北美红杉在云南的引种成效及其造林展望

北美红杉在云南引种栽培近30年,生长发育正常,与原产地比较相近,保持了速生特性和较强的抗逆性。引进的北美红杉不同种源、不同无性系,在云南不同生态环境生长有显著差异;在幼龄期表现较好的有SYA4s、SYA6s等6个优良种源和无性系,分别适应云南省的纬度范围为北纬22°59′～26°52′,海拔高度为1300～2400m的不同海拔、不同气候带、不同生态环境。还有少数耐寒种源和无性系,在海拔3200～3500m的高寒山地也能生长。该项研究对促进北美红杉在云南发展造林将起到积极推进作用。     

人工造林,更新实绩评价模型的研究与应用

应用特尔菲法,从人工造林、更新的核查实绩和难易程度两方面建立起了人工造林、更新实绩综合评价指标体系,并通过建立评价模型,对人工造林,更新全过程全方位实行定量评价。经实践检验,评价模型应用效果良好,具有推广价值。     

参与式乡村评估在青海海东地区CDM造林再造林项目中的应用

基于实地踏查、问卷调查、社区会议及关键人物访谈等参与式乡村评估工具对青海海东地区清洁发展机制(CDM)造林再造林项目进行评估,结果表明:拟议项目能很好地反映当地社区生计发展需求,不仅将对缓解气候变化做出贡献,还将为社区经济发展和环境保护做出贡献。农户、社区和政府等相关利益群体对项目实施提出进行更多的技术和业务培训,合理选择资金安排,采用混交种植方式等有益建议。     

Stockings for protection of containerized conifer seedlings against pine weevil (Hylobius abietis L.) damage

The effectiveness of a stocking, constructed of nylon and cotton netting, in protecting containerized conifer seedlings against pine weevil attack was evaluated in field tests on 37 clear‐cut reforestation areas in southern and central Sweden. The stockings significantly reduced pine weevil feeding on treated seedlings as well as seedling mortality. The protective effect of the stockings was similar to that of an insecticide (permethrin) treatment. In most experiments the survival of stocking‐enclosed seedlings was satisfactory from a practical point of view, whereas untreated control seedlings suffered heavy mortality.     

参与式乡村评估在青海大通县CDM造林再造林项目中的应用

基于实地踏查、问卷调查、社区会议及关键人物访谈等参与式乡村评估工具对青海大通县清洁发展机制(CDM)造林再造林项目进行评估,结果表明:拟议项目能很好地反应当地社区生计发展需求,不仅将对缓解气候变化做出贡献,还将为社区经济发展和环境保护做出贡献,农户、社区和政府等相关利益群体对项目实施提出了有益建议。     

关于营林更新造林财务成本核算的研究

更新造林,是以人工栽苗或人工直播、插条等方法作为恢复森林的手段,经过人工培育措施而形成森林,亦即人工更新。本文对更新造林的分类、核算对象和核算期等内容进行阐述,进而探讨了更新造林成本核算问题。     

Making Tropical Succession and Landscape Reforestation Successful

Forests are dynamic ecosystems, spatial mosaics of localized disturbances and regenerating vegetation. Following forest conversion to human land uses, expanding forest cover follows four different modes of reforestation: (a) spontaneous natural regeneration; (b) assisted natural regeneration; (c) agroforestry; and (d) commercial tree plantations. Natural regeneration fundamentally depends on the alignment of ecological and social factors at landscape scales. A deeper socioecological understanding of reforestation in the tropics will lead to the development of effective policies and governance structures that enhance forest cover and ecosystem services, protect biodiversity, and improve forest-dependent livelihoods.     

A Case Study Assessment of Agroforestry

Summary

Finding sustainable land-use systems within the Panama Canal Watershed will be necessary for future management by the Panamanian government. Agroforestry is a land-use option for small-scale farmers living within the Watershed that can help achieve the goals of both conservation and productivity. This case study qualitatively evaluates current agroforestry projects in the Canal Watershed using an analytical framework based on other evaluations of agroforestry systems in Central America. Designated criteria for the analysis include: management objectives, project life span, incentives, technology, economic feasibility, community involvement, and extension. These factors can present obstacles to wide-scale adoption of agroforestry systems by small-scale farmers, thus preventing the realization of associated benefits of agroforestry. The analysis of the three field sites visited in March 1998 is followed by recommendations for expanding agroforestry practices among farmers in the Watershed.     

封山育林对华北落叶松林枯落物层持水能力的影响

为了研究封山育林对华北落叶松枯落物层水源涵养能力的影响,选择未封育、封育2年与封育4年华北落叶松林作为研究对象,采用室内浸泡法来测定枯落物层各项指标,结果表明:(1)采取封育措施后华北落叶松人工林枯落物的厚度与蓄积量随时间增长而增加,大小排序为封育4年>封育2年>未封育;(2)采取封育措施后枯落物最大持水量都有所增加;(3)枯落物层有效拦蓄能力由大到小排序为封育4年(40.33thm^-2)>封育2年(37.40thm^-2)>未封育(34.97thm^-2)。封育措施对林分枯落物层有效拦蓄量有一定的影响,但是增加的幅度不大。在对林分进行封育措施的同时应结合其他经营措施,以更加有效地提高林分枯落物层对水分的拦蓄量。     

Predicting survival of planted Douglas-fir and ponderosa pine seedlings on dry,low-elevation sites in southwestern Oregon

Four equations were developed for predicting the probability of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] and ponderosa pine (Pinus ponderosa Dougl. ex Laws.) survival for the first (0–1) and first to third (1–3) growing seasons after applying mulching, scalping, or artificial shading (shade cards) treatments in plantations in southwestern Oregon, U.S.A. Variables describing conifer size, levels of competing vegetation, presence of silvicultural treatments, site factors, and climate factors were collected from 13 sites ranging from 0 to 6 years after planting and examined as potential predictors of survival. Age, stem diameter, a competition index for shrubs, severity of growing season at time of treatment, average annual precipitation, aspect, and slope angle were predictors of Douglas-fir survival during 0–1 and 1–3 growing seasons after treatment; the presence of silvicultural treatments was also a predictor only during the first growing season after treatment. Age, aspect, and slope angle were predictors of ponderosa pine survival over both 0–1 and 1–3 growing seasons after treatment; height-diameter ratio, competition indices for herbs, shrubs, and hardwoods, silvicultural treatment, severity of growing season at time of treatment, and average annual precipitation were also predictors only during the first growing season after treatment; crown width was a predictor of survival only during 1–3 growing seasons after treatment. When significant in the models, predicted probability of survival increases with treatments, less severe weather conditions, diameter, crown width, age, and precipitation; probability decreases with increasing height-diameter ratio and competition indices for herbs, shrubs, and hardwoods.