Streams are fundamental landscape connectors transporting organic and inorganic matter from headwaters to the sea, however their entire functioning depends on their interconnectance with the surrounding terrestrial vegetation. While terrestrial vegetation supplies a basal resource for streams throughout the year in the form of detritus, streams contribute with the emergence and movement of aquatic insects onto land, where these insects are resources for terrestrial predators. Stream ecosystems thus directly affect terrestrial food webs, and the subsequent deposition of emerging aquatic insects as carcass, if not preyed upon by terrestrial predators, converts them as important fertilizers to the surrounding vegetation. Thus, cross-ecosystem resource supply is an intrinsic part of stream-terrestrial ecosystems and emphasizes the interlinked ecological landscape. Climate change is expected to increase temperature and precipitation in the Arctic, increasing terrestrial primary production and runoff. However, recent climate-induced moth outbreaks have also increased the dramatic occurrence of tree dieback events, reducing both primary production and export of terrestrial detritus to freshwaters. These climate-induced changes in vegetation structure may affect cross-ecosystem linkages, altering carbon flow and food web structure both in streams and on land, but these remain unassessed. CATlink will pioneer the quantification of cross-ecosystem linkages in the tundra-forest ecotone under a key pressure with suspected high effect on both stream and terrestrial ecosystems. Taking a novel food web approach on carbon linkages, CATlink utilizes existing infrastructure from the Fram Centre project COAT and contributes to the Fram Center strategic goals of monitoring and managing northern Norwegian low-Arctic regions.
Project manager: André Frainer
Project code: 456 1092019