马关古林箐自然保护区植物多样性及综合评价

在物种多样性、遗传多样性和生态系统多样性3个层面上论述了古林箐自然保护区植物多样性现状,分析了植物多样性的特征．保护区内热带湿润雨林、季节雨林、石灰山季雨林、山地雨林和南亚热带季风常绿阔叶林、中山湿性常绿阔叶林均有着本区的特点：区系成分复杂而联系广泛,植被类型多样而分布集中,植物种类丰富而密集度大,起源古老而特有种多,具有很高的科学研究和保护价值．     

Succession and management of tropical dry forests in the Americas: Review and new perspectives

Understanding tropical forest succession is critical for the development of tropical forest conservation strategies worldwide, given that tropical secondary forests can be considered the forests of the future. Tropical dry forests (TDF) are among the most threatened tropical ecosystems, there are more secondary forests and forest restoration efforts that require a better understanding of successional processes. The main goal of this synthesis for this special issue on the ecology and management of tropical dry forests in the Americas is to present a summarized review of the current knowledge of the ecology and management implications associated to TDF succession. We explore specific issues associated to tropical dry forest succession with emphasis on the use of chronosequences, plant diversity and composition, plant phenology and remote sensing, pollination, and animal–plant interactions; all under the integrating umbrella of ecosystem succession. We also emphasize the need to conduct socio-ecological research to understand changes in land-use history and its effects on succession and forest regeneration of TDF. We close this paper with some thoughts and ideas associated with the strong need for an integrating dimension not considered until today: the role of cyberinfrastructure and eco-informatics as a tool to support sound conservation, management and understanding of TDF in the Americas.     

尖峰岭热带林的植物化学特征

根据63种植叶片及25种木材的化学的化学分析结果，应用数值分析方法，探讨尖峰岭热带林植物及不同植被类型的化学特征和主要元素含量水平，从化学角度揭示了热带林的结构、功能和空间分布节律，为热带林生态系统的深入研究提供基础的背景材料。     

海南岛尖峰岭热带林生态系统研究*Ⅰ.热带北缘生物基因库 Ⅱ.生态系列研究

本文系1979—1986年采用本底调查、小区实验和定位观测等方法对海南岛尖峰岭热带林生态系统进行多学科综合研究的总报告。本报告共分7部分:世界热带北缘的丰富的生物基因库;生态系列研究;热带林水热状况;热带林物质循环;游耕农业生态后果;热带林采伐后的更新与演替。长期本底调查查明本区有植物1668种,隶属 198科798属;已知昆虫26目 4000余种,已知大型真菌260种。对由海滨至主峰的滨海有刺灌丛、稀树草原、半落叶季雨林、常绿季雨林、山地雨林,山顶苔藓矮林所构成的生态系列进行了组成、结构、土壤、林分生长等特征及其形成的自然地理环境进行了综合性比较研究。     

Predatory beetles in cacao agroforestry systems in Brazilian Atlantic forest: a test of the natural enemy hypothesis

The natural enemy hypothesis predicts a positive correlation between plant species diversity and natural enemy control. This study aimed to evaluate the role of traditional cacao agroforests, known as “cabrucas,” on the conservation of the predatory beetle community compared to that of monodominant rubber agroforests. Predatory beetles were sampled in three habitats in Southeastern Bahia, Brazil: cabrucas and rubber agroforests and native Atlantic forests. In each habitat, 18 10 m² plots were established, in which canopy cover was measured and beetles were sampled with a modified Malaise/window trap. Land use intensification did not affect the composition of predatory beetles, with the presence of widely distributed species that are also capable of colonizing simpler environments such as the rubber agroforest. Canopy cover had a positive effect on generalist predator diversity and we observed a reduction in the abundance and species richness of generalist predators with increasing habitat homogenization. Despite the simplified structure of the habitat, the remaining tree diversity and canopy cover in cabrucas supported a community of generalist predators similar to the one found in the native forest. Species diversity of bark beetle predators was higher in cabrucas, which may be due to the high diversity of bark beetles and the favorable abiotic conditions, whereas the low abundance of prey in the native forest and severe abiotic conditions in the rubber agroforest probably determined the lower diversity of generalist predators in these habitats. Cabrucas play an important role in the conservation, supporting a community of predatory beetles more similar to the one found in native forest and that is more effective at controlling populations of herbivores than in homogeneous rubber agroforests.     

