Development and validation of a macroinvertebrate index of biotic integrity (IBI) for assessing urban impacts to Northern California freshwater wetlands

摘要: Despite California policies requiring assessment of ambient wetland condition and compensatory mitigations, no intensive monitoring tools have been developed to evaluate freshwater wetlands within the state. Therefore, we standardized, wadeable field methods sample macroinvertebrate communities evaluated 40 across Northern develop a index biotic integrity (IBI). A priori reference sites were selected with minimal urban impacts, representing best-attainable condition. We screened 56 metrics for inclusion in IBI based on responsiveness percent urbanization. Eight final IBI: three dominant taxa; scraper richness; Ephemeroptera, Odonata, Trichoptera (EOT); EOT Tanypodinae/Chironomidae; Oligochaeta Coleoptera; predator richness. The (potential range 0–100) demonstrated significant discriminatory power between (mean = 69) impacted (mean = 28). It also declined increasing urbanization (R 2 = 0.53, p < 0.005) among an independent validation dataset (n = 14). was robust showing bias environmental gradients. This is functional tool determine ecological at (stormwater flood control ponds), as well rural (stockponds, seasonal wetlands, natural ponds). Biological differences perennial non-perennial suggest that developing separate indicators these types may improve applicability, although existing data set not sufficient exploring this option.