关于森林经营分类与森林培育的思考

我国拥有非常丰富是森林资源,但是森林资源的人均占有量很低,在可持续发展观贯彻的过程中森林资源成为一项重要的因素。我国在较长一段时间内重视工业发展,忽视生态保护,导致现阶段我国面临比较严重的生态问题,尤其是在没有节制的运用生态资源的过程中,导致水土流失、土地荒漠化等现象加剧。针对当前林业发展工作中面临的问题,笔者从森林资源和森林培育的角度出发,阐述在森林资源经营和森林培育过程中的森林资源管理问题。阐述在此背景下加强对森林资源经营和培育的重视,努力提高森林资源的管理效率,贯彻中国可持续发展观。     

面向生态系统服务的森林经营研究发展

随着森林生态系统越来越多功能化,对人类发展起着不可替代的作用,面向森林生态系统服务目标的森林经营已成为林业可持续发展的战略任务。在阐明森林经营的概念、森林经营模式、森林经营尺度等森林经营及发展历程的基础上,界定了森林多效益利用、近自然经营、森林生态系统经营、可持续经营等理论,阐述了森林生态系统服务价值评估、森林生态系统服务权衡协同等森林生态系统服务的相关研究,从面向森林结构的生态系统服务、面向生态系统服务目标的森林经营途径2个方面综述了森林生态系统服务与森林经营的关系,提出了构建跨尺度的森林生态系统服务调控机制、实施“区域-景观-林分”多层次的森林可持续经营、分类实施面向生态系统服务的森林经营模式等建议。     

生态公益林建设对森林可持续经营的影响研究

森林面积直接影响着生态系统运行,且森林环境对人类生存环境影响较大。近年来,我国通过完善生态文明政策、加大生态环境治理力度,扩张了人造林面积及森林覆盖率,进而为森林可持续经营奠定了良好基础。人造林中生态公益林建设效果尤为明显,既可优化森林周边环境,又可改善生态系统循环、恢复自然秩序。本文基于生态公益林建设目的、意义,探究了生态公益林建设对森林可持续经营影响,同时分析了生态公益林建设现存问题、解决对策。     

气象要素对森林内外土壤含水量的影响

气象要素对森林内外土壤含水量的影响白连君森林对气象因素的影响，主要表现在降水和蒸发方面。由于森林枝叶对降水的截留作用，到达地面的雨量少，速度减弱，时间滞后，使地表径流形成的总量和速度减少。又由于森林的影响。使林内土壤蒸发量减少。森林对气象要素的影响，...     

林业经营与森林生态发展策略

简要阐述了目前存在制约林业开发的因素,并提出相应的优化建议,以期为森林经营提供帮助。     

试析生态公益林建设对森林可持续经营的影响

森林环境直接影响着人们的生存环境,森林面积对生态系统的良好运行起着至关重要的作用。随着我国生态文明政策不断加强,生态环境的治理力度也逐渐增大,当前,我国的造林面积、森林覆盖率都呈现扩大增长趋势,其中公益林的建设尤其明显。公益林不但能有效地调节森林的周边生态环境,而且能显著改善生态系统内循环,帮助自然秩序得到恢复。本文将从公益森林建设对森林可持续性经营的影响分析,并做出总结,希望对公益林的建设发展提供帮助。     

森林经营与可持续发展

通过阐述森林经营与可持续发展的概念,分析森林经营可持续发展的含义,进一步从经济发展、社会发展、生态文明的角度研究森林经营与可持续发展的关系问题。     

林业经营与森林生态发展对策

随着经济社会的不断快速发展,林业经营与森林生态发展方面的问题越来越受到人们的关注,有必要采用科学系统的方法,确保林业经营与森林发展的生态化与可持续化。在这种背景下本文从构建林业经营与森林生态发展的评价指标、推广林业经营与森林生态发展的科学研究两方面着手,给出了林业经营与森林生态发展相关对策建议。     

浅谈龙门林场森林经营

依据全国生态功能区划和国家公益林区划界定办法,龙门林场的森林全为国家公益林,主要林种为防护林,森林生态系统主体功能为涵养水源,主要发挥生态调节功能。本文根据小陇山林业实验局龙门林场实际从中划分了部分商品林进行探讨。     

森林经营分类与森林培育的几点思考

森林属于一种可再生的资源,提高其质量也是当今全世界需要注重的一个问题。对森林进行培育是实现经营的基础,而森林培育也是经营的一种保障,因此在实际的工作中,需要及时分析如今经营、培育中出现的各种问题,并提出合理的解决措施,以此保证能够提高经营工作和培育工作的质量,为森林资源实现长远发展奠定良好的基础。     

