欧洲城市森林及城市林业

文章介绍了欧洲主要国家及城市的城市森林概貌。目前关于城市林业的理解,不同国家的观点不同,但基本同意城市林业是一个综合体、是综合性的学科;城市林业目的在于为城市树木资源建立长期的政策与规划;强调城市森林能够提供的经济、环境、社会-文化产品及服务;是一项需要公众参与的事业。       

欧洲病虫害治理考察报告

中国昆虫学会赴欧洲考察团，访问了英、法、德等国的科研单位和院校。体会到，所到国家都具有重视环保，重视基础研究，重视生防技术应用和研究、生产、应用三方面密切使用的特点。     

对加快大理州森林生态旅游产业发展的几点思考

通过对大理州发展森林生态旅游的优势、制约因素分析,提出对加快大理州森林生态旅游产业持续、快速、可持续发展的对策和建议。     

Investigation of salinity impacts on germination and growth of two forest tree species at seedling stage

Soil salinity is becoming an increasingly serious constraint to plant growth in many parts of the world;this is particularly common in semi-arid and arid zones. This study was conducted to evaluate the...     

加速林木良种推广使用的几点思考

从分析现状入手 ,提出加速良种推广使用的措施与途径。作者从良种宣传、繁育推广体系建设、种质资源保护、扶持政策、规范化管理等方面论述了自己的观点。     

强化管理是促进"天保工程"实施的有效途径

随着国家天保工程的实施。我们在天然林保护方面采取了一系列管理措施。以促进天保工程健康，顺利实施。     

Carbon concentrations and stocks in forest soils of Europe

This study presents the results of a series of evaluations of a continent-wide soil database (EU/UN-ECE Level I) with the aim to estimate baseline soil carbon concentrations and stocks. The methodology included the biogeographic stratification of soil carbon measurements throughout Europe using climatic zones derived from the Soil Regions Map of Europe. The presented stock estimates range from 1.3 to 70.8 t C/ha for the O-layer, and from 11.3 to 126.3 t C/ha for the mineral soil 0–20 cm (Germany: 0–30 cm) (5 and 95 percentiles). Histosols were excluded because of methodological differences and data gaps. When looking at the median values of the strata investigated, relationships were found. For example, carbon stocks in the O-layer of sandy soils are distinctly higher than those of fine-textured soils. However, the variability is so high that some of these relationships disappear. For example in western and central Europe, the level of carbon stocks in the mineral soil between shallow soils (Leptosols) and more deeply developed soils (Podzols and Cambisols) do not differ very much. It was also found that just the investigation of topsoils is not sufficient to understand the regional pattern of organic matter in forest soils – unless the subsoil becomes included as well. It is hypothesized that for Europe, the impact of site factors such as climate, texture and relief are difficult to extract from such a database if the data are only stratified according to macro-climatic areas. It has to be considered that the effect of systematic error in the database is quite large (but cannot be identified on the level of the current data availability). In order to receive a first impression of the landscape-level distribution of carbon, a map of carbon concentrations in the topsoil was generated. The results support the relationships found between carbon stocks and site factors, such as climatic zones and soil type. Compared to the much lower carbon concentrations of agricultural soils, the results demonstrate clearly the importance of forest soils for the terrestrial carbon cycling in Europe.     

西藏天然林保护工程对森工企业的影响及对策的研究

随着我国长江中上游天保工程的实施，林芝地区的森工企业也将面临更多的困难。本文分析了形成我区森工企业目前困境的原因，并提出了解决的具体措施。     

Addressing climate change in the forest vegetation simulator to assess impacts on landscape forest dynamics

To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to climate and using it to modify growth rates, and (3) adding functions accounting for changing growth rates due to climate-induced genetic responses. For three climatically diverse landscapes, simulations were used to explore the change in species composition and tree growth that should accompany climate change during the 21st century. The simulations illustrated the changes in forest composition that could accompany climate change. Projections were the most sensitive to mortality, as the loss of trees of a dominant species heavily influenced stand dynamics. While additional work is needed on fundamental plant–climate relationships, this work incorporates climatic effects into FVS to produce a new model called Climate–FVS. This model provides for managers a tool that allows climate change impacts to be incorporated in forest plans.     

