土地利用变化对生态系统服务的影响——以张家口-承德地区为例

生态系统服务与人类福祉密切相关,人类活动引起的土地利用变化是生态系统服务变化的主要驱动力之一。运用InVEST模型估算张家口-承德地区产水量和土壤保持量,并分析不同海拔和坡度条件下,2011—2015年土地利用以及产水和土壤保持服务的变化,研究结果表明:建设用地和乔木林地分别为面积增加量和减少量最多的用地类型,陡坡地段建设用地增加的同时水体减少;灌木林地是产水和土壤保持能力均最高的生态用地类型;5年间产水量和土壤保持量分别增加了32.16×10~6 m~3和17.69×10~6 t;产水量在海拔900 m地段,海拔越高增加量越少,土壤保持量在较低海拔有所增加;坡度越陡产水增加量越少,土壤保持量在各坡度均有增加。基于此研究结果,有助于选择优先建设的用地类型,使当地在保护源头水系和维持生态功能的同时发展冰雪运动。

Impact of land use change on ecosystem services: Case study of the Zhangjiakou-Chengde area

Ecosystem services are closely related to human well-being, and anthropogenic land use change is one of the main drivers of changes in ecosystem services. In the present study, the InVEST model was used to estimate the water yield and soil conservation of the Zhangjiakou-Chengde region, and the ecosystem service capacities of each land-use type were compared. Changes in land use, water yield, and soil conservation services at different altitudes and slope conditions were also analysed. Of the various land-use types, the build-up land generally exhibited the greatest increase in area, with an increase of 1117.49 km², whereas arbour forest land and shrub land exhibited the greatest reductions in area, with reductions of 892.78 km² and 477.02 km², respectively. The build-up land in the steep slope area increased, whereas the water body decreased. The areas where farmland had been converted to forest land and grassland were mainly concentrated in the Bashang Plateau and the North Mountain of Hebei Province. The increased farmland was mainly concentrated at the junction of the Bashang Plateau and the Northwestern Loess Hilly Areas of Hebei Province, whereas the newly added build-up land was mainly distributed in the Northwestern Loess Hilly Areas of Hebei Province and the North Mountain of Hebei Province, and the urban land expansion in the Zhangjiakou and Chengde City areas was the most prominent. The areas of high water yield and high soil conservation were basically similar, mainly distributed in the North Mountain of Hebei Province. Meanwhile, the average water yield depths of the land-use types were as follows:unused land > build-up land > farmland > shrub land > grassland > arbour forest land > waters. The average soil conservation per unit area of each land-use type were as follows:shrub land > arbour forest land > grassland > waters > build-up land > farmland > unused land. Water yield increased by 32.16×10⁶ m³, with about 88.3% of regional water yield services remaining basically unchanged, whereas soil conservation increased by 17.69×10⁶ t, with about 91.3% of regional soil conservation services remaining basically unchanged. At higher altitudes (i.e., > 900 m above sea level), the increase in water yield decreases as the altitude increases. Soil conservation services increased at lower altitudes but decreased at altitudes above 1500 m. The increase in water yield decreased with slope steepness. Soil conservation increased to various degrees, depending on grade. These findings will help to deal with the relationship between regional development and ecological function maintenance during the development of the local ice and snow sports industry and will strengthen the protection awareness of river source streams by understanding and assessing the changes in land use and ecological service functions under different altitudes and slope conditions.