关于秦岭北坡森林的基带

有些研究者提出,秦岭北坡森林的基带是侧桕林。本文叙述了这里森林的主要类型以及生态分布特点。在此基础上根据古植物的研究资料,结合主要林木的生态特点和演替趋向,论叙了秦岭北坡森林的基带。文中指出,秦岭北麓的地带性森林是栎林,侧桕林只是作为森林恢复演替过程中的先锋乔木阶段而出现。     

黄土高原子午岭森林群落演替与结构特征演化

森林群落演替机制的研究对于加速黄土高原地区的生态环境建设,特别是人工植被建设具有重要的理论意义。采用时空互代的方法研究了黄土高原子午岭林区不同演替阶段3种演替森林群落山杨(Populus davidiana)林、油松(Pinus tabulaeformis)林与辽东栎(Quercus liaotungensis)林的群落结构特征,结果表明,(1)子午岭林区群落自然进展演替过程中,群落物种丰富度、植物多样性以及个体密度均呈降低趋势。该区森林群落以地面芽植物占绝对优势,而高位芽植物比例较低。各演替阶段群落的空间成层现象明显,并发育有一定数量的层间植物。群落各层主要优势种的水平分布均表现为均匀连续分布状态,而多数非优势种则为零星分布特征。(3)茶条械在该地区具有较宽的生态位,建议作为人工造林树种考虑。     

长白山典型林区森林资源利用适宜性分析

天然林保护不是简单的禁伐,东北林区作为天然林保护的限伐林区,目前仍有一定数量的成过熟林采伐任务,如何科学合理地选择伐区非常重要．鉴于传统森林资源采伐利用操作中存在顾此失彼的问题,现代科学的森林资源经营理论认为,森林资源利用要坚持可持续利用原则,并且要更多考虑森林资源的生态效益,遥感(RS)数据及地理信息系统(GIS)技术,通过提供空间选择技术支撑,可以准确定位符合采伐标准的森林资源地理位置,并确定其面积、森林类型等信息,从而促进森林资源的科学合理利用．本文综合考虑各方面要素,以长白山典型林区露水河林业局为例,以最大程度发挥森林生态系统的生态功能为原则,进行了森林资源利用状况评价,对研究区森林资源未来利用的空间选择以及采伐利用方式进行了探讨,以期为将来制订科学的森林经营策略提供依据。     

次生演替的主要类型及其在生产实际中的应用

次生演替在植物群落演替中居于十分重要的地位，次生演替主要有采伐演替，火烧演替，放牧演替和撩荒地演替等类型，不同类型的次生演替有其特殊的演替规律，掌握和利用这些规律，有利于合理地开发和利用森林，草地以及土壤资源。     

浙江海岛常绿阔叶林特征及其主要植物区系分析

我国东海的浙江沿海分布有星罗棋布的岛屿,其中较大的岛屿上分布有地带性的常绿阔叶林（如：樟木林、青冈林、石栎林和特殊的亮叶猴耳环林或以落叶成分占优的其他森林）,他们是标志性的植被类型或演替阶段,我们对这些植被类型中的优势植物种类进行了区系研究。结果显示,浙江海岛常绿阔叶林或类似森林中的优势和常见维管植物共有139种,只有热带亚洲成分、东亚成分中的中国-日本成分和中国特有成分贯穿于乔木层、灌木层、草本层和层外植物4大类中;进一步对15个木本中国特有种分析表明,其区系成分属亚热带性质,真正的温带性质不显著。在海岛这些植被出现的地段,还存在一些原生植被破坏后不同演替阶段的次生落叶阔叶林,其类型和面积都超过了地带性的常绿阔叶林,说明海岛除个别岛屿外曾经历了完全的破坏。目前,浙江海岛相应的演替阶段还不明确,它是研究特殊生境次生演替和恢复生态学的重要场所,这些常绿阔叶林和落叶林中富含重要的中国-日本海滨森林种类,对研究我国不同层次的常绿阔叶林具有重要的保护生物学意义。     

