CO_2倍增条件下中国亚热带常绿阔叶林优势种及常见种分布区的可能变迁

POTENTIAL CHANGES UNDER ELEVATED CARBON DIOXIDE OF DOMINANTS AND COMPANIONS OF EVERGREEN BROADLEAVED FOREST IN SUBTROPICAL CHINA

利用Ｈｏｌｄｒｉｄｇｅ生命地带分类系统预测了ＣＯ２浓度倍增条件下中国亚热带常绿阔叶林植被地带及优势种和常见种分布的可能变化，计算了优势种及常见种在气候变暖后分布区的变迁幅度。在ＣＯ２倍增，气温分别升高２℃和４℃，降水增加２０％的条件下，常绿阔叶林优势种及常见种的分布范围发生变化。气温升高２℃，纬向上扩大了３个纬度，经向上也扩大了３个经度左右；气温升高４℃，纬向上扩大了近６个纬度，经向上有的种扩大，有的种缩小。分布范围窄的优势种和常见种，在气候变暖后其分布区变得更窄，而那些分布范围较宽的种，则分布区越来越大。

The potential changes under elevated carbon dioxide of dominants and main companions of evergreen broadleaved forest in subtropical China have been forecast using Holdridge's life zone classification system.The extents to which distribution of dominants and main companions changed in relation to global change were calculated.The distribution range of dominants and companions was expected to extend for 3° both in latitude and longitude after temperature increases by 2℃ and precipitation increases by 20%.It was expected to extend for 6°in latitude but and to vary by about 1° in longitude after temperature increases by 4℃ and precipitation increases by 20%.The change in longitude may be in relation to the increasing in potential evapotranspiration ratio due to temperature increases.In all,there are two possibilities for distribution range of dominants and companions.The distribution of some species was expected to become wider and wider with global warming because its distribution range is very wide at present and the species have well adapted to thermal and water conditions.The distribution of other species was expected to change slightly because its distribution range is very narrow at present.