现代林学、森林与林业(英文)

文章论述了林学、森林与林业近两个多世纪以来的发展和变化 .林学经历了由传统林学向现代林学的转变 ,现代林学是以森林生态系统的营建、经营管理和利用为研究对象 ,以发挥森林生态系统的生态环境功能为核心 ,全面发挥森林的多种效益和多种功能为目的的学科 .对森林的认识也经历了从认识单株树木、树木群体到森林生态系统的变化 .由于人们对林学及森林认识的变化 ,使人们对林业的认识也从长期形成的以木材利用为中心 ,转变为发挥森林生态系统的生态环境作用为核心和重点 ,全面发挥森林的生态、经济和社会功能作为林业的指导思想和目标 ,以实现林业的可持续发展     

COMPETITION IN OLD GROWTH KOREAN PINE FOREST

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现代林学、森林与林业

论述了林学、森林与林业近两个多世纪以来的发展和变化.林学经历了由传统林学向现代林学的转变.现代林学是以森林生态系统的营建、经营管理和利用为研究对象，以发挥森林生态系统的生态环境功能为核心，全面发挥森林的多种效益和多种功能为目的的学科.对森林的认识也经历了由单株树木到树木群体到森林生态系统的变化.由于对林学及森林认识的深刻变化，人们对林业的认识也就从长期形成的以木材利用为中心，转变到以发挥森林生态系统的生态环境作用为核心和重点，全面发挥森林的生态、经济和社会功能作为林业的指导思想和目标，以实现林业的可持续发展.     

Biomass carbon pools of Cunninghamia lanceolata (Lamb.) Hook. forests in subtropical China: Characteristics and potential

Abstract

Swedish forestry has successfully developed systems for sustained yield production of wood. Silvicultural techniques are today completely dominated (96%) by clear-felling methods. By contrast, Swedish natural forests and preindustrial cultural woodlands were ecologically and culturally diverse, with a substantial proportion having a continuous tree cover as a response to natural disturbance dynamics and preindustrial agricultural land management. If forest management systems do not mimic this diversity of disturbance regimes sufficiently well, the scope of sustainable forest management to include biodiversity and sociocultural values will not be met. This study estimated the past and present amount of one cultural and two natural disturbance regimes known to deliver continuous tree cover in two study areas located around two important biophysical and sociocultural transition zones in northern and southern Sweden, respectively. Several approaches were used to estimate the amount of remaining continuous tree cover forests. The results indicate that 9–10% of the study areas is made up by site types that historically would have held a large proportion of continuous tree cover forests. Estimates for productive site types show that only 1–2% of these sites remain in southern Sweden and 10–20% in northern Sweden. The data indicate that present management in both study areas is similar. Thus, these differences between the regions will disappear in a few decades. To achieve the aim of Swedish forest and environmental policies there is a clear need to develop and use alternative forest management methods on appropriate sites.     

A model bridging distance-dependent and distance-independent tree models to simulate the growth of mixed forests

? It is widely believed that distance-independent tree models fail to take into account the complexity of mixed stands due to the fact that spatial structure often has a greater impact on growth and dynamics in mixed stands than in pure stands. On the other hand, distance-dependent tree models are difficult to use because they require a map of the stand, which is not only very costly but also impracticable in a routine management context.

? This paper reports the development of a model bridging distance-dependent and distanceindependent tree models, and that is designed to simulate the growth of a mixed forest. The model used distributions of the number of neighbours to reconstruct tree neighbourhoods and compute the competition indices needed as inputs to the growth model.

? Data were collected from a mixed forest of sessile oak and Scots pine in central France. The study showed that local competition indices explained a significant proportion of growth variability and that intraspecific competition was greater than interspecific competition. The model based on neighbourhood distributions gave consistent predictions compared to a distance-dependent model.

? This type of model could be used instead of distance-dependent models in management contexts.

