Scale-Dependent Effects of Restoration on a Grassland Arthropod Community

摘要

California's native perennial grasses have been displaced by exotic annuals of Mediterranean origin over the last two centuries. Efforts to restore native perennial species are costly, and so focus on increasing marketable ecosystem service benefits, mainly forage value. Restoration is vegetation centric and often overlooks higher trophic levels, despite their importance in maintaining ecosystem health. Arthropod diversity is essential to natural ecosystem function and provision of agricultural ecosystem services such as pest suppression by natural enemies. Little is known of how invasion and subsequent restoration of California's native grasslands affect the associated arthropod community. I used a manipulative experiment to test how botanical composition and the interspersion of annual and perennial grassland habitat at different spatial scales within 22 x 44 m plots affect the associated surface dwelling arthropod community during the grass growing season. Surface dwelling macroarthropods were sampled in transects between strips of annual and perennial vegetation seeded in varied proportions and grains using pitfall traps in 2014 and 2015.