Changes of forest Distribution and Biomass in Guizhou Province from 1996 to 2005

Based on the continuous forest inventory data of 1996-2000 and 2001-2005 in Guizhou Province,we estimated the biomass of different forest types in the two periods using the volume-biomass transfer function of the major forest types.Changes of forest spatial and temporal distribution and biomass in the two periods as well as their relationships with Karst landform and rocky desertification level were further analyzed.These provide the background information of productivity maintenance mechanism and adaptive the ecological restoration and desertification control in Karst areas.Results showed that between late 1990s and early 2000s,the forest land area increased 7.68?105hm2.Total biomass increased from 2.58?108 t to 3.43?108 t.A total increment of 0.85 billion ton was obtained during these ten years.The area of forest types was changed too.The shelter forest and special-purpose forest were substantially increased in their areas;while the area of timber forest and fuel wood forest was drastically reduced.Karst landform and rocky desertification have positive correlations with forest volume and biomass.Karst forest biomass is lower than non-Karst forests.The rocky desertification in Karst area is more serious than non-Karst area.