Loewen, C.J. (2017). Stressor response and spatial dynamics of mountain lake communities. Ph.D. Thesis, University of Alberta, Edmonton, Alberta, Canada. 178 pp.

508743

10.7939/R3H12VN4D [view]

Loewen, C.J.

2017

178 pp.

Publication

Available for editors  

Multiple novel and rapidly changing environmental factors (i.e. anthropogenic stressors) are increasingly affecting ecological communities, and their functional roles in ecosystems. Consequently, freshwater biodiversity has declined worldwide; however, the functional impacts of this loss should be contingent upon local species’ traits and the potential for tolerant species to compensate for sensitive taxa. In a metacommunity (i.e. a set of local communities connected regionally by species dispersal) context, stressor resistance may further depend on the arrival of stress-tolerant colonists from the regional species pool. My research, in collaboration with international colleagues, combines quantitative literature review, a manipulative field experiment, and innovative multivariate analyses of continental-scale observational data to address scientific knowledge gaps concerning the impacts of multiple stressors on freshwater communities. First, a meta-analytic approach was used to assess the tendency for freshwater stressors to interact by comparing the independent and combined effects of paired stressors across 286 experimental responses from 88 published articles. The nature of multiple stressor interactions is a key source of uncertainty for conservation practitioners, as co-occurring stressors may generate unanticipated non-additive interactions (i.e. ecological surprises) that either dampen or amplify their individual direct effects. Net impacts of stressors varied, but were less than expected (i.e. antagonistic) overall, indicating a potentially high degree of co-adaptation to stressors within freshwater ecosystems. Further, aggregate functional properties of communities were less sensitive than biodiversity, suggesting that compensation by stress-tolerant species may frequently lessen the functional consequences of co-occurring environmental changes.

RIS (EndNote, Reference Manager, ProCite, RefWorks)
BibTex (BibDesk, LaTeX)

[Back to search]