塞罕坝不同植被类型地表土壤动物群落特征

为了解塞罕坝地区不同植被地表土壤动物群落特征,分别以白桦林、阔叶混交林、落叶松林、针阔混交林、云杉林、草甸为研究对象,于2017年7月采用陷阱法采集不同植被土壤动物并对其群落组成、结构及多样性进行分析。结果显示,6种植被样地中共获得土壤动物8 351头,隶属5纲19目96科186种,优势类群为盲蛛目、弹尾目、膜翅目、鞘翅目和双翅目。白桦林、落叶松林、阔叶混交林和针阔混交林土壤动物类群数均显著高于草甸和云杉林;落叶松林土壤动物个体数显著高于其他林分。各植被类型之间土壤动物Shannon-Wiener多样性指数和均匀度指数无显著差异。主成分分析和相关分析显示不同植被地表土壤动物的空间分布差异显著,且土壤动物个体数与林分内凋落物生物量、厚度、全氮、全磷、全碳含量及土壤容重呈极显著正相关。可见,塞罕坝地区不同植被类地表土壤动物群落组成和分布存在一定差异,地表环境因子是影响其组成的重要因素。     

Seasonal dynamics of soil nitrogen availability and phosphorus fractions under urban forest remnants of different vegetation communities in Southern China

Urban forest remnants are a useful tool to study forest response to global change with urbanization. Soil nutrient status in urban forests has not been well understood, especially under the pressure of rapid urbanization in developing countries. In this study, ion-exchange resin bags and a modified Hedley P fractionation procedure were used to measure seasonal dynamics of soil N forms (ammonium and nitrate) and P fractions (available, labile, slow, occlude and weathered mineral P) under urban forest remnants across a successional sequence and non-forest land in the city of Nanchang, Southern China. Results showed that soil N availability varied with season and vegetation community (P < 0.05). Soil P fractions showed minimal seasonal variation except available P, while their averages generally increased with forest development from non-forest land to coniferous forest to conifer-broadleaf mixed forest to evergreen broad-leaved forest. The ratios of fresh soil N forms to P fractions generally decreased with forest development, while N forms absorbed by resins to P fractions generally increased from non-forest land to coniferous forest, then decreased from conifer-broadleaf mixed forest to evergreen broad-leaved forest. It is suggested that urban older forest remnants could easily move to N saturation status and soil P enrichment, causing urban water pollution due to the accumulative effect of elevated atmospheric N deposition and exogenous P input with urbanization.     

Landscape effects of forest loss in a pollination system

Forest loss has been invoked as a cause for changes in the reproductive success of animal-pollinated woodland plants, associated with changes in their pollinators. To analyze such effects, it is important to include all of the three key players: landscapes, pollinators and a plant. We investigated effects of forest loss on an insect-pollinated plant through landscapes in forested ecosystems to pollinator communities and plant populations. Then we questioned if abundance and species richness in pollinator communities decrease as forest loss increases, and this in turn leads to a decrease in reproductive output of an insect-pollinated plant. We made a study with 12 populations of the bee pollinated herb, Erythronium americanum, in a landscape characterized by scattered fragments of deciduous forest within intensively managed agricultural fields. We also sampled bees as the potential pollinators by pan traps. We quantified the study landscapes using the amount of forest cover and the length of forest edge within each of the six radii (250, 500, 750, 1,000, 1,250 and 1,500 m). Regression analyses showed that the abundance and species richness of all collected bees were positively related to only the forest cover at the radius of 750 m. We also found the positive relationships for the seed set of E. americanum when the forest cover at the same radius and abundance of all collected bees were used as the predictor variables. These results indicate that forest loss causes negative impacts on potential pollinator communities and seed sets of some woodland herbs.     