浙江海岛常绿阔叶林特征及其主要植物区系分析

我国东海的浙江沿海分布有星罗棋布的岛屿,其中较大的岛屿上分布有地带性的常绿阔叶林(如:樟木林、青冈林、石栎林和特殊的亮叶猴耳环林或以落叶成分占优的其他森林),他们是标志性的植被类型或演替阶段,我们对这些植被类型中的优势植物种类进行了区系研究。结果显示,浙江海岛常绿阔叶林或类似森林中的优势和常见维管植物共有139种,只有热带亚洲成分、东亚成分中的中国-日本成分和中国特有成分贯穿于乔木层、灌木层、草本层和层外植物4大类中;进一步对15个木本中国特有种分析表明,其区系成分属亚热带性质,真正的温带性质不显著。在海岛这些植被出现的地段,还存在一些原生植被破坏后不同演替阶段的次生落叶阔叶林,其类型和面积都超过了地带性的常绿阔叶林,说明海岛除个别岛屿外曾经历了完全的破坏。目前,浙江海岛相应的演替阶段还不明确,它是研究特殊生境次生演替和恢复生态学的重要场所,这些常绿阔叶林和落叶林中富含重要的中国-日本海滨森林种类,对研究我国不同层次的常绿阔叶林具有重要的保护生物学意义。     

长白山森林不同演替阶段采伐林隙土壤种子库特征

对长白山地区不同恢复演替阶段的杨桦次生林、次生阔叶林和阔叶红松林采伐林隙内的土壤种子库进行了研究.结果表明：次生阔叶林林隙内土壤种子库的种子密度最大,为652粒·m^-2.随着森林群落的演替,土壤种子库的多样性指数和均匀度指数逐渐增大,而优势度指数则逐渐降低;红松、臭松和色木槭等顶极种的种子密度逐渐增大,山槐、水曲柳等树种的种子密度逐步降低;种子库的物种组成同更新幼苗的相似性越来越高,相异性则越来越低.在3种林型中,非林隙林分土壤种子库的种子密度,以及同幼苗的相似性均与林隙内种子库相同.说明土壤种子库为群落的恢复演替提供了丰富的种源基础,且随着恢复演替的进行,对地表植被更新的影响越来越强.     

山东茶山高等植物资源及群落结构

目的:为有效保护和合理利用山东茶山国家级生态示范区植物资源提供科学依据.方法:对茶山进行了植物物种综合普查,调查范围涉及植物物种及野外分布、群落结构和区系组成.结果:记录到高等植物352种,隶属90科250属,其中国家二级重点保护植物4种.本区地带性植被为黑松人工林及次生杂木林,主要森林植被为黑松群落Pinus thunbergii community.其植物区系以热带分布类型和温带分布类型为主,纬度因素和"岛屿效应"应是形成该格局的主要成因.受强烈人为活动干扰,该区域原生植被类型已遭严重破坏,珍稀植物灭绝风险很高.结论:调查表明该区域群落结构简单,灌木层和层间结构不发达,群落演替时间短.     

峨眉山冷杉森林群落研究

依据 5 1个 40 0 m2乔木层和 1 0 2个 1 6m2灌木层、草本层与地被层样方调查资料 ,分析了峨嵋山冷杉森林的林型、环境、植物地理成分、群落结构和乔、灌层植被数量特征。结果表明 :当地冷杉森林分布区内生境多样 ;植物区系复杂 ,有一定的热性地理成分入侵和残遗性 ;各层次水平盖度具有精巧的消长关系 ,垂直结构在亚层水平上的发育与海拔和“混交”程度有关 ;冷杉在乔木层占绝对优势 ,但由于其种群衰退 ,冷杉所构成的森林有退化演替的趋势 ;灌木层的优势植物以竹类为主 ,亚优势种的变化多样。生物地史、生境和植物区系的种种特点 ,共同决定了当地冷杉林型的多样性及其某些少见的种群组合式样。     

