If we build it, will they come? Insect communities as indicators of restoration in an urban prairie network

Date of Award

2019

Degree Name

M.S. in Biology

Department

Department of Biology

Advisor/Chair

Advisor: Chelse Prather

Abstract

The increasing negative effects of human impacts on the Earth have led to the urgent need for large-scale ecological restoration. One ecosystem of particular interest for restoration is tallgrass prairie, which only has 4% of its original 167 million acre range remaining in North America. However, restored and constructed prairies often do not support the same biodiversity and ecosystem services as remnant prairies. Many restoration projects only focus on reinstating vegetation, assuming that other trophic levels will colonize on their own. These higher trophic levels include arthropods, which make up a majority of the biodiversity in prairie ecosystems. We sought to determine if there is a difference in the insect communities in constructed and remnant prairies. It was hypothesized that insect communities would be different, with higher arthropod abundance and diversity in remnant sites, and older constructed sites would more closely resemble remnant sites. It is possible that indicator species of high-quality prairie could be identified, and that they may possess certain functional traits (morphological or life history) that allow them to colonize these sites. Sweepnet samples (100 sweeps per site) were taken at 5 old fields, 5 constructed prairies, and 5 remnant prairies in 2017, and 7 constructed prairies and 6 remnant prairies in 2018. All arthropods were then sorted to order, and some orders to morphospecies.The only order of insects whose abundance was significantly different between habitat types was Coleoptera (p = 0.041), which were 3.5 times more abundant in remnant sites than constructed sites. The only family of Coleoptera whose abundance was significantly different between habitat types in 2017 was Phalacridae (p = 0.046) which were 7.6 times more abundant in remnant sites than constructed sites. The abundance of Phalacridae in constructed prairies increased with age since construction (p = 0.03, R▓ = 0.63; p = 0.09, R▓ = 0.47). Ordinations of beetle families show that certain families are not being restored soon after the project, but rather restored slowly over long periods of time as late-successional species are able to colonize, such as Phalacridae. These results could have large implications on how tallgrass prairies are restored and managed, and how these ecosystems should be assessed for restoration, specifically looking at other aspects of the ecosystem other than vegetation.

Keywords

Ecology, tallgrass prairie, Field of Dreams hypothesis, indicator species, Coleoptera, Phalacridae

Rights Statement

Copyright © 2019, author

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