Forest Ecosystem Service Value Change in Yuanmou Dry-hot Valley

Objective Yuanmou county was selected to studied the change of forest land utilization and forest ecosystem service value in the dry-hot valley so as to enrich forest ecology research and provide theoretical basis for regional ecological environment regulation.

Method Taking remote images of Landsat 7 ETM in 2008 and Landsat 8 OLI in 2016, national basic geographic information system and ASTER GDEM digital elevation model as data sources, the ENVI and ArcGIS software was used to interpret the remote sensing images, obtain the forest land-use data, and to analyze the temporal and spatial characteristics of forest land, and calculate the function value of farmland food production per unit area and coefficients per unit area of forest ecosystem service value. Then, the forest ecosystem service value and its changing characteristics were analyzed. The adjustment of coefficient of dynamic value of forest ecosystem service was constructed on the basis of payment ability, willingness to pay and land by using ENVI and ArcGIS software. Forest ecosystem equivalent coefficients were adjusted, as well as environmental capacity as main parameters in order to analyze the dynamic value characteristic and its change of forest ecosystem service.

Result Forest land is mainly distributed in southern and eastern parts of the middle-high mountains in the study area. A small amount of forest scatters in western, southwest, north and eastern foothills of the middle-high mountains. Few parts are sporadic in the valley dam area. Forest area increased by 64.24 hm², and variation range reached 11.42% from 2008 to 2016. The area of forest land converted into non-forestland reached 90.53 km², while the forest area converted from other land-use types was 154.77 km². There waere 73.61 km² of forest land converting to grassland and 123.11 km² converted from grassland. In 2016, the static value of forest ecosystem service in the study area was ￥1.497 billion, an increase of ￥153 million over ￥1.344 billion in 2008. In 2016, the proportion of forest land in the total static value of regional ecosystem service in the study area was 56.41%, which increased by 4.68% compared with 51.73% in 2008. The dynamic value of forest ecosystem service in 2008 and 2016 were respectively ￥ 475.8 million and ￥ 902.7 million, which only accounted for 35.40% and 60.30% of static value of forest ecosystem service in the same period.

Conclusion The forest land area increased rapidly, the forest land and non-forest land converted to each other frequently, leading to an obvious net increase of forest area. The area increase of forest land resulted in static value growth of forest ecosystem service. Among individual value of forest ecosystem service, soil formation and protection, gas regulation and biodiversity conservation scored the highest, while the food production had the lowest score. Although the dynamic value of forest ecosystem service is far less than the static value, the range of dynamic value change is obviously higher than that of static value. The forest land with high ecosystem service value is more sensitive to the growth of social and environmental regulation.