Effects of Climate Change on Terrestrial Arthropod Fauna in Tundra on the Antarctic Peninsula
Krieg, Michelle1,2; Strauss, Sarah2; and Day, Thomas2
1School of Earth and Space Exploration, Arizona State University; 2School of Life Sciences, Arizona State University
Over the past 60 years, air temperatures along the west coast of the Antarctic Peninsula have risen at a rate 5x the global average, and precipitation has increased. To understand the consequences of this change, a climate manipulation experiment, consisting of 20 plots, was conducted at Palmer Station along the Peninsula. Each plot contained intact cores of well-developed tundra that was dominated by vascular plants and contained an organic soil horizon. Infrared heaters above half the plots warmed canopy air and soil temperatures by 1 and 2°C, respectively, and half of the cores in each plot received supplemental rainfall (+25% ambient). Climate treatments were applied over two consecutive growing seasons (November - March). Each season, 10 replicate cores from each treatment combination were harvested and arthropods were extracted. Upon return to ASU, examination under a dissecting microscope revealed several species of Collembola (springtails) and Acarina (mites), along with larvae of Belgica Antarctica (Diptera). Treatment effects in each growing season were similar: Tundra cores that received supplemental precipitation had more arthropods than those receiving only ambient precipitation. Although warming by itself had no effect, cores that received supplemental precipitation in combination with warming had the most arthropods. These effects were primarily due to the effects on Collembola, specifically Cryptopygus antarcticus, which was the most prevalent microarthropod. Greater microarthropod abundance was also consistent with greater plant productivity found in cores under the same climate treatments. These findings suggest that as the Antarctic Peninsula continues to become warmer and wetter, microarthropods will become more abundant.