长白山自然保护区三个主要林型下土壤微生物生态分布的季节性动态

长白山自然保护区位于长白山北坡。从植被的分布,可把长白山北坡的林型划分为:杜鹃岳桦林、红松云冷杉暗针叶林、杜香落叶松林、灌木阔叶红松林和胡枝子长白赤松林五个主要林型。长白山北坡土壤也有明显的垂直带分布。从山顶到山麓,土壤的垂直分布可划分为:山地苔原土、山地生草森林土、山地棕色针叶林土和山地暗棕色森林土四个主要土壤类型。我们在1982年,对山地棕色针叶林土上生长的杜香落叶松林、山地暗棕色森林土上生长的胡枝子长白赤松林和灌木阔叶红松林。三个主要林型下土壤微生物生态分布的季节性动态变化?进行了调查和分析。     

中国,多样的森林

长白山林海整个长白山生态系统是我国北方最珍贵、特有的生物宝库,自上而下分布着高山苔原带、岳桦林带、针叶林带、红松阔叶混交林带、阔叶林带。其中苔原带属北极圈植被,是     

林海雪峰

围绕着长白山主峰,是一片茫茫的长白山原始林。原始林围着火山呈现出明显的垂直带状分布。画面近处是针叶阔叶混交林带,海拔更高的地方,依次是针叶林带、岳桦林带、高山苔原带。在长白山07号瞭望塔上远眺,原始林如万顷碧浪奔涌而来,而天际处的长白山皑皑雪峰,则如碧海中的仙岛。     

高山苔原

长白山有地球上最南的北极苔原景观。这里的高山苔原带,60种建群种和优势种中有3/4不仅为北极苔原共有,而且在北极苔原也常为建群种和优势种。每年的6月~8月,是长白山高山苔原带最美的季节,从海拔1900米到2500米,各种鲜花从低处到高处依次开放。     

张广才岭南段阔叶红松林天牛科昆虫物种多样性与成虫出现期时间动态

【目的】通过高频次的调查采集,比较不同时间天牛科成虫物种组成的差异,在科学描述各种类天牛成虫活跃期时间动态规律的同时,对天牛成虫活跃期进行精确比较,为害虫的种群监测和生物指示种的利用提供参考。【方法】2012—2013年在张广才岭南段蛟河林业实验区管理局阔叶红松林内,利用拦截诱捕器系统调查天牛科昆虫物种多样性的时间动态,并对11个天牛成虫标本回收时间点进行数量化系统分析。【结果】共采集到天牛科昆虫成虫标本1 252号,隶属7亚科41属64种,其中,稀有种44种,占物种总数的68.75%。该区多次普查未记录到的棍腿纹虎天牛被采集到的频度很高。不同时间天牛科昆虫物种数量和个体数量有显著差异,其成虫高峰期出现在6月下旬至7月中旬,然后逐渐下降,9月上旬物种数和个体数量最低;6月与7月天牛科昆虫的相似性最高,达到中等相似水平。锯天牛亚科(220±10)和瘦天牛亚科(220±10)成虫出现的平均顺序日期显著高于其他亚科;天牛亚科(187±25)、沟胫天牛亚科(187±24)、花天牛亚科(183±25)、锥天牛亚科(177±15)和膜花天牛亚科(175±13)成虫出现的平均顺序日期无显著差异。【结论】在顺序日期170、180和190时,天牛群落羽化或活跃达到高峰,同时,这个时间也是植物开花的盛期,部分具有访花行为的天牛成虫大量出来活动,天牛群落表现出较高物种多样性。本研究天牛科昆虫成虫活跃时间分布格局与Hanks等研究加拿大天牛科昆虫成虫的分布时间相似,但由于两地环境条件以及天牛区系等不同,本研究的高峰时间有所提前。在全部天牛种类中,不同天牛种类成虫活跃期开始时间、活跃期持续时间等均不相同,反映出天牛成虫羽化时间或活跃期的多样性。有13种天牛成虫只在一次调查中被采集到,说明这些种类成虫活跃期相对较短,对环境变化比较敏感。对优势天牛种类成虫活跃的高峰期应该给予更多的关注,尤其对一些具有潜在成灾风险的种类进行种群监测具有重要的价值。     

长白山北坡森林群落交错区优势树种动态

基于28个20mx90m样地的调查数据,利用Lotka-Volterra模型,本文分析了长白山北坡阔叶红松(Pinuskoraiensis)林和云冷杉林(也叫暗针叶林)群落交错区优势树种之间的竞争及动态。结果显示:在自然条件下,群落将向两个方向分化,一是以云杉(PiceajezoensisandP.koraiensis)和冷杉(Abiesnephrolepis)为优势的群落,并在达到平衡时冷杉占绝对优势(相对优势度的77.1%):另一种是以红松或云冷杉和阔叶树占绝对优势的针阔混交林,并在达到平衡时,阔叶树在阔叶红松林中占相对优势度的50%,在云冷杉一阔叶林类型中占66%。同时,本研究说明:(1)阔叶红松林和云冷杉林都是长白山气候顶极群落:(2)交错区具有过渡性质:(3)森林群落的分化结果说明演替的方向受局部生境的影响。图1表3参24。     

