Abstract:
The study arranged survey plots at intervals of 2.0 km × 2.0 km after the starting point was randomly determined in the 1:25 000 topographic map in 2008 and 2015. The boundary of city, county, town, village and ownership were used as administrative boundaries of forest resource inventory provided by the Civil Affairs Department. The change characteristics of forest land and forest resources at intervals were analyzed by comparing the forest resources survey data with GPS sample positioning, angle gauge control for measuring volume survey. The findings showed that forest land increased by 79 826.9 hm
2, 8.82%; The woodland decreased by 4 921.7 hm
2, 69.75%; shrub land decreased by 14 985.6 hm
2, 7.78%; immature forest plantations increased by 65 450.9 hm
2, 202.44%; area with no tree increased by 18 679.1 hm
2, 121.92%; suitable land for forest decreased by 48 565.2 hm
2, 53.91%; nursery land decreased by 442.8 hm
2, 42.94%; auxiliary production forest land increased by 47.3 hm
2, 52.61%; standing timber volume increase by 15 191 860 m
3, 37.61%; forest volume increased 15 184 910 m
3, 38.53%; open forest land volume decreased by 35 870 m
3, 58.90%; ′Four sides' tree volume decreased by 52 980 m
3. Scattered trees volume increased from 82 750 m
3 to 166 730 m
3, an increase of 83 980 m
3.