基于植被生产力的西南地区生态系统脆弱性特征

中国西南地区是全球生物多样性保护的重要地区之一.在全球气候变化背景下,该地区生态系统呈现出脆弱性增加的趋势.本研究基于生态系统总初级生产力(GPP),根据IPCC有关脆弱性的概念,计算西南地区生态系统的脆弱性,并分析了该区脆弱等级的空间分布格局,以及生态系统脆弱性与降水、温度、海拔、坡度和植被类型等因子间的相关性.结果表明: 西南地区生态系统脆弱性呈现由东南向西北逐渐增强的趋势,区域内多数地区为轻度、中度脆弱区(二者共占69%).脆弱等级随着区域内年平均降水量、多年平均温度的增加而减少,随着区域内海拔、坡度的增加而增加.西南喀斯特山区和西北山地农牧交错区呈现较高的脆弱性,更容易受气候变化或其他外界扰动的影响.针叶林、灌丛和草地的脆弱性相对较高,未来可能更容易受到气候变化的影响.

Characters of ecosystem vulnerability in southwestern China based on vegetation productivity.

Southwestern China is one of the most important areas for global biodiversity conservation. Under the background of global climate change, the vulnerability of this area has showed an increasing trend. According to the IPCC concept of vulnerability, we calculated the spatial distribution of ecosystem’s vulnerability in southwestern China based on gross primary productivity (GPP) and then analyzed the spatial variation of different levels of vulnerability. Besides, we analyzed the relationship between environmental factors and ecosystem vulnerability, including precipitation, temperature, altitude, slope and vegetation type. The results showed that ecosystem vulnerability in the southwestern China gradually increased from southeast to northwest, with most area within the region being slight and mild vulnerable area (together occupied 69% of the total). The vulnerability level decreased with the increasing of mean annual precipitation and temperature but increased with increasing elevation and slope. Karst area in southwest and borders between farming and ranging regions in northwest Mountain ecotone of the study area had higher vulnerability, being more easily affected by climate change or other disturbances. The vulnerabilities of needle-leaved forest, grassland, and shrubland were relatively higher than other vegetation types, with the potential to be more easily affected by climate change.