海珠国家湿地公园禾本科植物资源及其应用价值研究

对海珠国家湿地公园禾本科植物资源进行了野外实地调查,共记录到禾本科植物32属57种。属的分布类型以泛热带分布为主。生活型以多年生草本植物为主,占种数的50.88%。海珠国家湿地公园禾本科植物资源应用价值主要体现在药用、饲用、观赏、环保、维护生物多样性等方面。最后,对禾本科植物的管理和利用提出了有关建议。     

广西大新黑水河国家湿地公园维管植物多样性及区系特征分析

广西大新黑水河国家湿地公园为典型的桂西南石灰岩地貌河流湿地，生态系统完整，生境特殊。为给其资源保护提供参考，以2017—2018年黑水河湿地公园本底和监测调查数据为基础，分析黑水河湿地公园维管植物多样性、湿地植物群落种类和野生种子植物区系。结果表明，公园内维管植物物种丰富，有122科375属492种；其中，野生维管植物有119科365属477种，野生湿地维管植物有43科83属101种。野生种子植物以少种科和单种科为主，占野生种子植物总科数的72.17%；以单种属为主，占野生种子植物总属数的78.98%。湿生植物群落和水生植物群落面积占湿地植被总面积的比例分别为67.37%和32.63%，以湿生植物群落为主。野生种子植物区系科、属的R/T值分别为4.45和4.24，植物区系热带成分及特征明显。     

四川阿坝多美林卡国家湿地公园鸟类多样性研究

多美林卡国家湿地公园位于四川、青海和甘肃三省交界处,为永久性河流湿地公园。为系统掌握多美林卡湿地公园的鸟类资源情况,2017年至2019年,采用样线法与样点法对湿地公园进行9次调查,共记录到鸟类176种,隶属于17目44科116属。湿地公园以留鸟（90种）和夏候鸟（43种）为主,共计133种,占公园鸟类种数的75.57%;古北界鸟类占优势,共计111种,占公园种数的63.07%。湿地公园有各级保护鸟类44种,其中国家Ⅰ级11种,国家Ⅱ级重点保护鸟类25种,四川省重点保护鸟类8种。利用G-F指数对湿地公园鸟类多样性进行评估,结果显示,湿地公园鸟类在科属水平上具有较高的物种多样性。此外,湿地公园内不同生境鸟类物种多样性和群落构成表现出较大差异性,但也存在一定的相似性。本研究为多美林卡国家湿地公园鸟类保护和后期管理工作提供了一定科学依据。     

云南外来入侵植物研究

在查阅资料及多年实地观察的基础上,首次系统地对云南的外来入侵植物进行了研究。明确了云南现有的外来入侵植物计有129种,经对这些植物进行种类、来源、性状的构成以及危害程度的统计分析。结果表明,云南的外来入侵植物有39科,86属。含5种以上的有8科,来源于南美热带的种类最多,达63种,占云南外来入侵植物种数的49%;草本植物97种,占云南外来入侵植物种数的75%。依据这些外来入侵植物在云南的分布情况和在其分布地的优势度并予赋值,以此划分它们的危害等级。具Ⅰ级危害程度的有6种,Ⅱ级危害程度的有34种,Ⅲ级危害程度的有89种。据此得出云南外来入侵植物的种类数量居全国之首,已成为我国外来入侵植物最严重区域的结论。应引起相关部门的高度重视,采取有力措施,防止危害进一步加剧。     

湖南水府庙国家湿地公园植物多样性研究

为探究湖南水府庙国家湿地公园的植物组成种类及其生物多样性,在4种典型植被类型中设置乔木、灌木、草本样方220个,调查获取研究区的植物种类,并运用植物多样性分析方法,分析研究区内植物物种间的生物多样性关系。得出以下结论：湖南水府庙国家湿地公园植物共有95科260属450种,其中蕨类植物4科4属5种,苔藓植物2科2属3种,裸子植物4科6属7种,被子植物85科248属435种;典型植被类型中,常绿阔叶林的生物多样性相对丰富且分布均匀;乔木-灌木-草本三个层次中,草本植物的物种相对较多,且数量较大,生物多样性较高;灌丛和水生植被存在外来物种入侵现象,外来物种入侵对湖南水府庙国家湿地公园的生物多样性有一定的负面影响。     

