Abstract Detail


Madsen, Kathleen [1], Alexander, Patrick [2], Schenk, John [1].

Patterns of Dispersal Syndromes on Gypsum Outcrops.

The discontinuous distribution of gypsum outcrops play an important role in creating isolated edaphic floral communities. We know from insular island-biogeographic-studies that distance among islands plays an important role in selection for specific dispersal syndromes, but are different dispersal syndromes more common among the discontinuous gypsum outcrops? We hypothesize that selection can either favor dispersal syndromes associated with long distance dispersal or, alternatively, those associated with limited dispersal. To determine whether selection has favored dispersal syndromes associated with long distance dispersal or limited dispersal, we compared the composition of dispersal syndromes among gypsum outcrops and compared them to paired sites of nearby non-gypsum communities. Presence and absence data were collected for 156 sites (78 paired sites in total) in southern New Mexico and western Texas. Dispersal syndromes were assigned for all species using the following categories: anemochory, epizoochory, endozoochory, and achory. Each syndrome was analyzed separately using a paired T-test between gypsum and non-gypsum sites. To infer the relationship between dispersal syndrome frequency and gypsum site association, a chi-square test was run for all gypsum and non-gypsum sites in the data set. We found a significant association between dispersal syndrome frequency and site type. The dispersal syndromes anemochory and achory were found to be significantly more common on gypsum sites than non-gypsum sites. Adversely, endozoochory was more common on non-gypsum sites than gypsum sites. Finally, the dispersal syndrome epizoochory was not found to be significantly associated with either gypsum or non-gypsum sites. Our results suggest that an ecological filter likely selects for particular syndromes, and that they are related to dispersal distance probability, where gypsum communities are favoring abiotic dispersal syndromes, with syndromes that either favor long distance dispersal or a lack of any dispersal syndrome.

1 - Ohio University, Department Of Environmental And Plant Biology, 22 Richland Ave., 401 Porter Hall, Athens, OH, 45701, United States
2 - Bureau of Land Management, 1800 Marquess Street, Las Cruces, NM, 88005-3371, USA

Evolutionary biology
southwestern US

Presentation Type: Poster
Number: PEC031
Abstract ID:387
Candidate for Awards:None

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