How governance impacts non-timber forest product value chains in Cameroon

Non-timber forest products (NTFP) comprise a diversity of natural resources that support livelihoods of those along the chain from harvester to traders. The Central African Forest Commission (COMIFAC) recognises the importance of NTFPs in alleviating poverty and conserving biodiversity and has proposed directives to aid member states to implement appropriate regulations. Data on the regulations governing the chain and its impacts were collected from literature, 12 small and medium enterprises trading an NTFP known as okok (Gnetum spp.) from the production forests to the port of export in Cameroon, and workshops. Laws were bureaucratically, arbitrarily and weakly implemented and enforced. Of 18,368 financial transactions recorded, 81% were bribes, comprising 34% of trader's costs. Corruption in the permit system further creates high transaction costs, negative environmental impacts due to illegal and over-exploitation, and reduces government revenues. The regulatory framework does not promote an enabling business environment. Improvements in governance are imperative if the economic impact upon the livelihoods of thousands of people in the chain is to be maintained and enhanced to ensure sustainable trade. Recommendations to improve the sector in Cameroon include revisions in the regulatory framework and its implementation to increase transparency and counter corruption.     

Potential impacts of a climate change on forest ecosystems

Review of literature indicates that many uncertainties and assumptions exist in predicting the impacts of a climate change on forest ecosystems. However, current knowledge is sufficient to encourage any measures that are combating climate change, that is to reduce first and foremost the release of harmful substances to the atmosphere, lithosphere and biosphere.     

论森林生态服务的经济补偿

森林生态服务是一种公共物品,具有明显的外部性特征,依靠市场机制难以实现有效供给,即存在“市场失灵”问题。经济补偿是政府为了弥补市场机制的缺陷所做的一种制度安排。作为一项制度安排,如何补偿需要兼顾效率与公平,以免导致“政府失灵”。文章从补偿的额度、范围、方式三个方面进行了探讨。     

Large scale biotic damage impacts on forest ecosystem services

Insect outbreaks are natural phenomena that play a critical role in the development, senescence, and rebirth of forests. However, the damage caused by large-scale epidemics can have landscape scale consequences that are often poorly understood. The recent mountain pine beetle (MPB) outbreak in Canada has impacted a record >18.5 million hectares of pine forests, placing forest values at risk and significantly impacting forest-dependent communities within the region. To assess this impact, an ecosystem service-based approach was applied. Based on land cover information and monitoring data, four ecosystem services were assessed and mapped: merchantable timber, water provisioning, aboveground carbon storage, and vegetation diversity (supporting habitat). Timber is the most impacted provisioning ecosystem service followed by water provisioning, with peak stream flow in affected watersheds being positively related to mortality percent. Effects on carbon storage are substantial, with 20% of total timber aboveground carbon in dead pine trees. These effects may be mitigated, however, by the growth response of residual live trees and forest regeneration. The potential vegetation diversity showed a positive response to MPB-caused tree mortality. The results of our study may help with setting management priorities in response to large-scale biotic damage in forests in British Columbia and elsewhere.     

论森林旅游业对环境的影响及对策

森林旅游业必须考虑其自身的可持续发展问题,为此要研究旅游开发建设过程与经营活动过程对环境造成的负效应,提出从推广生态旅游、实行环境影响评估制度、确定环保旅游设施标准、严格准入制度等方面采取对策。     

Water quality impacts of forest fertilization with nitrogen and phosphorus

The drinking-water quality of streamwater in forests is typically very good, exceeding the quality of water in areas with other types of land use. Streams draining agricultural lands in the United States average about nine times greater concentrations of nitrate and phosphate than streams draining forested areas. Forest fertilization commonly increases nutrient concentrations in streamwater, and large increases could lead to unacceptable degradation of water quality. This review summarizes information from studies of forest fertilization around the world, and evaluates the responses of streamwater chemistry. In general, peak concentrations of nitrate-N in streamwater increase after forest fertilization, with a few studies reporting concentrations as high as 10–25 (mg N)/l as nitrate. Increases in average concentrations of nitrate are much lower than the peak values, and the highest annual average nitrate-N concentration ever reported was 4 (mg N)/l. Relatively high concentrations of streamwater nitrate-N tend to occur with repeated fertilization, use of ammonium nitrate (rather than urea), and fertilization of N-saturated hardwood forests. Ammonium-N concentrations may also show large peaks following fertilization (up to 15 (mg N)/l), but annual averages remain <0.5 (mg N)/l. Fertilization with phosphate can lead to increased peak concentrations of >1 (mg P)/l, but annual averages remain <0.25 (mg P)/l. No evidence has been reported of detectable effects of forest fertilization on the composition or productivity of stream communities, but more detailed studies may be warranted (especially in relation to P fertilization). Major limitations in current knowledge include the effects of repeated fertilization in short-rotation plantations, fertilization of large landscapes rather than small stands, and the effects of fertilization on streamwater chemistry in tropical plantations.     

