基于生态位适宜度的耕地可持续利用评价

Cultivated land sustainable use evaluation based on niche-fitness

耕地可持续利用评价是土地利用研究的重要内容。基于生态位理论,从区域耕地生态系统整体性出发,提出耕地生态元和耕地生态位的概念,并在此基础上构建了耕地可持续利用生态位适宜度评价模型(Fi模型)。然后,将所构建模型应用于河南省焦作市耕地可持续利用评价之中,测度了1997～2006年期间焦作市耕地可持续利用生态位适宜度Fi值。为了便于对照分析,采用限制因子模型(NFmin-i模型)和希尔伯脱空间模型(CHi模型)进行耕地可持续利用生态位适宜度NFmin-i值和CHi值的测算。测算结果表明:(1)1997～2006年期间,Fi值总体上呈递增趋势,从1997年的0.5088增加到2006年的0.6503,表明支撑焦作市耕地可持续利用的自然、经济和社会因子总体上呈良性发展趋势,即耕地可持续利用现实生态位趋于最适生态位。(2)1997～2006年期间,Fi与CHi值各年间的变化规律一致,与NFmin-i值总体变化规律一致,表明运用Fi模型进行耕地可持续利用评价具有较强的科学性和现实性。同时,Fi值有利于从综合角度表征区域耕地总体可持续利用水平。(3)利用最适生态位解释区域耕地可持续利用评价标准,以及运用n维资源(条件)生态位与最适生态位的匹配这一基本思想进行区域耕地可持续利用评价,生态意义明确,便于依据生态位适宜度值的大小及其变化制定区域耕地利用方案和措施。

It is an important topic in land use researches to carry out cultivated land sustainable evaluation.In this paper,the concepts of cultivated land eco-unit and cultivated land niche are put forward,and the niche-fitness model（Fi model） is constructed based on niche theory and cultivated land ecosystem theory.The Fi model deduced by absolute difference between two groups of standardization numerical value,can effectively measure the level of cultivated land sustainable use of a region.It can express suitability degree between real niche（Xm） and optimal niche（Xa） in an area.Then,the model is applied to measure the cultivated land niche-fitness of Jiaozuo during the years 1997-2006.As a contrast,the restriction factor model（NFmin-i model） and Hibert space model（CHi model）are also used as a measurement of the niche-fitness of cultivated land sustainable use.The results show that：（1） The value of Fi increases from 0.5088 to 0.6503 during 1997-2006,evidently indicating that the influencing factors related to nature,economy and society keep a good development trend.In other words,the real niche of cultivated land sustainable use tends to the optimal niche.But there is a fluctuation state during the years 1997-2002,which shows relevant policy of protecting cultivated land can not be thoroughly carried out.The maximum value of Fi is only 0.6503 during the years 1997-2006,which primarily deciphers the inconsistency between real niche and required niche.Consequently,the government should take pertinent measures to largely promote the cultivated land sustainable use.（2） The changes of the value of Fi are in coincidence with the variations of the value of CHi and the value of NFmin-i,remarkably denoting that the Fi model is scientific and realistic in cultivated land sustainable use evaluation.The cultivated land niche-fitness value of Fi has a wide distribution of 0.5088≤Fi≤0.6503 in interval of ,as compared with CHi value of 0.7613≤CHi≤0.8775.In addition,the Fi model has lots of advantages due to the alternative parameter α.Moreover,the value of Fi can properly represent the overall measurement of cultivated land sustainable use niche-fitness as compared with the value of NFmin-i.（3） The results reveal that the optimal niche can be regarded as the criterion of cultivated land sustainable use,and the matching way can be used to carry out cultivated land sustainable use evaluation.All these offer the theories and ways for cultivated land sustainable use evaluation.