| The low mountains and hillys region of shandong province can be divided into limestone mountains region and gneiss mountains region,due to severe soil erosion,barren soil,afforestation difficulties and other restrictions,the classification and evaluation of site types is of great significance to guide afforestation and improve the quality of afforestation.This study relies on and serves for the project called "Coastal shelter forest vegetation restoration technology research project in low mountains and hills area" in the project called "Coastal shelter forest project in Shandong province financed by the European investment bank(2017-2020)".Simultaneously,according to the area of coastal protection forest afforestation in the specification called "the outline of the 12 th Five-Year Plan of forestry development in Shandong province",select Weifang city(Qingzhou city,Linqu county)as the limestone mountain typical afforestation region which was main part of the area of the project and the plan.And select Weihai city(Huancui city,Rushan county)as the gneiss mountain typical afforestation region which was main part of the area of the project and the plan.Afterwards,in order to simplify the site classification work and make the research results more convenient to be used in the actual production,the two areas were combined and studied as the typical afforestation areas in low mountains and hillys region.With the help of the relevant departments around the city,combined the field investigation,a total of 406 field survey small class data were obtained,after screening,in the afforestation of small-class characteristics of landform,soil and vegetation characteristics of the data is used as basic data.Meanwhile,based on the Principal Component Analysis,the dominant factor of site classification in coastal shelter forest of the limestone mountainous region and the gneiss mountains region and the low mountains and hills region in Shandong province were determined,respectively,and combine the results of the monograph called “Classification of forest sites in China”,the site types were reclassified.Afterwards,on the basis of site type classification results,combining with the field investigate and laboratory experiments,soil physical and chemical properties of different site type have been measured,based on the principle of Data Envelopment Analysis,indirect evaluation method as the main thought,the site types of coastal shelter forest in the limestone mountainous region and the gneiss mountains region and the low mountains and hills region were evaluated,and combined with local economic development level and other factors,the suitable models of afforestation for coastal shelter forest in the low mountains and hills region were choose.The results indicated as follows:(1)there is a certain correlation between site factors,it can be indicated that the underlying data source is credible to a certain extent,and meanwhile,it can lay a foundation for the Principal Component Analysis.In the limestone mountainous region,there was an extremely significant relationship between soil texture and soil thickness,slope,subforest vegetation height and vegetation coverage,and between soil thickness and slope height,subforest vegetation height and vegetation coverage,while there was a significant relationship between soil thickness and slope position,and the correlation between other factors was not significant.In the gneiss mountains region,there was an extremely significant relationship between soil thickness and slope position,soil thickness and vegetation height,slope position and undergrowth vegetation height,while there was a significant relationship between slope position and vegetation coverage,and the correlation between other factors was not significant.(2)in the limestone mountainous region,the most importance dominant factor of site classification was soil texture,which was follows by soil thickness,elevation,and aspect.In the gneiss mountains region,the most importance dominant factor of site classification was slope,which was follows by aspect and soil thickness.In the the low mountains and hills region,the most importance dominant factor of site classification was soil type,which was follow by soil thickness and aspect.(3)according to the principles of regionalization of the national forest site classification,combining with the dominant factors of site classification determined by each region,the limestone mountainous region was divided into 2 site type groups and 18 site types,the gneiss mountains region was divided into 3 site type groups and 12 site types,and the low mountains and hills region was divided into 2 site type groups and 8 site types(4)using the indirect evaluation method as the main idea and based on the BCC model principle of DEA method,the site quality of the limestone mountainous region,the gneiss mountains region and the low mountains and hills region was evaluated,respectively.In the limestone mountainous region,the site type of sandy soil,thick sediments,hilly and sunny slope,the site type of heavy loam,thick sediments,hilly and sunny slope and the site type of heavy loam,thick sediments,hilly and shady slope were batter than other site types.In the gneiss mountains region,the site type of gentle slope,shady slope and thick sediments,the site type of gentle slope,sunny slope and thick sediments,the site type of more inclined slope,shady slope and thick sediments and the site type of more inclined slope,sunny slope and thick sediments were batter than other site types.Afterwards,in the low mountains and hillys region,the site type of brown soil,thick sediments and sunny slope was batter than other site types.(5)considering the principle of operability and simplicity,based on the results of site classification in the low mountains and hillys region,and combined with the results of field investigation and site quality evaluation,the suitable afforestation model was selected for each site type.The results indicated that economical shelterbelt model or timber shelterbelt model was suitable for the site type of cinnamon soil,thick sediments and sunny slope and the site type of brown soil,thick sediments and sunny slope.Ecological shelterbelt model or economic shelterbelt model with shade-tolerant tree species was suitable for the site type of cinnamon soil,thick sediments and shady slope and the site type of brown soil,thick sediments and shady slope.Simultaneously,ecological shelterbelt model was suitable for the site type of cinnamon soil,thin sediments and sunny slope,the site type of cinnamon soil,thin sediments and shady slope,the site type of brown soil,thin sediments and sunny slope and the site type of brown soil,thin sediments and shady slope.Sublot is the measure of practice in this research,and the results of study can meet the needs of optimizing vegetation structure and integrating afforestation technology in the project implementation area.The results of this research can provide theoretical support for realizing the accurate management,management and sustainable development of coastal sheltering forests in shandong province.Meanwhile,it provides a scientific reference for the subsequent study on the classification and evaluation of site types,and hopes to make a certain contribution to the improvement of the ecological environment of coastal areas and the increase of forest carbon sink and the promotion of regional economic development... |
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