葡萄园不同土壤管理模式对土壤理化性状及细菌群落的影响

在山东省蓬莱市瑞枫·奥塞斯葡萄基地检测了连续7年清耕、使用除草剂、自然生草、种植狗牙草和种植高羊茅对土壤理化性状和细菌群落的影响。结果表明:相比于清耕,其他4种土壤管理模式均降低了土壤容重,以种植高羊茅最为明显;除种植狗牙草显著提高土壤p H值外,其他3种土壤管理模式对土壤p H值无显著性影响;其他4种土壤管理模式均降低了土壤电导率,以自然生草最明显,降幅达48.1%;生草不同程度地提高了土壤氮磷钾和有机质含量,使用除草剂对氮磷钾含量无显著影响,而使有机质含量降低了39.6%。与清耕相比,生草和使用除草剂均增加了土壤微生物数量和群落多样性,以种植狗牙草的土壤细菌OTU数量和多样性最高;生草提高了土壤有益菌丰度,降低了有害菌丰度,总体上看以种植狗牙草效果最为突出;使用除草剂显著降低了大多数有益菌丰度。对土壤最主要的30个细菌菌落而言,不同土壤管理模式对其产生了不同影响,高羊茅和除草剂对微生物菌属的影响最接近,狗牙草对微生物菌属的影响与其他2种草差异较大。总之,生草模式优于清耕和使用除草剂,不同草种各具优势。     

Deforestation patterns and their effects on forest patches

Five identifiable patterns of deforestation are recognized - internal, indentation, cropping, fragmentation, and removal - and each has a distinct effect on habitat quality of forest patches in the eastern United States. By overlaying land use maps from 1973 and 1981 for three counties in the State of Maryland (Prince Georges, Anne Arundel, and Wicomico), changes in the interior core area and edge length of individual patches were measured. Forest interior declined by 23.8 km² in Anne Arundel, 16.3 km² in Prince Georges, and 8.4 km² in Wicomico. Within Anne Arundel and Prince Georges Counties, deforestation increased edge length by 52.1 km and 31.2 km, respectively, whereas, within Wicomico, it decreased edge length by 8.7 km. Differences among counties resulted from current land use patterns, percentage of forest cover, and the dominant deforestation pattern.     

森林群落发育阶段及其效益分析——以河北省木兰林场和塞罕坝机械林场为例

为揭示森林生态、经济和社会效益的发生、发展规律,为森林经营和资源管理提供依据,根据森林群落发育和演替理论并结合木兰林场塞罕坝机械林场经营实践,对森林群落的发育阶段及森林三大效益进行了分析,提出了稳定成熟森林群落的形成可分为森林群落形成阶段、森林群落发展阶段和森林群落稳定成熟阶段。阐述了森林群落不同阶段的基本特点和群落结构的基本特征。在此基础上分析了从森林群落形成阶段到发展为稳定成熟森林群落进程中,森林三大效益产生和发展的一般规律以及它们之间的相互关系,即森林三大效益不是平行关系而是相互区别、相互联系、相互伴生的关系,它们的产生是一个从无到有、由少到多、由小到大的发展进程,特别是生态效益和社会效益,从维度上讲还是一个从单一向复杂,从单维度向多维度的发展进程,并随森林群落林龄增长而逐渐增多增强。     

城市森林环境对正负情绪状态影响的Meta分析

明确城市森林环境对正负情绪状态的影响程度及影响因素,为城市森林建设提供科学依据。对Web of Science和CNKI数据库进行检索,对最终纳入的文献采用Meta分析的方法,研究城市森林环境对正负情绪状态的影响。结果表明,纳入的17篇文献中有13项随机对照试验,21项自身前后对照试验,文献质量一般;进入森林对积极情绪影响的总效应量SMD=0.33,I²=33%,95%置信区间Cl[0.23,0.44];进入森林环境对消极情绪影响总效应量SMD=-0.35,I²=0,95%置信区间Cl[-0H46,-0.25];与城市环境相比,处于城市森林对积极情绪状态总效应量SMD=0.59,I²=42%,95%置信区间Cl[0.44,0.75];对消极情绪的影响总效应量SMD=-0.45,I²=0,95%置信区间Cl[-0.61,-0.30],城市森林对积极情绪影响效果的异质性来源主要为心理健康程度和城市森林自然环境。综上所述,城市森林环境对人的心理健康有积极促进效果,进入森林环境后可降低人的消极情绪,心理健康状态和城市森林自然环境影响城市森林对积极情绪的提升效果。     

Modelling the effects of forest fragmentation on certain species of forest-breeding birds

Summary The influence of forest fragmentation was assessed on the abundance of six forest-breeding bird species. The study area (2327 sq Km) was located in south-west France. The forest cover, extracted from a Landsat MSS scene, was first reduced to a grid of 5865 quadrats, each 650 by 650 m. Two values were attributed with each quadrat: Quadrat Forest Cover (QFC), expressed in percent; and a local measure of forest fragmentation - the Neighbouring Forest Cover (NFC) - expressed on a 0–1000 scale. The distribution of six forest-breeding species was sampled on 556 quadrats.For each species, the local abundance appears to be more correlated with the fragmentation-oriented NFC value than with the local QFC value. For three species out of six (song thrush, robin, chaffinch) an incidence model, based on the Logistic regression, was built. A correct fit was obtained.An incidence map of these species was then built up over the whole study area. Their regional status was then estimated, for a sampling cost of less than 10% of censusing all the area.     

