Canopy Development Studies in an Ecoregeneration Site in Garhwal Himalaya, India

Abstract

Mixed plantations with 19 native or naturalized tree species valued by local communities were established in 1991 in the central Himalaya on abandoned agricultural land and degraded forestland. Apart from use values, the species varied in ecological attributes, such as nitrogen-fixing capability, phenology, and leaf morphology and dynamics. Density of mixed plantations at the two study sites was 1110 trees/ha. In 1996, tree species selected for the study were classified in three groups based on vertical stratification of the canopy during the 5-year growth period. Fast-growing upper canopy species were Alnus nepalensis, Dalbergia sissoo, and Ficus glomerata; slow-growing lower canopy species were Pyrus pashia and Quercus glauca; and the third group contained the remaining 14 species. All species showed better growth at the abandoned agricultural land site, where agricultural crops were grown under irrigated conditions, than at the degraded forestland site, where no crops were grown and no planted trees were irrigated. Fast-growing tree species responded to site conditions at a greater rate than did slow-growing species. The authors recommend further research on mixed plantations coupled with policy support to promote mixed-tree plantations in the Himalaya.