Beaver and Aspen: Synergy Among Keystone Species

In the West, climate change is likely to increase the frequency, intensity, and duration of drought. Restoration of soils and water storage capacity can help create resilient uplands and riverscapes (i.e., streams and the valley bottoms). Over the past two centuries, common land uses, the removal of beaver and wood, straightening of streams, and damage to riparian areas have created simplified, structurally starved, riverscapes. Degraded streams are very efficient at transporting water, sediment, and nutrients downstream. Aspen forests are also biological hotspots that have been degraded by past land uses such as overbrowsing ungulates, land clearing, fire suppression, and outright removal in favor of timber species. Loss of riverscape and aspen habitats has a disproportionate impact on biodiversity and landscape resilience. When aspen occur in or near riverscapes they are a preferred food and building material for beavers. Beaver, in-turn, can stimulate aspen regeneration, both through cutting and restoring hydrologic function in riparian areas. Adding beavers can reinstate riparian processes, increase aspen growth and diversity that extends to uplands, and buffer ecosystem sensitivity to extended drought