The Riverscape: A Transformative Ecological Paradigm Used to Understand Conservation Outcomes

Landscape homogenization and the degradation of proximate ecosystems have greatly impaired lotic environments throughout North America. Numerous conservation programs may mitigate lost ecological function to which a loosely defined collection of species are expected to respond. However, restoration efforts have rarely advanced biological goals; potentially a product of focused manipulations on isolated stream fragments without adequate consideration of riverscape properties involved. Restored landscapes with reestablished riparian corridors were appraised to quantify the indirect effects of prevalent prairie conservation practices on aquatic resources. Management improved local water quality and restored processes that create and maintain diverse habitat complexes; however, fish assemblage structure remained consistent with unrestored sites. Three alternative hypotheses potentially explain limited fish response: connectivity to newly available habitats by potential founder populations remain severed; local assemblages lack species adapted to utilize open niches; and local species do not benefit from the specific niches created. Subsequent reviews have substantiated each riverscape hypothesis; however, predictions of fish response will be ambiguous until the plurality of their interactions is quantified. Within the riverscape paradigm not all restored sites are created equally; each have constraints that dictate biotic response. The development of niche space doesn’t directly translate to successful colonization and subsequent occupation.