纵向岭谷区地表格局的生态效应及其区域分异

中国西南纵向高耸山岭与深切河谷并列排布的特殊地表格局对该区自然环境与生态地理区域分异的效应明显.利用纵向岭谷区1:5万DEM数据、建站以来至2010的气象观测数据、水文观测资料、MOD 13与MOD17的NDVI与NPP产品以及1:100万植被类型数据等,选取地表大气水汽含量、降水量、干湿指数、地表径流等水分指标,平均气温、年积温等温度指标以及太阳总辐射等热量指标,基于ANUSPLIN样条函数、GIS空间分析、小波分析、景观格局分析等方法,分析该区水热格局、生态系统结构与功能的地域分异特征及其主控因子,揭示地表格局对生态地理要素区域分异的效应.结果表明:受地表格局的影响,纵向岭谷区的水分、温度与热量都表现出明显的沿纬线方向间断式差异和经线方向连续式延伸的分布特征,纵向山系与河谷对地表主要自然物质和能量输送具有南北向通道作用和扩散效应以及东西向阻隔作用和屏障效应；特殊地表格局对植被景观多样性、生态系统结构与功能的空间格局产生重要影响,是植被景观多样性与生态系统空间分布的主要控制因子；小波方差分析反映了环境因子以及NDVI、NPP的空间各向异性,而小波一致性分析揭示了NDVI与NPP空间分布的控制因子,及其控制程度的定量关系.纵向岭谷特殊地表格局是该区生态地理区域分异的主要影响因素,在地带性规律与以“通道—阻隔”作用为主要特征的非地带性规律共同作用下,形成了纵向岭谷区生态地理区域系统的特殊空间特征.

Ecological Effects of Longitudinal Range-Gorge Land Surface Pattern and Its Regional Differentiation

The land surface pattern of Longitudinal Range-Gorge Region with towering mountains and deep valleys arranged vertically side by side has significant effects on physical environments and eco-geographical differentiation in Southwest China. Based on 1:50,000 DEM data, monthly meteorological and hydrological records, NDVI and NPP derived from MOD13 and MOD17, together with 1:1,000,000 vegetation types map, we select surface atmospheric water vapor content, precipitation, aridity/humidity index, and surface runoff as water indices; air temperature and accumulated temperature as temperature indices, and solar radiation as a heat index to study the hydrothermal pattern, regional differentiation of ecosystem structure and function and main influencing factors. The ANUSPLIN model, wavelet analysis, GIS spatial analysis and landscape pattern analysis were used to reveal the effects of land surface pattern on eco-geographical regional differentiation. Results show that the water, temperature and heat have significant differences along the latitudinal direction with intermittent difference and longitudinal direction with continuous extension, which reflects the special "corridor-barrier" effect of longitudinal range-gorge terrain, in which the vertical mountain and valleys on the surface of natural material and energy transport mainly showed significant north-south corridor and diffusion effects and the role of east-west barrier and barrier effect. The longitudinal range-gorge terrain also have important impacts on the spatial pattern of vegetation landscape diversity, ecosystem structure and function, which is the main influencing factor affecing the spatial distribution of vegetation landscape diversity and ecosystems pattern. Wavelet variance analysis reflects the spatial anisotropy of environmental factors as well as NDVI and NPP. The wavelet coherence reveals the spatial distribution of NDVI and NPP influencing factors, and also the quantitative degree of control. Conclusions believe that the longitudinal range-gorge land surface pattern is the main influencing factor of the eco-geographical elements. Under the interaction of the zonality law and the non-zonality "corridor-barrier" effects, the spatial differentiation formed in the eco-geographical system.