综合构成指数在森林生态系统健康评估中的应用

首次提出综合构成指数(IntegratedComposeIndex,ICI)模型ICI=ln∑B×∑IV×CAV。通过选取目前长白山阔叶红松林生态系统区主要林分类型(原始阔叶红松林,不同干扰模式造成的择伐林、次生白桦林和人工落叶松林等)共29块样地进行群落结构和生物量调查,以原始阔叶红松林作为健康基准,定量评估了各受损生态系统的健康现状及恢复趋势。结果表明综合构成指数是一种易操作的能定量描述受干扰系统健康差距的度量方法。利用分层[主林层(H≥18m)、亚主林层(18m>H≥10m)、演替层(10m>H≥2.5m)和更新层(H<2.5m)]的综合构成指数值可定量不同干扰模式造成的受损系统与健康基准之间的健康差距。健康基准是12.77,与之差距越大,表明受干扰破坏越大,系统健康程度越低。29块样地分为8个类型,6个受干扰类型依距离原始健康基准的远近排序为:结构转换型0.64<结构破坏型0.75<结构保留型0.85<严重干扰类型1.95<白桦林系列2.07<人工落叶松系列2.89。综合构成指数的上层(主林层和亚主林层)指数能表示群落结构现状和目前处于演替阶段的位置;下层(演替层和更新层)指数能表示群落向健康基准类型恢复的潜力,值越大,潜力越大。上下两层综合能说明群落受到干扰的强度和后果。上下两层差值D对于阔叶红松林生态系统来说,健康基准类型D位于0.28～0.35之间,如00.35说明群落主林层和亚主林层的阔叶树种受到干扰破坏,且红松更新困难或还没大量更新。D≤0说明群落遭受很大强度的干扰,如70%以上的生物存量被破坏取走,或直接导致裸地重新发育演替的白桦林、营造人工落叶松林等情况,差值D越大,红松的侵入程度越高,红松更新状况良好,该群落向顶级恢复的趋势良好。     

杉木人工林种子雨组成和季节动态

杉木人工林已成为亚热带森林的重要组成部分,它具有可持续的自然更新能力,是决定杉木林群落演替方向和维持杉木林大面积存在的基础.本文以杉阔混交林和杉木纯林为研究对象,分析其种子雨的物种组成、数量大小和季节动态,以及林分优势物种种子雨数量特征和季节变化,揭示种源条件是否是制约杉木人工林天然更新的主要因素.结果表明:杉阔混交林和杉木纯林分别收集到13科18属21种和12科16属19种的种子.混交林和纯林的所有物种种子雨强度分别为3797和3300粒·m^-2.乔木物种种子数量在种子雨中占绝对优势,混交林占89.1%,纯林占86.2%,其中杉木种子数量最多,其完整种子雨强度分别为825和345粒·m^-2.两林分种子雨各类型种子所占比例均为完整种子>干瘪或腐烂种子>被取食种子.两林分种子雨均具有明显的季节动态,均在秋季到达高峰,且在落种高峰期种子雨以完整种子为主.无论是杉阔混交林还是杉木纯林都有充足的种源,种源(种子雨)条件不是制约杉木林天然更新的主要因素.     

川西亚高山天然林岷江冷杉的更新结构与数量动态

岷江冷杉(Abies fargesii var.faxoniana)的天然更新是川西亚高山地区天然次生林生态恢复的关键。为揭示川西亚高山4种典型天然林林型(杜鹃-岷江冷杉林、箭竹-岷江冷杉林、红桦-岷江冷杉林和红桦林)中岷江冷杉的更新结构和其幼龄植株的生存过程,基于4块1 hm²样地的调查,通过单因素方差分析和多重比较对比不同林型中岷江冷杉的更新结构和更新质量;通过对数回归建立了岷江冷杉幼龄植株高度与年龄间的关系;通过建立幼龄植株的静态生命表、绘制存活曲线和计算数量动态指数分析其生存特征和存活瓶颈期。结果表明：4种林型中岷江冷杉的更新质量和幼龄植株存活状态依次为杜鹃-岷江冷杉林>红桦林>红桦-岷江冷杉林>箭竹-岷江冷杉林。各林型中岷江冷杉幼龄植株的死亡率与相邻龄级间的个体数量动态(V_n指数)随龄级增加的波动大。综合死亡率与V_n指数的龄级差异,杜鹃-岷江冷杉林和箭竹-岷江冷杉林中幼龄植株存活的年龄瓶颈期分别为第21—25年(树高0.66—1.04 m)和第11—15年(树高0.46—0.73 m);红桦-...     

