不同林型天然红松混交林林隙大小和枯叶分解对土壤微生物碳的影响

[目的]分析凉水国家级自然保护区不同林型天然红松混交林林隙大小、凋落物放置位置和采样时间对土壤微生物碳(SMBC)的影响,揭示影响本地区SMBC变化的因素,为天然红松混交林生态系统碳循环的研究提供基础数据。[方法]在天然红松混交林3种林型的大、中、小林隙内不同位置的土壤表层放置装有红松、椴树、枫桦枯叶的分解袋,并以各自的郁闭林分为对照,在2012年植物生长季的6—9月,每月采集枯叶分解袋下0 10 cm土层土样,采用氯仿熏蒸-K2SO4浸提法测定SMBC。[结果]在椴树红松混交林(TP)内,林隙大小对SMBC的影响依次为小林隙大林隙中林隙;在云冷杉红松混交林(PAP)内,依次为中林隙大林隙小林隙;在枫桦红松混交林(BP)内,依次为大林隙中林隙小林隙。3种林型下,采样时间(月份)对SMBC均有显著的影响(P0.05);林隙大小对其影响均不显著(P0.05);枯叶分解袋放置位置对大、中、小林隙内SMBC的影响均不显著(P0.05)。[结论]不同林型下林隙大小对SMBC的影响排列顺序不同;枯叶分解袋放置位置对天然红松混交林3种林型大、中和小林隙内SMBC的影响均未达到显著水平。     

长白山自然保护区阔叶红松林林隙更新状况

该以长白山大面积分布的阔叶红松林林隙为研究对象．系统调查了林隙形成木和林隙填充的特征，并对其主要树种的更新环境进行研究。结果表明，长白山阔叶红松林林隙多数是由1．4株形成木形成的，林隙形成木主要是红松、水曲柳、蒙古栎和紫椴；林隙填充中，紫椴和色木槭的数量最多，红松所占比例较小。不同大小林隙内填充的数量也不同，近似呈一个偏左的正态分布。现有的红松幼树一般都分布在林隙内或林隙边缘，更新环境良好。     

长白落叶松人工林不同林隙间伐对林下更新生长的影响

以黑龙江省佳木斯市孟家岗林场长白落叶松为研究对象,采用3种林隙大小的间伐(5 m×5 m,7 m×7 m,10 m×10 m),在采伐区域用5个树种(柞树、红松、胡桃楸、云杉和水曲柳)进行人工更新,研究更新幼树的成活率、苗高、苗高生长量及地径的生长情况,试验结果表明:不同林隙大小对各更新树种苗木的生长有显著影响,10 m×10 m的林隙间伐更能促进林下更新的生长。     

红松阔叶林主要树种对林隙大小及其发育阶段更新反应规律的研究

本文通过对长白山脉西部蛟河林场３２ｈｍ２原始红松阔叶林中７７个林隙的调查,研究了红松阔叶林中１３个主要乔木树种对林隙大小和发育阶段的更新反应规律。结果表明：树种更新密度随林隙大小的变化呈现出单峰型的反应,除沙松、紫椴和花楷槭在林隙面积为４０～６０ｍ２时更新密度最大外,其它１０个树种的更新密度都在林隙面积为２０～４０ｍ２时最大。树种更新密度对林隙发育阶段有单峰型、双峰型和变化不明显３种反应类型。所有树种在林隙内的更新密度都大于其在非林隙林分下的密度。     

小兴安岭阔叶红松林林分结构与修复

小兴安岭阔叶红松林（Pinus koraiensis）是地带性顶极植被.本文以黑龙江丰林国家级自然保护区阔叶红松林为研究对象,系统分析小兴安岭阔叶红松林林分类型分布的斑块和年龄特征、垂直分布特征,论证郁闭度对红松群落数量、幼林生长群落的影响,阐述不同林分类型对红松天然更新的影响、上层林冠抚育对红松幼树的影响、上层林冠抚育强度对红松生长的影响.结果证明：透光抚育为红松提供了良好的生长空间,上层抚育可显著提高林冠下红松幼树的高生长、地径生长和保存率,提出了小兴安岭阔叶红松林生态修复的策略.     

