Research On Forest Landscape Patches Coupling Network And Dynamics

Landscape spatial structure combined of several different ecolodical systems, interactions, coordination and dynamic change in the large region of the landscape ecology research are the important content in the research of ecology. The research of forest landscape pattern plays an important role in the study of landscape ecology. With the rapid development of the computer application technology, there is a significant development of exploring the forest landscape pattern rule both in the research means and research scope, especially since the late20th century of the introduction of the complex network technology, the systemic, complex and dynamic research ideas are widely used in research of control theory, social cooperation, Internet and other areas. In recent years, the use of complex network technolgy to the complexity of biological systems and self-organizing has started. Complex networks that are applied to the field of the forest landscape is a sublimation of the forest landscape study from the reality physical model to abstract logical model, it also has theoretical significance to the large-scale, systematic research on the forest landscape pattern and direct the Forest Landscape management.Taking the west Dongting Lake area as a research object.using the theory of the complex networks as a guide, this paper comprehensive used of graph theory, probability theory, matrix theory, mathematical statistics, database technology, operations research, computer simulation, and other areas of knowledge, around "to see the relationships from a complex network perspective amang the forest landscape pattern, the landscape index and the network topology index","the invulnerability ability of the forest landscape pattern network","the forest landscape patches network dynamic change prediction of using edge effect as coupling effect "the three questions, to construct models, analyse, optimize, simulate the forest landscape plaque coupling network. This paper’s main researches and innovations are as follows:1.This paper defined the landscape patches coupled network model, and constructed landscape plaque coupling network.Based on the study of regional forest landscape distribution pattern, Forest landscape patch was classified into12landscapes: broad-leaved forest (young, mid-aged, mature), pine forest (young, mid-aged, mature), fir forest (young, mid-aged, mature), bamboo forest, shrub forest, economic forest and so on; based on the object of the closed area that formed by the roads, rivers, and non-forestry land, the forest landscape patch coupling body had been extracted; the forest landscape was divided by the vertical dimension into the three levels:arbors, shrubs and herbals, and this paper calculated the adjacent edge effects at all levels of the different landscape types; regarded landscape patches as node and regarded edge effects as the weight of edge to build a network based on the coupling between patches of forest landscape with the weight.2.This paper have studied the topological index of landscape plaque coupling network under different coupling conditions. Based on the adjacency relationship of landscape patch coupling network, through analysing the coupling network of Lixian, Yellowstone, Longtan, Changde forest and the state-owned forest farms of Hefu which are selected randomly, the result showed that the distribution of forest landscapethe pattern network’s degree follows a power law distribution, and it is a scale-free network. The node’s degree, plaque’s size and the index of shape showed a strong relationship when the value of network’s degree is smaller. The average value of the landscape plaque node is depend on the region where the plaque is located;When making the value of edge effect of the arbors, shrubs and herbals in plaques as weight, the total intensity based on the notes of arbors network is greatly related to the total number of nodes of the network, the absolute value of total intensity based on the edge effect of shrubs is associated with the total number of nodes of the network, the total intensity based on the notes of herbals network is irrelevant to the total number of nodes of the network. The degree of coupling network notes based on the edge effect of arbors and shrubs is related to the type of plaque,the degree of notes is irrelevant to the type of plaque.When taking arbors’ productivity as the main operating target and biodiversity as the secondary business objective, the edge effect’s weight of arbors, shrubs and herbals are:0.731,0.188and0.081,the degree of landscape plaque coupling network’s notes is related to the types of landscape plaque, and the total intensity of network’s notes is related to the scale of network.3. Built up survivability model of landscape patches coupled network, and combined with the characteristics of the forest landscape, optimizing and emulating network invulnerability. This document defines that contraposing the strategy for the the forest landscape plaque network attacking, constraint conditions and invulnerability indicators according to analyze landscape patch coupling network robustness and vulnerability simulation, when the network with25%nodes in subjected to random attack, can still maintain most of the nodes communicating. However, if when the critical nodes (i.e. degree of the largest value of1to2nodes) attacked, the network will quickly collapsed. It can improve anti-attack capability of the network by changing the size and shape of the key plaque index, removing the island plaques, increasing network density et. In the forest landscape management process, the forest harvesting intensity should not exceed25%of the area landscape patch, and should strengthen the protection of the landscape type which consists of lots of surrounding adjacent plaques,the larger size, complex shape.4. Defined the evolution dynamics model of the forest landscape patches coupling network, put forward the control objectives and control strategy of forest landscape management. Along with the time change, the edge effect between patches of forest landscape will produce corresponding change, thus causing the landscape patches coupling network nodes total intensity changes.The article fits the curve of average height, average diameter of Chinese fir plantation, pine forests and broad-leaved forest along with forest age changes and deduces the model of plaque edge effect varies with stand age changes.The simulation results show that the higher proportion of mature forest and the denser network in the forest landscape, the more relatively stable the total strength of the network nodes. It can improve network node strength, enhance the survivability of the network and develop the forest landscape towards the direction which can help for improving tree productivity, increasing biodiversity through landscape patch of returning farmland to forest, high degree of decomposition of complexity and large area.