Seasonal variations in species diversity, dry matter and net primary productivity of herb layer of Quercus leucotrichophora-Pinus roxburghii mixed forest in Kumaun Himalaya, India

摘要

Plant biomass,species diversity and net primary productivity are presented for herb layer of banj oak (Quercus leucotrichophora A.Camus)-chir pine (Pinus roxburghii Sarg.) mixed forest in Kumaun,central Himalaya,India.The species diversity declined from a maximum (3.56) in September to a minimum (2.11) in December.The monthly live shoots biomass exhibited a single peak growth pattern with highest live shoot biomass of 185 g·m-2 in August.The seasonal pattern showed that the maximum above-ground production (131 g·m-2) occurred during the rainy season and the minimum (1 g·m-2) during winter season.The below-ground production was maximum during winter season (84 g·m-2) and minimum during summer season (34 g·m-2).The annual net shoot production was 171 g·m-2 and total below-ground production was 165 g·m-2.Of the total input 61％ was channeled to above-ground parts and 39％ to below-ground parts.Transfer of live shoots to dead shoots compartments and that of dead shoots to litter compartments was 61％ and 66％,respectively.The total dry matter disappearance was 61％ of the total input within annual cycle.The herb layer showed a net accumulation of organic matter,indicating the seral nature of the community.