AHP Evaluation On Water Storage And Soil Conservation And Landscape Benefit Of Mixed Forest Of Platycladus Orientalis In The Limestone Mountains Of Central South Of Shandong Province

In order to choose a forest type with good protection and landscape effects,and the scientific basis for upgrading the forest quality of the limestone mountains of central south of Shandong Province was explored.In this study,by using pure Platycladus orientalis forest as a control,eight?5a?mixed forest of Platycladus orientalis in the limestone mountains of central south of Shandong were selected.The combination of field investigation and indoor measurement was used to measure soil saturated water storage,steady infiltration rate and average percolation rate,times infiltration time,soil erosion reduction and soil bulk density,soil total porosity,soil available nitrogen content,soil available phosphorus content,soil available potassium content,soil hydrological benefits and soil erosion reduction benefits.The water and soil conservation benefits of mixed forest of Platycladus orientalis,by the above indicators,were studied from three aspects:soil hydrological benefits,soil erosion reduction benefits and soil improvement benefits.The method of literature review and expert consultation combined the previous studies to select seasonal changes,ornamental value,tree shape,coverage,crown width,tree height.The landscape benefit,by the above indicators,was studied from three aspects of stand color,structure and growth status.Then,based on AHP analytic hierarchy process,the water and soil conservation benefits and landscape benefits of cypress and its mixed stand were evaluated respectively,and a comprehensive evaluation system was established by combining 16 indexes from two aspects for selecting target stand with good protection function and landscape effect.The main findings are as follows:?1?In terms of soil hydrological benefits,in soil saturated water storage,soil steady infiltration rate,average percolation rate,and infiltration time,Platycladus orientalis+Melia azedarace is the largest,and Platycladus orientalis+Robinia pseudoacacia is the second,Platycladus orientalis+Armeniaca sibirica were the worst;in terms of soil erosion reduction,the soil erosion amount of different mixed forest types was significantly different from that of Platycladus orientalis.The amount of soil erosion was the largest Platycladus orientalis+Cotinus coggygria,which was 23.70 t·hm^-2·a^-1,Platycladus orientalis+Melia azedarace was 22.46 t·hm^-2·a^-1,and Platycladus orientalis+Armeniaca sibirica was the smallest,21.81 t·hm^-2·a^-1;in terms of benefits soil bulk density performance,Platycladus orientalis+Robinia pseudoacacia was the best,followed by Platycladus orientalis+Melia azedarace.Among the total soil porosity,Platycladus orientalis+Melia azedarace was the largest,and Platycladus orientalis+Robinia pseudoacacia was the second,Platycladus orientalis+Armeniaca sibirica was the smallest.Among the performances of available nitrogen,available phosphorus and available potassium,Platycladus orientalis+Melia azedarace was the largest,and Platycladus orientalis+Armeniaca sibirica was the smallest.AHP analytic hierarchy process was used to comprehensively evaluate the water storage and soil conservation benefits of Platycladus orientalis and its mixed forest stands.The results showed that:Platycladus orientalis+Cotinus coggygria and Platycladus orientalis+Forsythia suspensa and Platycladus orientalis+Robinia pseudoacacia had excellent water storage and soil conservation benefits.?2?In terms of forest color,Platycladus orientalis+Cotinus coggygria was the best.Platycladus orientalis+Acermono maxin and Platycladus orientalis+Ailanthus altissima was the second;the best performance of stand structure was Platycladus orientalis+Melia azedarace,Platycladus orientalis+Robinia pseudoacacia was the second;in terms of growth status,Platycladus orientalis+Robinia pseudoacaciathe was the best,Platycladus orientalis+Melia azedarace was the second,and Platycladus orientalis+Forsythia suspensa was mixed.The AHP analytic hierarchy process was used to comprehensively evaluate the landscape benefits of mixed forest of Platycladus orientalis.The results showed that:Platycladus orientalis+Cotinus coggygria and Platycladus orientalis+Acermono maxin had excellent performance.?3?Combined with 16 indicators of water storage and soil conservation benefits and landscape benefits,a comprehensive evaluation system was established.Based on the AHP analytic hierarchy process,the comprehensive evaluation was carried out.The results showed that Platycladus orientalis+Cotinus coggygria,Platycladus orientalis+Robinia pseudoacacia had excellent performance.It is a mixed forest type with good benefits both water storage and soil conservation and landscape.It should be given priority as a mixed forest type for upgrading and transforming traditional oriental arborvitae pure forest.Relevant research results were helpful to improve the ecological environment and forest quality of limestone mountain,and meet people's yearning for beautiful forest landscape,which played an important guiding role for better forest multi-functional benefits.