Land ecosystems classification and eco-economic evaluationin Wuding River Basin of Yulin Region

The loess phateau, one of the most serious soil erosion region in the world, has the complex landecosystem constituting the various natural factors, such as the highly dissected ground . gullies, the typicallysurface materials , and human activity. Three main units and thirty-seven sub - units of land ecosystem are di-vided based on the analysis of the characteristics, relation, spatial combination of the relevant factors. Thestructural character and ecological, economic effect of some typical and land ecosystem were discussed, usuallythe reactively stable land ecosystem has a good ecological and economic effect compared with the degraded andsensitive land ecosystem.