Species Richness and Abundance of Invertebrates Across a Subalpine Forest-Meadow Ecotone

Adianez Santiago
University of Puerto Rico, Mayagüez

Sweeping for insects in Tuolumne Meadow

Adianez measuring DBH of Lodgepole Pine trees (Pinus contorta) encroaching into Tuolumne Meadow.

Abstract Forest-meadow ecotones were studied between the months of June-July 2005 because they present the common phenomenon called the “edge effect”. The edge effect refers to higher species richness and abundance forinterfaces between two habitats. This can occur because the edge unites both adjacent communities, making it unique for many animals to inhabit. The area of study was located in Tuolumne Meadows, Yosemite National Park, CA. Sweep-netting was used to capture 61 groups of invertebrates in forest,edge and meadow habitats on the vegetation, Carex filifolia (short-haired sedge). In the lab they were sorted, counted and classified to Order (Diptera, Homoptera, Hymenoptera, Araneae,Coleoptera, Lepidoptera and Other). Invertebrates were used in this study because they are easy to catch; and the process of capture can be repeated with ease. Species richness and abundance was calculated for each group of these invertebrates. Species Richness and abundance was observed to not be significantly different for the three habitats. This is thought to be for various reasons; two reasons take priority. Invertebrates are not affected by the presence or absence of Pinus contorta (Lodgepole Pine). Other factors are involved that decrease the edge effect and produce balanced species richness and abundance for all three of the habitats.