从生态地理特征论中国东北样带(NECT)在全球变化研究中的科学意义

The scientific significance of the north east China transect (NECT) to global change study by its ecogeographical characteristics

中国东北样带(NECT)是国际地圈生物圈计划(IGBP)全球变化研究的陆地样带之一。该样带在东经112°与130°30′之间沿北纬43°30′设置,长约1600km,跨越北纬42°～46°,宽约300km,位于中纬度温带地区以降水或湿润度/干燥度为主要全球变化驱动因素,自东至西沿一个连续的空间过渡梯度,植被类型或生物群区是由温带针阔叶混交林、温带落叶阔叶林、农田及温带草原的3个亚地带:草甸草原、典型草原和荒漠草原等类型组成。给出了样带的基本生态地理特征及其梯度分析,包括其地理位置、地形地貌、气候梯度、土壤类型、土地利用格局、植被类型、主要优势种和群落类型的生态地理特征以及全新世适宜期的植被分布格局。这些特征沿经向均表现出明显的梯度分布。

North East China Transect(NECT)is listed as one of the first set of IGBP Terrestrial Transects It is placed along the latitute 43°30′N,between longtitudes 112°and 130°30′E,latitude 42°and 46°E,and approximately 1600 km in length and 300 km in width NECT is basically a gradient driven by precipitation or moisture/aridity located in the mid latitude of the temperate zone The vegetation zones or biomes where NECT laying on are temperate mixed evergreen coniferous and broadleaved deciduous forest,temperate deciduous broadleaved forest,farmland and temperate steppe,including three subzones,meadow steppe,typical steppe,and desert steppe along an east west ward continuously transitional spatial gradients,respectively The ecogeographical characteristics along the NECT,including geographical location,topography,geomorphology,climate,soil,pattern of land use, the vegetation types,main communities and dominants,distributional pattern of vegetation in Holocene Megathermal,and initial gradient analysis were given for the whole transect These characteristics present the significant gradient distribution in longitude The important scientific significance of NECT in the global change study is furthermore discussed