基于物质量评估的贵州南部地区生态系统服务及其县域差异比较

以贵州南部地区为例,对涵养水源、固碳释氧、净化大气环境、保育土壤和生物多样性保护5个功能类别共14项指标的生态系统服务物质量进行了区域尺度和县域尺度上的估算。结果表明：① 贵州南部地区林草生态系统年调节水量145.41×10⁸m³,年固碳量和年释氧量分别为819.96×10⁴t和1 538.48×10⁴t,年提供负离子达2.32×10²⁵个,年吸收二氧化硫(SO₂)、氟化物(F)、氮氧化物(NO_X)分别达到58.07×10⁴t、1.29×10⁴t和7.76×10⁴t,年滞尘量1.04×10⁸t,年固土总量9.07×10⁸t,年保育N、P、K以及有机质量分别为184.81×10⁴t、59.26×10⁴t、1 138.80×10⁴t以及4 045.85×10⁴t,平均生物多样性综合评价指数为54.87;② 各类生态系统服务物质量均表现出明显的空间分布趋势,整体表现为东高西低,南高北低;③ 县域尺度上,黎平县、榕江县、从江县和望谟县提供的生态系统服务物质量最多,普定县、三穗县、长顺县和丹寨县则最少;就生态系统服务供给能力而言,雷山县、望谟县、榕江县和从江县最强,兴仁县、普定县、长顺县和贞丰县则最弱。

The Ecosystem Services and Its Spatial Variation at Countyscale in the Southern Guizhou Based on Physical Assessment Method

Quantitative assessment for ecosystem services(ES) is perceived as the basis of decision-making to optimize the allocation of regional environmental resources and to formulate eco-compensation policies. Using physical assessment method (PAM) to estimate regional ES could surmount the limitation of traditional valuation method which was effected deeply by price factor and incapable of reflecting the dynamic characteristic of ES. In addition, exploring the variation of ES at county scale is important to reveal spatial inequality of regional eco-resources, therefore to optimize ecosystem spatial structure and harmonize regional economic development. Based on the PAM, this paper estimated the physical quantity of main ES within southern Guizhou Region, which was specialized into fourteen indices of five categories consist of water conservation, carbon fixation and oxygen release, atmosphere environmental purification, soil conservation and biodiversity protection, at both regional and county scale. Plenty of methods including the rainfall storage capacity method, revised universal soil loss equation (RUSLE), and biodiversity composite assessment index method were employed. The results indicated that the forest and grassland ecosystem in Southern Guizhou regulates water 1.45×10¹⁰m³/a, fixes carbon 8.20×10⁶t/a, releases oxygen 1.54×10⁷t/a, supplies negative-ions 2.32×10²⁵/a while absorbing of sulfur dioxide(SO₂), Fluoride(F), Nitrous oxides(NO_X) and dust 5.81×10⁵t, 1.29×10⁴t, 7.76×10⁴t and 1.04×10⁸t per year, respectively. The soil conservation approaches 9.07×10⁸t/a, reducing loss of N, P, K and organic matter 1.85×10⁶t, 5.93×10⁵t, 1.14×10⁷t and 4.05×10⁷t per year, respectively. The average biodiversity composite assessment index reaches 54.87. It presented a pattern of high in east and south, low in west and north as a whole in the spatial distribution of physical quantity at each categories of ES. At county scale, Liping, Rongjiang, Congjiang and Wangmo were estimated to have provisioned the most physical quantity of ES, while Puding, Sansui,Changshun and Danzhai being the less ones. In terms of the capacity of provisioning ES, the strongest counties were Leishan, Wangmo, Rongjiang and Congjiang, and the weakest ones were Xingren, Puding, Changshun and Zhenfeng.