红松阔叶林生长量初步研究

红松阔叶林是吉林省典型的森林群落,这里主要以红松阔叶林生长量为研究对象,研究红松阔叶林的生长与更新。研究结果表明,红松阔叶林总生长量的大小顺序为中龄林>近熟林>成熟林>过熟林>幼龄林,其中,中龄林生长最旺盛。干扰对红松阔叶林生长存在着一定的影响,同时也影响了红松阔叶林的林下更新。     

林隙透光抚育对红松林结构稳定性的影响

以经历过林隙透光抚育的红松人工林为研究对象,利用树种的存活曲线以及重要值两种方法,对林隙透光抚育红松林的结构及稳定程度进行研究的结果表明,抚育后的林分中的主要树种红松、杨树和白桦的存活曲线均接近直线型,表明各主要树种均处于稳定状态;红松的重要值均明显高于阔叶树种,阔叶树种中白桦与杨树的重要值是最高的,红松的重要值与阔叶树重要值总和相当,表明抚育措施在达到保留与培育目的树种红松的前提下,为群落正向演替提供了良好的环境基础,使群落的树种结构得到优化。     

长白山南部次生林冠下红松人工林空间结构调整研究

以长白山南部地区次生林冠下栽植的红松(Pinus koraiensis)为试验对象,通过对林分树种组成的调查和对开敞度、大小比数、混交度等量化指标的比较,开展了该区次生林冠下红松人工林空间结构调整的研究,结果表明:柞木林和杂木林下红松高生长模型分别为y=1.013 0 x+0.033 5和y=1.042 7 x+0.050 8,R~2分别达到0.990和0.992(P<0.001);通过树高生长模型,确定柞木林下栽植的红松应该在生长第13年末进行第1次上层林木的调整,生长到第17年末进行第2次上层林木的调整;杂木林下红松应该在红松生长第13年末进行林分调整。     

西藏色季拉山冷杉原始林林隙更新研究

通过对西藏色季拉山急尖长苞冷杉原始林林隙更新调查，研究了林隙大小与更新以及林隙形成年龄与更新的关系，对林隙和非林隙林分内幼苗和幼树的高生长进行了比较。结果表明：林隙大小在100m^2左右，最适合于苗高20cm以下的更新幼苗生存，超过100m^2，更新幼苗随着林隙面积的增大而减少；林隙大小在300m^2左右，最适合冷杉幼树和小径木的生存。林隙形成年龄在30a左右，更新幼苗和幼树的数量最多，而小径木数量有限，随着林隙形成年龄的增大，小径木数量逐渐增多，而幼苗和幼树逐渐减少；林隙内幼苗、幼树和小径木的密度均大于非林隙林分；林隙对3年生以下幼苗的高生长影响不大，对4年生以上幼树的高生长有促进作用，特别是对9年生至16年生幼树高生长的促进作用最明显。     

长白山杨桦次生林采伐林隙幼苗更新动态

采用样线调查法,从林隙大小和林隙年龄2个方面研究长白山杨桦次生林经营采伐形成的林隙及其更新特征.结果表明;＜50 m2的林隙占7%,50～100 m2的占21%,100～150 m2的占36%,150～200 m2的占29%,＞200 m2的占7%;林隙一般由7～10株山杨、白桦或山槐被伐后形成;林隙内更新幼苗的种类组成较简单,但分布极不均匀;林隙内更新幼苗的种数、个体密度、叶面积指数、平均高生长和径生长均优于非林隙林分;色木槭、花楸、山槐等适合于在林隙内更新,而水曲柳、山荆等更适合于在郁闭林下更新;随着采伐林隙形成时间的延长,林隙内的凋落物和土壤养分含量不断提高,更新幼苗的种数、个体密度显著增加,生长状况也明显提高,相比于非林隙更新,林隙更新的优势更加突出;由于林隙内的光照、土壤养分和凋落物存在较大的空间异质性,不同位置的更新状况差异也较大,3龄林隙的西缘最好,中心及北部最差,9龄林隙内规律不明显;＜50 m2林隙内的更新状况与非林隙林分相近,＞200 m2林隙内的更新最差,100～150 m2林隙内更新状况最优,不但幼苗个体密度大,而且叶面积指数、平均高生长和径生长也最好,这主要是由不同大小林隙内和非林隙林分光合有效辐射的强度差异较大造成的.100～150 m2是长白山杨桦次生林林隙更新的最适面积.     

