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正最新植物物种清查结果修改亚马孙雨林树种数量最新科研成果表明,在亚马孙地区广袤的低地雨林(海拔低于1000m)有6727种乡土树种,这一数字远低于之前研究中所估计的16200种。然而,最新研究也表明,这并不意味着亚马孙热带雨林的多样性就减少了。亚马孙地区的植物极其丰富,目前已知的树种数量仅是这个世界上最大的热带雨林     

巴西政府关于“防止亚马孙森林遭受破坏的行动计划”

巴西亚马孙雨林的毁林面积继续直线上升，引起了国际社会的严重关注。国际林业研究中心的调查表明，近年来国际市场对巴西牛肉需求激增是导致亚马孙森林遭到大规模破坏的主要原因。即乱砍滥伐森林用作牧场，发展肉牛产业。     

巴西热带雨林的破坏正在加速

巴西：巴政府称，2008年新年前后的几个月巴西亚马孙雨林的破坏正在急剧增加。每月破坏的速度已从之前的234km^2增加到948km^2。     

世界上热带森林分布最多的国家

世界上热带森林分布最多的国家是巴西,有森林面积3.57亿hm~2,覆盖率为42％。世界上5大雨林之一的亚马孙林区主要部分在巴西的西北部。     

加拿大北方森林——地球的绿色皇冠

在北高纬度地区的冻土苔原带以下，生长着常绿林，这就是北方森林一一世界上最大的陆地生态系统。它分布广袤，没有受到人为干扰，也未修建道路和工业发展，特别在加拿大，拥有的北方森林面积竟达13亿英亩。全球北方森林的面积远大于亚马孙雨林。     

拯救亚马孙雨林

不要以为草原、丘陵和山地等植被薄的才会变成沙漠,森林也会出现沙漠化现象。美国科学家的最新研究显示,南美亚马孙雨林连续第二年出现大面积的干旱现象,而且有沙漠化的倾向。     

亚马孙地区天然气管道修建计划正在酝酿之中

由委内瑞拉通往阿根廷的庞大的天然气管道计划于2006年1月被披露，该天然气管道将横穿亚马孙雨林。目前还不知道该计划的详细情况，但可以肯定的是：耗资200亿美元的天然气管道将对具有重要生态作用的亚马孙地区造成破坏。环境学家认为，天然气管道网的修建将会污染水源、破坏树木，所修建的道路将会更加方便垦荒者和伐木者涌入亚马孙丛林。     

亚马孙雨林正以2倍于前所预计的速度消失

日前发表在美国《科学》周刊上的一篇研究报告称，亚马孙流域的雨林正以2倍于前所预计的速度遭到破坏。科学家说，雨林遭到破坏，使其更易发生火灾，且使更多的二氧化碳释放到大气中。     

海南岛尖峰岭热带林型的主分量排序

一、林地概况 尖峰岭林区位于北纬18°23′13″—18°52′30″,东经108°46′04″—109°02′43″,在中国植被区划中属琼南丘陵山地季雨林湿润雨林区。植被种类极其丰富,野生高等植物有1500多种,植被可分为四个垂直带,六个类型:1.稀树草原带:(1)稀树草原,(2)砂生植被,2.常绿季雨林带:(3)常绿季雨林,(4)沟谷雨林,3.山地雨林带:(5)山地雨林,4.山顶苔藓矮林带:(6)山顶苔藓矮林。     

热带兴奋性饮料作物瓜拉那

<正> 瓜拉那(Raullinia cupana H.B.K.syn:P.sor ilis Mart.)是英文名guarana的音译,是无患子科的木质藤本植物。药用部分为种子。 一、产地 瓜拉那原产于巴西亚马孙河流域的热带森林,是亚马孙地区特有的一种经济作物。主要分布于亚马孙州马代腊河和塔帕     

亚马逊热带雨林遥感监测及保护发展基本做法和启示

亚马逊热带雨林毁林遥感监测是目前最先进遥感体系。通过探讨亚马逊热带雨林的遥感监测及保护发展基本做法,以期为中国森林资源监测与保护提供借鉴和启示。     

西双版纳人工雨林土壤温度变化规律

以旷地、单层橡胶林及自然雨林作为对照，分析了人工雨林土壤温度及土壤热通量的日、年变化规律。结果表明：（１）土壤温波振幅减小幅度表现为旷地＞单层橡胶林＞人工雨林＞自然雨林，位相滞后则是旷地＜单层橡胶林＜人工雨林＜自然雨林。（２）地面最高温度表现为旷地＞单层橡胶林＞人工雨林＞自然雨林，地面最低温度相反，以自然雨林最高，旷地最低。（３）土壤热通量的绝对值以旷地＞单层橡胶林＞人工雨林，而位相依次滞后     

