Broadleaf competition interferes with balsam fir regeneration following experimental removal of moose

Changes to ecosystems caused by introduced herbivores can be predictable, stepwise transitions or unpredictable and even irreversible state changes. This study's objectives were to explore effects on forest succession and soil development 5 years after moose (Alces alces L.) were fenced out of areas within and adjacent to a national park in Newfoundland, Canada. Study plots spanned a range of understorey broadleaf plant associations with regenerating balsam fir (Abies balsamea (L.) Mill.), an important winter forage plant for moose and a dominant canopy tree throughout Newfoundland. After 5 years, height–diameter ratios were significantly larger for larger basal diameters of understorey balsam fir in unfenced, but not in fenced subplots, suggesting that growth of the conifer is compromised within the exclosure. In contrast, for most broadleaf trees and shrubs, moose removal by fencing results in greater heights and basal diameters than in control subplots. The competitive advantage of broadleaf trees and shrubs over balsam fir in the short-term may be a result of past sustained heavy moose browsing benefiting plants that are better at investing resources into below-ground growth or benefiting plants that have broader leaf canopies. It is not clear how long the broadleaf transition state we document will continue. Restorative actions intended to mimic usual patterns of forest regeneration in this region of Newfoundland might best consider moose removal with site preparation and/or planting to historic densities.     

徐州山地森林生态质量评价研究

利用徐州山地森林标准地调查数据,从森林结构与功能和森林健康状况2个方面来构建森林生态质量评价指标体系,采用层次分析法、等级评分法、加权综合指数法来评价徐州山地森林生态质量状况。结果表明：无论是森林结构与功能还是健康状况,森林生态质量都是天然林好于混交林,混交林好于人工林;徐州山地森林生态质量等级好、中、差所占的比重大小悬殊,其中质量等级为差的所占比重最大,说明了徐州山地提高森林生态质量还有很大的潜力。     

林木生物质能源开发和利用

林木生物质能源作为生物质能源的一个重要分支,清洁性和可循环再生利用等特点使其在新世纪具有广阔发展前景。本文结合国外做法介绍了我国木质能源开发和利用现状,阐述了林木质能源开发和利用方式,并对发展前景和对策作了初步探讨。     

Proximity to a forest leads to higher honey yield: Another reason to conserve

Although tropical forest conservation is a top priority for human and environmental health, deforestation persists, mainly because of food and economic needs. No community will totally give up economic activities for the sake of ecological integrity, unless it is given alternative economic activities from which to draw its livelihood. Beekeeping in the forest buffer zone instead of traditional destructive honey-harvesting from forest trees is one such option at Arabuko Sokoke Forest (ASF) in Kenya. ASF is a dry coastal forest which is home to endangered and threatened fauna and is a hotspot considered a priority for conservation. In order to find out whether honey quantity and quality differed with distance from the forest, we studied honey yield per harvest (kg) and obtained samples from hives placed at varying distances from ASF in two successive years. Honey yield increased with proximity to the forest. Indeed the yield almost doubled in hives placed less than 1 km from the forest compared to those placed more than 3 km from the forest. All the honey samples met internationally required quality standards, although sugar levels were at the lower limit. This study demonstrates that the conservation of tropical forest ecosystems can have real local economic benefits. The documentation of the services provided by nearby natural areas should help make conservation of these areas a priority, even for the local communities.     

森林与海洋文化的融合——黄海缘居小区景观设计

以城市资源、区位优势寻求小区特色,绿色生态提升环境效益,以人为本创建和谐园区的原则对青岛市黄海缘居小区环境进行了景观规划设计,确定了"森林海洋文化"为设计主题,人与自然和谐共存为目的。以此将全园划分为7个景观区,并运用园林艺术及工程技术手段再现了四季景观之美,创造了富有文化特色的个性居住小区。       

森林资源资产评估程序和基本方法

论述了森林资源资产评估程序,简要介绍了基本方法。     

林业生产管理系统设计

林业生产管理中既要处理空间数据又要处理属性数据,因此,借助GIS的特点,在Visual Basic 6.0可视化编程环境中,开发设计了林业生产管理系统。对系统进行了总体设计,系统界面采用MDI多文档菜单界面,系统可扩充性好。经测试,系统实现了林火防治、木材运输管理、林业缓冲区分析、树种分布叠加、林业病虫害防治、林业档案管理等功能,为林业管理提供了较为快速、准确的服务,同时也为森林防火点的选取及建立提供了快速、准确的方案。     

森林资源经营管理的形势与问题探讨

本文结合当前我国林业发展的实际,探讨分析了森林资源经营管理面临的形势与问题,提出了加强森林资源经营管理的具体措施,以期为森林资源经营管理跟上现代林业建设步伐提供参考。     

长白山8种林型土壤有机碳和全氮的质量分数及垂直分布特征1）

基于样地调查和室内分析,比较研究了长白山地区典型的8种森林类型土壤有机碳和全氮的质量分数、碳氮比、碳密度和氮密度的分布特征。结果表明,8种林型土壤有机碳和全氮的质量分数变化范围分别是36．99～70．33、3．14～6．04 g· kg－1,有机碳、全氮质量分数最大的林型均是阔叶混交天然林。红松天然林土壤C ／N值最大为15．56,其它C ／N值变化范围为10．55～12．19。在土壤垂直剖面上,随着土层深度的增加,土壤的有机碳、全氮质量分数随之递减,土壤密度随之递增。8种林型土壤碳密度是杨树天然林最大,为22．13 kg· m－2,氮密度是落叶松人工林最大,为1．97 kg· m－2;针阔混交人工林的碳密度和氮密度均为最小,分别是12．37、1．11 kg· m－2。     

Projecting impacts of human disturbances to inform conservation planning and management in a dryland forest landscape

Systematic approaches to conservation planning and management require spatially explicit information on the dynamics of multiple disturbance processes, but progress in providing such information has been limited to date. Here we examine the use of a spatially explicit model of forest dynamics (LANDIS-II), incorporating a range of ecological processes, to examine the impacts of different types of disturbance on a dryland forest landscape in Central Chile. The model was parameterized using spatial data and results of a field survey, in which 21 native tree species were recorded, and one invasive exotic (Acacia dealbata). Seven disturbance scenarios were simulated, with different combinations of fire, browsing and tree cutting. Model results indicated relatively little impact of disturbance on forest cover but substantial differences in forest structure, with relatively old-growth forest stands (>120 years old) being virtually eliminated from the landscape in scenarios with both browsing and cutting. Tree species richness tended to be lower in those scenarios without disturbance, highlighting potential trade-offs between forest structure and species richness. Spread of A. dealbata was projected only to occur in the presence of fire when combined with browsing and/or cutting. These interactive effects of different forms of disturbance illustrate the value of process-based modeling approaches for exploring the spatial dynamics of multiple disturbance processes, but highlight the difficulty of identifying an optimum disturbance regime that would enable conservation objectives to be achieved. It is suggested that process-based models should form part of an analytical ‘toolkit’ to support the practical implementation of systematic conservation planning approaches.