Diversity parameters of Quercus leucotrichophora based agroforestry systems and pure forest in Garhwal Himalaya

Present study estimated the importance value index (IVI), density, frequency, total species richness and diversity parameters, and similarity index of Quercus leucotrichophora based agri-silviculture system, silvipasture system and forest, and also calculated the productivity of wheat (Triticum aestivum) under agri-silviculture system at 12 different villages of two elevations (i.e. 1400–1800 and 1800–2200 m) in Tehri Garhwal district of Uttarakhand. The study revealed that Q. leucotrichophora formed an important part of agri-silviculture, silvipasture systems and forests at different altitudinal gradient. The IVI value of Q. leucotrichophora varied from 180.85 to 205.21 in all land-use systems. The highest value of density, frequency and total species richness was recorded in forest area, followed by silvipasture and agri-silviculture systems. The maximum values of Jaccard (S) and Sorensen (K) index were obtained in agri-silviculture system, followed by silvipasture system and forest area. Diversity parameters of tree species varied between sites and altitudinal ranges. The average grain yield (7.398 q ha⁻¹), straw yield (17.420 q ha⁻¹), biological yield (24.812 q ha⁻¹) and harvest index (29.866) of T. aestivum was higher at lower elevation in comparison to upper elevation in the Q. leucotrichophora based agri-silviculture system.