NICOLA

NICOLA (NIche differentiation and COexistence in alpine pastures under changing LAnd use) investigated the role of belowground niche differentiation for the coexistance of plants, and how this is related to resource use complementarity among species. We used ¹⁵N-tracers to follow the uptake of soil nitrogen forms (nitrate, ammonium and glycine), at different soil depths, and at different times of the growing season. Neighbouring pastures of different grazing intensity and thus different plant diversity at the ETH Research Station Alp Weissenstein were selected as study sites.

Background

Niche differentiation may promote species coexistence and hence species richness by reducing interspecific competition among plants. It is the prerequisite of complementary resource use that enhances important ecosystem processes such as productivity or nutrient retention. Below-ground complementarity can occur through the use of different chemical forms of the same nutrient by different species, or through differences in spatial or temporal activity of resource uptake.