Effects Of Site Conditions On Growth, Yield,and Site Type Division Of Trachycarpus Fortunei

Trachycarpus fortunei?Hook.?H.Wendl.is an important economic tree species in southern China and has high value.The main products are brown tablets and handles and are important industrial raw materials.In recent years,due to the deepening of the concept of green consumption and the improvement of living standards,People's quest for new eco-friendly household items is increasing,and the demand for Trachycarpus fortunei raw materials is gradually increasing.Trachycarpus fortunei resources are widely distributed in the southern region.Large-scale plantations are mainly distributed in Honghe County,Yunnan Province.There are also a small number of plantations in Xingyi City,Guizhou Province.Most of the rest are scattered wild resources.The existing source of Trachycarpus fortunei materials has been unable to meet the market's needs.The cultivation of Trachycarpus fortunei plantation is an important way to solve this problem.Therefore,this paper takes the Trachycarpus fortunei plantation in Honghe County of Yunnan Province and the Trachycarpus fortunei resources of Guizhou Province as the research object,analyze the growth and yield conditions of Trachycarpus fortunei plantations under different environmental conditions,establish a functional model for Trachycarpus fortunei growth and yield prediction,conduct site classification and site quality evaluation of Trachycarpus fortunei survey plots,and draw the following main conclusions:1.The height and total yield of Trachycarpus fortunei decreased with elevation respectively,and the diameter at breast height?DBH?increased with elevation.The growth and yield trends of different slope positions were similar to those of different elevations.Trachycarpus fortunei growing on sunny slopes were better than shady slopes.Valleys were more conducive to palm growth than ridges.The total yield varied with elevation in different aspect and different small terrain.2.The results of soil nutrient analysis under different site conditions indicated that,Low-altitude?1750m-1800m?soil contained high levels of total elements,The content of available elements in soils with medium altitude?2100m-2150m?was high,and the soil nutrient status was the worst at high altitude?2150m-2200m?,which was the most unfavorable to the increase of Trachycarpus fortunei growth.The correlation analysis between Trachycarpus fortunei growth,yield factors and soil nutrients showed that,the total potassium content of soil had the most significant effect on growth and yield,the contents of available potassium,total nitrogen,hydrolyzable nitrogen,total phosphorus,and organic matter also had a certain effect on palm growth and yield.3.Under different cultivation measures,the mixed type of Trachycarpus fortunei and Pinus armandii facilitated the growth of DBH,but it had a greater limitation on the growth of tree height,which is not conducive to the increase of total yield;both Trachycarpus fortunei+Grass and Palm+Agriculture had higher palm growth and yields,while pure forests centered.Under different operating densities,the planting densities of 333/667m² and 667/667m² were most conducive to growth and yield.4.The primary screening of the optimal function model for the prediction of brown yield was:y₁=-61.722+5.558x₂+0.768x₅,R²=0.307,estimated accuracy P was 86%;the optimal function model for palm stalk yield prediction was:y₂=-78.846+23.318x₃+1.238x₇+5.122x₈,R²=0.432,estimated accuracy P was 87.1%.5.The average height,DBH,and crown width of the 5-year-old Trachycarpus fortunei plantations in Guizhou Province were only 53.56%,76.26%,and 63.46%,respectively of Sunjiaba Town,Sinan County.For the 5-year-old plantations of different types of karst geomorphology,the Trachycarpus fortunei growth showed that the DBH of the Trachycarpus fortunei growing on the stone surface was maximum and the height of the tree was the smallest;the soil surface was opposite to the stone surface;the height and DBH of the Trachycarpus fortunei which growing in stone nest and stone ditch were close to the average value of the stand.In the 10-year-old plantation with normal landforms,the soil nutrient status of the Longjiashan Park was the best,and the Trachycarpus fortunei growth effect was the best,the yield of the brown chip was the highest.The height and crown width of the trees in Guidin Yunwu Township are the smallest,only63.58%and 62.4%of the Longjiashan Park respectively.The weight of brown sheets in Liujiashan and Yunwu Townships is relatively small,only 60.85%and 55.13%of the weight of Longjiashan Brown Sheets respectively.6.In the 2-year-old forests of karst Trachycarpus fortunei plantation,the shady slopes were more conducive to the growth of juvenile Trachycarpus fortunei,and the downside Trachycarpus fortunei growth was better than the uphill position.The effect of different niches on the growth of Trachycarpus fortunei in pure forest was more obvious than that of the forest farmers'mixed management.Under different planting patterns,mixed forest farmers were more conducive to high growth of Trachycarpus fortunei.7.The sample plots of 69 Trachycarpus fortunei plantations in Honghe County of Yunnan Province were divided into 12 different site type groups,with a total of 23 different site types.There were120 Trachycarpus fortunei survey sites in Guizhou Province,normal landforms were divided into12 different site types,among them,Trachycarpus fortunei wild resources were mainly distributed in four different site types of low elevation shady/sunny downhill gentle slope,low altitude shady/sunny uphill slope,and the results of site quality evaluation showed that Trachycarpus fortunei wild resources on the No.V of high elevation shady slopes with gently declined site type had the best growth effect,Trachycarpus fortunei wild resource growth effect was poor in No.I of high altitude uphill slope type site and No.?of high altitude shady uphill slope type site.The karst geomorphological survey samples were divided into 9 different site types,among which the No.VIII of low elevation sunny downhill gentle slope was most suitable for Trachycarpus fortunei growth.