长白山的密林里

<正>长白山是中国东北最高峰,是中国与朝鲜两国的界山,有"关东第一山"之称,地处中国境内的白云峰海拔2691米。长白山从山下到山顶垂直分布着阔叶林带、红松阔叶混交林林带、针叶林带、岳桦林带、高山苔原带5个景观带,能在几十公里内领略从温带到极地的自然景观,是野生动物天然的栖息地。动物们倚时而动,在大山中自由迁徙。马鹿、野猪、黑熊等在夏季常迁到高海拔地区避暑,冬天大雪封山,它们又到海拔较低、雪层较浅的红松阔叶混交林吃种子、     

安徽牯牛降北坡种子植物区系特征及其多样性的海拔梯度变化

【目的】分析安徽省牯牛降国家级自然保护区北坡种子植物区以及植物多样性,为该区植物资源保护和利用提供依据。【方法】对牯牛降北坡植被垂直带进行样地调查并划分植物区系,分析不同海拔梯度植物群落的物种多样性。【结果】保护区种子植物丰富,区系起源古老,地理成分复杂;共有种子植物145科687属1 414种(含种下分类单位);科属的优势现象明显,属的组成相对较为分散,寡种属和单种属占总属数的94.32%;植物分布区类型表现出从亚热带到温带过渡的区系特点;牯牛降北坡植被垂直带谱为海拔800 m以下为常绿阔叶林,800~1 100 m为常绿落叶阔叶混交林,1 100~1 300 m为落叶阔叶林,300~1 500 m为针阔叶混交林,海拔1 500 m以上为黄山松针叶林;随海拔升高,植被类型表现为从亚热带常绿阔叶林向暖温带落叶阔叶林过渡;物种丰富度和多样性指数大致表现出沿海拔升高而降低的趋势;受冰川影响,南坡海拔高差大,地势陡峭,土壤层薄,因而在相同海拔条件下,北坡的物种丰富度往往大于南坡。【结论】该保护区北坡具有很高的物种多样性保护价值,物种多样性随海拔升高而下降,最大的物种多样性出现在中海拔地带。对牯牛降保护区北坡进行植被监测时,应以大样地为主要监测方法,以海拔700~1 000 m的落叶阔叶林作为主要监测对象。对北坡科普、旅游区域需进行全面系统的环境承载力和环境影响评估,建立完善生态旅游规划体系,并依照自然景观进行合理布局。     

内蒙古乌兰坝国家级自然保护区天牛调查

内蒙古乌兰坝国家级自然保护区位于大兴安岭南部山地东南坡典型的森林草原交错过渡带,具有森林、灌丛、草原、湿地等多样生态系统。经调查发现,保护区内天牛科(Cerambycidae)昆虫有4亚科17属23种,其中幽天牛亚科(Aseminae)1属1种,花天牛亚科(Lepturinae)5属7种,天牛亚科(Cerambycinae)5属6种,沟胫天牛亚科(Lamiinae)6属9种;赤峰市昆虫分布新记录种13种。区系分析表明,保护区天牛科昆虫以古北界种类占绝对优势,仅分布于古北界的种类有15种;古北界和东洋界分布的共有种为7种;古北界和澳洲界分布的共有种有1种。以幼虫危害乔木树种的17种天牛中,仅危害针叶树的5种,仅危害阔叶乔木11种,既危害针叶树、又危害阔叶树的1种。     

陕西秦岭西段繁殖鸟类多样性研究

陕西秦岭西段包括南坡的凤县，留坝县，勉县和略阳县以及北坡的陈仓区，渭滨区和陇县。为了了解秦岭西段南北坡繁殖鸟类的物种多样性，我们于2020-2022年的4-7月采用可变距离样线法进行了调查。共调查到鸟类182种，隶属于15目49科，其中国家级保护鸟类27种。无论是南坡还是北坡，东洋界物种和古北界物种的比例都接近于1∶1。不同生境中，落叶阔叶林带鸟类物种数最多，其次是农耕带，再次是针阔混交林带。而针叶林和草甸带物种数最低。各生境的优势种有很大差异，但是南北坡相似生境的优势种组成也趋于相似。总体上，南北坡鸟类多样性的海拔分布均呈现中峰模式。本研究为秦岭西段鸟类多样性的保护提供了基础数据。     

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.