The dynamic changes of natural forest resources from 1978 to 2012 in Guangdong province and its causes were analyzed and studied according to total status, forest category, dominate tree species group, and age structure. The data of area, volume and volume per hectare of natural forest were based on 8 periods continuous forest inventory data from 1978 to 2012. In general, natural forest increased with the average annual growth rate of 0.73% for area and 1.55% for volume. The results showed that area varied with a droprisedrop curve of three stages, while volume maintained steady growth. The forest category structure of natural forest with priority of commercial forests was gradually improved, meanwhile, area and volume proportion of ecological forest increased steadily to 45.94% and 50.45%, respectively, by 2012. The broadleaf forest gradually turned to be domain forest with a steady increase in its area and volume proportion from 37.68% and 45.17% in 1978 to 70.69% and 75.03% in 2012, respectively. It has been the main position of young and middleaged forests, although the area and volume proportion of near mature, mature and over mature significantly increased from 3.22% and 8.98% in 1978 to 20.31% and 30.90% by 2012, respectively. Volume per hectare increased by 47.26% since 1978, reached 64.34 m3hm-2 by 2012, which indicated that the forest land productivity was gradually improved. 1983 and 2002 were the changing inflection points of many indicators, indicated that economic situation and policy was the priory reason for varieties of natural forest resources.
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