Biodiversity of novel ecosystems

It is hard to imagine the boreal landscape, with its vast uninhabited expanses and relatively natural forests, as altered by humans in similar ways to urban or agricultural areas. But in fact, an extensive, yet largely unaccounted for man-made network of ditches extends throughout forests of Europe and Russia, and parts of Canada. Ditching has a long and controversial history of being used to promote forest growth, and almost 25% of the wetlands in Fennoscandia have been artificially drained over the past century. Indeed, there is an estimated 1 million km of ditches that occur in all of Sweden, twice the length of the natural river network. These ditches have largely unknown effects on biodiversity, hydrology, and geomorphology of headwater stream networks, and over time may have developed stream-like properties and be valuable in themselves. Yet, ditch properties may depend on time since digging or size of the catchment that is drained. Either way, these well-established preferential flow paths might now be refugia for aquatic or wetland plants and animals that were once more widespread, creating a novel combination of species that would not have occurred in this system otherwise. As with urban and agricultural counterparts, it critical that we understand the value of forest ditch networks from the standpoint of biodiversity and ecosystem services. The goal of this project is to identify and assess the biodiversity of boreal forest ditches and determine how they are fundamentally the same or different from ‘natural’ headwater streams.

Contact eliza.hasselquist@slu.se