A Study On The Forest Ecosystem Function Of The Jiuzhaigou National Nature Reserve

The accumulation of carbon compounds formed by plants present on a site at any given time is called biomass, whose production is a primary function of forest ecosystems. For another, nutrients from litter decomposition are of great significance for trees and for biogeochemical cycling within forest ecosystems. As a result, a study on the biomass production and litter decomposition in the forest of the Jiuzhaigou National Nature Reserve, a world famous place for tourism for its beauty, which lies on the upper Yangtze River basin, will contribute to the conservation of the river and future development of the reserve.Harvesting method (for understory) and allometry method (for trees) were used in the study of forest biomass production in the Jiuzhaigou Valley. The results suggest that a) the tree layers in all communities have the largest amounts of forest biomass, the percentage of which are over 95%. The high succession of needle forests and anthropological disturbance in broad leaf forests may be the reason; b) the biomass distribution among various forest communities is not even. The biomass of Abies forests and Picea forests is the largest, and its total biomass accounts for 80.12% of that of the Jiuzhaigou Valley. Their mean biomss is high as well, up to more than 300 t ? hm"2. The biomass of broad leaf and needle forest is the second, total biomass accounts for 12.42%, with the mean biomass 214.86 t ? hm^-2. The biomass of broad leaf forest is the lowest in Jiuzhaigou Valley, and is also low comparing with other forest in China. Their total biomass accounts for no more than 5% while their area more than 10% of that of forest in Jiuzhaigou Valley. c) the total forest biomass of Jiuzhaigou Valley is about 7.115×10⁶t, while the average net primary productivity is between 10.533 and 11.165t ? hm^-2 ? a^-1, which is higher than temperate forest NPP.