Urbanization is accelerating in the United States and is contributing to fragmentation of natural habitats, causing changes in species composition and declines in native species. Human population growth in Orlando is typical of growth in the southeastern United States and throughout the range of cypress (Taxodium distichum). Orlando has numerous isolated cypress wetlands, called cypress domes, and many remain among the current urbanized area. This makes Orlando ideal to study the effects of urbanization on cypress domes. Specifically, I tested how urbanization and its effects on fragmentation, hydrology, and fire regime) affected (a) the numbers and spatial pattern of cypress domes in central Florida and (b) the recruitment of cypress within cypress domes. Analysis of historical loss found over 3,000 cypress domes identified in images from1984, of which 26% were lost or degraded (i.e., no longer cypressdominated) by 2004. Due to changed land use, many remaining cypress domes, formerly surrounded by natural lands, have become surrounded by urban lands causing spatial clustering and homogenization. Surprisingly, I found that both natural and urban cypress domes showed lower recruitment than agricultural cypress domes, where the natural fire regime has not been altered. The probability of cypress recruitment in cypress domes urbanized for more than 20 years is very low. Previous to that, cypress tends to recruit on the edge of cypress domes where there is less competition and hydrological conditions are more favorable. I estimate that only ~50% of the current cypress domes are recruiting and the existence of those wetlands are tied to the lifespan of the current adults. By 2104, I estimate that ~89% of the cypress domes currently recruiting will fail to recruit. I believe that reducing urban sprawl and restoring the natural fire iii regime to natural cypress domes will mitigate the current fate of cypress domes. Without this, cypress in isolated wetlands in central Florida, and providing Orlando urbanization is typical, throughout urbanized areas of the range, could be at risk. Cypress in urban areas will be then relegated to riparian zones and with unknown consequences for the species that utilize the former cypress dome habitat
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-2770 |
| Date | 01 January 2011 |
| Creators | McCauley, Lisa A |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
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