     

基于分层的典型中亚热带天然阔叶林林木竞争关系研究

[目的]通过分析不同林层林木之间的竞争情况,以期揭示林木间相互竞争的类型、林木受到的竞争压力与林木垂直分布之间的关系,为森林资源的保护与利用提供科学依据。[方法]在福建万木林自然保护区内设5块典型中亚热带天然阔叶林样地,采用Hegyi的竞争指数,按分层和不分层两种情形研究林木间的竞争强度。[结果]在1—5号样地,当取样半径超过4 m后,林木间的竞争强度随取样半径的增大而减小的趋势变缓,4 m是分析林木竞争的适宜半径;以4 m为半径分析林木间的竞争,发现有一半以上的组成树种只发生种间竞争,剩余同时发生种间和种内竞争的树种,其竞争木构成中数量占优势的普遍是与其相异的树种,且种间竞争强度普遍强于种内竞争;各样地的乔木层都可以划分出由高到低的3个林层,在平均水平,越高层的林木距离竞争木越远、在竞争木的组成中较矮小的第3林层林木数量也越多;越高层的林木,平均每株对象木与其全部竞争木之间的竞争压力越小。[结论]在调查的典型群落中,普遍发生的是种间竞争,而林木受到的竞争压力及其竞争木的组成都与它们的垂直分布关系密切,在森林资源保护和经营中应对垂直分布予以更多的关注;乔木层中的优势树种未发生激烈种间或种内竞争;可以发生激烈种间竞争的乔木树种有米槠、庆元冬青、少叶黄杞和杜英,不存在特定的竞争木与它们竞争,它们与竞争木相近、主要分布在第2或第3林层;种内竞争过于激烈的有山杜英、华杜英、山黄皮、野含笑和羊舌树,也主要分布在第2或第3林层。     

用动态规划方法确定华北落叶松最优轮伐期及最佳林分密度

本文采用Richards函数的修正式拟合林分胸高断面积生长方程,并考虑株数密度对断面积生长的影响;用每公顷胸高断面积和每公顷株数作为状态变量,用森林纯收益作为指标函数,建立了离散确定性动态规划模型,确定了塞罕坝林场华北落叶松人工林的最优轮伐期,并为各地位指数及不同年龄、不同初始状态的林分提供了确定最适经营密度的方法。     

笔架山常绿阔叶林优势种群种内种间竞争的数量研究

Hegyi' s competition index model for individual tree was introduced to study intraspecific and interspecificcompetition for dominant population of evergreen broad-leaved forest in Bijia Mountain of Longyan, Fujian. The resultsshow that the competition is more intense in intraspecies than in interspecies, which indicated indirectly that the horizontalspatial pattern of dominant populations conform to aggregated distribution. There existed difference in interspecific competi-tions, and the competitions can be divided into four groups according to the competition index. Relationship between thecompetition index and the base diameter of objective tree conformed closely to power function, and competition intensity re-duced with the growth in base diameter of objective tree.     

庞泉沟自然保护区优势种种群竞争关系及其动态预测

利用Hegyi单木竞争指数模型对庞泉沟自然保护区优势种群的种内、种间竞争关系进行了定量分析。结果表明:种内和种间竞争强度随着林木径级的增大而逐渐减小,种内竞争较之与其伴生树种间的竞争剧烈。华北落叶松种内、种间竞争强度大小顺序为:种内>云杉>红桦>白桦>关帝柳>花楸>山杨。竞争强度与对象木胸径之间存在显著的幂函数非线性回归关系,回归结果与林分实际相符,从而为庞泉沟自然保护区混交林理论研究和合理经营提供了科学依据。     

海南岛热带天然次生林生长动态研究

本文对两类处于不同演替阶段的天然次生林,从直径生长、胸高断面积生长、材积生长、林木死亡率等方面进行了对比分析。研究结果表明:随着演替的进程,天然次生林直径生长、胸高断面生长和材积生长呈现下降趋势,林木死亡率也呈现明显的下降趋势,其主要原因是,在演替的早期阶段,速生喜光先锋种在林分中占据较高比例,进而林分表现出较高的死亡率和较高的生长力,但是随着演替的进行,喜光先锋速生树种逐步被耐荫的顶级或亚顶级树种所取代,进而表现出低生长和低的死亡率。     

Monitoring managed forest structure at the compartment-level under different silvicultural heritages: An exploratory data analysis in Italy

ABSTRACT

The more and more diffused multifunctional role addressed nowadays to public forests, calls for targeted analysis aimed at highlighting the overall outcome of different practices implemented on the same forest compartment, according to the locally prevailing function. This study was carried out in four Italian beech forests across a latitudinal gradient representative of multiple management history, stand structure, and dominant stand age. We analyze forest structure at the compartment scale before and after silvicultural practices. We aim to explore relationships and similarities between 10 stand attributes (mensurational and structural variables) to identify relevant indicators for the monitoring and management of forest ecosystems. Results indicate changing patterns of correlation and similarity among mensurational variables following practice implementation. A sensitivity gradient to silvicultural practice was finally identified within the four sites investigated as a result of the diverging stand structure. Our approach suggests a way and provides an insight for the design of adaptive forestry management practices required to meet environmental targets, in addition to the already acknowledged supply of primary goods and services.     

