NITRATE IN STREAMWATER AS AN INDICATOR OF FOREST STATUS AND FOREST ECOSYSTEM MANIPULATIONS - EXAMPLE AT MONT-LOZERE (SOUTH-EAST FRANCE)

The water from a coniferous catchment was sampled over a 14-year perio d, corresponding to different phases of forest status: healthy, then d eclining, whole-tree-harvested and finally newly afforested. The conce ntrations of nitrate and basic cations were found to vary, particularl y after the clearfelling, as a consequence of the mineralization of th e organic matter. Losses of nutrients are temporarily important, and f or nitrogen account for less than 10% of the organic nitrogen stored i n the forest floor and in the felling debris. (C) Academie des science s / Elsevier, Paris.).