云南松林近自然化采伐的改造效果

以云南松林近自然化采伐样地的调查资料为依据,分析了改造措施对云南松群落特征的影响。结果表明,通过近自然化采伐降低了云南松在林冠层的地位和作用而提高了阔叶树在林冠层的地位和作用,并使云南松种群的树干通直度结构得到明显改善,更新层和草本层物种多样性也显著提高。而且,近自然化采伐在经济上具有可行性。     

Multipurpose conversion management of Scots pine towards mixed oak–birch stands—A long-term simulation approach

The forest growth model 4C was used to investigate how conversion management of a Scots pine (Pinus sylvestris L.) stand towards a mixed oak–birch stand would affect stand structural development – and hence biodiversity and productivity – in the long term. For this purpose the 4C model was parameterised for natural regeneration of light demanding species and extended for management of multi-layered stands. A series of structural indicators was selected to describe key factors of forest biodiversity at the stand scale. Two consecutive aspects of Scots pine conversion were tested: (1) the choice of conversion strategy between thinning and gap creation and (2) the choice of conversion regime in terms of cutting cycle, thinning type and pine tree retention. Three simulated conversion strategies aim at the gradual removal of the pine canopy but differ in the spatial organisation of pine cuttings and hence result in different light conditions for regeneration. Only the directed gap creation strategy was able to maintain and increase birch admixture to the stand and to approach natural stand structural development. Simulation of 12 conversion regimes for the directed gap creation strategy indicated that thinning type (from above or from below), pine tree retention at final felling (50% of the standing volume or none) and cutting cycle (6, 9 or 12 years) all significantly influence stand structural development. These effects were clearest for oak development. Birch occurred in a few mixed clusters, but tended to disappear when longer cutting cycles were used. Based on a multi-criteria analysis we conclude that the optimal conversion regime – in which both stand productivity and biodiversity objectives can be combined – implies thinning from above, pine tree retention, and cutting cycles of 6 years. The conceptual validity of the model as well as the applicability of the results are discussed.     

Restoring longleaf pine (Pinus palustris Mill.) in loblolly pine (Pinus taeda L.) stands: Effects of restoration treatments on natural loblolly pine regeneration

Historical land use and management practices in the southeastern United States have resulted in the dominance of loblolly pine (Pinus taeda L.) on many upland sites that historically were occupied by longleaf pine (Pinus palustris Mill.). There is currently much interest in restoring high quality longleaf pine habitats to such areas, but managers may also desire the retention of some existing canopy trees to meet current conservation objectives. However, fast-growing natural loblolly pine regeneration may threaten the success of artificially regenerated longleaf pine seedlings. We evaluated the establishment and growth of natural loblolly pine regeneration following different levels of timber harvest using single-tree selection (Control (uncut, residual basal area ∼16 m²/ha), MedBA (residual basal area of ∼9 m²/ha), LowBA (residual basal area of ∼6 m²/ha), and Clearcut (complete canopy removal)) and to different positions within canopy gaps (approximately 2800 m²) created by patch cutting at two ecologically distinct sites within the longleaf pine range: Fort Benning, GA in the Middle Coastal Plain and Camp Lejeune, NC in the Lower Coastal Plain. The density of loblolly pine seedlings was much higher at Camp Lejeune than at Fort Benning at the end of the first growing season after harvesting. Following two growing seasons, there were no significant effects of canopy density or gap position on the density of loblolly pine seedlings at either site, but loblolly pine seedlings were taller on treatments with greater canopy removal. Prescribed fires applied following the second growing season killed 70.6% of loblolly pine seedlings at Fort Benning and 64.3% of seedlings at Camp Lejeune. Loblolly pine seedlings were generally less than 2 m tall, and completeness of the prescribed burns appeared more important for determining seedling survival than seedling size. Silvicultural treatments that include canopy removal, such as patch cutting or clearcuts, will increase loblolly pine seedling growth and shorten the window of opportunity for control with prescribed fire. Therefore, application of prescribed fire every 2-3 years will be critical for control of loblolly pine regeneration during restoration of longleaf pine in existing loblolly pine stands.     

不同间伐强度对人工阔叶红松林生长的影响

文章针对不同间伐强度对人工阔叶红松林生长的影响进行了调查研究。结果表明:阔叶树胸径生长和蓄积增长率随间伐强度加大而增加,但对树高的影响较小;间伐强度的增大会明显促进红松胸径和树高的生长,但是首次抚育间伐会使当年的树高生长量显著降低,以后随林龄的增加树高生长量会逐渐恢复正常生长;中度间伐措施对阔叶树和红松的生长均比较有利,10a生的阔叶红松林实施上层抚育的适宜间伐强度为45%左右;中度间伐的林分由于资源水平适中(主要是光资源),因而有利于林下植被均匀度和多样性的提高。     

Forest Management and Regeneration Success in Protection Forests near the Timberline in Finnish Lapland

