Competitive interactions between populations of Poa pratensis and Agrostis tenuis from ecologically-contrasting environments.
Abstract
Populations of P. pratensis and A. tenuis [A. capillaris] were collected from high fertility and low fertility plots of long-term fertilizer experiments at Rothamsted (UK) and Samsstadir (Iceland). The populations were grown in the field in pure stands and in mixtures at Reading (UK) and Korpa (Iceland) during 1979-80; 25 and 200 kg N/ha year were applied. A. capillaris was more competitive at Reading, while P. pratensis was more competitive at Korpa. N application increased the competitive ability of P. pratensis relative to A. capillaris at both locations. In pure stands, populations generally grew better in their native country; in mixtures, populations of contrasting climatic origin were more competitive in their native country. The yield advantages of mixtures, as measured by the relative yield total, was greater when populations were grown in fertility conditions resembling those of their native habitat.