Electronic Thesis and Dissertation Repository


Master of Science




Yates, Adam G.


Agricultural land use affects benthic macroinvertebrate (BMI) community structure but riparian forest may mitigate its impact to within a specific threshold. BMI communities were sampled in small streams within the Grand River, Thames River, and Long Point watersheds in southwestern Ontario. The study assessed the location and amount of agricultural land use associated with variation in BMI assemblage structure. Three land use distribution scenarios were evaluated to isolate specific ranges of agricultural land use at either the riparian or catchment scale, with the adjoining scale covering as wide a gradient of agricultural land use as possible. We did identify thresholds but the amount of variation associated with our thresholds would not enable us to suggest specific target ranges for land use managers looking to incorporate them into their stream biomonitoring programs. Further studies that assess various geologies and share wider gradients will improve upon our findings.