福建梅花山国家级自然保护区种子植物区系研究

福建梅花山国家级自然保护区是我国亚热带森林生态系统类型自然保护区之一，区内物种丰富，有种子植物154科672属1521种及亚种，区系成份丰富，含单种属和少种属多，区系起源古老，成份过渡性明显。根据区系的地理成份分析，泛热带和热带分布的热性成份种的比例较高。     

Productivity of two Douglas fir/subclover/sheep agroforests compared to pasture and forest monocultures

Resource sharing between tree and forage plant components in silvopastoral systems includes a complex set of facilitative and competitive interactions. To the extent that facilitation exceeds competition, agroforests are expected to outyield monocultures of their components. Pasture and Douglas fir (Pseudotsuga menziesii) tree production of young agroforests was compared to pasture and forest monocultures under both grid and cluster patterns of tree planting near Corvallis, Oregon, USA, during 1983–1987. The height and diameter growth of forest and agroforest trees was similar, regardless of tree planting pattern. Five-year average annual forage production was 6500, 5800, and 2800 kg ha^–1 on pasture, agroforest, and forest plots, respectively. The total cumulative 1982–1987 above-ground phytomass yield of forage plus trees was similar for pasture and conventional grid forest monocultures. The total productivity of agroforests, however, was over 30% greater than either pasture or forest components grown in monoculture. Approximately 1.6 ha (0.96 ha forest + 0.64 ha pasture) of monocultures would be needed to equal the productivity of 1 ha of agroforest.Oregon Agricultural Experiment Station Technical Paper No. 10, 825.     

海南岛热带森林生物多样性研究进展

生物多样性是生态学研究中一个重要的领域,海南岛热带林有很高的生物多样性。阐述海南岛热带林生物多样性的意义和研究进展,介绍海南岛热带林物种多样性、遗传多样性、生态系统多样性和景观多样性特点,结合生物多样性锐减的现状提出了相应的保护建议。     

Temporal changes in VAM fungi in the cocoa agroforestry systems of central Cameroon

In Cameroon, cocoa trees are mostly grown in forests and without fertilization. Our aim was to learn more about the temporal dynamics of soils in cocoa agroforests by comparing young (1–4 years old) and old (over 25 years old) cocoa agroforests. Short fallow and secondary forest were used as treeless and forest references. The numbers and diversities of soil vesicular arbuscular mycorrhizal (VAM) fungi on 60 cocoa producing farms in the Central province of Cameroon were assessed based on the classical morphotyping of spore morphology. We also observed the soil organic matter, nitrogen and major soil nutrients. VAM spore density was significantly lower in the young cocoa agroforests (16 spores g⁻¹ dry soil) than in the old cocoa agroforests (36 spores g⁻¹ dry soil). Levels in the nearby secondary forest (46 spores g⁻¹ dry soil) were not significantly different from old cocoa. The spore density was significantly highest in the short fallow (98 spores g⁻¹ dry soil). The Shannon–Weaver index also showed significantly lower biodiversity in young cocoa (0.39) than in old cocoa agroforests (0.48), secondary forest (0.49) and short fallow (0.47). These observations were supported by significant differences in the C:N ratio, Ca, Mg, and cation exchange capacity between young and old cocoa agroforests. We concluded that unfertilized cocoa agroforests could be sustainable, despite a decrease in some soil characteristics at a young stage, due to traditional land-conversion practices based on selective clearing and burning of secondary forest.     

