【作者】 李东丽；

【导师】 曾思齐；

【作者基本信息】 中南林业科技大学 ， 森林经理学， 2012， 硕士

【摘要】 本文以湖北省国有桂花林场的檫木混交林为研究对象,运用混交度、胸径大小比数、树高大小比数和角尺度等空间结构参数对檫木混交林分空间结构规律进行了分析；结合解析木和样地数据运用经验方程和理论方程相结合的方法对林分的生长进行了分类建模。本文在按树种分类的基础上再根据林分空间结构参数——胸径大小比数对解析木进行分类,通过胸径大小比数将林分的空间结构分析和林分的生长模拟联系到了一起,这种分类方法法比单纯根据树种将解析木进行分类模拟得出的结果准确性更高。本文属于国家林业公益性行业科研专项“南方集体林区次生林抚育间伐与高效利用技术研究(项目编号201004032)”的部分研究内容。本文的主要内容包括：檫木混交林林分空间结构规律研究；擦木混交林林分生长规律与生长模型研究。(1)林分空间结构规律的研究：运用角尺度、大小比数和混交度等3个林分空间结构参数,对国有桂花林场的檫木与杉木、马尾松、南酸枣、鹅掌楸等不同树种形成的混交林进行了空间结构分析和比较。结果表明,檫木在檫杉混交林中混交度最大,树种空间隔离程度最大,而在与其它树种形成的混交林中混交度较小,树种空间隔离程度较小；檫木与杉木混交时在生长上处于优势,与马尾松混交时则稍微处于劣势；从林木分布格局上看,檫杉混交林为轻度团状分布,其余为随机分布。综合对比分析,此地檫木的最佳混交树种是杉木。(2)林分生长规律与生长模型研究：运用Logistic模型、Weibull函数、Compertz模型、负指数函数、Gauss模型、JohnsonSchumacher模型、Richards模型、Bertalanffy模型等8种包括经验方程和理论方程在内的生长方程对解析木的胸径和龄阶、材积和龄阶的关系进行分类拟合,得到当前林分的年龄和蓄积,并在此基础上对各样地蓄积的生长进行了15年短期预测,由预测结果可以看出檫杉混交林一般在21年左右达到最大蓄积生长量且林分的混交度越大,越有利于林分的生长；檫木马尾松混交林在最近的15年内林分的蓄积连年生长量是呈逐年上升的趋势,但是与檫杉混交林相比,檫木马尾松混交林要迟些到达最大蓄积连年生长量；檫木南酸枣混交林在31年时林分的蓄积连年生长量达到最大,此后蓄积连年生长量开始下降,但与檫杉混交林的最大蓄积连年生长量相比要小很多,达到最大蓄积连年生长量的年龄也晚了8、9年。由此可以看出在此研究地檫木的最佳混交树种是杉木。综合考虑各样地林分空间结构规律和林分蓄积的生长变化情况,对各样地提出了主要以抚育间伐为主的经营措施。对于1号、4号和5号檫杉混交林,为了维持样地最大生长量需对样地中达到数量成熟的杉木进行间伐；2号檫木鹅掌楸混交林,需要对样地中角尺度大于0.517的檫木进行间伐；3号檫木马尾松混交林15年内只需要进行抚育；6号檫木南酸枣混交林需要对样地中达到数量成熟的檫木和南酸枣进行间伐。更多还原

【Abstract】 Taking the Sassafras tsumu mixed forest in the national osmanthus forest farm in Hubei province as the research object, we study on its spatial structure and growth. Four indices (mingling intensity, neighborhood comparison of the diameter and the tree height, uniform angle index) are used to describe and compare the spatial structure of the Sassafras tsumu mixed forest. Using the empirical equation and theoretical equation to fit the analytic trees and test plots. Using the neighborhood comparison of the diameter to classify each plant trees, this classification method is better than the classification method just based on the tree species. This article’s content is a part of the public welfare industry of the state forestry administration research projects:"Southern collective secondary forest tending and thinning and efficient use of technology research (The Item Number:201004032)." In this paper the study contents include:the study on the law of the spatial structure and the growth, modeling its growth changes of the Sassafras tsumu mixed forest.(1) The part of the study on the law of the spatial structure was as followed:four indices (mingling intensity, neighborhood comparison of the diameter and the tree height, uniform angle index) are used to describe and compare the spatial structure of the mixed forest of Sassafras tsumu-Cunninghamia lanceolata, Sassafras tsumu-Choerospondias axillaris, Sassafras tsumu-Pinus massoniana, Sassafras tsumu-Liriodendron chinense.The results showed that the mingling intensity of Sassafras tsumu in Sassafras tsumu-Cunninghamia lanceolata mixed forest was maximum, so the space isolation degree was largest. When using neighborhood comparison method to characterize the size differentiation of trees, Sassafras tsumu had an advantage in Sassafras tsumu-Cunninghamia lanceolata mixed forest but had an disadvantage in Sassafras tsumu-Pinus massoniana mixed forest. Considering tree distribution pattern using uniform angle index, the stands in Sassafras tsumu-Cunninghamia lanceolata mixed forest was found to be a clumped distribution, but random distribution in other mixed forest. In conclusion, here the best mixed tree of Sassafras tsumu is Cunninghamia lanceolata. (2) The part of the study on the law of its growth and modeling was as followed: using Logistic model、Weibull function、Compertz model、Negative exponential function、Gauss model、Johnson Schumacher model、Richards model and Bertalanffy model to fit the relationship between the diameter and the age gradation, the relationship between the volume and the age gradation to get the age and the stock of the current stand. Then use the classification model to forecast the growth changes in the next15years. From the forecasting results we can see that when the age of the Sassafras tsumu-Cunninghamia lanceolata mixed forest is21,the stand can get the maximum stock increment, at the same time mingling intensity is bigger, the stand have a better growth; in the next15years, the stock increment of the Sassafras tsumu-Pinus massoniana mixed forest is rising trend year by year; the age of the maximum stock increment of the Sassafras tsumu-Choerospondias axillaris mixed forest is31,after that year the stock increment will become to decrease, at the same time its stock increment is much smaller than the Sassafras tsumu-Cunninghamia lanceolata mixed forest, and the age of the maximum stock increment is8、9years later than the Sassafras tsumu-Cunninghamia lanceolata mixed forest. So, here the best mixed tree of Sassafras tsumu is Cunninghamia lanceolata.Comprehensively consider the law of the spatial structure and the stand stock growth changes of each plot, we put forward the management practice based on the intermediate cutting. In plot1,4and5, we need to intermediately cut the quantitatively mature Cunninghamia lanceolata to keep the maximum stand growth; in plot2, we need to intermediately cut the Sassafras tsumu whose uniform angle index is bigger than0.517; in plot3, in the next15years we just need to tend the forest; in plot6, we need to intermediately cut the quantitatively mature Sassafras tsumu and Choerospondias axillaris.更多还原