Sustainable forestry is practised in Finnish Lapland north of latitude 69°, i.e. farther north than anywhere else in the world. The Protection Forests Act was passed in 1922 to guarantee the stability of timberline forests in this climatically extreme, unique area. This review, based on earlier studies, covers forest and climate statistics, and legislation, regulations and recommendations of forest management, and the effects of management practices and climatic trends on the results of natural and artificial regeneration of conifer forests, as well as on shifts in the timberline. The review is mainly based on Finnish research, but references from the other Fennoscandian countries have also been used. Temperature plays the main role in forest regeneration success, and the effective temperature sum has been found to express well the location of the Scots pine (Pinus sylvestris L.) timberline. Natural regeneration of pine has been satisfactory, especially when combined with soil preparation. In many cases the pine forests regenerate in the form of advance growth without any silvicultural action. The success of artificial regeneration seems to be associated with favourable, warm periods lasting for at least 20 yrs. The effects of cutting, forest fires, reindeer herding, biotic damage and air pollution on forest regeneration and the conifer timberlines are discussed.     

A succession and silviculture model for the broad-leaved Korean pine forests of Changbai Mountain Area

IntroductionGaPSinforestSwereoftenfomledduetobigtreesfalldown.Regenerationandgrowtl1inthegapsincreasebe-causeofIheAnprovementoflightcondition-Thegapwillbefilledwithnewregeneratedtrees.Wattnamedtl1isforesIdynamicsastheforestgrowtllcycle.SinceD.Bot-kindevelopedthefirstGapmo`Iel(JANOWAnlodel)basedontheforestgrowthcycletheory,dleresearchongapmodelbecameoneofthemostactivedirectio11slilecologybecauseofJANoWAnlodeI'ssuccess.H.Sl1ug-artandhisstUdentSmadegreatc()ntributio11stogapmodeI'sdeve…     

天然林冠下红松被压木极限生长形态学指标的研究

通过研究１００株原始红松林内树高小于１４ｍ的红松解析木，分析了林下红松生长类型，林下红松生长与上层结构因子的关系，林下红松的形态特征及生理特性，结果表明，林下红松生长可划分为恒定型、下降型和上升型。被自然淘汰的林下红松皆属于恒定型和下降型。林下红松的生长受上层林冠结构因子的制约，没有合适的结构条件，林下红松很难存活。研究得出了天然林冠下红松被压木能够上升到上层林冠所需胸径、树高、树冠面积、边材宽、冠长／树高等形态学指标的最低极限值。     

Stone Pine Forests in Siberia

hitt.oductionStOneglnefOrestsinRussiaareco111POsedofthreestonePinespeCesfSiberianstonepine(PinIissibiIjcaDuTour),Koreanshnepine(PinlisKoIxiiensisSieb.EtZucc.),andJapanesestonepine(PinIispumila[Pall.]Ropl).AllthesespeciesoccuPyabout4Omillionhm',SiberianstO…     

Age structure and spatial pattern of old-growth korean pine forest in Xiaoxing’anling Mountain

Spatial pattern of trees, basal stem increment and height were examined in a 5.0 ha mixed deciduous/Pinus koraiensis forest from October in 1984 to May in 1987. Conclusions are as following: 1. Analysis of the age-structure of the korcan pine forest shows that it is different from general steady-state forest type. The lack of saplings and individuals in small-diameter class clearly indicates that regeneration is not continuous. Continuous regeneration depends on thinning of the canopy to form a gap. Similar-aged korcan pine sccdings grow in these gaps. 2. The horizontal structure of the korcan pine is a mosaic of more or less even-aged groups of trees. The mosaic is a result of korcan pine by regeneration strategy. The aggregations of korcan pine of different ages overlaps to form a continuous population generation. As a results, the population is maintained in steady state.     

AGE STRUCTURE AND SPATIAL PATTERN OF OLD-GROWTH KOREAN PINE FOREST IN XIAOXING''''ANLING MOUNTAIN

Spatial pattern of trees,basal stem increment and height were examined in a 5.0 hamixed deciduous/Pinus koraiensis forest from October in 1984 to May in 1987.Conclusions are asfollowing:1:Analysis of the age-structure of the korean pinc forest shows that it is different fromgeneral steady-statc forest typc.The lack of sapings and individuals in small-diameter class clearlyindicates that regeneration is not continuous.Continuous regeneration depends on thinning of thecanopy to form a gap.Similar-aged korean pine seeding grow in these gaps.2.The horizontalstructure of the korean pine is a mosaic more or less even-aged groups of trees.The mosaic is aresult of korean pine by regeneration stratcgy.The aggregations of korean pine of different agesoverlaps to form a continuous population generation.As a results,the population is maintainde instesady state.