四川盆地浅丘陵区农林复合系统内部天空散射辐射分布特性理论分析

根据四川盆地浅丘区农林复合系统特点,从理论上分析了该系统内天空散射辐射令布特征。提出了在林带和地形(坡度变化)的双重影响下的林带间平均相对辐照成分布特征,为农林复合系统的设计提供了依据;除林带本身产生“光胁地”外,地形变化即坡度的增加,叶“光胁地”效应有增强作用,对其范围有扩大作用。     

日本松干蚧疫情在吉林省发生发展趋势及治理情况分析报告

1994年，吉林省日本松干蚧分布面积256.7hm^2，到2002年，分布面积达到10867.2hm^2，呈快速扩散蔓延趋势。日本松干阶主要治理对策是：在疫情发生区，以营林抚育、封山育林、生物防治为主，以化学防治为辅，全力封锁控制疫情，严防继续扩散蔓延，努力减轻危害损失，对无防治前途的疫林进行有计划地砍伐更新；在疫情保护区，通过隔离带和检疫检查站建设，阻断日本松干蚧的自然和人为传播。     

红锥天然分布区表型变异研究

研究了红锥天然分布区各种源的主要特性，从总体看可划分为3大类，来自水热充沛地区的种源（21．1℃）具有嫁接植株生长快、形成花蕾和开花时间较早，展枝展叶早，叶片短小、枝叶数量多等特性；来自年均温低或较低（〈19．9℃）的其余两类种源则嫁接植株生长较慢，物候较迟，叶片较宽大。从全分布区嫁接植株的生长变异看，其变异属随机变异，天然分布中种源的生长变异大于种源内的单株变异，种源选择基础上进一步进行单株选择是一种理想的生长改良途径。     

Species composition of Modellidae and Cerambycidae (Coleoptera) in a coppice woodland

A continuous sampling of canopy beetles was carried out to determine variations in the abundance, species diversity, richness, and composition of the Mordellidae and Cerambycidae in a coppice woodland. Changes in the abundance and the species richness were monitored at three heights in the forest throughout the season in 1999, using yellow and blue water pan traps. The results showed significant variations in the abundance of Mordellidae among the canopy layers, while little variation was found for Cerambycidae. The abundance, species diversity, and richness were generally greater in summer. The results showed distinct species compositions in both families among layers.     

Delignification of cell walls of <Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis> during alkaline nitrobenzene oxidation

To clarify the behavior of whole lignins in wood cell walls during alkaline nitrobenzene oxidation, the delignification process from cell walls in normal and compression woods of Chamaecyparis obtusa Endl. (Cupressaceae) was observed using ultraviolet and transmission electron microscopies. The lignin content conspicuously decreased to around 10% after 35min in normal wood. The lignin content in compression wood finally leveled off at aroumd 10% after 50min. In gel filtration of oxidation products in ethyl acetate, a high molecular weight fraction was prominent in extracts from the early stage of the reaction. As the oxidation progressed, the high molecular weight fraction became less prominent in both normal and compression wood. Changes in the weights of cell wall residues during reaction indicated that approximately half of the components other than lignin were also removed from the cell walls. This shows that the majority of lignin with relatively high molecular weight is removed from the cell walls together with polysaccharides in the early stage of the reaction and that further oxidative degradation occurs in solution in later stages. Only a small amount of the lignin with low molecular weight could be analyzed by gas chromatography.Parts of this report were presented at the 47th (Kochi, April 1997) and 48th (Shizuoka, April 1998) Annual Meetings of the Japan Wood Research Society, and at the Lignin Symposium, Sapporo, October 1997     

我国楠木属植物资源的地理分布、研究现状和开发利用前景

系统介绍了楠木属植物在我国的地理分布规律以及各省资源的分布状况,概述了楠木属植物资源的研究现状,对楠木属植物资源的研究方向、资源保护、综合开发利用提出建议。     

福建省森林景观类型及地理分布概述

福建省自然地理条件优越 ,生物多样性繁多 ,森林景观类型丰富。本文根据森林景观类型等级系统 ,将福建省森林景观划分为 10个森林景观组和 4 0多个森林景观型 ,概述了各类森林景观的不同特征及其地理分布状况 ,为全省森林旅游区划及合理改造和配置森林景观类型提供理论依据     

Effect of snow cover on the distribution of non-migratory sika deer on the top of Mt. Tanzawa,Japan

On the basis of 268 direct sika deer observations and 212 ratio locations of three individuals, the influence of snow on deer distribution was studied. During the period of snow absence or its shallow cover, the deer did not show any preferences towards slope aspect. However, when the snow coverage became deeper, the deer used westerly exposures (having shallower snow cover) more intensively. Later on, when the snow started to melt on the easterly slope aspects deer mostly used those exposures due to relatively abundant food resources.     

咸宁市红汁乳菇的分布和生态考察报告

经初步考察 ,咸宁市红汁乳菇分布广泛。发生时间为 4月下旬至 1 1月上旬。发生的迟早、发生量及持续时间的长短与海拔、土壤、植被、坡向、气候等因素有关 ,尤其是与发生时期内温度和降雨量的关系最大。     

浙江分布新记录——白花映山红

报道了在浙江温岭大溪镇水坦村岩火尖发现的浙江分布新记录植物：白花映山红（Rhododendron simsii vat．albiflorum），并对其形态特征、生境及伴生植物作了介绍。