Diversity,distribution, and abundance of ground dwelling spiders at Lick Creek Park, College Station, Texas

Lick Creek Park is a 515 acre nature park that was acquired in 1987 by the City of College Station, Texas. The site has a variety of indigenous plant and animal species and is an important natural resource for citizens of the region. There is a long-term commitment to inventory this natural park to monitor the changes as our urban community expands to surround the park. There are 989 species of spiders currently recorded from Texas and 332 of them are known to occur in Brazos County. My focus was on improving the ground spider inventory at Lick Creek Park. Spider collections were made using 18 regularly-sampled pitfall traps distributed evenly among three habitats. Spiders from 24 families, 66 genera, and 111 species were identified from 918 specimens, including 627 immature and 291 adult spiders, captured in pitfall traps from April 2005-April 2006. Of the 111 species found, 45 were represented by one specimen only and 20 were represented by two specimens. Rarefaction analyses indicated that the majority of spider species were readily detectable using pitfall traps and inventoried during this study (111 found and 168 estimated to be present). Simpson’s Diversity measure bootstrap estimates determined species diversity overall to be very diverse (0.966), as did a Shannon Weiner Diversity bootstrap estimate (5.483). Also, Simpson’s measure of species evenness (0.264) indicated a low species evenness. Those species found in only one habitat comprised 50% of the total species, and their densities ranged from 1-5 individuals. Those species found in just two habitats comprised 25% of the total species, and their densities ranged from 2-21 individuals. Species found in all three habitats comprised the remaining 25%, and their densities ranged from 4-53 individuals found. Most species occurred at low densities in this study and this often precluded conducting more detailed analyses. Additional sampling is expected to, first, detect known species occurring in previously unrecorded habitats and, second, to detect species not previously found in the park. This inventory of spiders at Lick Creek will provide a basis for further studies on biodiversity and the assessment of human impact on the environment