Multi-Objective Forest Landscape Projection Modelling-Problems and Prospects

Abstract

To be able to make the right decisions in forestry today, the long-term effect of these decisions has to be considered. Multi-objective forest landscape projection models are tools that can be used to illustrate the effect of different management alternatives in a landscape. An integrated approach facilitates multi-objective considerations and decisions. A number of modelling systems has been developed. A modelling system contains numerous sub-models, each one modelling a particular part of the forest ecosystem, the socio-economy or other aspects of interest. Models and data are intimately connected, and different methods for collecting data and their relevance for different models are examined. The sub-models interact with each other in such a way that the dynamics of a forest is simulated.

This article examines different sub-models for tree growth, economy, biodiversity, forest recreation and soil, and various uses for multi-objective forest landscape projection models are suggested and some examples are presented. Almost every model is associated with variation, uncertainty, and underlying assumptions. Errors in data and models, their origin and propagation through models, are discussed. The future development of forest models and their employment in planning and decision making are considered.     

不同密度油松飞播林灌草多样性与林分空间结构关系

林下植被是森林生态系统的重要组成部分,物种多样性和林分空间结构是评估森林生态系统功能和林分经营质量的关键指标。本文以44年生油松飞播林为研究对象,通过典型样地调查,运用单因素方差分析和相关分析,分析林分密度对油松飞播林灌草多样性和林分空间结构的影响。结果表明:(1)林分密度对灌草多样性指数影响差异显著,灌草多样性指数均在低密度的样地中达到最大值。(2)混交度和密集度受林分密度影响显著,而林分密度对乔木胸径和树高的影响体现在林分水平上,而非空间结构单元中。(3)林分空间结构与灌草多样性之间有密切联系,影响林下植被多样性的最主要因子是乔木层混交度。因此,未来在飞播林经营活动中,调整林分密度的同时,应综合考虑林木分布格局,兼顾灌草多样性保护。     

腾冲县加快推进中低产林改造的必要性与建议

介绍腾冲县中低产林现状,从林业自身发展、提高森林经营水平、扩大森林资源总量、加快树种结构调整、增加林农收入和巩固集体林权制度改革成果、促进林业产业发展等方面论述了加快推进中低产林改造的必要性、提出要提高对中低产林改造的认识,将中低产林改造与林业生态建设、特色经济林产业发展、短轮伐期工业原料林建设、发展林下经济、林木良种生产基地建设、实施科技兴林战略结合起来,建立完善的管理体系和一批高标准的示范样板,多渠道筹措资金等加快中低产林改造的建议.     

Estimation of forest stem volume using multispectral optical satellite and tree height data in combination

Abstract

The accuracy of forest stem volume estimation at stand level was investigated using multispectral optical satellite and tree height data in combination. The stem volumes for the investigated coniferous stands, located in southern Sweden, were in the range of 15–585 m³ ha^?1 with an average stem volume of 266 m³ ha^?1. The results from regression analysis showed a substantial improvement for the combined stem volume estimates compared with using satellite data only. The accuracy in terms of root mean square error (RMSE) was calculated to 11.2% of the average stem volume using SPOT-4 data and tree height data in combination compared with 23.9% using SPOT-4 data only. By replacing SPOT-4 data with Landsat TM data the RMSE was improved from 25.2% to 12.2%. In addition, a sensitivity analysis was performed on the combined stem volume estimates by adding random errors, normally distributed with zero expectations, with standard deviations of 1, 1.5 and 2 m to tree height data. The results showed that the RMSE increased with increasing random tree height error to 15.4%, 18.0% and 19.9% using SPOT-4 data and 16.3%, 19.2% and 21.2% using Landsat TM data. The results imply that multispectral optical satellite data in combination with accurate tree height data could be used for standwise stem volume estimation in forestry applications.     