国际社会消除区域性贫困的林业实践及启示

森林资源既是一项重要资产,也是发展生产的重要资本。林业实践是改善民生、消除贫困的主要措施之一也已成为广泛的国际共识。文中介绍非洲、东南亚和亚马孙雨林等地区长期以来依靠林业消除区域性贫困的具体实践,并对实践经验进行归纳总结,包括中央与地方权力的有效协调及合理分配以及非木质林产品的有效利用;指出林业消除区域性贫困的过程具有差异性、长期性和挑战性等突出特征,且仍面临着经济社会发展与生态保护的矛盾始终存在、收入与福利分配不均等现实挑战;提出对中国推进消除区域性贫困林业实践的启示,包括持续创新森林资源严格约束下的非木质林产品经营模式、持续探索生态文明建设背景下的民生林业实践模式以及持续探索和创新森林生态补偿实践模式。     

西双版纳2种热带雨林类型土壤节肢动物群落结构及分布特征

分析了西双版纳山地雨林和季节雨林土壤节肢动物群落的组成、分布特征及多样性状况。 2块样地 2次取样 ,共获取大、中小型土壤节肢动物 6 6 0 6个 ,分属 2 3目。蜱螨目、鞘翅目、弹尾目、膜翅目仍是 2林地土壤节肢动物群落组成共有的优势类群 ,但它们在不同样地生境中构成的数量比例不同 ,而常见和稀有类群组成较为复杂且样地间的差异更为突出 ,总体表现出季节雨林具有更多的热带成分 ,山地雨林则界于热带和亚热带之间。土壤节肢动物类群总数、个体总数及重要生物类群 (个体数量在 10 0 0个·m- 2 以上 )的分布 ,表现为山地雨林 (2 2类 ,4 974个 )多于季节雨林 (19类 ,16 32个 ) ,垂直分布结果表明 2类林地均具明显的表聚现象。从多样性尺度看 ,山地雨林密度 -类群指数高于季节雨林 ,这与 2林地土壤条件的优劣相符合     

Forecasting hotspots of forest clearing in Kakamega Forest,Western Kenya

Kakamega Forest is the last remaining rainforest in Kenya and the easternmost remnant of the Guinean-Congolian rainforest belt. As such, it is home to a large number of endemic fauna and flora species. Yet the remaining natural forest is under imminent threat of degradation due to a rapidly growing population in its vicinity and a poverty rate far above the national average. The growing demand for forest resources and ecosystem services will continue to exert great pressure on the remaining forest fragments. In this paper, we predict future hotspots of forest clearing of the remaining natural and old-growth secondary forest in Kakamega Forest. We parameterized an artificial neural network model using resilient backpropagation to simulate the likelihood of forest clearing for each location. Input variables into the network included historic information on forest clearings together with variables capturing the status of forest protection, accessibility to roads and markets, as well as topography and forest density. Simulation results were used to predict future clearings based on observed rates of change. Hotspots of forest clearing were derived by assessing the neighborhood density of predicted clearings.     

Use of 3-PG and 3-PGS to simulate forest growth dynamics of Australian tropical rainforests: II. An integrated system for modelling forest growth and scenario assessment within the wet tropics bioregion

Regional model analyses of forest growth are critical for capturing global aspects of tropical rainforest carbon exchange. This research presents the development of a multi-model approach for assessing forest growth and biomass accumulation within the wet tropics bioregion (WTB) based on 10 years of available data and existing model parameter sets. The Tropical Rainforest Growth (TRG) model system employs the 3-PG and 3-PGS models to account for both old-growth rainforest and forest regeneration from seedlings in response to human-induced and natural disturbances. Above-ground biomass (AGB) stocks of the mature forest throughout the WTB for 2000 were estimated to be ∼202 t C/ha. Replacement of areas of old-growth with commercial timber plantations decreased overall AGB stocks to approximately 146 t C/ha. However, plantation carbon accumulation rates were higher than the mature rainforest, representing their potential to accumulate more biomass over a longer analysis time period. As tropical cyclones may significantly alter the carbon stocks of old-growth rainforests, the effect of tropical cyclone Rona on the WTB was assessed. The cyclone had a minimal impact on total AGB stocks within the region, yet these systems are an important factor to be considered in carbon and forest regeneration modelling activities in the tropics. The TRG system is an advanced modelling tool providing a rapid process-based assessment of biomass stocks and accumulation dynamics within Australia's tropical rainforest bioregion and has the potential for application in tropical forest ecosystems at both national and international levels.     

The power of discourse: Hard lessons for traditional forest communities in the Amazon

In the contemporary Amazon, ‘discourse’ is increasingly a new means of exercising power, influencing local society and the ways in which natural resources are managed. As society becomes ever more complex, direct means of exercising power no longer enjoy the same legitimacy and efficacy. Discourses are instead now assuming a dominant role in defining governance regimes; the sense of what is correct and socially acceptable, and what is not. This is particularly relevant for the rapidly advancing development frontiers in the Amazon region, where local communities are coming into contact with external players highly interested in their forest resources. This study focuses on understanding how external discourses can restrict the Amazonian communities' options for using their forests, but also how communities can harness these discourses to achieve their own claims and objectives. Empirical evidence from four study areas in the Bolivian, Brazilian and Peruvian Amazon regions is used to show how discourses on sustainable forest management are moulding forestry governance. The conclusion shows that while the discourses used by loggers and development organisations are strongly influencing the way communities manage their forests, some communities are also successfully using these discourses in alliances with environmental organisations to achieve acknowledgment of their demands.     