Macrocharcoal-Based Chronosequences Reveal Shifting Dominance of Conifer Boreal Forests Under Changing Fire Regime

Balsam fir (Abies balsamea) and black spruce (Picea mariana) forests are the main conifer forest types in the North American boreal zone. The coexistence of the two species as well as their respective canopy dominance in distinct stands raises questions about the long-term evolution from one forest type to the other in relation to environmental factors including climate and stand disturbance. We tested the hypothesis that repetitive fire events promote the succession of balsam fir forest to black spruce forest and vice versa. Postfire chronosequences of one black spruce (BSP) and one balsam fir (BFI) sites were reconstructed based on the botanical composition and ¹⁴C-dated soil macrocharcoals. The results support the hypothesis of a successional dynamics. The BSP site has been affected by fires for the last 7600 years, whereas the BFI site, after having been impacted by several fires during the first half of the Holocene, evolved in a fire-free environment for the last 4400 years. Periods of fire activity facilitated the dominance of black spruce forests. The cessation of fires around 4400 cal. years BP on BFI site marks the beginning of the transition from black spruce to balsam fir stands. This succession is a long process, due to the ability of black spruce to regenerate by layering in the absence of fire. The resulting balsam fir stands are ancient and precarious ecosystems, since fire generally leads to the return of black spruce. The increase in balsam fir to the detriment of black spruce in boreal forests is a response to a decrease in fire frequency.     

Gruppo VI: Bloenergetlca e Fotosintesi

Abstract

Understanding forest stand structural change is crucial for forest ecosystem research and management. The aim of our research was to identify structural and compositional changes and possible natural and anthropogenic causes of these changes in an old‐growth silver fir‐beech forest in the Dinaric mountains of Slovenia. Data on stand structure of the Rajhenavski Rog (51.14 ha) forest reserve originated from traditional methods, including five successive full callipering (1957–2007), two regeneration inventories and analysis of developmental phases (1984, 2007). A drastic decrease in the silver fir proportion in the last 50 years was probably caused by two indirect anthropogenic factors: polluted air and heavy browsing damage of silver fir regeneration. Nevertheless, other factors including reciprocal replacement of fir and beech and climate change also influenced the species composition, as similar processes were documented in the past with less air pollution. Furthermore, the alternation of fir and beech often developed asynchronously, regardless of ungulate density. Although the vertical profile of the old‐growth forest was opened due to the loss of fir trees during past decades, the establishment of more light‐demanding species was uncommon, primarily because the growing stock and forest climate were sustained. The results suggest a high stability of mixed Dinaric old‐growth forest ecosystems.     

森林土壤种子库与天然更新

论述了森林土壤种子库的特点：（1）森林土壤种子库密度小于耕作土壤和草地,并且受森林类型和年龄的影响,变化幅度很大;（2）森林土壤种库的种类组成在森林的不同演替阶段,受其地上植被影响的程度不同;（3）森林土壤种子库的动态变化是周期化因数和随机性因数的结合,并从土壤种子库的时间动态和空间分布角度,分析了土壤种子库对天然更新的影响,森林土壤种子库是天然更新的物质基础,种子库的结构和功能影响天然更新能力的方向,因此能影响土壤种子库格局变化的各种因子或措施,均能显著地促进或妨碍森林的天然更新,根据森林土训种子库的时空格局特点及影响更新的障碍因子,可以采用人工的辅助措施促进更新,同时,对于森林土壤种子库的研究应着眼于应用干扰生态学的基本理论,以退化生态系统的重建和群落交错区的演替为主要内容,研究方法应以长期定位观测为宜。     

Changes in the ecological diversity of the forest population of ground beetles (Coleoptera,Carabidae) after deforestation and during the initial period of reforestation

The ecological structure of ground beetles was studied. Its dynamics during the migration of ground beetles from one habitat to another as a result of severe ecological disturbances caused by tree felling and subsequent reforestation was considered. Some regularities in the formation and development of a ground beetle community in the early stage of secondary succession at the felling site were determined. Further trends were revealed using the simplest indices of diversity, species, abundance, distribution, and dominance of species. The species richness of ground beetles at the site one year after felling increased from 28 to 41 species. It decreased to 36 species in four years. According to the ecological preference, the basis of the complex of ground beetles at the forest site before felling was formed by spring-breeding species. Four years after felling, the proportion of forest species decreased (from 73.4 to 65.7%) and the significance of forestmarsh and meadow-field species increased. The proportion of summer- and autumn-breeding species also increased. The species and quantitative composition of ground beetles at the site during the first year after felling was mostly determined by neighboring forests. As reforestation proceeded, a separate biocenosis developed at the felling site and the influence of the forests became lower. The proportion of summer- and autumnbreeding species increased. The species and quantitative composition of ground beetles at the felling site was mostly determined by the neighboring forest during the first year. A separate biocenosis developed at the felling site in the following years, and the influence exercised by the forest diminished.     

