https://scholarworks.seattleu.edu/fss-2019/1005/thumbnail.jp

Cowal, Sanya

Grandia, Caroline

Liere, Heidi

Nguyen, Emily

English

ScholarWorks @ SeattleU (Seattle University)

Abstract1. Goddard MA, Dougill AJ, Benton TG (2010) Scaling up from gardens: biodiversity conservation in urban environments. Trends in Ecology & Evolution 25(2):90–98.2. Hall DM, et al. (2017) The city as a refuge for insect pollinators. Conservation Biology 31(1):24–29.3. Philpott SM, et al. (2014) Local and landscape drivers of arthropod abundance, richness, and trophic composition in urban habitats. Urban Ecosyst 17(2):513–5324. Team, R. D. C. 2018. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. 5. Calcagno, V., and C. de Mazancourt. 2010. glmulti: an R package for easy automated model selection with (generalized) linear models. Journal of Statistical Software 34:1-29.The purpose of my research project is to investigate how garden management practices and landscape context affect beneficial arthropods in urban community gardens.Understanding this is significant because, despite the overall detrimental effects of urbanization to biodiversity, there is a growing recognition of the potential value of cities and their various green spaces 1 for biodiversity conservation, especially for small organisms2.Farm and community garden management practices, such as planting hedgerows of nectar-rich plants or setting aside beetle refuges, can directly or indirectly benefit both pollinators and pest control agents 3.Even so, due to limited size, relative isolation from natural areas, and constant disturbances, small-scale urban agricultural systems may not be able to sustain the necessary biodiversity to fulfill their pollination and pest control needs.Thus it is important to also investigate whether the maintenance of biodiversity in these habitats depends on the quality of the surrounding landscape.Data analysisEliminated collinear variablesGLM to test the effect of local and landscape variables 4These preliminary analyses show that beneficial arthropods respond to both local garden management features and landscape context.Some of the trends found here contrast with those expected from rural agricultural systems.• Funding: Summer Faculty Fellowship Programm, CSE Undergraduate Student/Faculty Research Support Award, Environmental Studies Department• Garden access: King County P-patch coordinators and P-patch gardeners• Illustrations by Charlotte GrenierMethods/Experimental designConclusionIntroductionResultsAcknowledgementsReferencesLocal and landscape factors affecting biodiversity in urban community gardens in SeattleHeidi Liere1, Sanya Cowal1, Emily Nguyen1, and Caroline Grandia21Environmental Studies and 2Biology Departments, Seattle Universityabundance# ornamental sppabundancetree & shrub abundancegarden size (sqm)spp. richnessgarden size (sqm) mulch cover# flowers prop. parks 500m abundancerock coverfamily  richnessFig. 1. Results for the best model GLM (Generalized Linear Model) examining the effect of local and landscape features of urban gardens in Seattle on abundance and richness of beneficial arthropods• Groundbeetles (Coleoptera: Carabidae, Staphylinidae): 127 individuals• Ladybeeetles (Coleoptera: Coccinellidae): 276 individuals from 13 species  College of Arts and Sciences• Spiders (Arachnida and Opiliones): 743 individuals from 12 FamilesStudy site10 community gardens in SeattleGardens varied in local and landscape compositionBeneficial insects provide important ecosystem services for food production, like pollination and natural pest control. We surveyed natural enemies (predatory and parasitic insects that consume crop pests) in community gardens in the city of Seattle. We assessed how the local garden features interact with the surrounding green spaces to allow these beneficial organisms to occupy and persist in these habitats. Our findings could contribute to mitigate urban biodiversity loss and improve human well-being.Arthropod surveys3 sampling rounds (June, July, August) 20193 sampling methods (visual, sticky traps, pitfall trapsFor each dependent variable, we tested all combinations of the selected explanatory variables (with the ‘glmulti’ package in R 5) and selected the top model based on the AICcIndependent variablesLocal: ground cover and vegetation variablesLandscape: prop. of area (in 500m buffers) covered by city-managed parks

Local and Landscape Factors Affecting Biodiversity in Urban Community Gardens in Seattle

https://scholarworks.seattleu.edu/cgi/viewcontent.cgi?article=1005&amp;context=fss-2019

Local and Landscape Factors Affecting Biodiversity in Urban Community Gardens in Seattle

Abstract

Similar works

Full text

Available Versions

ScholarWorks @ SeattleU (Seattle University)