Interrelationships between plant functional types and soil moisture heterogeneity for semiarid landscapes within the grassland/forest continuum: a unified conceptual model

In semiarid landscapes, the ratio of herbaceous to woody plant biomass is a major determinant of ecosystem properties. This ratio depends to a large extent on the amount and spatial distribution of soil moisture that is available to plants, and these variables, in turn, are determined primarily by climate and land use. Current conceptual models for determining the ratio of herbaceous to woody plant biomass in semiarid plant communities are based either on differences in soil moisture with depth (vertical heterogeneity) from one site to another (Walter's two-layer model) or on differences in soil moisture between canopy and intercanopy patches at the same site (horizontal heterogeneity) that result from disturbances associated with land use (Schlesinger et al.'s model of desertification). We developed a model that unifies these two perspectives by relaxing two assumptions of Walter's two-layer model. First, our model recognizes that soil moisture varies horizontally between canopy and intercanopy patches, not only due to land-use disturbance, a general assumption of the Schlesinger et al. model, but also due to the physical nature of the canopy itself. Second, while retaining the general assumption of Walter that woody plants obtain moisture from deeper soil layers than do herbaceous plants, our model recognizes the existence of two types of woody plants: those that extract a substantial proportion of their moisture from deeper layers and those that extract mainly from shallower layers. By modifying the two-layer hypothesis to include four soil compartments and distinguishing between shallow- and deeper-rooted woody species, our model integrates three key concepts in semiarid ecology: (1) the proportion of woody cover increases as moisture in the deeper soil layers increases (Walter's two-layer hypothesis for coexistence of herbaceous and woody plants); (2) land use practices that cause a reduction in herbaceous vegetation and compaction of intercanopy soils lead to a long-term increase in the proportion of woody plants (Schlesinger et al.'s concept, or more generally, that at a given site multiple variations in the proportions of herbaceous and woody plant biomass are possible); and (3) changes in the ratios of herbaceous to woody plant biomass exhibit complex behavior (changes can happen quickly and are not directly reversible without intensive management). This integration of concepts results because rather than assuming a simple, one-way dependence of plant functional types on soil moisture heterogeneity, our model assumes an interdependence between the two: soil moisture heterogeneity constrains the composition of the plant community, which in turn modifies soil moisture heterogeneity. The four-compartment model that we propose enables, for the first time, an integrated picture of both dimensions of soil moisture heterogeneity – horizontal and vertical – and of the interdependence between soil moisture heterogeneity and the proportions of the plant functional types that make up a given plant community. This unified conceptual model can be applied to provide insight into the individual and the combined effects of climate and land use on semiarid plant communities within the grassland/forest continuum, which vary in the proportions of canopy and intercanopy patches.     

塞罕坝地区云杉人工林土壤养分的研究

研究了塞罕坝地区云杉人工林土壤有机质、pH、全磷、全氮、全钾、速效磷、速效钾和碱解氮的含量在不同地势（沟底、坡面和曼甸）和不同土层深度条件下的差异。结果表明,0～10 cm深度土壤各类养分在坡面地势的含量显著高于沟底和曼甸,其中有机质、全磷、速效磷和碱解氮含量平均相差50.7%、34.8%、37.4%和46.3%,沟底的速效钾和碱解氮显著高于曼甸;10～20 cm深度土壤有机质含量、全磷含量、全钾含量、速效磷含量和碱解氮含量存在显著差异,以上元素在坡面地势的含量比沟底和曼甸平均高出46.7%、34.2%、22.7%、27.3%和63.8%,但沟底和曼甸中各类元素的差异不显著;20～40 cm深度土壤有机质、速效磷和碱解氮含量存在显著差异,坡面的含量明显高于沟底和曼甸,但沟底和曼甸中各类元素的差异不显著。相同地势条件下,各类土壤养分元素均呈现出地表高于地下的现象,其中0～10 cm深度土壤有机质、全氮、全钾和碱解氮含量分别比20～40 cm深度土壤高出65.2%、53.2%、80.3%和64.8%,pH在不同土壤深度间无明显差异。研究结果为塞罕坝云杉人工林经营提供了理论依据。