Growth Of Robinia Pseudoacacia And Pinus Tabulaeformis And The Relationship With Climatic Factors In Loess Plateau Of Western Shanxi Province

In this paper,the method of sampling survey was used to analyze the afforestation of Robinia pseudoacacia plantation and the Pinus tabulaeformis plantation in Loess Plateau,western Shanxi province.By using of tree trunk analysis,sampling method,stratified harvesting method and ring analysis method to analyze biomass,productivity,growth patterns,and climatic factors of Robinia pseudoacacia plantation and the Pinus tabulaeformis plantation.The main conclusions are as follows:The biomass of 24a and 28a plants of Robinia pseudoacacia plantation respectively were 61.07kg and 84.55kg.The biomass of 34a and 38a of Pinus tabulaeformis plantation respectively were 38.46kg and 63.86kg,and the biomass growth respectively were 23.48kg and 23.40kg.The biomass of Pinus tabulaeformis respectively were 64.84t/hm2 and 80.90t/hm2,and the biomass of Pinus tabulaeformis respectively were 41.82t/hm2 and 74.08t/hm2.The biomass growth rate was 16.36 t/hm2 and 32.26t/hm2.The total productivity of 24a and 28a Robinia pseudoacacia plantation were 5.63t/(hm2a)and 9.32t/(hm2a).The productivity of 34a and 38a Pinus tabulaeformis plantation respectively were 2.35 t/(hm2 a)and 5.52t/(hm2·a).The Simpson diversity index of Robinia pseudoacacia and Pinus tabulaeformis respectively were 0.4955 and 0.6355,and the herb layers respectively were 0.7314 and 0.7367;The Shannon-Wiener diversity index of Robinia pseudoacacia and Pinus tabulaeformis Shrub were 0.8610 and 1.1792,and the herb layer respectively were 1.6748 and 1.5392.The Pielou evenness index of Robinia pseudoacacia and Pinus tabulaeformis respectively were 0.3260 and 1.070,and the herb layers were 0.7655 and 1.586.The Whitney index,Cody index and Roultedge index of Robinia pseudoacacia forest and Pinus tabulaeformis forest respectively were 1.5385,1.9259 and 7.5070.The forest diversity of Pinus tabulaeformis forest was higher than that of Robinia pseudoacacia forest and Pinus tabulaeformis forest.The Whitney index,Cody index and Roultedge index respectively were 3.2500,6.3704 and 27.9952.The ? diversity of the shrub layer of Robinia pseudoacacia forest and Pinus tabulaeformis forest was less than that of herbaceous layer.The similarity coefficient of Jaccard in Robinia pseudoacacia forest in the shrub layer was 0.991 and in the herb layer was 0.2953.In the shrub layer,the Jaccard similarity coefficient in Pinus tabulaeformis forest was 0.2988,and in herb layer was 0.1005.Jaccard similarity coefficient between Robinia pseudoacacia and Pinus tabulaeformis forest in the bush and herbs respectively were 0.3055 and 0.2988.The Similarity of forest stands are low,vegetation diversity and stability should to be improved.The correlation coefficient was 0.982,and the correlation coefficient was 0.982.The total growth of tree height was linear with the age of tree,and the correlation function was linear.The correlation coefficient was y=0.2968x+2.3724,And the correlation coefficient was 0.994,the total growth of Robinia pseudoacacia DBT was proportional to the age of the tree,the function relation was y=0.8148x0.7603,the correlation coefficient 0.984,the total growth of the diameter of the pine diameter of Pinus tabulaeformis.And the correlation coefficient is y=0.3367x-0.8133,the correlation coefficient was 0.986.The total biomass growth and the age of the plantation are the power function,the function relation was y=0.0002x1.6212 and y=3E-06x2.7589,the correlation coefficient was 0.99 and 0.996.The width of Robinia pseudoacacia and Pinus tabulaeformis was generally decreased.The width of Robinia pseudoacacia in the young was faster than that in middle age.The width of Robinia pseudoacacia increased large in the age of twenty years.The width of Pinus tabulaeformis was larger initial tree growth,and the fluctuation became small.The early wood of Robinia pseudoacacia was stable,and the late wood changed greatly.The late wood of Pinus tabulaeformis was stable,and the early wood changed greatly.The correlation coefficients between annual precipitation with annual increment of tree height,DBH increment and annual increment of volume respectively were 0.526,0.593 and 0.611.The results showed that they had significantly positive correlation.There was a significant positive correlation between the DBH increment and the mean annual temperature on Robinia pseudoacacia.There was a significant positive correlation between the annual increment of the volume of Pinus tabulaeformis and the average temperature of the year.The ring width of Robinia pseudoacacia and Pinus tabulaeformis were all negatively correlated with average annual temperature and average annual temperature before year.