Construction Of Coupling Network Of Forest Landscape Patches Based On Minimum Cost

In this paper,using landscape ecology theory and model,using map theory,3S technology and statistical analysis of spatial data,the source patch based on species habitat adaptability is determined,and different landscape patch types are determined according to the migration ability of species in different patches.The resistance value forms the landscape resistance surface,and calculates the minimum cost distance between the source patches.The gravity model is used to calculate the force between the source patches,and the main path of species migration is selected as the edge,using ArcGIS software.The forest landscape patches at the intersection of the edge,edge and cumulative resistance maximum in the coupling network of forest landscape patches are extracted,and they are abstracted into nodes together with the source patches to construct a forest landscape patch coupling network of Mangshan Forest Farm;The structural characteristics of forest landscape patch coupling network were analyzed by usingaindex,pindex,yindex and cost ratio.The overall connectivity index(?C)and importance index of landscape patches were calculated by Conefor Sensinode 2.6 software.d?C),identified key forest landscape patches in the study area;on this basis,proposed landscape patch protection in the study area Measures and proposals,provides a theoretical basis for the full effect of multi-functional forest landscapes.The main findings are as follows:(1)The construction of the coupling network of forest landscape patches based on the minimum cost:Based on the existing research of the research group,combined with the characteristics of the forest landscape types in the study area and the purpose of the study,the construction is based on the land type,age group,The multi-level classification index system of forest landscape type elements based on three heterogeneity factors of dominant tree species group,the landscape types of the study area are divided into 16 categories,of which 13 are forest landscape types.A broad-leaved mature forest was selected,and plaques with an area of more than 20 hectares were used as source plaques for the study.There were 31 plaques.According to the resistance values of different types of landscapes to the target species,the landscape of the study area was rasterized to form landscape resistance.Based on the minimum cost distance model,the path of species migration between source patches was determined,a total of 465,and the gravity model was used to calculate and screen out the path with force greater than 1000,a total of 60,using ArcGlS10.2 extracted 63 The plaques of other important niche forest landscapes are abstracted into nodes together with the source patches,and the weighted forest landscape patch coupling network is constructed with the interaction force between the nodes as the edge.(2)Analysis of characteristics of forest landscape patch coupling network and determination of key nodes:From the analysis of the composition of the network,the network consists of 94 nodes and 198 edges,and the ratio of source patch nodes to special nodes is 1:2;The closedness indexa=0.5738,indicating that the loop in the network is large and its closure degree is high;the complexity indexp=2.1064,indicating that the average number of connections per node in the network is high,the complexity of the network is high;the connectivity index?=0.7174,indicating that all nodes in the network have a large degree of connection with the edge,and the overall connectivity of the network is better;the cost ratio C= 0.8809 indicates that the cost of the network is relatively high,mainly due to the long span between network nodes,the network The structure is complicated;the special nodes of the network are removed,and the network?,?,andyindexes are reduced to 0.5263,1.9355,and 0.6897,respectively,and the cost ratio is increased to 0.9370,indicating that the more complex the network structure,the more the degree of closure and connectivity High,it is beneficial to the migration of species;corresponding to the function of forest landscape,it indicates that the source plaque controls the connectivity effect of the whole forest landscape,and the special node acts as the source patch node.The transition between nodes,is a stepping stone plaque in the forest landscape,strengthening the overall complexity of the forest landscape;The overall connectivity index of forest landscape patches(?C)=0.489 was calculated by Conefor Sensinode 2.6 software.Based on this,the plaque importance index(d?C)was used to calculate the top five plaques 11,12,13,20 The importance values of No.7 are 13.326,12.036,11.389,10.456,10.032,which are much larger than the average important value of all source patches,3.198,and the total importance value accounts for 58%of all nodes;from the size of the plaque Analysis,the area of 11,12,13 is the largest,and the area of 20 and 7 is at the middle level of all patches;from the spatial location distribution analysis of each node,the five nodes are the west,middle and east regions of the network.If the main hub,if removed,the connectivity effect of the network will be significantly reduced or even unable to connect,indicating that the importance of the network node has a certain relationship with the area of the node plaque,but it is not completely controlled by the area size,but also with the node in the network.The spatial location is related,and the nodes that bear the main connectivity are of great importance;according to the research in this paper,7,11,12,13,and 20 are the key nodes in the network.(3)Optimization of forest management in the study area:First,protect the core source patches,propose to prioritize the construction of small and scattered source patches in the east and west,and distribute the concentrated source patches in the central part;the main channel for the network It is necessary to establish buffer protection.The plaques corresponding to the five key nodes of 7,11,12,13,and 20 on the channel should be optimized for construction.By reconstructing the landscape plaque around the source plaque,the source plaque is achieved.Block the same landscape type,thereby increasing the area of the source patch to ensure the integrity of the source patch;Second,planning and constructing the landscape patch corresponding to the special node of the network,the landscape patches corresponding to the 63 special nodes in the network are mainly Enclosure protection is the main focus.For some special types of landscapes,such as no standing woodland,construction land,etc.,special measures such as reforestation and buffer zone around the plaque should be taken to change the landscape type and ensure the forest landscape structure.Integrity;finally generate the planning and design map of the study area,which has certain guiding significance for the conservation of species diversity,and then provides the full effect of the multi-functional effect of the forest.The theoretical basis.