油松不同种群1年生苗木生长节律研究

摘要

[目的]油松(Pinus tabuliformis)是中国西北荒山造林的主要树种,对9个种群油松生长节律进行研究.[方法]采用Logis-tic方程对油松各种群苗高、地径生长过程进行拟合.[结果]油松各种群1年生苗高、地径生长与Logistic方程相关系数均在0.9以上,显示出相关性;各种群苗高、地径生长都符合“慢-快-慢”的“S”型生长曲线;苗高与地径存在异速生长现象,苗高较地径早进入速生期.根据Logistic方程将油松各种群生长过程划分为3个阶段:生长前期、速生期、生长后期;不同种群苗高、地径进入速生期的时间不同,苗高为第26～ 36天,地径为第26～ 61天;各种群速生期持续时间占整个生长过程的2/5以下,但速生期生长量占整个生长期生长量的比重不同,苗高变化于48.53％～58.48％,主要集中在56.87％～58.48％,地径占57.59％～57.98％.各种群的苗高、地径生长量与方程拟合的理论生长量间均显示极显著相关性,其相关系数分别为0.9719和0.9899.各种群苗高、地径速生期生长量与理论生长极值k间均显示极显著正相关关系,相关系数为0.9173和0.9999.[结论]利用Logistic方程可以准确估测油松生长量以及划分各生长阶段.%[Objective] Pinus tabulaeformis was the main species of the Northwest afforestation.The growth rhythm of nine populations of P.tabulaeformis was studied.[Method] The seeding height and ground diameter growth process were fitted using logistic equation.[Result]The relationships were significant between height,ground diameter and the logistic equation in P.tabuliformis populations (r＞0.9).Each population showed the rhythm in ‘slow-fast-slow'for both seedling height and ground diameter,which accorded with the ‘S' growing curve.There existed allometric phenomenon for seedling height and ground diameter,the growth of seeding height entered the fast-growing phase earlier than that of the ground diameter.According to the logistic equation,the growth of P.tabulaeformis populations was divided into three phases:early growth,fast-growing period,growth of late.There were different fast-growing period of time for different populations in seedling height and ground diameter,which were 26-36 and 26-61 d,respectively.The fast-growing phase accounted for two fifths of the duration of the whole growth process,but the proportion of the growth increment during fast-growing phase were different for each population.The proportion for seedling height varied 48.53 ％ to 58.48 ％,focused on 56.87 ％-58.48 ％,and the ground diameter growth focused 57.59 ％-57.98 ％.There were significant correlations for seedling height and the theory of growth based on the logistic equation.The case was the same for the ground diameter.The correlation coefficients were 0.9719 and 0.9899,respectively.The seedling height and ground diameter were correlated significantly with the extreme value k based on the logistic equation,the correlation coefficient were 0.9173 and 0.9999,respectively.[Conclusion] The growth increment and divided in different growth stages of Pinus tabulaeformis can be estimated accurately by using the logistic equation.