Block, Timothy , Rhoads, Ann F. .
Occurrence and Distribution of Aquatic Vascular Plants of Northeast Pennsylvania’s Glacial Lakes and Ponds as Related to Water Chemistry Parameters.
The glacial lakes and ponds of Northeast Pennsylvania contain more than 130 species of aquatic vascular plants. These lakes and ponds range from a nearly pristine, oligotrophic condition to eutrophic due, in part, to various anthropogenic influences. The purposes of this study were to determine if some species are significantly related to water quality parameters and if species suites are associated with the general trophic status of the lakes. Data were collected on the presence of aquatic macrophyte species from 115 lakes and ponds. Water chemistry data were collected from 45 lakes by the Pennsylvania Department of Environmental Protection. Binary logistic regression was used to look for statistically significant relationships between species and water chemistry parameters individually. The matrix of presence/absence data was transformed using Beal’s smoothing to derive a matrix of probabilities of each species occurring in each lake. The resulting matrix of probabilities was used in cluster analysis to search for suites of species. The regression analysis shows that some, but not all, species are significantly related to either high or low levels of total alkalinity, phosphorous, nitrogen, or pH. The results of cluster analysis reveal the occurrence of two distinct suites of species. In one cluster are most of the species associated with more oligotrophic, low-nutrient situations while a second cluster contains most of the species associated with higher-nutrient more eutrophic lakes, including all of the non-native invasive plant species found. These results are consistent with those of similar studies conducted in Northern Europe and Northeastern U.S.
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1 - University of Pennsylvania, Morris Arboretum, Botany Department, 9414 Meadowbrook Avenue, Philadelphia, Pennsylvania, 19118-2624, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM