Biomass, Net Primary Productivity, And Ecological Restoration Of Sparse Forest Grassland Ecosystem Of Hunshandake Sandy Land

Desertification is one of the serious environmental problems affecting arid and semi-arid regions of China. The four main sandy lands are undergoing desertification severely in recent decades. Exploring sandy land in ecological view, estimating its biomass and net primary productivity (NPP) are critical aspects of understanding the structure and function of sandy lands. We took Hunshandake Sandy Land as an example to study sandy land's vegetation structure, biomass, NPP, as well as restoration strategy in desertification control.By transect survey, we found that the sparse forest grassland landscape, which was typical in Hunshandake Sandy Land, was formed by alternatively appeared herb layer, scrub and Ulmus pumila sparse forest. Herbaceous plants and willow scrub occuped interdunal lowlands and transition zones between lowlands and dune systems, respectively. U. pumila was dominant tree species, account for up to 95% of all trees. Elm sparse forest usually existed on fixed dunes, where 84% trees distributed. The trees with diameter at breast height between 10 and 25 cm amounted to 60%, while young trees were few because of grazing disturbance. Sandy sparse forest grassland was intrazonal vegetation with extrazoanl characteristics. It was different from the surrounding temperate steppe, although it was controlled by grassland zone climate and had some zonal traits.The biomass of Hunshandake Sandy Land was estimated in order to understand sandy land ecosystem's carbon storage in carbon cycle. We divide the sandy land into six habitats, whose biomass was estimated separately and then summed up. Allometric relationships were fitted to calculated elm biomass. The average biomass...