Recent Topics Posters
Tessler, Michael , Truhn, Kam , Wehr, John D. .
Stream bryophyte distributions and diversity in southeastern New York State, USA.
Bryophytes are a key component of head water stream ecosystems, often the major primary producers in low-order streams, both in terms of in biomass and primary production. They also have central roles in nutrient cycling and trophic dynamics. But, few studies have examined the factors that influence the distribution of stream bryophyte species, and of these almost none have looked across a large pH gradient. To assess the effect of a broad pH gradient on the distribution and niche properties of stream bryophyte species, 27 streams in southeastern NY State (USA) that ranged from pH 4 to 7, largely due to differing underlying bedrock,were surveyed for the presence and abundance of bryophyte species. Hygrohypnum eugyrium and Racomitrium aciculare appeared to be pH generalists and were found in both low pH and neutral pH streams. However,several species only occurred in streams with either neutral or low pH.Specifically, Eurhynchium riparioides,Brachythecium rivulare, Hygroamblystegium varium, and Sciaromium lescurii were only found in relatively neutral pH streams, whereas Andreaearothii appeared to be restricted to low pH streams. Each stream was also characterized in terms of multiple physical and chemical factors; specifically,stream width and depth, percent canopy cover, type of substratum colonized, substratum size, temperature, pH, dissolved oxygen,turbidity, specific conductivity, current velocity, NH4+,and PO43- were measured. A multivariate analysis will be utilized to characterize the relative importance of these ecological variables among the study streams.However, preliminary analyses indicate that pH is of importance in the distributions of several species.
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1 - Fordham University, Biological Sciences-Louis Calder Field Station, 53 Whippoorwill Road, Armonk, NY, 10504, USA
Presentation Type: Recent Topics Poster
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM