黄龙山不同郁闭度油松中龄林林木形质评价  

Evaluation of the tree form quality of middle-aged Pinus tabuliformis plantation under different canopy densities in Huanglong Mountains,Northwest China

作　　者：尤健健[1] 张文辉[1] 邓磊[1] 

机构地区：[1]西北农林科技大学西部环境与生态教育部重点实验室,陕西杨凌712100

出　　处：《应用生态学报》2015年第7期1945-1953,共9页Chinese Journal of Applied Ecology

基　　金：陕西省科技统筹创新工程计划项目(2014KTCL02-04);国家"十二五"科技支撑计划项目(2012BAD22B0302)资助

摘　　要：以黄土高原南部黄龙山林区油松人工中龄林为研究对象,按郁闭度CD<0.65(类型1)、0.65≤CD<0.75(类型2)、0.75≤CD<0.85(类型3)、CD≥0.85(类型4)将样地划分4个等级.综合林木生长、干形和分枝情况,运用层次分析法建立林木形质评价层次结构模型和指标体系,对4种郁闭度类型的油松林林木的形质水平进行了综合评价.结果表明:林木生长、干形和分枝3大类形质评价因素及其包括的胸径、树高、径高比、尖削度、通直度、分杈率、活枝下高、侧枝数、最大侧枝基径和侧枝平均基径10项指标,可以全面地反映油松林木形质水平.其中,通直度、分杈率和胸径3个指标的总权重达0.7382,对林木形质水平影响最大,是油松林木形质的主要决定因素.随着林分郁闭度的减小,林木形质综合得分表现为先升高后下降,类型2郁闭度下达到最高的90.28分,该类郁闭度下林木形质水平最优.本评价方法操作简单,可解决林木形质评价的量化问题,评价模型体系也可在黄土高原其他林木形质评价中借鉴和应用.To clarify the effects of different canopy densities on tree form quality of Pinus tabulifor- mis, a hierarchical indicator system was structured, which brought about a set of grading criteria to evaluate tree form quality of the middle-aged P. tabuliformis plantation under four canopy densities in Huanglong Mountains by using the analytic hierarchy process （AHP）. Plots were divided into four classes according to the stand canopy density （ CD ） ： CD 〈 0.65 （ type 1 ）, 0.65 ≤ CD 〈 0.75 （type 2）, 0.75≤CD〈0.85 （type 3） and CD≥0.85 （type 4）. The results indicated that, by com- prehensive analysis of ten related indicators, i.e., diameter at breast height （DBH） , tree height, diameter height ratio, taperingness, stem straightness, forking ratio, height under living branch, number of branches, max-branch base diameter and average base diameter of branches, the tree form quality could be evaluated. Among these factors, stem straightness, forking ratio and DBH were the most important ones influencing the tree form quality with a total weight of 0.7382. So, these three indicators were the major determinants of tree form quality. The comprehensive scores of the tree form quality evaluations fluctuated as the canopy density decreased and topped at 90.28 when CD was valued at 0.75 （type 2）. The indicators and evaluation system developed in this study were easy to operate, and quite fit for solving the quantity problem of the tree form quality evalua- tion. Our system would be capable for applications in evaluating the tree form quality of other tree species on the Loess Plateau.

关 键 词：油松中龄林 郁闭度 林木形质 层次分析法 黄土高原 

分 类 号：S791.254[农业科学—林木遗传育种]