Benefit: Avoided erosion
Benefit of natural erosion control is the avoided erosion. Erosion causes problems both in terrestrial and aquatic ecosystems.
In terrestrial ecosystems the loss of nutrients, minerals and organic compounds reduce the soil fertility. This has undesirable consequences for many trades such as agriculture, forestry and reindeer husbandry – the same fields that also cause erosion. In particularly agriculture suffers from the erosion of nutrients. Annually 39 500 tonnes of nitrogen and 2 750 tonnes of phosphorous leach into the water system from areas under agriculture. This loss is replaced by fertilizers. Reindeer husbandry suffers from erosion in northern Finland where overgrazing has led to deterioration of lichen pastures. This increases the need for supplementary feeding. (See Reindeer > Structure)
Erosion causes many changes in aquatic ecosystems. The most significant consequence is eutrophication. Eutrophication is a result of excessive load of nutrients and organic compounds that originates from terrestrial ecosystems.
Eutrophication alters the proportions of species in the whole aquatic food network. The most common consequence is that the primary production of algae escalates and generates excessive algal blooms which might be even poisonous (e.g. cyanobacterium). Algal cover reduces the light in lower water layers and thus hinders the growth of bottom flora. Bottom flora acts as shelter and nutrition for benthos and are important breeding and nursery grounds for many fish species. Eventually eutrophication alters also the fish species composition. Fishes become generally more abundant, but fish communities become dominated by roach and other cyprinid species. At the same time salmonoids become rarer.
- Updated (12.01.2015)