清凉峰自然保护区华南梅花鹿采食研究

华南梅花鹿(Cervus nippon kopschi)属国家一级保护动物.2007年1-12月,采用直接观察采食法、食痕法、试喂法和粪便显微分析法对清凉峰自然保护区华南梅花鹿采食种类和部位进行调查、观察、记录和鉴别.研究表明,华南梅花鹿采食食物共174种,其中草本101种、灌木56种、乔木17种,禾本科、蔷薇科、豆科、百合科、菊科、莎草科、忍冬科、樟科和虎儿草科约占总采食种类的56%.采食部位在草本主要是茎叶和花果,在木本主要是嫩枝叶、芽、枝梢和花果.采食种类和部位随季节的更迭而有较大的变化,冬春季,可采食的种类极少,草本类几乎没有,主要利用灌木的果实和嫩梢,夏秋季,则大量采食草本类,禾本科、豆科、莎草科和菊科植物占比例较大.     

铜－吡啶类络合物模拟漆酶催化漆酚氧化聚合成膜的红外光谱分析

用红外光谱研究了Ｃｕ－ｐｙ、Ｃｕ－ＰＶＰｙ和Ｃｕ－ＱＰＶＰｙ催化漆酚氧化聚合交联过程。漆酚氧化聚合阶段的共同特征是：１．漆酚酿吸收峰１６５２ｃｒｎ￣－１先涨后落；２．共轭双烯吸收峰９８２和９４５ｃｍ￣－１逐渐减弱，而共轭三烯吸收峰９９２ｃｍ￣－１和芳醚吸收峰１２１５ｃｍ￣－１却逐步增强；３．苯环三取代吸收峰８３０、７６５ｃｍ￣－１都有所减弱，苯环四取代吸收峰８７５和８０５ｃｍ￣－１出现；４．苯环骨架吸收峰１６２０、１５９２ｃｍ￣－１之间的界限缩小甚至消失。到了漆膜的实于阶段，漆酚酿吸收峰１６５２ｃｍ￣－１再度兴起，但９９２ｃｍ￣－１吸收峰却由涨转落，其他吸收峰也有变化。以上光谱变化表明这３种催化剂都模拟了漆酶的催化作用。在Ｃｕ－ＰＶＰｙ催化漆酚氧化聚合阶段，发现孤立双键吸收峰３００８ｃｍ￣－１比共轭双烯吸收峰９８２和９４５ｃｍ￣－１消失得更早；并且从反应一开始就出现了１７１５ｃｍ｀－１羰基吸收峰。还比较了Ｃｕ－ＰＶＰｙ与Ｃｕ－ＱＰＶＰｙ催化的异同。     

小叶黄杨播种育苗技术研究

经过多年试验研究，结果表明，小叶黄杨种子具有胚轴休眠特性，小叶黄杨种子含水量低于１２．５％时，种子生命力下降，在辽西地区适宜９月上旬播种，播种量为５０￣７０ｇ／ｍ＾２，覆土厚度１．５ｃｍ，覆草厚度１￣２ｃｍ，冬季要重点保护胚根不受危害，留苗密度７００株／ｍ＾２；小叶黄杨１￣２年生苗木对湿度敏感，在风沙干旱地区越冬必须覆盖防寒。     

南方型杨树新无性系引种试验初报

１９９２年春于浙江临海进行南方型杨树新无性系引种试验２年。结果其平均胸径达９￣１０ｃｍ，，平均树高达８￣９ｍ，单株材积平均为０．０３￣０．０６ｍ＾３，生长量均比对照增加；各试验中树高、胸径和材积的重复率都比较高，且表现出高度的生长性状遗传相关，无性系之间的主要生长性状差异已十分明显，无性系７２５和１３８８已经具有比其它无性系更明显的超亲优势。     

秦岭地区圈养大熊猫对投食竹种的选择研究

大熊猫在长期的历史进化过程中形成了高度特化的以竹类为主要食物的采食习性,高山竹类成为大熊猫一年四季的主要食物。笔者在查阅秦岭地区竹类资源的基础上,开展了圈养大熊猫投食竹选择研究,发现大熊猫对竹种的选择范围较宽。通过差异显著性检验,大熊猫对不同投喂竹种具有选择性,文中进一步运用Forage ratio选择指数分析了大熊猫对不同竹种的取食倾向,即大熊猫对投喂的不同竹种是喜好、回避还是随机选择。     

