Patterns of Nutrient Loss from Unpolluted, Old‐Growth Temperate Forests: Evaluation of Biogeochemical Theory

作者：Lars O. Hedin, Juan J. Armestó, Arthur H. Johnson · 发表于：Ecology · 年份：1995 · DOI：10.2307/1941208 · 被引用次数：704 · 研究领域：Heavy metals in environment、Sustainability and Ecological Systems Analysis、Lichen and fungal ecology

Atmospheric pollution and other human activities have altered natural element cycles over large regions of the world. Much current understanding of nutrient dynamics in temperate region ecosystems has been derived from such biogeochemically altered areas. While it is increasingly difficult to find regions of temperate forest that can be classified as free from human influences, studies of unpolluted and undisturbed areas can (1) provide important °baseline° information about natural patterns of element cycling, against which disturbed cycles can be compared; (2) provide insights into the biogeochemical conditions that acted as evolutionary and selective constraints on biotic communities before the advent of regional—scale human impacts; and (3) provide an opportunity to evaluate the general nature of biogeochemical theories that have been developed in areas subject to strong human influences. We here report on patterns of hydrologic nutrient loss from old—growth temperate forest ecosystems in southern Chile based on chemical analyses of small streams draining 31 watersheds. These forests have not been subject to air pollution inputs and have remained floristically stable throughout the Holocene. For major elements our results support predictions from current biogeochemical theory (the °nutrient retention hypothesis°) that net biotic retention of elements should be minimal in old—growth ecosystems. Despite the dilute nature of watershed streams, the overall patterns of loss of...