日本森林资源供求变动趋势和经营管理战略创新

丰富的森林资源促进了第2次世界大战结束后日本经济的恢复和高速发展。此后,林产品市场供求、生产经营和产业政策发生了重大变化。文中分析了日本森林资源和森林经营现状、木材供求和森林功能多样化的趋势,以及林业政策、经营管理和技术创新的动向,以期为理论研究和业务决策提供参考。日本在经济高速增长期过后,木材需求量减少,自给率维持低位。近年来,日本林木进入集中主伐利用期,社会对森林生态环保需求增大,森林经营面临着规模过小、国有林缺乏经营活力、年轻劳动力减少等问题。日本森林经营管理创新的重点包括提高科技贡献率、改革林业特别是国有林的生产经营体制、提升森林在生态与环境和经济减贫等多方面价值。目前,上述创新已经效果初现,也是今后日本林业改革发展的主要方向。     

Developing an airborne laser scanning dominant height model from a countrywide scanning survey and national forest inventory data

Abstract

An airborne laser scanning (ALS) dominant height model was developed based on data from a national scanning survey with the aim of developing a digital terrain model (DTM) for Denmark. Data obtained in the ongoing Danish national forest inventory (NFI) were used as reference data. The data comprised a total of 2072 measurements of dominant height on NFI sample plots inventoried in 2006–2007 and their corresponding ALS data. The dominant height model included four variables derived from the ALS point cloud distribution. The variables were related to canopy height, canopy density and species composition on individual plots. The RMSE of the final model was 2.25 m and the model explained 93.9% of the variation (R ²). The model was successful in predicting dominant height across a wide range of forest tree species, stand heights, stand densities, canopy cover and growing conditions. The study demonstrated how low-density ALS data obtained in a survey not specifically aimed at forest applications may be used for obtaining biophysical forest properties such as dominant height, thereby reducing the overall forest inventory costs.     

系统收获表研究的概念和功能(英文)

传统收获表是指某一树种在特定地区和管理体系下，以立地条件和年龄为变量描述林分平均生长过程的数表．林分密度管理图是根据林分密度效果编制的可预测林分平均收获的图．通过与传统收获表和林分密度管理图的概观比较和探讨，该文系统地阐述了系统收获表的概念和功能．系统收获表的基本特点是为预测现实林分在不同立地条件和管理体系下生长过程的计算机程序．因此，系统收获表能描述在多维变量（如年龄、立地条件、林分密度、胸径和树高）条件下的现实林分和单木的无数生长过程     

马尾松闽粤栲混交林生长与竞争效应

对10年生马尾松闽粤栲6∶1混交林的生长状况和竞争态势进行了分析研究。研究结果表明:闽粤栲与马尾松混交林分生长较好,闽粤栲是马尾松的优良的混交树种。混交林中马尾松比纯林中马尾松的平均树高和平均胸分别增加12.8%和6.1%。混交林中马尾松生长量有着越靠近闽粤栲列中心,生长量越高。运用Hegyi单木竞争指数模型分析混交林种内、种间竞争。结果表明:两种群间存在较剧烈竞争,种间竞争大于闽粤栲种内竞争。     

Extending a physiological forest growth model by an observation-based tree competition module improves spatial representation of diameter growth

One of the pivotal objectives in forestry research is to estimate the response of silvicultural target variables to climate change scenarios at high temporal resolution in order to consider within-year feedbacks between growth and environmental conditions. To meet this challenge, models are needed which support and complement the widely used observation-based decision systems in forest management and consulting. Physiological models in particular provide the fundamental prerequisites to reflect the impact of various simultaneously changing environmental conditions. However, a physiological representation at the individual tree level is computationally very expensive and sensitive to uncertain initializations. We thus propose an approach that combines a modern representative of the physiological cohort model type, MoBiLE-PSIM, with the individual tree competition concept of a distance-dependent empirical growth simulator (SILVA). The resulting hybrid provides a key feature for the consideration of forest management in long-term simulations at high computational efficiency. The extended model was evaluated with growth-diameter distributions obtained from core-boring at two beech (Fagus sylvatica L.) forest sites in south-west Germany that differ in exposure and soil conditions. The mean bias of annual stand-scale growth from 2001 to 2007 decreased from ?0.59 to ?0.41 mm at one evaluation plot and from ?0.55 to ?0.24 mm at the other when the competition module was coupled in. Inclusion of the SILVA-based individual tree module into MoBiLE-PSIM improved the size-dependent representation of competition and growth on five-year and even annual timescale. This was particularly the case where the spatial distribution of dominant trees was clustered.