| Researches on methods of mid-term forest management planning for the southern collective forest area,which had important theoretical and practical significance for promoting the sustainable forest management in the southern collective forest areas in China.In the southern collective forest area,the objectives of regional forest management planning are usually constrained by various factors such as land use change,forestry guidelines and policies.As a key forestry city in Jiangsu Province,the forest resources in Jurong had the shortages of badly quality of forest resources,the fragility of ecological functions as well as the imbalance forest structure,which was not conducive to the sustainable forest management and forestry development,and also constrained the healthy development of regional social economy.Therefore,it is more urgent to make forest management plan with the goal of improving forest quality in Jurong.This study was conducted in Jurong,in this study,based on the land use data of the interpretation of remote sensing images of Jurong in the two periods of 2006 and 2013 of the institute of remote sensing of the Chinese Academy of Sciences.we first reclassified the land use data of 2006 and 2013 into 7 land types,including paddy fields,dry lands,forest lands,shrub lands,water areas,construction lands,and other land types;and then constructed seven driving factors including altitude,slope,aspect,forest disturbance index,distance to residential area,distance to road,distance to water;Thirdly,we used binary Logistic regression method to analyze the relationship between driving force of land use change and 7 kinds of land use types,and the regression results were tested using the ROC curve(receiver operating characteristic curve).In addition,we validated 7 parameters used for the CLUE-S model(small scale land use change and effect model)and applied this model to predict land use types,and the prediction accuracy were assessed with Kappa index.Besides,based on Markov model,?Land use planning(2006-2020)?,?The Jurong Forest Land Conservation Planning Plan”,we established three scenarios of natural development,ecological protection,and forestry priority;and used the CLUE-S model to simulate spatial distribution map of land use in Jurong in 2020 under three scenarios based on the real land use types of 2013.Based on planning goals the southern subtropical evergreen broad-leaved forest and coniferous and broad-leaved mixed forest management areas in the?National Forest Management Plan of the National Forest Management Plan(2020)?and the"Thirteenth Five-Year Plan for Forestry Development in Jiangsu Province?,we Selected five assessment indexes of forest coverage broad-leaved forests,forest carbon density,and forest area per unit area from total forest volume,forest structure,ecological functions,and forest quality,and we used the multi-Euclidean distance in MCDA(Multiple Criterion Decision Analysis)method to evaluate the results and choose the optimal scenario.In the end,based on the optimal scenario plan,combined with the key points of the?county-level forest management plan?,explored the essential points to implement the optimization scenario from the aspects of forest functional zoning,forest management organization and design,and forest management countermeasures.Research indicated:1)Binary Logistic Regression Analysis in Driving forcesWe used Logistic regression model and selected 7driving factors to explore the driving mechanism of land use patterns evolution in Jurong.The results showed that,the driving factors of slope and forest disturbance index played key role in land use classification in Jurong.For the driving factor of slope,it had the largest weight on paddy field,dryland and shrubwood,with the regression coefficients of-0.208,-0.161,and 0.063 respectively.For forest land,water areas,construction land,and other land types,the driving factor of forest disturbance index had the maximum impact with the regression coefficients of-0.644,-0.577,0.101 and 0.135 respectively.It can be concluded that both natural factors and disturbance factors had significantly influence on the distribution pattern of land use in Jurong.2)Regression fit test(ROC)The ROC test was used to check the consistency between Logistic regression modeled land use patterns and the real land use pattern distributions and the results were presented by the area under the curve.In this study,the ROC values for 7 land use types were both greater than 0.7,for paddy field,dryland,forest land,shrubwood,water areas,construction land,and other land types,with the ROC values of 0.771,0.711,0.993,0.700,0.953,0.724 and 0.904 respectively.It showed that the spatial distributions of land use patterns calculated by the regression equation was consistent with the real distribution of various types.The Logistic regression relationships between land use types and driving factors were credible,and the driving factors we selected were well explain he land use types change in Jurong.3)CLUE-S simulation accuracy verificationBased on the land use types of 2006,we used the CLUE-S model to predict the land use of2013,and then the Kappa index verification method was used to test the consistency between models predicted results and the real land use distributions of 2013.The results showed that,with the Kappa value of 0.83,it meant that the CLUE-S model can be used for predicting the land use distributions in Jurong.4)Prediction results of three scenariosWe used the CLUE-S model to forecast the land use types of 2020 in three different scenarios(natural progression scenario,ecological protection scenario and forestry first scenario)by changing the model parameters of land demand and the other parameters.The results showed that,in the scenario of natural progression,only the land use area for construction increased and other land types were decreased;in the context of ecological protection,the areas of paddy fields,and forested land were increased,whereas,for dry land,shrub land,and water area,their land use area were decreased.In the forestry first situation,the land use area of forest lands,shrub lands,and shrub lands were increased,and the other land use area were decreased.5)MCDA Evaluation Scenario Simulation SchemeWe also calculated the forest coverage rate,broad-leaved forest ratio,forest carbon density,forest unit area accumulation volume,and large-diameter timber ratio these five indexes of 2020 in three different scenarios,and then multidimensional Euclidean distance between indexes and targets were computed.For natural progression scenario,ecological protection scenario and forestry first scenario these three scenarios,the distance was 0.455,0.309 and 0.291.Based on the method of MCDA,the scenario of forestry first was chosen to be the optimal method.6)Key points for implementing forest management under the optimized planning scenarioAccording to the scenario of forestry priority,we calculate the increased forest land area for three forest functional areas,every town and forest farms from 2013 to 2020 in Jurong.The results showed that in the Baohua Mountain Ecological Construction Forest,it will had increased 146.3hm~2;t in the Central and Western Urban Forestry Development Zone,it will had increased 138.7hm~2.;and in the eastern Maoshan Landscape Ecological Area,it will had increased 257.2.hm~2.In addition,we ranked the forest land use types according to the land use area,the top four were combined forests with mainly water and soil conservation,mixed-use forests with landscape-based recreation,and water-based conservation forests and bamboo.Product-based dual-use forest.In the end,based on the scenario of forestry first,the forest land area in Jurong will have reached to21,717.43 hm~2.,with the forest coverage rate of 17.8%,we should be pay more attentions on the increasing the quality over quantity of forest resources,insect disease prevention and the infrastructure construction of forestry. |
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