Print PageAs temperature regimes shift and species ranges are placed under stress, it is essential that we gain a better understanding of the structure and dynamics of arctic communities in order to predict their response to environmental change. Phylogenetic beta-diversity— or the phylogenetic distance between communities— combined with traditional measures of diversity allows us further insight into spatial changes in the functional diversity of communities. This research investigates the spatial patterns of non-vascular (cryptogam) plant communities in the Subarctic of Canada in an effort to elucidate those biotic and abiotic factors important in dictating community composition. These communities play an important role in arctic ecosystems and are projected to be significantly affected by climate-driven shifts in vascular plant ranges. The study site lies on an elevational gradient in Western Labrador, transitioning the Boreal forest to the Arctic biome. Diversity and abundance estimates of cryptogams were collected in 88 plots set out over the southern slope of Mount Irony and in situ environmental sensors were placed to document temperature, moisture and relative humidity.
Results/Conclusions
Results to date indicate that cryptogams exhibit differential responses to changes in environment over an elevational gradient. Lichen species richness and phylogenetic diversity increased linearly with altitude. In contrast, bryophyte richness remained relatively constant over an elevational gradient. These results suggest that turnover is highly guild-specific, and that some factor associated with elevational change is playing an important role in structuring arctic communities. Future work will include documenting microhabitat environmental measures and spatial analysis of community composition. Beta-diversity measures are projected to show a greater distance-decay relationship for phylogenetic similarity than species or functional richness.
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