长江中游地区生态系统服务价值的地形梯度效应

采用长江中游地区1995、2005、2014年3期土地利用数据,基于修正后的长江中游地区生态系统服务价值系数表,估算各县域生态系统服务价值,并分析其时空变化特征及地形梯度效应.结果表明:长江中游地区生态系统服务价值在空间上总体呈山区高而平原低的分布格局,地形梯度分布特征明显.县域地形起伏度与生态系统服务价值呈现较为显著的对数关系,二者拟合优度为0.53;地均生态系统服务价值随地形起伏度上升而增加,2014年1~5级地形起伏度区从400.35万元·km^-2增至554.57万元·km^-2;研究期间随着地形起伏度增加,各级别内县域生态价值变化从下降型逐渐向稳定型转变.从不同生态系统服务价值看,受不同地形起伏度上土地利用结构改变及不同地类的主导生态系统服务差异的影响,随着地形起伏度的增加,食物生产、废物处理服务价值有所下降,其他生态系统服务(如原材料生产、气体调节等)的价值总体呈上升趋势.

Terrain gradient effect of ecosystem service value in middle reach of Yangtze River,China.

Using land use data in the year 1995, 2005 and 2014, this study estimated the ecosystem service value (ESV) in each county located in the middle reach of Yangtze River and analyzed its spatiotemporal variation features and terrain gradient effects based on “the equivalent value per unit area of ecosystem services in China”. The results showed that ESV in the middle reach of Yangtze River was generally higher in mountainous area but lower in plain region, with an obvious terrain gradient effect. Specifically, the relationship of the relief degree of land surface (RDLS) and the ESV showed significant logarithm function at county scale with a high curve fitting degree of 0.53. The ESV increased from 400.35×10⁴ yuan·km^-2 to 554.57×10⁴ yuan·km^-2 with the increasing RDLS (grade 1-5) in 2014. During 1995-2004, the ecosystem service value variation changed from decreasing to stable with the increases of the RDLS. With a perspective of ecosystem service values, the value of food production and waste treatment service value decreased with the increase of the RDLS, while the others increased in general, such as the production of raw materials and gas regulation service value, because of the influences of dynamic land use structure in varied topography and distinct dominant ecosystem services from different land types.