吉林省天然阔叶混交林生态系统多功能性及驱动因素

量化天然林生态系统的多功能性，分析不同功能间的权衡-协同关系及驱动因子，对于天然林保护及修复具有重要的意义。基于吉林省第8次森林资源清查天然阔叶混交林固定样地调查数据、土壤及气候数据，选取土壤保持、涵养水源、碳储量、气候调节、土壤肥力维持、生物多样性、生产力和木材生产8个生态系统功能来表征生态系统多功能性。利用平均值法中的最大值转换法计算多功能性指数。结果表明：（1）8个功能间权衡、协同和中性关系均存在，但以协同关系为主。生物多样性除与气候调节为权衡关系外，与其他功能均为协同关系；碳储量-木材生产协同关系最强（r=0.960，P<0.01），气候调节-涵养水源间权衡关系最强（r=-0.934，P<0.01）；（2）吉林省天然阔叶混交林的多功能性指数在0.31-0.89之间，且生物多样性和气候调节为主导功能；（3）多功能性与驱动因子的结构方程模型确定系数为R²=0.795，多功能性的驱动因子的总路径系数依次为：林分密度指数（0.752） > 平均年龄（0.375） > 年降雨量（0.365） > 树种丰富度（0.101） > 土壤pH（0.064） > 结构多样性（-0.037） > 年均温（-0.105），林分密度是最重要的驱动因子。结果对理解天然阔叶混交林的多功能形成及经营调控有一定的意义。

Multi-functionality of natural mixed broad-leaved forests and driving forces in Jilin Province

Quantifying the multifunctionality of natural forest ecosystem, and analyzing the trade-off and synergy between different functions and driving factors are of great significance for natural forest protection and restoration. The data of the study include permanent sample plots from the eighth national forest inventory in Jilin Province, soil data and climate data of natural mixed broad-leaved forest. To characterize the ecosystem multifunctionality, eight ecosystem functions were selected, including soil conservation, water conservation, carbon storage, climate regulation, soil fertility maintenance, biodiversity, productivity and wood production. The Ecosystem Multifunctional Index is calculated by using standardization of a maximum observed value in the average method. The results show that:(1) There are trade-offs, synergies and neutrals among the eight functions, but the synergy is dominant. In addition to the trade-off between biodiversity and climate regulation, it has a synergy with other functions. The synergy between carbon storage and wood production is the strongest(r=0.960, P<0.01). The trade-off between climate regulation and water conservation is the strongest(r=-0.934, P<0.01). (2) The multifunctional index of natural mixed broad-leaved forest in Jilin Province is between 0.31 and 0.89, and biodiversity and climate regulation are the leading functions. (3) The coefficient of determination by structural equation model of multifunctionality and driving factors is 0.795. The total path coefficients of the driving factors of multifunctionality are as follows:stand density index (0.752) > average age (0.375) > annual precipitation (0.365) > tree species richness (0.101) > soil pH (0.064) > structural diversity (-0.037) > annual average temperature (-0.105), and stand density is the most important driving factor. The results are of great significance to understand the formation and management of natural mixed broad-leaved forest multifunctionality.