Managing the Tropical Agriculture Revolution

ABSTRACT

Industrial production of beef, soybeans, cotton, and biofuels is expanding into the tropical latitudes of South America and may soon reach tropical Africa in the most important agricultural transition since the Green Revolution. This shift is driven by the shortage of land suitable for expansion of cultivation and grazing in the temperate zone, increased global demands for agricultural commodities, the rising price of petroleum, and technological advances. At risk are some of the world's most ecologically and culturally-rich landscapes in the world, such as the Amazon rainforest, the Cerrado woodland complex, and African savannas. A strategy for reducing the negative ecological and social impacts of this transition could harness the rising environmental and social standards imposed by many importers and purchasers of agricultural commodities, similar reforms underway among “Equator” banks, growing corporate governance, and Brazil's prominence in international diplomacy. Integrated certification of commodity sanitation, compliance with rigorous environmental standards, and sound labor practices could become the norm for participation in commodity markets. These reforms in agro-industrial behavior could be reinforced by trade agreements and strategic support from non-governmental organizations.     

Colonisation of clearfelled coupes by rainforest tree species from mature mixed forest edges, Tasmania, Australia

Mixed forest, containing a eucalypt overstorey and an understorey of rainforest tree species, accounts for approximately 20% (195,000 ha) of Tasmania's wet eucalypt forest. In wood production areas it is typically clearfelled, burnt and then sown with eucalypt seed. This management removes virtually all standing seed sources within the coupe, so that recolonisation of coupes by rainforest tree species depends largely on seed sources located at the coupe edges. We quantified the influence of mature mixed forest edges on rainforest regeneration following clearfelling by modelling the change in the density of the regeneration of the four dominant rainforest tree species (Nothofagus cunninghamii, Atherosperma moschatum, Phyllocladus aspleniifolius and Eucryphia lucida) with increasing distance from forest edge. We also assessed the influence on rainforest tree regeneration of prevailing wind direction, age of regeneration, characteristics of the mature edge vegetation and of the competing regenerating vegetation within the coupe. Distance from edge and age of coupe were highly significant (p < 0.01) effects in each of the species models. We found that the abundance of regeneration declined with increasing distance from edge for all four rainforest tree species, and with the exception of A. moschatum regeneration, increased with coupe age up to the age of 15 years. The abundance of N. cunninghamii and E. lucida, which are species with restricted seed dispersal, declined most steeply with increasing distance from the edge. A. moschatum, which is a species with the potential for long distance seed dispersal by wind, was more abundant than N. cunninghamii and E. lucida at distances greater than 20 m from coupe edges. More than 500 seedlings ha⁻¹ were present at all distances from coupe edge for P. aspleniifolius, reflecting its capacity to germinate after disturbance from soil-stored and bird-dispersed seed. There were no significant differences in seedling density upwind or downwind of coupe edges, although the potential for dense regeneration of N. cunninghamii and E. lucida and for long distance dispersal of A. moschatum appeared to be greatest downwind of edges. Other variables that significantly affected the abundance of regeneration were the height of rainforest tree species in the edge vegetation (N. cunninghamii model), the cover of rainforest tree species in the edge vegetation (A. moschatum model) and the cover of competing eucalypt regeneration within the coupe (P. aspleniifolius model). The proportion of rainforest tree species that regenerated vegetatively was small (3.1%). We concluded that management which maintains mature mixed forest edges, or patches of mature forest within coupes, is likely to result in greater levels of rainforest regeneration and a more rapid shift towards pre-harvest composition following logging. We use our results to demonstrate that variable retention harvesting systems, such as aggregated retention or stripfelling, which reduce the distance to rainforest seed source, would result in a greater abundance of rainforest regeneration over a larger proportion of the coupe than current clearfell, burn and sow silviculture.     

海南岛霸王岭热带山地雨林采伐经营初期土壤碳氮储量

测定了海南岛霸王岭热带山地雨林不同择伐强度经营试验初期土壤 C、N含量及其储量 ,结果表明 :原始热带山地雨林土壤 C、N背景值分别为 10 8.91t· hm-2 、9.58t· hm-2 ,表层 50 cm土壤 C储量占深 10 0 cm土层 C储量的 77.6 % ,相应的 N储量占 73.8% ;30 %、50 %择伐强度经营 5个月后林地土壤 C储量分别比原始林降低 4 .5%和 5.3% ,但 30 %强度经营林地土壤 C/N接近未采伐的原始林。结果可作为对热带山地雨林选取持续经营模式的动态参考指标