CHANGES IN PHYSICOCHEMICAL PROPERTIES AND METABOLIC-ACTIVITY OF SOIL IN POPLAR PLANTATIONS REPLACING NATURAL BROAD-LEAVED FORESTS IN KUMAUNHIMALAYA

Physico-chemical properties and metabolic activity of soil were measur ed during the first 8 years of new plantations of Populus deltoides Ba rtr. raised after the clear-felling of natural mixed broad-leaved fore sts in the subtropical zone of the Kumaun Himalaya. Results were compa red with similar measurements under the original forest cover. Several soil physical properties changed detrimentally with increasing planta tion age; soil chemical properties, notably organic carbon, total N, P and K concentration decreased as a result of reforestation with Popul us and further decreased with increasing age of the plantation. Soil m etabolic activity also decreased as a result of reforestation with Pop ulus and there was a further decrease with plantation development. (C) 1997 Academic Press Limited