stochastic matrix model using the programs RAMAS Metapop and ArcGIS . These
management scenarios include clearance of airfield vegetation , habitat conversion , and
control of feral cats as an invasive species . Model results provided the Navy with
relative risk estimates under these different scenarios . Airfield clearance with habitat
conversion increased extinction risk , but when coupled with feral cat control , risk was
decreased .
Because of the potential of sea -level rise due to human -induced global climate
change , and its projected impact on the biodiversity of the Florida Keys , I estimated the impacts of rising sea levels on LKMR across its geographic distribution under scenarios
of no , low (0 .3m ) , medium (0 .6m ) , and high (0 .9m ) sea -level rise . I also investigated
impacts due to 2 treatments (allowing vegetation to migrate upslope and not allowing
migration ) , and 2 land -use planning decisions (protection and abandonment of humandominated
areas ) . Not surprisingly , under both treatments and both land -use planning
decisions , I found a general trend of decreasing total potential LKMR habitat with
increasing sea -level rise . Not allowing migration and protecting human -dominated areas
both tended to decrease potential LKMR habitat as compared with allowing migration
and abandoning human -dominated areas . In conclusion , conservation strategies at
multiple scales need to be implemented in order to reduce threats to LKMR , such as
development , invasive species , and global climate change . |