Micro-islands in Oklahoma? Species-area Relationships in Lichen Invertebrate Communities.

Abstract

Species-area relationships are well studied in many ecosystems, especially islands, and consistently show an increase in species richness as the area increases. Species-area curves generally show an increase in species richness as area increases until the regional species pool is exhausted. We examined species-area relationships in lichen invertebrate communities to deepen the overall understanding of these less studied micro-communities. We hypothesized that lichen patches would display the same species-area distribution trends documented in other isolated communities, such as islands. Lichen samples were collected from three trees on the main campus of Southwestern Oklahoma State University in Weatherford, Oklahoma. Five lichen patches were randomly selected from a similar location on each tree. A perimeter measurement and sample of each lichen patch was obtained. The samples were hydrated, then agitated to expel the organisms from the solid matter. Each patch was individually examined under a compound microscope, documenting morphospecies and abundances. We discovered that the species-area relationship of lichen communities did not produce the classic sigmoidal curve. Species accumulation in lichen invertebrate communities may not be governed by the same underlying processes as other isolated communities.