云南西双版纳普文山地雨林植物区系研究

采用样地调查法对云南西双版纳普文山地雨林植物区系进行了研究。结果表明:其山地雨林有维管束植物83种,隶属48科76属。该植物区系科、属的分布区类型组成均以热带分布为主,分别占总科数和总属数的81.24%和89.47%,温带成分分别占8.34%和5.26%。种的分布区类型组成以热带亚洲分布为主,占总种数的49.40%;其次是中国特有分布种,占25.30%;热带分布种占70.33%,温带分布种占8.43%。这些特征均表明该植物区系热带性质显著,特有种丰富,并具有明显的热带亚洲植物区系特点和热带北缘性质,属热带亚洲植物区系向东亚植物区系的过渡区。     

Leaf and litter nitrogen and phosphorus in three forests with low P supply

We compared the N and P contents of the main labile components of nutrient cycles in three different forest ecosystems [a tropical evergreen forest (TEF); a tropical dry forest (TDF); and a Mediterranean temperate forest (MTF)] with low P supply. A mass-balance approach was used to estimate mean residence times for organic matter, N and P in the forest floor, and to examine the flexibility of N and P intra-system cycling in the three forest ecosystems. For this purpose, we combined published values of N and P in foliage, litterfall, forest floor litter and mineral soils in these three forest ecosystems. The results of our analysis were consistent with the widely held belief that the N content of leaves (both green and senescent) and litter increases with increasing temperatures. In contrast, the data did not support the hypothesis that leaf P content decreases with increasing temperatures and precipitation: leaf and litterfall P contents were higher in both tropical forests than they were in the temperate forest. The TEF had the highest P content of the three forests studied. The mass-balance analysis indicated that although P mineralization in the TDF can run ahead of litter decomposition stoichiometry when P is in short supply, flexibility is much reduced or absent in the TEF and the MTF. Our analysis provides additional evidence of the importance of climatic factors in forest ecosystem processes and highlights the role of flexibility in ecosystem nutrient cycling, especially for P in ecosystems with a limited P supply.     

印度东北部南梅加拉亚邦摈榔复合农林生态系统植物多样性(英文)

在南梅加拉亚邦摈榔复合农林生态系统内,农民种有多种具有重要经济价值的植物。调查了摈榔复合农林生态系统内植物组成情况,共发现160种植物,其中木本植物83种,灌木22种,草本41种,攀缘植物14种。研究表明,摈榔复合农林生态系统为当地农民带来了经济收入,提供医药、木材、燃材和食用品以及外售。这些复合农林生态系统有利于保护重要经济价值的植物物种、保持生物多样性,并在结构组成和生态经济功能上模拟自然森林。     

Dominant species’ resprout biomass dynamics after cutting in the Sudanian savanna-woodlands of West Africa: long term effects of annual early fire and grazing

Background   

The potential of forest to regenerate after harvesting is a key element for sustainability of the ecosystem. For semi-arid tropical savanna environments, managing resprouts after tree cutting is ideally suited because of the natural ability of many indigenous species to regenerate vegetatively. Regeneration in this ecosystem is, however, prone to many disturbance factors such as fire and grazing by livestock.     

海南岛霸王岭热带山地雨林林隙更新生态位的研究

通过对海南岛霸王岭热带山地雨林林隙更新生态位的研究表明：同一树种在不同大小和年龄级林隙内的优势度不同，不同树种在同一大小和年龄级林隙内的优势度不同。根据树种在不同大小级林隙内的生态位宽度的变化，可分为生态位幅度宽、中等、较小和狭小4类；根据树种在不同年龄级林隙内的生态位宽度的变化，可分为对林隙时间生态资源利用充分、利用较充分、利用不充分和利用很少的4类树种。不同的树种或树种组对不同大小和年龄阶段林隙生态资源利用的不一致性，表明热带山地雨林中不同树种的林隙大小级生态位和林隙时间段生态位是相对分离的。分析表明，海南岛热带山地雨林中有很大一部分树种是属于低密度、狭生态位的树种。从物种多样性的角度来看，大量低密度、狭生态位树种的存在表明热带山地雨林是一种较为脆弱的生态系统类型。     

Carbon stocks in coffee agroforests and mixed dry tropical forests in the western highlands of Guatemala

