林业生态安全的共生耦合测度模型与判据

Measuring Model and Criterion of Forestry Ecological Security by Symbiotic Coupling Method

基于生态与产业共生理论,推导和改进林业生态安全测度的模型、算法和判据,使之成为可操作的实用技术。为了既能保留林业生态安全特征指数的生态经济意义,又能通过其指标体系追溯生态安全问题的原因,构建了森林生态—林业产业复合系统的Lotka-Volterra共生模型(林业L-V共生模型),以实现指标体系与特征指数的耦合。为此,首先采用包含林业生态安全的压力—状态—影响—响应结构模型(FES-PSIR模型)和结构方程模型(SEM)的结构化和定量化方法,建立林业生态安全测度指标体系。同时,根据上述SEM方法,可以得出各指标的权重系数,从而克服传统权重确定方法的主观性。然后,根据权重系数和林业L-V共生模型,将指标体系进行逐层耦合,构造出综合特征指数:森林生态与林业产业的共生度指数。在此基础上,通过分析林业生态安全在共生空间的动态演化规律,构建包含共生度和生态受力系数两个维度的林业生态安全级别动态判断矩阵。研究表明,本文提出的林业生态安全测度方法能够显著提高林业生态安全测控技术的效能。第一,由于共生度指数是林业生态安全的前因,因此该测度方法能够实现林业生态安全的"前因性预警",克服了"就生态论生态"的传统方法的滞后性。第二,通过动态判断矩阵又可以预测林业生态安全的未来走势,因此该测度方法在"前因性预警"的基础上又进一步实现了"后果性预测"。第三,对上述林业生态安全的共生耦合测度过程进行回溯解耦,可以逐层分析出导致林业生态安全问题的各种具体原因,从而为相关部门制定林业生态安全的有效管理措施提供科学依据。

Measuring model, algorithm and criterion of forestry ecological security （FES） are derived and improved based on ecology- industry symbiosis theory, in order to develop an operable and practical technology of FES measuring. Not only for remaining the ecological economy significance of FES characteristic index, but also for tracing FES problem back to its reasons through indicators system, Lotka-Volterra symbiosis model of forest ecology-industry compound system （ forestry L-V symbiosis model） is established to couple indicators system to characteristic indexes. First of all for this purpose, the indicators system of FES measuring is set up by a structured and quantified method that includes FES pressure-state-impact-response structure model （ FES-PSIR model） and structural equation modeling （SEM）. At the same time,the weight coefficients of the indicators are calculated by the above SEM to overcome the subjectivity in traditional weighting ways. Then according to the weight coefficients and the forestry L-V symbiosis model, a composite characteristic index-forest ecology-industry symbiotic degree is constructed by coupling lower-hierarchy indicators to higher-hierarchy characteristic indexes. On that basis, the dynamic judgment matrix for FES rating is built, which has two dimensions of symbiotic degree and force coefficient on ecosystem, by analyzing dynamic evolvement rule of FES in symbiotic space. The research shows that the efficiency of FES measuring and controlling technology can be enhanced greatly based on the method developed in this thesis. Firstly, the method has ＇ causative pre-warning＇ function for FES, because the symbiotic degree index is the cause of FES, so that the hysteresis of traditional methods, in which FES cause factors aren＇t considered, is overcome. Secondly, ＇ causative pre-warning＇ and ＇consequent forecasting＇ function are realized by this method, because the future trend of FES can be forecasted by the dynamic judgment matrix. Thirdly, possible detailed reasons of FES problem can be traced back through a decoupling process in the opposite direction of the above mentioned symbiotic coupling measuring, in order to provide scientific basis for relevant government departments to adopt effective measures on FES management.