湖南省驼背蚱属一新种记述(直翅目:蚱总科:枝背蚱科)

记述分布在湖南省石门县壶瓶山国家森林公园的枝背蚱科Cladonotidae驼背蚱属Gibbotettix一新种,即壶瓶山驼背蚱Gibbotettix hupingshanensis sp.nov..该新种接近红河驼背蚱Gibbotettix hongheensis Zheng,两者主要在触角、头顶宽、前胸背板前缘等部位有区别.     

Production,restoration, mitigation: a new generation of plantations

New Forests - Forests provide a wide variety of ecosystem services and international conventions and national policies for climate change mitigation and biodiversity conservation recommend forest...     

森林生态制度文化:机构·法律·行为守则

由于个人、政府、企业通过对森林物质文化的生态认知、生态情感、生态响应而产生的生态法律法规、生态行为守则、生态机构组织和管理机制等组成了森林生态制度文化;森林制度文化是森林管理文化的核心,是国家管理森林的主要工具;研究森林制度文化,分析其薄弱环节、落后因素,并加以改进,有助于建设先进、和谐、科学的森林制度文化.     

感知-入境-认知：中国古典园林实践教学理念探索

基于对中国古典园林考察课程的思考，探索一种古典园林实践教学理念，从“感知-入境-认知”建立古典园林认知途径。鼓励学生打开所有感官，以纯真之心进入真实环境中进行感知，通过旷奥游观、四时联想与历史想象，实现沉浸式综合体验，融入情思，从而理解和体悟中国古典园林的精神内核：善境与营境。     

The Imperata grasslands of tropical Asia: area, distribution, and typology

The rehabilitation or intensified use of Imperata grasslands will require a much better understanding of their area, distribution, and characteristics. We generated estimates of the area of Imperata grasslands in tropical Asia, and suggested a typology of Imperata grasslands that may be useful to define the pathways toward appropriate land use intensification. We conclude that the area of Imperata grasslands in Asia is about 35 million ha. This about 4% of the total land area. The countries with the largest area of Imperata grasslands are Indonesia (8.5 million ha) and India (8.0 million ha). Those with the largest proportion of their surface area covered with Imperata are Sri Lanka (23%), the Philippines (17%), and Vietnam (9%). Laos, Thailand, Myanmar, and Bangladesh evidently all have similar proportions of their land area infested with Imperata (about 3 to 4%). Malaysia (< 1%), Cambodia (1%), and the southern part of China (2%) have but a minor proportion of their total land area in Imperata. The species was found widely distributed on the full range of soil orders. It occupied both fertile (e.g. some of the Inceptisols and Andisols) and infertile soils (Ultisols and Oxisols) across a wide range of climates and elevations. Imperata lands fall into four mapping scale-related categories: Mega-grasslands, itmacro-grasslands, meso-grasslands, and micro-grasslands. The mega-grasslands are often referred to as sheet Imperata. They are the large contiguous areas of Imperata that would appear on small-scale maps of say 1:1,000,000. We propose that this basic typology be supplemented with a number of additional components that have a key influence on intensification pathways: land quality, market access, and the source of power for tillage. The typology was applied in a case study of Indonesian villages in the vicinity of Imperata grasslands. We propose an international initiative to map and derive a more complete and uniform picture of the area of the Imperata grasslands. This should include selected studies to understand conditions at the local level. These are critical to build the appreciation of change agents for the indigenous systems of resource exploitation, and how they relate to local needs, values and constraints.     

Forest landscape models: Definitions,characterization, and classification

Previous model classification efforts have led to a broad group of models from site-scale (non-spatial) gap models to continental-scale biogeographical models due to a lack of definition of landscape models. Such classifications become inefficient to compare approaches and techniques that are specifically associated with forest landscape modeling. This paper provides definitions of key terminologies commonly used in forest landscape modeling to classify forest landscape models. It presents a set of qualitative criteria for model classification. These criteria represent model definitions and key model implementation decisions, including the temporal resolution, number of spatial processes simulated, and approaches to simulate site-level succession. Four approaches of simulating site level succession are summarized: (1) no site-level succession (spatial processes as surrogates), (2) successional pathway, (3) vital attribute, and (4) model coupling. Computational load for the first three approaches is calculated using the Big O Notation, a standard method. Classification criteria are organized in a hierarchical order that creates a dichotomous tree with each end node representing a group of models with similar traits. The classified models fall into various groups ranging from theoretical and empirical to strategic and tactical. The paper summarizes the applications of forest landscape models into three categories: (1) spatiotemporal patterns of model objects, (2) sensitivities of model object to input parameters, and (3) scenario analyses. Finally, the paper discusses two dilemmas related to the use of forest landscape models: result validation and circular reasoning.     

Forests,discourses, institutions: A discursive-institutional analysis of global forest governance

The leading question of this Forest Policy and Economics special issue is whether, how and to what extent forest governance processes can be better understood by means of discourse analysis and the science-policy interface. This article focuses on discourses only, but it does so from an institutional perspective. The reasons to advocate this so-called discursive-institutional approach are threefold: (1) to acknowledge the relevance of both meanings and rules in policy continuity and change; (2) to emphasize the role of ideas, concepts and narratives in institutional dynamics; and (3) to make a useful distinction between discourses and practices (‘analytical dualism’). As an example of applying this approach, we analyze the case of global forest politics from the early 1980s till today. It shows that new ideas and meanings concerning sustainability, biodiversity and governance have been institutionalized in this field over time, implying policy change and innovation. Compared to more ‘classical’ analyses, for example based on rationalistic or (purely) institutional accounts, the discursive-institutional approach draws another picture of global forest policy.     

