Soorten bos en hei missen essentiële voedingsstoffen

vermesting, verzuring, fosforgebrek, aminozuurgebrek, fauna

Summary

Nitrogen deposition drains fauna

Arnold van den Burg & Joost Vogels

nitrogen deposition, acidification, P-deficiency, amino acid deficiency, fauna

The faunal biodiversity in Dutch dry-sand regions is strongly impacted by acidification and nitrogen deposition. This is firstly due to changes in vegetation composition, e.g. grass encroachment and loss of flowering plants. On heathlands, management has been focused on removing excess nitrogen and restoring ericaceous vegetation. However, other nutrients (like P) have also been removed simultaneously. As a result, plant nutrients have become increasingly unbalanced, resulting in lowered nutritive values for herbivores (P deficits), and decreased insect populations. Nitrogen deposition also leads to soil acidification which accelerates P sequestering in the soil and nutrient leaching, further undermining balanced plant nutrition. Plants cope with nitrogen excesses relative to other nutrients by reducing protein synthesis. Excess N is channeled towards other N-compounds than amino acids, causing a further reduction of plant nutritional value. These effects propel up the food chain: in Sparrowhawks, amino acid shortages lead to laying hens metabolizing flight muscle protein, egg failures, and hence strong population decline. Without reduction of nitrogen deposition and restoration of acidified soils it is unlikely the fauna of the Dutch sand region will recover. However, especially for heathlands, a variety of restoration measures is available to alleviate some pressure on the faunal community.

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