自然生态承载力是当前国际可持续发展定量研究的前沿问题之一。提出按照各类土地的实际生产能力和实际生态服务功能计算各类土地的生态承载力,将消纳污染和水资源的供给功能纳入区域自然生态承载力计算模型,并简称该方法为"实际供给法"。依据海南省统计年鉴资料和生态调查资料,应用"实际供给法"计算和分析了海南省1952~2004年自然生态承载力的动态变化特征:①海南省自然生态承载力长期持续增长,由1952年的7.0804hm²/人上升到2004年的8.5984hm²/人,增加了1.5180hm²/人,年均增长0.4%;②可再生资源生态承载力占总生态承载力的绝大部分,1952年和2004年分别占98.6%和92.3%,而不可再生资源生态承载力仅分别占1.4%和7.7%;③水资源生态承载力呈跳跃式下降,从1952年的6.8165hm²/人下降到2004年的0.4473hm²/人;耕地、海域和淡水水域的承载力呈上升趋势,分别从1952年的0.1277、0.0057和0.0001hm2/人上升到2004年的2.6066、3.1192和1.1468hm²/人,其它土地类型生态承载力变化不明显;④在生态承载力组成中,水资源比例由大到小变化显著,从96.3%下降到5.2%,耕地、海域的比例由小到大变化显著,分别从1.8%、0.1%上升到30.3%、36.3%,其它土地都由小到大,但所占比例较小;海域、耕地和水资源是海南生态承载力的主要贡献因素,三者之和占到总量的71.8%~98.2%。并分析了海南省自然生态承载力动态变化的原因。

Natural ecological carrying capacity is one of the leading fields of international quantitative study of sustainable development.The model calculated regional natural ecological carrying capacity with actual productivity and effective service function of natural ecological system and coupled self-purification ability with water resource supplying function.Therefore the model was named as "actual supply law".The research indicated that "actual supply law" reflects a regional natural ecological carrying capacity objectively and accurately.This paper applied "actual supply law" to the calculation and analysis of the characteristics of dynamic changes of natural ecological carrying capacity of Hainan province from 1952 to 2004 based on the existing data of Hainan Province Statistical Yearbooks and ecological survey data: ①The natural ecological carrying capacity of Hainan Province has been increasing for a long time,per capita natural ecological carrying capacity increased from 7.0804 ha in 1952 to 8.5984 ha in 2004,an increase of 1.5180 ha and an annual average increasing rate of 0.4%.②The carrying capacity of renewable resource occupied considerable proportion of total ecological carrying capacity,accounting for respectively 98.6% and 92.3%;however,the ecological carrying capacity of un-renewable resource occupied only 1.4% and 7.7% in 1952 and 2004.③The carrying capacity of water resource decreased from per capita 6.8165 ha in 1952 to 0.4473 ha in 2004;but the carrying capacity of arable land,sea sector and freshwater body showed a rising tendency,which increased from 0.1277 ha,0.0057 ha and 0.0001 ha in 1952 to 2.6066 ha,3.1192 ha and 1.1468 ha in 2004,and other types of land ecological carrying capacity kept basically unchanged.④In the composition of the ecological carrying capacity,the proportion of water resources changed significantly from 96.3% in 1952 to 5.2% in 2004 dramatically;but the arable land,sea sector and freshwater body had a reversed remarkable change,respectively from 0.1277 ha,0.0057 ha and 0.0001 ha in 1952 increased to 2.6066 ha,3.1192 ha and 1.1468 ha in 2004,and other types of land showed ascending change but the proportion is relatively small.The arable land,sea sector and water resources are the main factors of the ecological carrying capacity of Hainan,the summation of these three factors occupies 71.8%-98.2%.The paper analyzed the causes of dynamic changes of ecological carrying capacity in Hainan Province.Firstly,the advancement of science and technology and improvement of management level are the fundamental reasons for the continuous increase of ecological carrying capacity in Hainan Province.Secondly,dynamic changes of ecological carrying capacity of all types of land are induced by synthetically factors of nature and society reflected the change of their actual ecological service function.Thirdly,the module amelioration is a key factor reflecting mainly the regional natural ecological carrying capacity.Finally,a pronounced drop of ecological carrying capacity of water resources in Hainan Province has both natural and man-made causes.