Characterization of Douglas-fir grown in Portugal: heartwood,sapwood, bark,ring width and taper

Douglas-fir (Pseudotsuga menziesii) is one of the best timber conifers providing long sawnwood components. Original from North America, it has been planted in Europe on approximately 550 thousand ha. Twenty Douglas-fir trees growing in two sites in Portugal were studied regarding ring analysis, heartwood, sapwood and bark development, and taper. The radial growth rate was 7.1 and 6.6 mm year⁻¹ at stem base for 45- and 50-year-old trees, respectively, in the two sites. Initial growth rate was slower, increasing until about 20 years and decreasing afterwards. Heartwood proportion represented on average 49% of the cross section in the lower part of the stem and decreased upwards. Heartwood formation was estimated to start at a cambial age of 8–9 years and increasing by 0.7–0.9 rings year⁻¹. Sapwood width was on average 75 mm at stem base, decreasing upwards. Bark was 26–27 mm thick at stem base, where it represented 15% of the cross-sectional area and decreased to 3–5 mm at the top. Stemwood and heartwood tapers were on average 15 mm m⁻¹ in the lower stem part and 21 and 18 mm m⁻¹, respectively, in the upper part. Douglas-fir showed a good potential for the mountain areas of Portugal, and under the silvicultural conditions of both stands the trees presented ring homogeneity, small conicity and low taper suitable for long wood components.

     

Environmental impacts of forest monocultures: water use,acidification, wildlife conservation,and carbon storage

A broad assessment is given of the contentions that plantation forests are high consumers of water, increase acidification, sustain a low diversity of wildlife, and store more carbon than do unmanaged forests. The following conclusions are drawn: (1) Evapotranspiration from planted forest monocultures is greater than from short vegetation, as a result of greater interception loss. Water loss from conifer forests is usually greater than from deciduous hardwoods, but evapotranspiration from Eucalyptus in the dry tropics is often no greater than from native hardwoods. (2) Compared to short vegetation, forests can significantly increase the transfer of acidifying pollutants from the air to the soil and surface waters, and conifers are more likely to enhance acidification than are hardwoods. (3) There are normally sufficient plantation management options available to make most plantation landscapes the homes of a rich diversity of flora and fauna. (4) An area covered with a plantation managed for maximum volume yield will normally contain substantially less carbon than the same area of unmanaged forest.     

The Summerwood: Springwood Ratio in Conifers: How it arises, varies, and affects end use for timber, board, and paper

A theoretical discussion of variation in summerwood and springwoodcontents among conifers. Three methods of measuring these, bycross-sectional area of logs, by dryweight fibre percentage,and by nominal specific gravity, are compared. High-summerwood tissues have a nominal specific gravity of 0?45or over; low-summerwood tissues have a specific gravity below0?45. All conifers have a low summerwood content in their juvenilewood or core wood formed towards their stem-tips. In Pinus,Larix, and Pseudotsuga the summerwood percentage increases markedlywith age, but only in the outer layers towards the butt; inPicea, Abies, and Tsuga similar increases occur, but high-summerwoodtissues are seldom found. Within any species, and for any particulargrowth rate, low-summerwood tissues are characteristic of regionsof high relative humidity where summer water deficits rarelyoccur, such as high altitudes, far northern latitudes, and themaritime climate of western Britain. High-summerwood tissuesdevelop where summer temperatures are high, with associatedstrong sunshine, low relative humidity, and frequent summerwater deficits. High-summerwood tissues have greater strength in compressionand bending, relative to volume; but low-summerwood tissueshave greater strength relative to their weight. Low-summerwoodmaterial has proved satisfactory for most structural purposes,and for the manufacture of several kinds of artificial board.Its technical properties for the making of many types of paperare excellent, provided high resistance to tearing is not required.Likely summerwood content should guide planting programmes andmarketing policies.     

社区保护地:缘起发展、地位作用与当代价值

社区保护地是世居民族基于当地传统生态智慧自发地对生态环境进行保护和管理的实践产物,是人与自然和谐相处的典范。文中通过梳理国内外社区保护地的缘起和发展脉络,指出其发展贯穿于当地世居民族的生态保护实践过程中;通过对社区保护地地位与作用的分析,阐明其在保护主体、保护方法、保护对象、保护动力、保护效果等方面均与自然保护地相补充,可多方位助力我国自然保护地体系建设;在此基础上对社区保护地由生态价值、文化价值、精神价值和社会价值构成的多元价值体系进行挖掘剖析,旨在提高认知深度,为后续保护与发展奠定基础。     

Australia's forests: Contested past,tenure-driven present,uncertain future

Australia's forests have been characterized by a history of contestation and conflict since British colonization in 1788. This paper adopts a “pathways to sustainability” approach to review Australia's forest governance models, which are strongly tenure-dependent, and generally vary between sub-national jurisdictions; only climate change-related policies, which are in a state of considerable flux, apply to all forests. Consequently, pathways to sustainability are defined largely in terms of the dominant purpose of particular tenures, and are now little-integrated across institutions, landscapes or tenures. Three decades of trialing devolved models of natural resource governance have effectively been abandoned, as have many of the initiatives intended to support development of a more diverse and more integrated ‘forestry’ sector. While the near-term prospects for sustainability of Australia's forests in anything more than the narrowest sense are poor, there are both knowledge-based and historical institutional foundations from which more substantive progress towards sustainability could be realized. This progress will need to be founded on approaches to policy development and implementation that recognize and accommodate the plurality of interests in forests, that enhance coordination and integration between institutions and across landscapes, and that empower and enable the diverse communities of interests in forests.