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International Journal of Ecology and Environmental Sciences 27: 89-96, 2001
© International Scientific Publications, New Delhi

Effect of Soil Nitrogen and Competition on Certain Leaf Characteristics of Quercus leucotrichophora and Alnus nepalensis Seedlings

Asha Tiwari (née Joshi), S.P. Singh and D.N. Joshi


The effect of different soil nitrogen and competition levels on certain leaf characteristics of Quercus leucotrichophora (banj oak) and Alnus nepalensis (Alder) seedlings was investigated. Seedlings were grown at five nitrogen levels, and both species were grown in pure and mixed culture. In banj oak, leaf production, leaf area, leaf drop (percent of biomass), leaf weight ratio, leaf N concentration and leaf nitrogen mass increased with increasing nitrogen levels in both the cultures, whereas in alder these parameters (except leaf drop) increased up to a certain level only in pure culture and declined under competition with banj oak. Leaf efficiency, loss of leaf mass and re-translocation from senescent leaves declined with increasing nitrogen levels. Competition reduced the re-translocation in both the species.

Key Words: Nitrogen, Competition, Banj oak, Alder, Leaf efficiency, Seedlings.