The Surface Photosynthetic Active Radiation And Avegetation Net Primary Productivity Estimate In Inner Mongulia

Inner Mongolia Autonomous Region in northern frontier of china, a vast territory, including the 28 cross-longitude, latitude16 north and south Vietnam, with a total area of about1.18 million km2, accounting for12.13% of total area, grassland is rich in resources, is the largest grasslands in pastoral areas of China. Inner Mongolia is the world's a typical mid-latitude semi-arid temperate grassland ecosystem types, in the temperate grasslands of representative and typical of global change research in IGBP land of Northeast China Transect Transect within the land, is the most sensitive area of global change. Meanwhile, due to reclamation of arid climate and human destruction, more vulnerable ecological environment, and the central and western Inner Mongolia in North China dust weather and dust storms of the primary origin (Zhu Wenquan, etc., 2005). Therefore, vegetation in Inner Mongolia to carry out its distribution of NPP for the control of the region's eco-system quality and natural production capacity is of great significance.By using MODIS data, using the improved inversion algorithm PARCAL to estimate PAR, drive GLO-PEM model to simulate net primary production in Inner Mongolia , a large amount of field work data plots to verify the model simulated NPP result . The thesis do spatial analysis with simulated PAR and NPP ,with the following conclusions:(1) in the Inner Mongolia region, when elevation less than 300 meters, the photosynthetic active radiation of 6.6 MJ / day, when elevation more than 2,700 meters, the photosynthetic active radiation of 8.2 MJ / day. Each additional 300 meters of elevation, photosynthetic active radiation increased by about 0.2 MJ / day. Inner Mongolia PAR obvious seasonal variation, summer largest, while in winter smallest. PAR began to increase from January to June for one year maximum, and then began to decline from July to December to a minimum.(2) NPP in Inner Mongolia's total annual average of 0.25PgC×a-1from 2003 to2008. The result slightly lower than Zhu Wenquan (2005) simulation results (0.39 PgC×a-1), according to Pu Shilong et al (2001) Simulation of the national net primary production was 1.69 PgC× a^-1, the total NPP of vegetation in Inner Mongolia account for about 14.79% of national.wide.(3) NPP increased from the southwest to northeast in Inner Mongolia between 2003 and 2008, the distribution of the overall trend is not changed, but some areas have changed. Nearly 6 years, the total NPP in Inner Mongolia in general showed a decreased tendency, with litter extent and short-term fluctuations.(4) Inner Mongolia terrestrial ecosystem NPP of different vegetation types show different characteristics. Among them, the highest average NPP values for deciduous broad-leaved forest, reaching 498.21gC/m²/yr, followed by the evergreen broad-leaved forest, as 434.2gC/m²/yr, followed by mixed forest, evergreen coniferous forest, farmland etc. The average NPP are more than 300 gC/m²/yr. Grass for the 260.44gC/m²/yr, desert region only 13.33gC/m²yr.