Study On Weighted Network Construction Based On Coupling Effects Of Forest Landscape Patches

Complex ecological network is an effective method to study ecological phenomena from the perspective of system and complex network technology.In the previous study,the project set up an unweighted forest landscape patch coupled network.Describe the connection of forest landscape patches qualitatively,but in the actual forest landscape ecological system,material,energy and information continuously flow between different forest landscape patches.Patches between couplings are strong or weak,and the interaction strength between patches have an important effect on nature forest landscape ecological system.In this paper,the coupling between forest landscape patches is emphasized,and the weighted forest landscape patch coupling network is constructed.It abstract the complex forest landscape ecosystem more realistically and objectively.The West Dongting Lake region is the research object.Carry on the classification to the regional forest landscape types.Coupling effect between patches were studied based on the species diversity and soil fertility,patches is the nodes,and the coupling effect between patches is the right side.Construct weighted forest landscape patch coupling network.The topological structure of the weighted forest landscape patch coupled network and the unauthorized network are analyzed and compared.The main research contents and conclusions are as follows:(1)Study on coupling effect based on species diversity.This paper analyzes the different forest landscape patches in species diversity,species diversity is calculated by entropy comprehensive index method and comprehensive evaluation method,comprehensive quantitative level of different forest landscape forest species diversity,and the coupling effect between different forest landscapes patches were analyzed.Results show:The coupling effect between broad-leaved forest and bamboo forest is the strongest,the coupling effect of broad-leaved forest and pine forest was weakest.Based on the analysis of forest landscape types,the coupling effect between broad-leaved forest and other forest landscape patches has the rule of the coupling effect of broad-leaved forest and bamboo forest>the coupling effects of broad-leaved forest and shrub forest>the coupling effect of broad-leaved forest and pine forest>the coupling effect of broad-leaved forest and Chinese fir forest.From the analysis of different age groups in Chinese fir and pine forest,the rule is that the coupling effect between young and mature forest patches was greater than that of young and middle age forest,and the coupling effect between middle age forest and mature forest was smaller.(2)Study on coupling effect based on soil fertility.In this paper,the physical and chemical properties of soil were analyzed,Principal component analysis was used to calculate the soil fertility index in different forest landscapes,and the coupling effect is analyzed.The results showed that the coupling effect between broad-leaved forest and bamboo forest was the strongest,and the coupling effect between young and middle aged forest was the weakest;the coupling effect between Chinese fir and pine is between 0-0.2.The coupling effect between broad-leaved forest and other forest landscape patches was in the range of 0.2-0.4;the coupling effect between bamboo forest and other forest landscape patch types was in the range of 0.4-1.0;Stand type is the main influencing factor of the coupling effect between forest landscape patches.(3)In this paper,a method of constructing weighted forest landscape patch coupling network is proposed,which is based on the coupling between patches.Select 15 Forest landscape couplings,patch as node,based on the coupling effect of the species diversity and soil fertility quality,Construct 30 weighted forest landscape patch coupled networks.(4)This paper studies and compares the weighted forest landscape patch coupling network and the unweighted forest landscape patch coupling network topology.The results show that the node degree distribution of the forest landscape patch coupling network is in accordance with the power law distribution,which has the scale-free property.Based on species diversity and soil fertility quality index,the weighted forest landscape patch coupling network has small world characteristics.Its small world characteristics are proportional to the size of the network.The small world characteristics of the unweighted forest landscape patch coupling network are not universal.The weighted forest landscape patch coupling network is more significant than the unweighted forest landscape patch coupling network.Therefore,the weighted forest landscape patch coupling network can better reflect the species,energy and information transmission ability of forest landscape ecosystem.