NUTRIENT CYCLING STRATEGIES

This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of t heir competitors. Higher or lower internal nutrient use efficiency pos itively feeds back into the nutrient cycle, and helps to increase or d ecrease soil fertility. These tendencies are further enhanced by secon dary effects (higher or lower rates of decomposition of litter and hen ce of nutrient mineralization) in resp, fertile and infertile soils. S uch feedbacks may strongly increase the fitness of the plants involved . Plants can also influence the external inputs and outputs into the p lant-soil system, by affecting the general hydrology of their environm ent. Sphagnum pear bogs exemplify an extreme degree of control of plan ts over the hydrological cycle, causing intense nutrient impoverishmen t by making the ecosystem dependent on nutrient supply from the atmosp here, apparently giving Sphagnum a competitive edge over other plants.