XVI International Botanical Congess

We studied the competition between two perennial grass species that differed in their ability to acquire nutrients from enriched soil patches. The species competed for two years in homogeneous and heterogeneous soils. The relative biomass production of the species, in mixtures relative to monocultures, differed between the treatments. In heterogeneous soils, the growth of the better forager (Anthoxanthum) increased compared with homogeneous soils, at the expense of the less effective foraging species (Festuca). Strontium pulse-labeling confirmed that the former species acquired more nutrients from the enriched patches than the latter species, explaining its improved competitive success. We conclude that the foraging abilities of plants may play an important role in competitive interactions.