Changes in physico-chemical properties and metabolic activity of soil in poplar plantations replacing natural broad-leaved forests in Kumaun Himalaya

Physico-chemical properties and metabolic activity of soil were measured during the first 8 years of new plantations ofPopulus deltoidesBartr. raised after the clear-felling of natural mixed broad-leaved forests in the subtropical zone of the Kumaun Himalaya. Results were compared with similar measurements under the original forest cover. Several soil physical properties changed detrimentally with increasing plantation age; soil chemical properties, notably organic carbon, total N, P and K concentration decreased as a result of reforestation withPopulusand further decreased with increasing age of the plantation. Soil metabolic activity also decreased as a result of reforestation withPopulusand there was a further decrease with plantation development