SEASONAL CHANGES IN SPECIES DIVERSITY, PHYTOMASS AND NET PRIMARY PRODUCTION IN A TEMPERATE GRADDLAND IN KUMAUN, CENTRAL HIMALAYA, INDIA

Abstract

Species diversity, plant biomass and net primary productivity are presented for a temperate grassland of Kumaun, Central Himalaya, India. The species diversity declined from a maximum in September (2.5) to a minimum in December (1.7). The monthly live shoot biomass exhibited a unimodel growth pattern with peak live shoot biomass of 278 g m^-2 that was attained in September. The seasonal pattern showed that maximum (84%) above-ground production occurred during the rainy season and minimum (< 1%) during the winter season. The below-ground production was maximum (52%) during the winter season and minimum (11%) during the summer season. The annual net shoot production was 361 g m^-2 and total below-ground production was 193gm^-2. Of the total input, 65% was chanelled to above-ground parts and 36% to below-ground parts. Transfer of live shoots to dead shoots compartment and dead shoots to litter compartment was 51% and 72% respectively. The total dry matter disappearance was 48% of the total input within the annual cycle. The grassland showed a net accumulation of surplus organic matter, indicating the serai nature of this grassland.