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.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4402 |
| Date | 30 October 2006 |
| Creators | LaFever, David Howard |
| Contributors | Lopez, Roel R. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 293246 bytes, electronic, application/pdf, born digital |
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