利用广西昭平县2009年二类调查控制样点的数据中的杉木的地径和胸径、树高为样本数据,并通过SPSS统计分析软件和数理统计知识,对地径与胸径、树高和材积的相关关系进行分析,分别建立地径与胸径、地径与材积的相关关系或曲线回归模型,最后选出最优模型,从而可利用模型由地径推算胸径和材积。结果表明,地径与树高存在显著正相关性,且地径6~20 cm 径阶与胸径之间最佳的回归模型为 D1．3=-0．199+0．851D地,地径22~40 cm径阶与胸径之间回归模型为D1．3=-1．652+0．913D地,精度是98．7%；同时地径与胸径也存在显著的正线性相关性,地径与材积的回归模型为V=0．000082D地2．48679,精度为95．2%。本次所建立的模型精度在允许范围内,可应用到实际中。

Using ground diameter, DBH and tree height of Cunninghamia lanceolata from the control samples of second class investigation in Zhaoping county, Hezhou city, Guaingxi in 2009 as the sample data, and using the SPSS statistical analysis software and the knowledge of mathematical statistics, the correlation about the ground diameter and DBH, tree height and volume was analyzed. The correlations or curve regression models on ground diameter and DBH, and ground diameter and volume were established and the optimal model was selected , which could be used to calculate DBH and volume by ground diam-eter. The results showed that the ground diameter and tree height accumulated in strong positive correla-tion. The best regression model of ground diameter from 6cm to 20cm and DBH was D1. 3 = -0. 199 +0. 851D地. The regression model of ground diameter from 22cm to 40cm and DBH was D1. 3 = -1. 652+0. 913 D地, with precision 98. 7 %. Ground diameter and DBH also had a strong positive linear

基于全挖法测定了海南省国营岛东林场的无性木麻黄的根的生物量，分别采用胸径和树高、地径和树高、地径和胸径及树高、材积作为自变量构建海南木麻黄根生物量生长方程。结果表明，单独以胸径、地径、材积等作自变量都能以较高的精度估算出木麻黄根的生物量，以树高为自变量的根系生物量预测精度不是很理想；采用地径与树高等复合变量的根生物量预测精度有所提高，但不明显；基于胸径、地径、材积等的根生物量估计中，以胸径为自变量的估计精度最高，在无性木麻黄根系生物量估计中，可以根据精度与外业工作量选择合适的估计方法。

We determined the root biomass of clonal Casuarina equisetifolia of the state-run Hainan Island East Forest by whole digging, constructed the root biomass growth equation of C.equisetifolia in Hainan Province with DBH and tree height, ground diameter and tree height, ground diameter and DBH and tree height, volume variable, respectively.The high preci-sion of the C.equisetifolia root biomass can be estimated with separated variable of diameter, root collar diameter, volume, and the prediction precision of root biomass is not very ideal with variable using the tree height.The prediction precision of root biomass can get improvement but not obvious using root collar diameter and tree height composite variables.The esti-mation accuracy of root biomass with diameter variables is highest among diameter, root collar diameter and volume varia-bles, and we can select the suitable estimation method according to the precision and field workload in estimating clonal C. equisetifolia roo

以欧洲鹅耳枥2年生播种苗为研究对象,对其苗高、地径、生物量的年动态变化和苗高与地径、生态因子的关系等进行研究。结果表明:苗高、地径两者生长基本符合"慢—快—慢"的生长规律,可用Logistic方程来拟合,同时把苗高和地径的生长可分为生长初期、生长盛期和生长末期;苗高在生长盛期有一连续生长高峰期,而地径在生长盛期有2次高峰期,且后期比前期更明显;苗高与地径变化之间呈线性相关,播种苗各部分生长具密切相关性,呈负相关性;通过苗高、地径生长规律与气象因子的相关性分析,表明旬平均气温是影响苗高的主导因子,其他气象因子对地径生长无显著影响。

In order to reveal the annual dynamic growth of Carpinus betulus, the two-year-old seedlings were taken as materials. The dynamic variations of seedling height, ground diameter and biomass accumulations were measured,and the correlation between the height, ground diameter and ecological factors were investigated. The results indicated that in the experiments, the growth of seedling height,ground diameter basically accorded with the rhythm of slow-fast-slow, which wasiftted by Logistic equation, and the growth stage of seedling height,ground diameter could be divided into three phases: the early stage, fast-growing stage and last stage; the seedling height in the fast-growing stage had one continuous rapid growth period, while the ground diameter had two intermittent growth peaks and the latter was more obvious than the previous; besides, there was a signiifcant linear relation between seedling height and ground diameter, but there was a negative correlation between the parts of seedlin

为了制定1年生桢楠容器苗的分级标准，提高桢楠苗木种植成活率，采用系统聚类分析方法，建立以苗高和地径为质量分级指标的分级体系，获得3级分级标准，即Ⅰ级苗：苗高≥38 cm，地径≥0.65 cm；Ⅱ级苗：38 cm＞苗高≥31.7 cm，0.65 cm＞地径≥0.56 cm；Ⅲ级苗：苗高＜31.7 cm，地径＜0.56 cm。

In order to improve the survival rate of planting seedlings of Phoebe zhen-nan, the grading standard for one-year-old container seedlings of Phoebe zhennan was developed by using cluster analysis. The results showed that the quality of Phoebe zhennan container seedlings could be estimated from seedling height and ground diameter. The Phoebe zhennan container seedlings were divided into 3 grades: Grade 1 (seedling height ≥ 38 cm; ground diameter ≥ 0.65 cm), Grade 2 (31.7 cm ≤ seedling height < 38 cm; 0.56 cm ≤ ground diameter < 0.65 cm) and Grade 3 (seedling height < 31.7 cm; ground diameter < 0.56 cm).

对杂交选育和引种的9个杨树无性系进行扦插试验,结果表明：不同无性系的苗期地径、胸径和苗高生长量存在极显著差异,其中黑小2号、J10、J7等3个无性系表现最优,地径、胸径、树高分别较小黑杨提高45.03%～22.16%、70.99%～14.96%、44.31%～16.43%。

Cutting experiments of introduced hybridization breeding clones of nine poplars were conducted .Result shows that :ground diameter ,DBH ,seedling height (H) of different clones at the seedling stage have very significant differences ;the seedling growth of P .nigra× P .simonii ,J10 ,J7 are optimal ,the ground diameter ,DBH ,tree height increased by 45 .03%-22 .16% ,70 .99%-14 .96% ,44 .31%-16 .43% than that of P .simonii× P .nigra .