杭州西溪湿地维管植物多样性及区系分析

2010-2018年,通过对9个监测点的野外调查和复查,对杭州西溪国家湿地公园(西溪湿地)的野生维管植物的生活型、珍稀濒危植物和外来入侵植物及植物区系情况进行了研究。结果表明,西溪湿地分布野生维管植物有94科270属424种;共记录到4种国家二级重点保护野生植物,分别为金荞麦Fagopyrum dibotrys,樟Cinnamomum camphora,野大豆Glycine soja和四角刻叶菱Trapa incisa;外来入侵植物有28种,隶属于13科22属;西溪湿地植物可分为乔木、灌木、藤本、草本4种生活型,以草本植物占优势。对表征科及属的地理分布进行分析,结果表明,温带成分与热带成分之间没有显著差异,体现了热带向温带过渡的特征;植物区系有一定的复杂性和古老性,与日本植物区系关系较密切;分布有中国特有植物1属,为皿果草属Omphalotrigonotis。     

广东罗定金银湖国家湿地公园生物多样性现状及问题分析

2021年11月至2022年10月,采用样方、样线及红外相机拍摄相结合的调查方法,对广东罗定金银湖国家湿地公园生物多样性进行调查。结果显示,湿地公园生物多样性较为丰富,记录到维管植物94科216属313种,兽类5目9科19种,鸟类15目43科125种,爬行类2目16科41种,两栖类1目18科18种,鱼类3目7科18属19种。针对湿地公园面临的人类活动干扰强、外来入侵物种覆盖面积过大,生物多样性受到冲击,候鸟栖息环境亟待改造等问题,提出进一步落实湿地管护责任,加大湿地生物多样性科研监测,掌握生物多样性动态变化,强化外来入侵物种防治,广泛开展宣传教育,提高公众生物多样性保护意识。     

粤东地区外来入侵植物的调查研究

通过实地调查和标本采集,共记录粤东地区外来入侵植物126种,隶属于39科99属。分析了粤东地区外来入侵植物的种类、生活型、来源、生境、危害程度及入侵途径等,并提出了防控建议。     

浙江海宁长水塘省级湿地公园植物区系初步研究

2019年8～10月，采用线路调查和重点普查相结合的方法对浙江海宁长水塘省级湿地公园维管植物进行实地调查，分析了该湿地公园植物的物种组成和区系特征。结果表明，长水塘湿地公园维管植物共83科186属232种，其中，蕨类植物3科3属3种，裸子植物6科8属9种，被子植物74科175属220种。维管植物生活型以草本占绝对优势。珍稀濒危植物6科6属6种，外来入侵植物12科20属23种，主要集中在菊科、苋科和豆科植物。该湿地公园内的野生种子植物分布区系类型多样，在科的层次上有6类型和3变型，以热带分布型为主；在属的层次上有13类型和6变型，表现出由热带属性向温带属性过渡的特性。与邻近湿地植物区系进行比较分析显示，长水塘湿地公园植物区系与地理位置较近的西溪湿地公园关系最为接近，与地理位置较远的云和梯田湿地公园关系最远。     

甘肃民勤石羊河国家湿地公园植物多样性调查分析

为掌握石羊河国家湿地公园内植物本底资源状况,更好地保护区内湿地资源,促进湿地公园健康发展,采取野外调查和室内查阅相关文献鉴定的方法对石羊河国家湿地公园内植物资源进行了调查分析。结果为:(1)调查区内有植物197种,隶属38科123属,其中有国家稀珍濒危植物3种,特有属种1种。双子叶植物是该区内植物群系的主要建群种,分别占总科属种数的68.42%、73.98%、75.13%,丰富度高。(2)区系分析表明,该区系有10个分布类型,其中北温带分布,世界分布,地中海区、西亚至中亚分布,旧世界温带分布,泛热带分布等5个分布区类型所含属数均≥10属,温带分布型占总属数的67.8%,表明该区系植物是典型温带性质。(3)该湿地公园内植被可分为4个植被型组、7个植被型、26个主要群系,为典型的河岸地带湿地植被,具有明显的地带性特征,水分梯度影响明显。     

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.