Linking macroinvertebrates traits to secondary production in historically acidified streams

Acidification inhibits macroinvertebrate ion exchange causing decreased taxon fitness and survival. While it is understood that macroinvertebrate diversity declines with acidification, less is known about how community secondary production responds to acidification. Because secondary production incorporates individual fitness over time to inform resource use, it is the most comprehensive assessment of stress. Unfortunately, production is labor intensive and approximate measures are required for a sustained analysis. Trait-based metrics indicate how organism live within their environment to inform macroinvertebrate functions. While traits can illustrate what a taxon is doing in the environment, their use as proxies of secondary production metrics needs to be tested. We hypothesized that decreased trait richness will correspond to decreased production because of diminished resource use in acidified streams. From July 2019 - June 2020, five Hess samples were collected monthly from one acidified and one circumneutral stream in Shenandoah National Park. Trait richness and density were compared with measures of secondary production. Preliminary analyses suggest decreased richness and density of large bodied and semivoltine taxa corresponded to lower annual production in the more acidified stream. Trait structure and secondary production will be compared to identify proxies of function.