清凉峰华南梅花鹿冬季食物资源特征研究

于2006年12月至2007年3月,采用食痕法和样方法观测清凉峰华南梅花鹿采食食物的种类、丰富度及生物量。研究表明,可供华南梅花鹿冬季采食的有15种灌木、8种草本和3种乔木,在生境中出现频次由高至低灌木依次为中国绣球、野山楂、绣线菊、拔葜、映山红、小果蔷薇、悬钩子和盐肤木,草本依次为野古草、牛筋草和蕨。灌木占清凉峰华南梅花鹿冬季食物生物量的57%,草本占31%,乔木占12%。在华南梅花鹿种群分布较多的大坪溪、道场坪、千倾塘、螺蛳尖和马啸5个小区,食物丰富度为95.47 g/m2,显著大于无种群分布的大源塘、干坑、小平溪3个小区(食物丰富度为68.52 g/m2)。研究结果表明,灌木不仅是冬季清凉峰华南梅花鹿的主要食物来源,还为梅花鹿提供良好的隐蔽条件。     

异氰酸酯胶在刨花板中的应用

异氰酸酯胶作为刨花板胶粘剂，具有刨花含水率适应范围广（０～２５％），施胶量低、无游离甲醛释放、适合制造轻质刨花板等优点。施胶量为５％、密度为０．４５ｇ／ｃｍ３和０．６１ｇ／ｃｍ￣３的二苯基甲烷二异氰酸酯（ＭＤＩ）小黑杨刨花板的物理力学性能分别达到Ａ类刨花板二等品和优等品的指标要求。密度为０．６５ｇ／ｃｍ￣３时，只要ＭＤＩ施胶量达到３％，刨花板的物理力学性能指标能达到Ａ类刨花板的国家标准要求。试验还表明：ＭＤＩ具有较好的耐水性，但耐湿热性和长期耐水性不如酚醛胶。生产１ｍ￣３刨花板ＭＤＩ与ＰＦ和ＵＦ胶粘剂成本比为２．０５：１．７８：１．００。     

浅谈动物贮食与生态环境的关系

动物贮存食物,以调节食物的时空分布,度过食物缺乏期。贮食行为是一种特化的采食行为。动物贮食包括寻找食物、采集、处理、搬运、放置及掩蔽、保护和找回、食用等环节。动物贮藏食物并不意味着它日后能食用这些食物。作为食物埋藏的动物和植物繁殖体,可能由于霉变、腐烂、萌发、被盗用而丢失。关键问题是如何减少贮藏损失。进化过程中,贮食动物已经发育了种种行为对策以保护贮存的食物,减少储藏损失。     

冷箭竹更新幼龄无性系种群冠层结构的研究

本文研究了卧龙自然保护区冷箭竹更新幼龄无性系种群层结构的数量特征。结果表明：１９８３年开花枯死后自然更新形成的冷箭竹幼龄种群，其冠层结构的龄级变化呈正态分布格局，峰值点位于３￣５龄级，种群冠层结构的各面指标分别为冠层高度１０．００ｃｍ、竹枝数量２１．０２枝／ｍ＾２、竹枝长度６．６０ｃｍ、叶片数量７９９．４０片／ｍ＾２、叶长３．６５ｃｍ和叶宽．５６ｃｍ。不同林分类型的各群冠层结构相异，各项指标的排序     

航空喷洒设备及监测技术的研究 Ⅰ.喷洒设备性能测试

报道新研制的ＨＵ２－ＨＷ１型超低容量喷洒设备与海燕６５０Ｂ飞机配套的技术参数的测试方法和结果。在超音速风洞实验室,用来流风速２７ｍ／ｓ和３３ｍ／ｓ,测试１号雾化头转速依次为７４６０、９３５０ｒ／ｍｉｎ,２号雾化头为８４１０、１１８００ｒ／ｍｉｎ,药液泵压力３．５￣５．０ｋｇ／ｃｍ＾２,流量１５．０￣２１．０Ｌ／ｍｉｎ,有效喷幅４０ｍ,雾滴粒径９５￣１７０μｍ,雾滴密度平均９￣１６滴／ｃｍ＾２,雾滴     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。