Commercial Medicinal Plant Extraction in the Hills of Nepal: Local Management System and Ecological Sustainability

This paper presents a case study from Jumla District, Nepal, investigating local management systems and ecological sustainability of commercial collection of a medicinal plant, spikenard (Nardostachys grandiflora DC, Valerianaceae), growing in alpine meadows. Interviews were undertaken with local collectors, traders, and district forest office staff, and the dynamics of people–plant interactions are analyzed using the Oakerson model. In all, 110 sample plots 1m square were laid out in three areas with differing collection and grazing pressures for recording of floristic composition and abundance of spikenard root biomass. Comparisons show significantly more root biomass in uncollected than collected areas with local management and the interpretation of differences in abundance is discussed. The combination of qualitative and quantitative investigations can provide a framework for the study of people–plant interactions, and this study can serve as first step in a compilation of cases to create a more detailed picture of local management systems of Nepali nontimber forest products in general and commercially collected medicinal and aromatic plants in particular.     

林火对土壤结构的影响

通过对大兴安岭新林林业局 2 0年内不同年数间隔的 10块火烧迹地土壤进行调查取样和室内实验分析 ,发现不同年限、不同强度的火烧迹地土壤结构变化情况如下 :低、中强度火烧对土壤密度和孔隙度的影响不大 ,对土壤分散系数有一定影响 ;高强度火烧对土壤密度、孔隙度和分散系数的影响显著。降雨能使火烧迹地的土壤密度和分散系数升高、孔隙度下降。连年火烧使土壤密度比未烧林地下降 ,而孔隙度和分散系数升高。由此可见 ,高强度火烧对土壤结构破坏严重 ,而低中强度火烧对土壤坚实度和孔隙状况影响不大 ,但对土壤的保水保肥能力有显著影响。     

林火对景观格局的影响及其应用

通过查阅国内外有关林火与景观生态学的资料，综述了景观对林火的可能响应过程，从景观尺度上，分析了林火干扰对景观的结构、功能、动态、格局及多样性规律的双重影响。分析了景观格局对林火的影响，阐述了林火与景观的相互关系，列举了林火在景观生态学研究中的作用。     

安徽"两山一湖"区域生态不稳定因素辨识及其对策

通过对“两山一湖“区域生态系统的分析,认识到影响该区域生态不稳定的主要因素是人类活动对野生动植物栖息地的破坏、毁林垦种、外来物种入侵、森林火灾等;提出了保护森林资源、调整土地利用结构、实行退耕还林、推广水流域综合治理、加强物种保护、预防松材线虫病和森林火灾、建立以森林为主体的生态安全保障体系.     

A biological assessment of best management practice effectiveness during intensive silviculture and forest chemical application

A multi-year study was conducted to evaluate the effectiveness of Florida's Best Management Practices (BMPs) for protecting aquatic ecosystems during intensive forestry operations and forest chemical applications. Five silviculture sites adjacent to stream systems were selected for study from major eco-regions of the state. Replicate stream bioassessments, using a multimetric approach (the Stream Condition Index), were conducted as part of a `before-after, control-impact' (BACI) study design. Bioassessment stations were established above and below the treatment area to determine pre-treatment reference and test conditions. Silviculture treatments of clearcut harvesting, intensive mechanical site preparation and machine planting were then completed, during which all applicable BMPs were adhered to. In addition, two sites received an herbicide application and one site was fertilized. Following the treatments, the sites were re-sampled at the same points both one year, and two years after the first bioassessment. No significant differences in the SCI were observed between the reference and test portions of the streams that could be attributed to the silviculture operations using BMPs. Hence, the study showed that BMPs provided protection to adjacent stream ecosystems, even during intensive silviculture and forest chemical applications.     

