关键词: 长期施氮, 叶绿素荧光, 冬小麦, 旱地

Abstract: Fenglin National Class Nature Reserve is the largest wellsaved virginal Korean pine（Pinus koraiensis） forest area and a precious species gene bank in China.In this study,the indexes diversity,naturalness,representativity, rarity，area suitability，stability,and anthropogenic interference were selected to establish a ranking ecological evaluation system to estimate the ecological condition of the Reserve.The value of each index was determined by the evaluation system,and the weight percentage was decided by Analytical Hierarchy Process(AHP).In the Reserve,there were 568 higher plant species belonging to 113 families and 220 higher animal species,with score 3 of species diversity.The zonal “climax" vegetation type broad-leaved Korean pine forest and the intrazonal community type spruce-fir forest constituted the principal part of the Reserve forest,which was the epitome of the virgin broadleaved Korean pine forest in Lesser Xing'an Mountains,with representativity score 3.During the past 20～30 years,the natural habitat in the Reserve was quite good,and secondary succession was obtained effective control with few natural or anthropogenic disturbance,with score 4 of naturalness and anthropogenic interference.There were a lot of ancient species of the tertiary period,such as Pinus koraiensis,Fraxinus mandsurica, Juglans mandshurica,Pellodendron amurense,Tilia amurensis and Acer mono,and Pinus koraiensis was listed as one of severe danger species by the FAO of UN,with rarity score 4.The Reserve covered an area of 18165 hm²,with an enough size to maintain the structure and function of the ecosystem. Accordingly,its area suitability score was 4.Broad-leaved Korean pine forest was the most typical and stable vegetation type in the Reserve,and thus,its stability score was 4.Finally,the composite evaluation index (CEI) was figured out as 0.87,showing that the ecological quality of the Reserve was very good,and the protection value was quite high.In conclusion,the present area,structure,and management of the Reserve could satisfy the requirement of sustainable development.

Key words: Long term nitrogen fertilization, Chlorophyll fluorescence, Winter wheat, Dryland