Lake Ladoga Region: human impacts and recent environmental changes

This paper presents a landscape-ecological analysis of Ladoga Region, a 30 000 km² territory around Lake Ladoga, which is the largest lake in Europe. The Region includes the contact zone between the crystalline bedrock of Baltic Shield and the sedimentary rocks of the East European plain, and the transition from Boreonemoral to Southern Boreal (Taiga) forest vegetation; it is characterized by abundance of lakes. The Region is divided into 17 discrete landscape areas that are classified in 6 groups.The author uses the landscape-dynamcal approach to the analysis of recent (from 2–3 to 40–50 yr) environmental changes in the region, caused by human activities: forest felling, fires, peat excavation, agriculture, recreational development etc. The following processes are observed: vegetation successions after clearcutting and selective logging; effects of forest fires on the spreading and conservation of pine forests; consequences of peatland drainage; landscape effects of collective farming and gardening; forest succession from pine and deciduous tree dominance towards spruce dominance (observable in all landscape regions); natural vegetation succession on former Finnish arable lands (two types of scenarios: forest succession or development of sedge meadows).     

北京地区油松人工林不同演替类型空间结构对林下植被及土壤的影响

以北京地区油松(Pinus tabuliformis)人工林不同演替类型林分为研究对象,研究油松纯林、油松-栓皮栎(Quercus variabilis)混交林和栓皮栎纯林三种不同演替类型林分的空间结构、林下植被和土壤水分的变化规律及其相互作用关系。结果表明：(1)林分水平及垂直空间结构、草本层物种多样性、更新幼树生长、土壤持水和透气性能等指标在三种不同演替类型林分间差异显著(P<0.05),林分空间结构参数中的角尺度、林层指数和开敞度显著影响了各类型林分的灌草多样性,混交度、林层指数和大小比数显著影响了更新幼树的生长,混交度和林层指数显著影响了土壤水分的变化(P<0.05)。(2)松栎混交林灌草生物量、天然更新幼树的生长以及土壤水分物理状况均好于纯林,并主要受林分混交度和林层指数的共同作用。(3)各演替类型林分内均存在栓皮栎更新幼树,混交林栓皮栎更新幼树数量最多、长势最好,对林地资源的竞争最为激烈。因此,可以通过调整林分空间结构实现种间关系及林地资源的调控,以充分发挥森林生态系统的各项功能与价值。     

气候变化对森林演替的影响

森林演替是森林生态动力源驱动下森林再生的生态学过程,自20世纪初建立群落演替理论以来,演替研究成为生态学研究中的热点．客观准确地认识森林演替规律,研究森林演替动力学机理及其模型,是科学管理森林生态系统的需要;对于天然林保护工程与森林植被的恢复重建,具有重要的理论与实际意义．干扰是森林循环的驱动力,导致森林生态系统时空异质性,是更新格局和生态学过程的主要影响因素．它可改变资源的有效性,干扰导致的林隙是森林循环的起点．回顾了目前演替研究的几种方法,即马尔科夫模型、林窗模型(GAP)、陆地生物圈模型(BIOME)和非线性演替模式．介绍了气候变化对森林演替的影响;并在已有成果的基础上,提出了目前研究存在的问题及未来的发展方向．     

Direction of regeneration waves in grid-based models for forest dynamics

Progressing waves of regeneration are observed in forest ecosystems such as Shimagare fir forests. The patterns generated by lattice models for forest dynamics often show similar waves of disturbance and recovery. This paper introduces a method to detect and quantify the directional movement of these waves. The method is based only on the disturbance times of the sites and allows to distinguish three types of wave patterns: patterns with global direction, patterns with local direction, and patterns without direction. We apply this to several grid-based models for forest dynamics which are evaluated analytically or by simulation. The results reveal a clear distinction of the models which earlier studies were not able to detect.