浅谈伊犁地区山地天然林资源的保护和发展

伊犁地区林牧区生态系统的保水功能受到畜牧业生产活动的影响已明显下降,尤其是山地天然林资源的生态总体质量和生态功能都同步处于下降趋势。伊犁地区的生态建设重点应放在山地天然林分布区。保护和大力发展山地天然林资源是伊犁地区生态产业发展的核心内容。大力营造山地人工林,是目前条件下保护和发展山地森林资源的最有效手段。每年营造山地人工林不少于0 3×104hm2,才能够基本保持山地森林生态系统在资源总量和生态效能上的稳定,才能够基本维持伊犁地区以往良好的生态形象。建议自治区人民政府继续启动实施天山、阿尔泰山百万亩山林再造工程。     

NITROGEN AND PHOSPHORUS CONCENTRATIONS IN FOREST STREAMS OF THE UNITED STATES1

ABSTRACT: Seventy to eighty percent of the water flowing in rivers in the United States originates as precipitation in forests. This project developed a synoptic picture of the patterns in water chemistry for over 300 streams in small, forested watersheds across the United States. Nitrate (NO₃^?) concentrations averaged 0.31 mg N/L, with some streams averaging ten times this level. Nitrate concentrations tended to be higher in the northeastern United States in watersheds dominated by hardwood forests (especially hardwoods other than oaks) and in recently harvested watersheds. Concentrations of dissolved organic N (mean 0.32 mg N/L) were similar to those of NO₃～, whereas ammonium (NH₄⁺) concentrations were much lower (mean 0.05 mg N/L). Nitrate dominated the N loads of streams draining hardwood forests, whereas dissolved organic N dominated the streams in coniferous forests. Concentrations of inorganic phosphate were typically much lower (mean 12 mg P/L) than dissolved organic phosphate (mean 84 mg P/L). The frequencies of chemical concentrations in streams in small, forested watersheds showed more streams with higher NO₃^? concentrations than the streams used in national monitoring programs of larger, mostly forested watersheds. At a local scale, no trend in nitrate concentration with stream order or basin size was consistent across studies.     

森林野外火火区上的浮力流动与降雨的相互作用模型

本文是在《森林野外火火区上的浮力流动及其与一些环境气象因素关系的数值模拟》的基础上进行的。上文求解了无降雨时的气体流动情况,本文在此基础上加入了降雨模型,形成了能体现降雨与气流相互作用的程序。本文算出了不同大小的雨滴的下落过程,并能估计出多大的雨滴可落入燃烧区。     

STORMFLOW AND SEDIMENT LOSS FROM INTENSIVELY MANAGED FOREST WATERSHEDS IN EAST TEXAS1

ABSTRACT: Five small (4 ha) forested watersheds in East Texas were instrumented in December 1980 to determine the effect of forest harvesting, mechanical site preparation, and livestock grazing on stormflow, peak discharge rate, and sediment loss. After three pretreatment years, four of the watersheds were treated as follows: (1) clearcutting followed by roller chopping; (2) clearcutting following by shearing and windrowing; (3) clearcutting following by shearing, windrowing, and continuous grazing; and (4) clearcutting followed by shearing, windrowing, and rotational grazing. Clearcut harvesting and all site preparation treatments significantly increased stormflow, peak discharge, and sediment losses over the undisturbed condition. Roller chopping and shearing/windrowing had little impact on sediment loss from these watersheds and appears to be a sound forest conservation practice for gently sloping watersheds (> 8 percent). As applied, livestock grazing had minimal impact on stormflow and peak discharge. The moderately stocked continuously grazed treatment had little impact on sediment loss, but the high stocking density of the rotational grazing treatment increased sediment losses over the undisturbed condition. Sediment losses from these intensively managed forest watersheds, even though significantly greater than from undisturbed conditions, were within the range of sediment losses from undisturbed watersheds in the Southeast, below the range of losses from mechanically prepared watersheds elsewhere, and well below potential losses from pasture and cropland.     

Carbon sequestration,biological diversity,and sustainable development: Integrated forest management

Tropical deforestation provides a significant contribution to anthropogenic increases in atmospheric CO₂ concentration that may lead to global warming. Forestation and other forest management options to sequester CO₂ in the tropical latitudes may fail unless they address local economic, social, environmental, and political needs of people in the developing world. Forest management is discussed in terms of three objectives: carbon sequestration, sustainable development, and biodiversity conservation. An integrated forest management strategy of land-use planning is proposed to achieve these objectives and is centered around: preservation of primary forest, intensified use of nontimber resources, agroforestry, and selective use of plantation forestry. The information in this document has been wholly funded by the US Environmental Protection Agency. It has been subjected to the agency's peer and administrative review and approved for publication of an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.