Small Mammals from the Cloud Forest at Cerro Bobi, Sierra

S 99 Over time, a population of rotifers had contaminated the Scenedesmus sp. cultures, triggering the production of multicelluar, spinous forms, a typical anti-predator strategy for this genus. It is then concluded that Scenedesmus sp. does exhibit phenotypic plasticity in response to biotic and abiotic changes in the surrounding environment. Additionally, some genetic variation was found in several other isolates from a pure Scenedesmus sp. culture, all of which, group within the Scenedesmus-Desmodesmus complex. SALAMANDER DIVERSITY AT C. F. PHELPS WILDLIFE MANAGEMENT AREA, FAUQUIER AND CULPEPER COUNTIES, VIRGINIA. J. D. McGhee & M. D. Killian, Department of Biological Sciences, University of Mary Washington, Fredericksburg, VA 22407. Salamander guilds are important components of ecosystems, and may be declining in Virginia. Consequently baseline information on salamander diversity and abundance is needed. Our objective was to assess salamander diversity at a single site in the Rappahannock River watershed, C. F. Phelps Wildlife Management Area. We randomly selected stream and upland terrestrial sites to run 50meter transects, for both quadrat and natural cover searches. We assessed diversity using a Shannon-Weiner index on all captures and non-larval captures, compared findings quantitatively to similar studies, and assessed diversity in on-site watersheds. We found 11 of 13 expected species, with H’ = 1.33 ± 0.05 SD, J’= 0.55, and for nonlarval diversity H’ = 1.18 ± 0.08 SD, J = 0.49. The slope of captures per species was 1 similar to other studies, â = -0.50 ± 0.10. A single watershed (Fishing Run stream) was considered more diverse than other watersheds on site. We conclude that C. F. Phelps Wildlife Management Area supports a relatively diverse salamander community, and may act as a baseline for the surrounding region. Management efforts should be focused to maintain stream structural diversity, and monitoring agricultural input. GEOGRAPHIC INFORMATION SYSTEMS AUGMENT ECOLOGICAL MONITORING IN DAM REMOVAL PROJECT. Alan B. Griffith & Damon Lowery. Dept. of Biological Sciences, University of Mary Washington, Fredericksburg, Virginia, 22401. As dam removals have increased in frequency, due to dam deterioration and interest in ecosystem restoration, there is a growing need to determine the ecological effects of dam removal. Few studies have been conducted on dam removals and pre-dam removal data is particularly limited. We present here a case study that explores the use of Geographical Information Systems (GIS) to supplement vegetation sampling data on the ground. Our part of an interdisciplinary study aims to measure changes in distribution and abundance of vegetation after the removal of 2 earthen dams on a tributary of Holts Creek in New Kent County, VA. We previously reported results of plant distributions and abundances measured before the removal of these dams. Our sampling revealed that at least one invasive species, Murdannia keisak and Microstegium vimineum were broadly distributed and in high abundance within the dams’ watershed. As dam removal proceeds, it will be essential to monitor the establishment of these invasive species and other species. Based on our current knowledge of GIS applications we 1) will visualize vegetation samples as spatially related information, 2) have gathered existing geo-referenced information for the Virginia Journal of Science, Vol. 60, No. 2, 2009 http://digitalcommons.odu.edu/vjs/vol60/iss2 100 VIRGINIA JOURNAL OF SCIENCE impacted watershed, and 3) have uncovered potentially useful spatially related information, for which no data exists. This process has led us to collect geo-referenced data that will improve our ability to monitor vegetation changes after dam deconstruction. PHYTOPLANKTON DIVERSITY TRENDS IN THE RAPPAHANNOCK, YORK AND JAMES RIVERS. Todd A. Egerton & Harold G. Marshall. Dept. of Biological Sciences, Old Dominion University. Norfolk VA 23529. The examination of the causes and consequences of biodiversity is a central tenet in ecological research. In estuarine habitats, one factor which has been shown to have an effect on diversity is salinity. Remane (1934) described the change in community composition of benthic invertebrates along a salinity gradient and the accompanying change in species richness. He observed the greatest numbers of species in the freshwater and marine portions, and the lowest in the brackish mesohaline region. This study examines the long term diversity of phytoplankton species along the Rappahannock, York/Pamunkey, and James rivers, tidal tributaries to Chesapeake Bay. These three rivers have varying levels of algal productivity and diversity, and show the same general pattern as described by Remane, with reduced species richness in the mesohaline. Additionally, there is a significant positive correlation between phytoplankton diversity and productivity, but only in the upstream, low salinity stations. This may be attributed to the large seasonal fluctuations in phytoplankton abundance in the freshwater sites, and the relative constancy of the populations in the Chesapeake Bay. This study is based on the long-term phytoplankton monitoring data, gathered as a component of the Chesapeake Bay Program. PHYLOGENY OF THE CARYOPHYLLALES (ANGIOSPERMS): EXPLORING THE EFFECTS OF GENE CHOICE AND MISSING DATA. Sunny S. Crawley, Shelli A Newman & Khidir W Hilu, Department of Biological Sciences, Virginia Tech, Blacksburg VA 24061. Previous work on reconstructing Caryophyllales phylogeny has relied on data from two to many genomic regions, totaling 3,000 to 46,000 base pairs of sequence information. Topology, resolution, and support for the internal structure of the order have varied, but improvement has been noted as the number of genes/characters increased. We explore here the impact of gene choice and degree of missing data on tree topology and support within Caryophyllales. We chose two rapidly evolving regions (matK and surrounding trnK intron), two slowly evolving regions (atpB and rbcL) and one with an intermediate rate of evolution (ndhF). We supplemented new matK/trnK sequences with complete and partial sequences from GenBank for all genomic regions. Maximum parsimony and maximum likelihood methods were used to analyze 130 species with six basal eudicot species as outgroup. Varying degrees of missing data were analyzed as several different data partitions. The phylogenetic structure of the order recovered with rapidly evolving regions was comparable to that obtained with the three other regions. Topology and support based on combined analysis of five regions was remarkably similar to those obtained using much larger numbers of genes/characters; this was achieved despite having about 46% missing data. Combining genes of different mode of evolution and inclusion of partial Virginia Journal of Science, Vol. 60, No. 2, 2009 http://digitalcommons.odu.edu/vjs/vol60/iss2