白石砬子国家级自然保护区观赏树木多样性及经济价值的研究

经过15a的调查研究，首次报道了白石砬子国家级自然保护区共有观赏树木36科、74属、142种。其中国家级珍稀濒危保护树木11种，占保护区观赏树木种数的7．75％。从观赏特性看：观花类、观果类及观叶类最多，分别占观赏树木种数的45．07％，59．15％，33．80％；从园林用途看：园景树类、盆景类、花灌木类最多，分别占观赏树木种数的49．30％，37．83％，33．10％。69．90％的种类属于北温带分布区类型。优势科主要是蔷薇科、忍冬科和械树科等。文中还介绍了观赏树木其它方面的用途。     

石湖省级自然保护区药用植物资源及其多样性研究

经过3a的调查研究，首次报道了石湖省级自然保护区共有药用植物89科、244属、355种，分别占保护区植物资源科、属、种数的91．75％，74．62％，60．27％。其中国家级珍稀濒危保护药用植物13种，占国家珍稀濒危保护药用植物的7．74％，吉林省重点保护药用植物47种，国家第一批保护药材8种，东北道地药材13种。全株和根及根茎类的药用植物最多，分别占39．72％，23．10％，12．39％；清热类和祛风湿类最多，分别占32、39％和15．49％。98．03％的种类分布在海拔700～1000m红松针阔混交林中，42.86％的种类属北温带分布区类型，优势科主要有菊科、蔷薇科、毛茛科、百合科等。文中还提出了保护与开发的具体建议。     

箬寮岘自然保护区药用植物资源及其多样性

经野外调查和资料整理已知箬寮岘自然保护区共有药用植物17科572属991种,分别占保护区植物资源科、属、种数的91．4％、72．9％、56．6％;其中国家级珍稀濒危保护药用植物9种,占国家珍稀濒危保护药用植物的5．36％;全草类和根及根状茎类药用植物较多,分别占38．85％、34．11％;清热类、祛湿类和活血类药用植物较多,分别占41．98％、16．35％、11．00％。温带性属(43．76％)和热带性属(40．10％)所占比例大体相当。优势科主要有豆科、菊科、蔷薇科、唇形科、蓼科。     

广东东源康禾省级自然保护区野生药用植物资源调查

广东东源康禾省级自然保护区有药用植物175科520属801种,种数占保护区维管植物总种数的78.3%,即超过3/4的种类为药用植物,种类非常丰富。其中蕨类植物31科61种,裸子植物3科3属3种,被子植物141科470属737种,双子叶植物比例优势明显。在这些药用植物中,菊科、草本类、全草(全株)类、清热类、平性类、苦味类分别在种类数量、生活型、药用部分、药性、药味中占优势。文章分析了广东东源康禾省级自然保护区野生药用植物资源的特点和用途,并就如何使保护区的药用植物资源更好地得到保护和利用提出了相关建议。     

丹东地区野生乡土观赏植物多样性研究

为合理利用和保护丹东地区野生乡土观赏植物资源,对丹东地区野生乡土观赏植物资源的分布规律、生活型和观赏性进行调查。结果表明:丹东地区野生乡土观赏植物有76科180属290种,其中以双子叶植物为主,共213种,占野生乡土观赏植物总种数的73.4%;多年生草本野生乡土观赏植物144种,占49.7%;观花类野生乡土观赏植物种数最多,为232种,占46%;优势科是百合科、蔷薇科,无绝对优势属,相对优势属是百合属、槭属。     

云龙天池国家级自然保护区野生观赏植物资源调查研究

对云龙天池国家级自然保护区168科477属1 118种维管植物进行观赏性调查分析。结果表明,保护区内共有野生观赏植物94科208属342种,其中木本植物191种,草本植物151种。野生观赏植物中优势科包括杜鹃花科、蔷薇科,龙胆科、兰科和毛茛科。观花、观叶、观果和观姿态这几类植物分别占观赏植物总数的59.36%、22.22%、10.53%和7.89%。在园林应用上包括盆景类、花灌木类、花坛花镜和花丛类,分别占观赏植物总数的20.47%、16.96%、14.62%和12.87%。珍稀野生观赏植物5科7属9种,分别占区内野生珍稀濒危植物的55.56%、63.64%和64.29%。文中对保护区在野生植物资源的保护与利用前景方面进行了探讨。     

南岭国家级自然保护区植物资源调查研究

根据野外调查整理编制了南岭国家级自然保护区植物名录,报道了保护区植物资源状况,保护区共有维管束植物221科、1093属、3539种,其中以被子植物最丰富,共168科970属3157种,分别占总科、属、种的76.02%、88.75%和89.21%;蕨类植物次之,共46科112属363种;裸子植物共7科11属19种;国家保护的珍稀濒危植物共28种。保护区植物资源丰富,按其经济用途将它们分为13类:材用植物198种,药用植物1481种,油脂植物213种,纤维植物111种,淀粉植物172种,杂果植物87种,花卉观赏植物55种,水土保持植物18种,有毒植物53种,绿化观赏植物132种。     

广西木论国家级自然保护区兰科植物资源状况及其特点

对广西木论国家级自然保护区野生兰科植物资源调查资料进行整理分析,结果表明,木论保护区野生兰科植物资源十分丰富,迄今已发现48属122种,属种数分别占广西野生兰科植物107属347种的44．8％和35．2％,为广西兰科植物的主要分布区之一．保护区内兰科植物具有种类多样,生境多样,生活型全面、丰富,区系来源多样等特征．基于木论保护区兰科植物的资源状况、分布特征及保护现状,提出了保护及利用对策．     

内蒙古贺兰山国家级自然保护区饲用植物资源调查

在调查鉴定内蒙古贺兰山国家级自然保护区内的植物标本的基础上,结合查阅有关研究饲用植物资源文献,统计分析了保护区的野生饲用植物资源,结果表明,保护区内分布的野生饲用植物共有370种(含种以下单位),隶属57科188属。其中草本植物占绝对优势,共计302种,占保护区内饲用植物总种数的81.62%;从水分生态型分析,中生植物最多,有199种,占保护区内饲用植物总种数的53.79%。从饲用价值上看优等37种、良等101种、中等121种、低等91种、劣等20种,分别占保护区内饲用植物总种数的10%、27.30%、32.70%、24.59%和5.41%。良等以上饲用植物占该保护区野生饲用植物总种数的37.30%,可以看出该保护区饲用植物价值高,具有很高的开发利用潜力。本文还对该保护区野生饲用植物资源的保护及开发利用提出建议。     

神农架野生观赏植物资源与多样性研究

神农架拥有丰富的野生观赏植物资源,本文在野外实地调查的基础上,结合查阅文献的方法,整理了神农架具有观赏价值的野生植物名录,分析它们的种类组成、科属特征及其生活型和观赏类型多样性.结果表明,神农架观赏种子植物共117科327属800种,其中裸子植物4科11属19种,被子植物113科316属781种.神农架观赏植物中大科和单种科较少,小科较多,含2～20种的科占总科数的77.78％;单种属最多,其次为含2～5种的属,而含5种以上的属较少.从生活型来看,乔木43科95属178种,灌木及小乔木43科91属268种,草本48科115属260种,藤本20科33属78种,水生植物5科9属16种.根据不同的观赏部位来看,观花植物种类最多,484种,占总种数的60.50％.     

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.     

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.