Cross Breeding of Populus and Its Hybrids for Cold Resistance

Populus tomento a was crossed with P. tremuloidis, P grandiden ata, P. lba × P. grandidentata and P. alba × Ulmus s . ta pumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold. Two methods were used to increase the germination rate from 1.5% to 41.1% and the remaining rate from 1.7% to 44.2%. Forty crossing combinations were conducted and 2 744 hybrid seedlings were obtained. MX. t4 × P grandiden ata (G-1-58), MX3 × P. tremuloidis (T-44-60), MX2 × P. tremuloidis (l-13-87-37) and MX2 × (P. alba × P. grandidentata) were regarded as superior combinations after analysis and selection. Thirty seedlings of these combinations and 11 triploid seedlings identified by counting their chromosomes were selected as super plants.     

Salt distribution in response to optical stratification porosity and relative windspeed in a coastal forest in Niigata, Japan

Wind velocity, vertical stand structure and seasalt distribution were measured at various heights inside a plantation of coastal pine forest, with thinning and unthinning, to assess whether any relationships exist between the wind profile, stand structure and seasalt distribution in the coastal pine forest. The vertical stand structure, i.e., optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was determined for each height by computer analysis of digital images taken with a hemispherical lens. The distribution of OSP in the coastal forest follows the Lambert-Beer's law with absorbency coefficient (). The relative windspeed within canopy can be described using the exponential form with the attenuation coefficient (). The sea-salt was collected using salt gauze (a surgical dressing of loosely woven cotton) both inside and outside the coastal forest, and the distribution of sea-salt within canopy was also in accordance with an exponential function. The relationships among windspeed, OSP and sea-salt indicate that the distributions of both sea-salt and windspeed within canopy were very closely correlated with the distribution of OSP. A linear relationship between OSP and sea-salt has been found. Additionally, linear regression between coefficients and has been obtained as well. Based on these relationships between OSP, wind and sea-salt in the coastal forest, the sea-salt distribution and wind profile within the canopy of the coastal forest can be predicted according to OSP. These results may therefore be useful in analyzing the effects of sea-salt on vegetation and evaluating the filter functions of coastal forests.This revised version was published online in November 2005 with corrections to the Cover Date.     

杜仲生长节律与施肥技术简报

杜仲高生长以4－7月份生长最快，6月份达最高峰；径生长以5－7月为旺盛期，其中6、9月各有一次生长高峰；杜仲林地施肥以4－5月为最佳；施肥量为一个区间，且因树龄而异；施肥按坡台地和平地进行沟施和穴施。     

汽车车厢底板用竹木复合板的研制

采用马尾松作芯板、竹片作表板、酚醛树脂作胶粘剂，制造汽车车厢底板用竹木复合板。在确定的涂胶量、热压温度、热压时间条件下，研究了不同的热压压力与竹木复合板性能的关系，得出了适宜的热压工艺条件。研究结果表明，竹木复合板的物理力学性能达到林业行业标准ＬＹ１０５５—９１规定的指标值，为充分、合理、经济、有效地利用竹木资源提供了依据     

间伐小径木指接技术研究

间伐材指接胶合加工，变短材为长材，弯材为直材，为合理，有效利用间伐材开辟了新路。对间伐材木材含水率，指接端压的大小和时间，指接后养护时间，涂胶量，指榫规格等对指接材抗弯强度的影响进行了研究，并测定了苯酚，间苯二酚，甲醛树脂胶胶合的指接材快速老化性能。     

Evaluation of potential land productivity in Wulushan,West China

The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is described. The potential land productivity was evaluated by a fuzzy comprehensive method, We take each plot as a basic unit of evaluation on the basis of an index system of land resources in Wulushan which was developed from the investigation data. Evaluation of potential land productivity is the key part of land management. A guideline is presented in this paper for a proper utilization of the land resources and to develop the productive capacity of the land.     

基于能值分析的森林生态系统能效程度指标构建

能值分析一直是定量分析评价生态经济系统中各生态流得重要工具之一。以森林生态系统为研究对象，结合森林生态系统能值分析透视，以经典能值分析指标体系的调整为基础。对森林生态系统能值分析指标体系进行研究，从而达到对森林生态系统效能程度的综合判断。     

营林技术决策系统的研究与开发

A set of forestation decision-making system which covers 140 tree species growing extensively in Zhejiang Province including coniferous forest, broad-leaf forest, production forest, and bamboo forest, was developed by cooperation of silvicultural techniques and computer programming based on the experience of forestry management and mathematical models. It can be easily operated to help user selecting tree species in given site types and optimize their benefits, which advances the efficiency of forestation and improves the rationality of decision-making.     

对住宅建设的一点看法

本文着重从几个方面论述住宅建设今后的发展方向。使住宅总体规划合理,经济适用,住宅建设与环境协调,达到可持续发展原则的绿色住宅和生态住宅区。     

沟环线虫属一新种-合川沟环线虫(垫刃目:环科)

合川沟环线虫Ogma hechuanensis n.sp.采自四川合川县柑桔根围土壤中，该种雌虫体较长，R＝64－74。第一头环直矩大于第二环。头体间缢缩明显。体中部鳞片列通常为11－12。鳞片近方形，近阴门处其先端呈锯齿状。口针长116．54－13．7．91μm,Rexp=19-22。阴门、肛门距尾端近，Rv=5-7，Ra=2－4。尾端钝，具数个鳞片，与近似种O.querci在以上特征上可相区别。