Date of Award

2019

Document Type

Honors Thesis (Open Access)

Department

Colby College. Biology Dept.

Advisor(s)

Justin Becknell

Second Advisor

Catherine Bevier

Third Advisor

Chris Moore

Abstract

Asian Jumping worms (Megascolecid spp) were introduced to North America in the early 1900s and have been altering soils in forest ecosystems as they spread throughout the continent. The worms differ from other introduced earthworms in their ability to consume large densities of organic material and potentially alter nutrient cycling in the ecosystems that they invade (Greiner et al. 2012). This study examined if and how Asian jumping worms alter turfgrass systems by changing the biological or physical properties of soil. To do this we conducted a mesocosm experiment and observational field study. For the mesocosm study we inoculated boxes that replicated a backyard environment with Asian jumping worms, and we evaluated how microbial extracellular enzyme activity, soil chemistry, biomass, and organic matter changed over time in boxes with and without worms. For the field study we collected soil samples from Coastal Maine Botanic Gardens and analyzed enzyme activity and ammonium concentration for sites with and without worms. The mesocosm study did not produce evidence of worms altering any of the biological or physical metrics that we studied. However, in the field study, we found that sites with high worm presence had increased chitinase and peptidase activity. Overall, the results of the study are inconclusive but support previous findings that worms effect grassy ecosystems differently than forest ecosystems (Qui and Turner 2017). Further studies are needed to determine how Asian Jumping worms effect turf grass systems and how those effects differ from what has been found in forests.

Keywords

earthworm, turfgrass, microbes, soil

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