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Socioeconomic Conditions and Landscape Features Shape Insect Communities in Urban Areas

Danford, Ellen
http://rave.ohiolink.edu/etdc/view?acc_num=osu1701370900016285

Abstract Details

2023, Master of Science, Ohio State University, Environmental Science.
Urban landscapes are actively exerting new and unique pressures on insect and plant communities which affect the way ecosystems function. Features of human landscapes include impervious surfaces, built environments, vacant land, and socioeconomic variation in landscaping. In the first chapter, we investigated what urban variables are impacting web-building spider (Linyphiidae & Tetragnathidae) community richness and abundance in shrinking cities. We sought to determine if vegetative biomass, land management through mowing of vacant lots, urban fragmentation, or dietary niche partitioning were driving abundance and richness of small web-building spiders in vacant lots in Cleveland, OH. To measure the abundance and richness of spiders we set pitfall traps at our seven sites (3 mown biannually and 4 mown monthly). We also hand collected three specific web-building spiders: Glenognatha foxi, Erigone autmnalis & Tenuiphantes tenuis and utilized gut content analysis techniques to identify the breadth of their prey availability and the overlap between species. We also calculated biomass on site and fragmentation using Arcmap. We found that fragmentation and biomass both positively influenced dietary breadth and dietary overlap, and that breadth and overlap positively drove abundance and richness of spiders. Niche partitioning is an important aspect of spider community assemblage, and our findings suggest that it is influenced by the urban environment. We found that fragmented lots with high biomass hosted the highest abundance of spiders, but not the richest communities. We suggest that biomass is an important aspect of conserving for spiders, but that more connected groups of lots may conserve greater richness of spiders across shrinking cities. In our second chapter, we tested the Luxury Effect Hypothesis, which posits that as median household income of an area increases, so will the plant richness and abundance of that area. As plants are a basis of insect ecosystems, we sought to determine if the Luxury Effect Hypothesis extends also to total insect abundance and lady beetle communities, as they are of conservation concern. We recruited 15 sites across Columbus, OH and sampled with non-baited, yellow sticky traps May-August in 2022 and 2023 once a month. Cards were left out for a week then brought to the lab where each insect on the card was counted under a microscope to get an estimate of total insect biomass and lady beetles (Coccinellidae) were pulled off the cards and identified. We additionally counted bloom abundance at each site, as lady beetles and other insects can feed off nectar and pollen and we calculated fragmentation at each site in ArcGIS pro. We found that lady beetle abundance and richness followed the Luxury Effect Hypothesis, though total insect abundance was predicted by bloom abundance and not income. Income is shaping the landscape across our cities; we need to conserve in cooperation with communities in order to create suitable and attractive habitat across whole city landscapes. We found that the urban environment does shape insect communities. Rather than using solely dietary and competitive interactions to understand insect community assemblage, we must also consider the effects of human-created urban variables to conserve properly in both growing and shrinking cities.
Mary Gardiner (Advisor)
Desheng Liu (Committee Member)
Matthew Davies (Committee Member)
65 p.
Ecology; Entomology; Geographic Information Science
Vacant Lots; Landscape Ecology; Lady Beetles; Luxury Effect

Recommended Citations

Citations

  • Danford, E. (2023). Socioeconomic Conditions and Landscape Features Shape Insect Communities in Urban Areas [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1701370900016285

    APA Style (7th edition)

  • Danford, Ellen. Socioeconomic Conditions and Landscape Features Shape Insect Communities in Urban Areas. 2023. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1701370900016285.

    MLA Style (8th edition)

  • Danford, Ellen. "Socioeconomic Conditions and Landscape Features Shape Insect Communities in Urban Areas." Master's thesis, Ohio State University, 2023. http://rave.ohiolink.edu/etdc/view?acc_num=osu1701370900016285

    Chicago Manual of Style (17th edition)

osu1701370900016285
94
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This open access ETD is published by The Ohio State University and OhioLINK.