Research On Forest Landscape Patch Coupling Network Construction And Node Evaluation Based On Suitability Index

Modern forest management emphasizes the improvement of forest quality and the utilization of forest ecological value and service efficiency.This requires that people should no longer be limited to forest stand scale,but should also include landscape scale management.How to determine the key management area of forest management is landscape Management,management and protection of forest resources on a scale.This paper takes Jindong Forest Farm in Yongzhou City,Hunan Province as an example,adopts the method of suitability index model to evaluate the ecological suitability of forest landscape patches,and constructs a forest landscape patch coupling network model,with two.topologies of utilization centrality and betweenness centrality.The index evaluates the importance of nodes(patches)in the network and determines the location of key forest landscape patches.The main research contents and conclusions are as follows:(1)Follow the principles of systemicity,representativeness,scientificity,operability,etc.,and search for relevant documents,and select 10 forest ecological suitability indicators from topographical conditions,soil conditions,forest conditions,hydrological conditions,and social conditions.:Slope,slope position,aspect,soil thickness,soil type,distance to water,origin and forest age structure,canopy closure,distance to main road,distance to residential area,the weight of each index is determined by the analytic hierarchy process.The weighted average method is used to establish a forest ecological suitability evaluation model.Using the analytic hierarchy process to determine the weight of the forest ecological suitability index,the results show that:in the criterion layer,the forest stand condition is the most important,and the order of the criterion layer is:stand condition(0.3939)>soil condition(0.2344),hydrological condition(0.1239))>Topographic conditions(0.1239)>Social conditions(0.1238).The order of index layer factors is:origin and forest age structure(0.2626)>soil layer thickness(0.1563)>canopy closure(0.1313)>water area distance(0.1239)>soil type(0.0781)>slope direction(0.0668)>road distance(0.0619)=distance between villages and towns(0.0619)>slope(0.0368)>slope position(0.0203).(2)The ecological suitability of the forest is evaluated based on a single factor,and the areas with suitability values greater than or equal to 3 are divided into suitable areas.The results show:slope,slope direction,slope position,canopy closure,soil thickness,soil Type,distance from road,origin and structure of forest age,distance from residential area,distance from water area,the proportion of suitable area to the total area of the study area are:70.85%,80.14%,73.82%,74.86%,64.46%,59.92%,84.39%,50.25%,23.28%,24.62%.The results show that the overall suitability of the study area is relatively ideal,and the overall suitability performance of the distance from the residential area and the distance from the water area is low.(3)The forest ecological suitability evaluation model is used to evaluate the ecological suitability of forest landscapes,and the results of forest ecological suitability are divided into five grades.The results show that the proportion of each grade of forest ecological suitability is:unsuitable area(level Ⅰ)19.68km2(3.78%),less suitable area(level Ⅱ)128.438km2(24.64%),generally suitable area(level Ⅲ)182.92 km2(35.10%),higher suitable area(level Ⅳ)170.33 km2(32.68%),High-suitability area(Grade Ⅴ)19.82 km2(3.80%),the largest proportion is the general suitable area(Grade Ⅲ).The area of the entire study area with suitability grade higher than Grade Ⅲ is 373.06 km2,accounting for 71.58%.The results show that most areas of Jindong Forest Farm are suitable areas for forest resources.The regions with lower suitability for Grade I and Grade II are generally distributed closer and exist in blocks.They are mainly distributed in the southwest,north and south-central regions.Based on the status of land use,it can be known that these areas are mostly located in areas with frequent human activities.Comparing Goole Earth images and small-group survey data,appropriate measures have been added to strengthen the protection of forest landscapes that have not yet formed a scale.(4)Select the areas where the forest ecological suitability degree reaches "generally suitable(Ⅲ)","more suitable(Ⅳ)",and"suitable(Ⅴ)" as the source patches,abstract them as nodes,and take the European style between nodes The distance is the edge block to construct the forest landscape patch coupling network model,the network connection graph is denoised based on the minimum spanning tree method,and the two topological indicators of degree centrality and betweenness centrality are used to determine the importance of each node.The results show that the area of patches that play an important role in the local network and the global network is about 156km2,and these important patches are mainly distributed in the middle and southwest of the forest farm.The results show that the development of the forest landscape with patches located in these patches has a stronger external spillover effect than other patches,and is more able to communicate with and form connections with the surrounding forest landscape patches.For these key patches,proposed Corresponding business measures.