The potential rural development impacts of utilizing non-merchantable forest biomass

The development of a market for currently non-merchantable forest material, such as harvest residues or small diameter trees, has been suggested as a possible win-win solution that could: (i) provide a material that can be processed in rural communities reeling from changes in the forest products industry and policy environment; (ii) capture more value from timber management activities; and (iii) provide a financial incentive for treatments to reduce wildfire risk or restore forest stands. Modeling the supply of this material with spatially-explicit potential demand locations allows for a realistic analysis of the feasibility of such a market to stimulate rural development. We model multiple scenarios for the utilization of harvest residues within the current forest products market in western Oregon. Sensitivity analysis explored the effects of cost of the depots on feasibility, including policy designed to support depot establishment through subsidies. Scenarios were also used to assess the effects of increases in federal harvest activities. Results suggest that with relatively high biomass prices, there is some potential for investment in depots to aid rural communities in western Oregon, but there is little change in either the overall feasibility or the location of depot establishment under scenarios of increased federal harvest.     

Responses of deciduous forest trees to severe drought in Central Europe

In 2003, Central Europe experienced the warmest summer on record combined with unusually low precipitation. We studied plant water relations and phenology in a 100-year- old mixed deciduous forest on a slope (no ground water table) near Basel using the Swiss Canopy Crane (SCC). The drought lasted from early June to mid September. We studied five deciduous tree species; half of the individuals were exposed to elevated CO(2) concentration ([CO(2)]) (530 ppm) using a free-air, atmospheric CO(2)-enrichment system. In late July, after the first eight weeks of drought, mean predawn leaf water potential about 30 m above ground was -0.9 MPa across all trees, dropping to a mean of -1.5 MPa in mid-August when the top 1 m of the soil profile had no plant accessible moisture. Mean stomatal conductance and rates of maximum net photosynthesis decreased considerably in mid-August across all species. However, daily peak values of sap flow remained surprisingly constant over the whole period in Quercus petraea (Matt.) Liebl., and decreased to only about half of the early summer maxima in Fagus sylvatica L. and Carpinus betulus L. (stomatal down- regulation of flux). Although we detected no differences in most parameters between CO(2)-treated and control trees, predawn leaf water potential tended to be less negative in trees exposed to elevated [CO(2)]. Leaf longevity was greater in 2003 compared with the previous years, but the seasonal increase in stem basal area reached only about 75% of that in previous years. Our data suggest that the investigated tree species, particularly Q. petraea, did not experience severe water stress. However, an increased frequency of such exceptionally dry summers may have a more serious impact than a single event and would give Q. petraea a competitive advantage in the long run.     

Future impacts of climate change on forest fire danger in northeastern China

Climate warming has a rapid and far-reaching impact on forest fire management in the boreal forests of China. Regional climate model outputs and the Canadian Forest Fire Weather Index (FWI) Sys- tem were used to analyze changes to fire danger and the fire season for future periods under IPCC Special Report on Emission Scenarios (SRES) A2 and B2, and the data will guide future fire management planning. We used regional climate in China (1961 1990) as our validation data, and the period (1991-2100) was modeled under SRES A2 and B2 through the weather simulated by the regional climate model system (PRECIS). Meteorological data and fire danger were interpolated to 1 km 2 by using ANUSPLIN software. The average FWI value for future spring fire sea- sons under Scenarios A2 and B2 shows an increase over most of the region. Compared with the baseline, FWI averages of spring fire season will increase by 0.40, 0.26 and 1.32 under Scenario A2, and increase by 0.60, 1.54 and 2.56 under Scenario B2 in 2020s, 2050s and 2080s, respectively. FWI averages of autumn fire season also show an increase over most of the region. FWI values increase more for Scenario B2 than for Scenario A2 in the same periods, particularly during the 2050s and 2080s. Average future FWI values will increase under both scenarios for autumn fire season. The potential burned areas are expected to increase by 10% and 18% in spring for 2080s under Scenario A2 and B2, respectively. Fire season will be prolonged by 21 and 26 days under ScenariosA2 and B2 in 2080s respectively.     

深化集体林权改革促进林业又好又快发展

长期以来辽宁省的集体林实行"两权合一"、统一经营的管理体制,由于责权利不统一,挫伤了林农发展林业的积极性,制约了林业的发展.本次集体林权制度改革就是还林还利还权于民,实现责权利的统一,辽宁的改革实践已经显现了良好的效果.要想取得更好的效果,还要进一步完善或制定林业金融和保险支持制度、森林采伐限额制度、森林资源流转规范和生态效益补偿制度等.