浅谈黑龙江黑河森林生态定位观测研究站建设的必要性

黑龙江黑河森林生态定位观测研究站是中国森林生态系统定位观测研究网络(CFERN)中的第91个森林生态站,主要对大小兴安岭过渡区的生物多样性、红松天然分布北界群落特征、火山森林生态系统结构与功能、森林功能对环境质量的影响等进行长期系统的定位观测研究。目的是为揭示过渡区森林生态系统的演替和恢复规律、为量化生态服务功能与生态效益补偿、为森林与人居环境的规划与管理提供理论依据和技术支撑。文章对黑龙江黑河森林生态定位观测研究站建设必要性进行了论述。     

森林群落结构研究进展

结构特征是森林群落的重要特征之一,不同群落中相对固定的结构反映了群落对环境的适应、动态和机能,研究群落结构是了解森林物种基本组成及动态变化的首要条件和重要基础。通过查阅文献对群落结构的研究内容及方法进行了分类归纳,森林群落结构主要包括非空间结构特征和空间结构特征两个基本类型,且点格局分析是空间格局的主要研究方法。查阅文献发现：森林群落结构的研究内容目前多基于物种组成,分析物种的多度、区系、垂直、径级结构、空间格局等,而结合气候、水分、土壤等多因子的综合性研究相对薄弱。同时,森林生态系统定位监测站数量及功能质量的拓展建设也必不可少,这可为后期群落生态学的研究提供可靠的基础保障。     

洋溪自然保护区森林群落主要优势种生态位特征分析

对贵州洋溪自然保护区森林群落的12种主要优势种的生态位进行研究。结果表明,组成洋溪自然保护区森林群落的12个优势种中,7个生态位宽度指数较大,说明它们对环境的适应能力较强且能较好地利用环境资源,是组成洋溪自然保护区森林群落的优势树建群种;枫香、杉木、鹅耳枥等树种在资源利用上有较大的重叠性和相似性;常绿阔叶林的构建种楠木以及大叶桂樱在整个森林群落有较重要的地位,但其生态位宽度和相似比例以及重叠值均不高,表明保护区演替后期的群落较少,建议在保护区的建设与管理中要加强对这些群落的保护。     

通道县万佛山阔叶林植物群落结构特征调查研究

森林是重要的生态资源,而通道县万佛山森林资源丰富,植被完整。调查了万佛山森林生态系统的结构、类型及特性,对境内较典型的森林阔叶林群落进行了研究,并对其群落外貌、层次结构以及组成特征进行了分析和总结,以期提供参考。     

广西饮用水水源保护区桉树群落结构及生态功能

为研究广西饮用水水源保护区桉树群落结构及生态功能,利用2015年广西林地与森林资源"一张图",叠加到广西已建县以上城市集中式饮用水水源保护区范围,提取桉树数据进行研究。结果表明:广西饮用水水源保护区桉树群落结构为完整结构的仅占0.8%,复杂结构占63.4%,简单结构多达35.8%;其森林生态功能等级评价结果为"中等"的占47.4%;"差等"的占52.6%,评价为"好"的没有。森林生态功能等级总体表现为中等偏差,对于以强调水源涵养和水土保持功能的饮用水水源保护区来说,显然不是理想的。     

森林群落垂直层次划分方法

森林是以乔木为主的群落,不同森林群落类型的垂直结构不同.森林群落的垂直结构系森林高度上的层次性,即构成群落的植物个体在垂直空间上的配置方式.这种林冠层的垂直层次,不但能增加森林的自然美感,同时对于群落的很多生态功能和生态过程的进行都有重要的意义.例如,森林的枝叶分层分布,有利于林冠截留更多降水,促进植物对水分和无机养分的吸收利用等.再如,森林的分层为森林动物提供不同的生境.研究表明,森林中的鸟类和昆虫等,其种类多少与群落的垂直层次的复杂性有关,而和树木组成成分的关系相对要弱一些,一般森林的垂直层次越多,动物种类越多.同时,垂直分层还在森林群落内部形成了光、温度等生态因子的异质性分布,从而影响下层灌木、草本及附生苔藓等生物的生长,对群落的生物多样性具有重要的指示意义.因此,对于森林垂直结构的定量描述和变化规律的研究具有重要的理论和现实意义.     

森林植物园的可持续发展

正随着人们对旅游的需求增加,生态旅游作为旅游的一个重要组成,其地位不断提高。森林植物园作为森林旅游的重要组成部分,同时,森林植物园是我们人为规划管理的森林生态群落,是人们作为森林旅游休闲的最佳选择之一,其森林植物园旅游定位是以服务为主的生态休闲观光旅游。因此,在建设与发展旅游的过程中应注意保持植物园生态多样性的特色,丰富和完善植物园作为植物保护的功能,强化生态文明建设。是一种以保护为前提利用森林的多种功能为     

湖南石灰岩石山青冈栎落叶阔叶树混交林的群落分析

青冈栎、落叶阔叶树混交林,是石灰岩地区广泛分布的一种森林群落。通过等级聚类、区系分析、物种多样性测定和种间联结方法,对其群落类型、区系组成、群落生态组织水平等进行研究,结果表明:这种森林群落与它所处的石灰岩生境是相适应的,是属于亚热带湿润气候条件下的一种特殊类型的顶极群落。     

贵州习水自然保护区森林群落主要优势种的生态位研究

对20种主要优势树种的生态位进行研究的结果表明,组成习水自然保护区森林群落的20个优势树种中,18个生态位宽度指数较大,说明它们对环境的适应能力较强且能较好地利用环境资源,是构成习水国家级自然保护区森林群落的优势树种。保护区的生态位重叠普遍较高,但它们之间的竞争为利用性竞争,从而形成保护区较稳定的森林群落。建议保护区根据植物生态位的特点,采用相应的方法促进天然林树种的恢复与发展。     

全面开创森林生态系统定位研究工作新局面

党的十六大把生态建设确定为全面建设小康社会的奋斗目标之一,对林业发展提出了新的更高的要求,《中国可持续发展林业战略研究》确定的“生态建设、生态安全、生态文明”的“三生态”战略思想,为新世纪我国林业发展及生态建设进一步指明了方向。林业要大发展,出奇制胜在科技。林业发展的新形势、新任务给林业科技工作带来了前所未有的发展机遇。森林生态系统定位研究工作,作为林业科技特别是林业基础研究的重要组成部分,同样迎来了千载难逢的历史机遇,进入了加速发展、全面推进的关键时期。森林生态系统定位研究工作的主要成就与问题森林生…     

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.