2018/09/17 by Ziyi Wang, Schep, Willem, Abels-Sullivan, Hanan +1
#California #dolomite #ecotone #edge effects #subalpine
paper · doi:10.21973/n3m65v
Abiotic stress and heavy competition each limit the assemblages of plant communities, defining their composition as well as their boundaries. One plant community governed by stress and another by competition may abut one another, forming a biotic gradient called an ecotone. In California’s White Mountains, this gradient occurs across the meeting point between a calcareous (dolomite) and non-calcareous (quartzite) soil types. In this study, we tested the effects of this gradient on plant community compositions and diversity, surveying plant communities across an edaphic gradient from quartzitic to dolomitic substrates. We found that the higher presence of sagebrush within quartzite decreased diversity while increased rockiness in dolomite decreased plant cover. Diversity was highest in the ecotone between the two habitats, potentially due to heavy competition from sagebrush on one side and the increase in edaphically stressful dolomite rock on the other. In addition, the ecotone plant community was unique from those on either soil type. These findings provide insight into edge effects on subalpine plant communities, and the nuances by which edaphic conditions produce these effects.