Tree removal in Latin American coffee agroforestry systems has been widespread due to complex and interacting factors that include fluctuating international markets, government-supported agricultural policies, and climate change. Despite shade tree removal and land conversion risks, there is currently no widespread policy incentive encouraging the maintenance of shade trees for the benefit of carbon sequestration. In facilitation of such incentives, an understanding of the capacity of coffee agroforests to store carbon relative to tropical forests must be developed. Drawing on ecological inventories conducted in 2007 and 2010 in the Lake Atitlán region of Guatemala, this research examines the carbon pools of smallholder coffee agroforests (CAFs) as they compare to a mixed dry forest (MDF) system. Data from 61 plots, covering a total area of 2.24 ha, was used to assess the aboveground, coarse root, and soil carbon reservoirs of the two land-use systems. Results of this research demonstrate the total carbon stocks of CAFs to range from 74.0 to 259.0 Megagrams (Mg)?C ha^?1 with a mean of 127.6?±?6.6 (SE)?Mg?C ha^?1. The average carbon stocks of CAFs was significantly lower than estimated for the MDF (198.7?±?32.1?Mg?C?ha^?1); however, individual tree and soil pools were not significantly different suggesting that agroforest shade trees play an important role in facilitating carbon sequestration and soil conservation. This research demonstrates the need for conservation-based initiatives which recognize the carbon sequestration benefits of coffee agroforests alongside natural forest systems.     

广东湛江沿海木麻黄防护林生态系统的辐射通量特征

木麻黄（Casuarina）防护林是我国热带、南亚热带海岸带及岛屿防护林的典型代表,建立海岸带防护林的主要目的是改善包括局域小气候在内的海陆交错带的生态环境,太阳辐射因子是森林固碳和森林小气候形成的重要基础。该研究基于广东省湛江沿海岛屿典型木麻黄（Casuarina equisetifolia）防护林2010年1—12月共1 a 的辐射观测数据,分析了其辐射通量特征。结果表明：（1）2010年太阳短波辐射总量是5537.42 MJ · m-2,净辐射总量是6027.17 MJ · m-2,其中4—9月雨季太阳短波辐射总量和净辐射总量占全年的比例分别为62.72%和61.73%。（2）生态系统太阳短波辐射反射率全年变化集中在8%~15%之间。（3）长波有效辐射全年均为负值,说明大气温度常年高于下垫面防护林生态系统的冠层表面温度,在夜间太阳辐射为零时有利于大气中所含大量水汽在植被表面的凝结,这是沿海和岛屿生态系统重要的水分来源。     

Carbon and nitrogen storage in agroforests, tree plantations, and pastures in western Oregon, USA

Pastures store over 90% of their carbon and nitrogen below-ground as soil organic matter. In contrast, temperate conifer forests often store large amounts of organic matter above-ground in woody plant tissue and fibrous litter. Silvopastures, which combine managed pastures with forest trees, should accrete more carbon and nitrogen than pastures or timber plantations because they may produce more total annual biomass and have both forest and grassland nutrient cycling patterns active. This hypothesis was investigated by conducting carbon and nitrogen inventories on three replications of 11 year-old Douglas-fir (Pseudotsuga menziesii)/perennial ryegrass (Lolium perenne)/subclover (Trifolium subterraneum) agroforests, ryegrasss/subclover pastures, and Douglas-fir timber plantations near Corvallis, Oregon in August 2000. Over the 11 years since planting, agroforests accumulated approximately 740 kg ha^–1 year ^–1 more C than forests and 520 kg ha^–1 year^–1 more C than pastures. Agroforests stored approximately 12% of C and 2% of N aboveground compared to 9% of C and 1% of N above ground in plantations and less than 1% of N and C aboveground in pastures. Total N content of agroforests and pastures, both of which included a nitrogen-fixing legume, were approximately 530 and 1200 kg ha^–1 greater than plantations, respectively. These results support the proposition that agroforests, such as silvopastures, may be more efficient at accreting C than plantations or pasture monocultures. However, pastures may accrete more N than agroforests or plantations. This apparent separation of response in obviously interrelated agroecosystem processes, points out the difficulty in using forest plantation or pasture research results to predict outcomes for mixed systems such as agroforests. This revised version was published online in June 2006 with corrections to the Cover Date.     

Response of pine forest to disturbance of pine wood nematode with interpretative structural model

Pine wood nematode (PWN, Bursaphelenchus xylophilus), originating from North America, causes destructive pine wilt disease. Different pine forest ecosystems have different resistances to B. xylophilus, and after its invasion, the resilience and restoration direction of different ecosystems also varies. In this study, an interpretative structural model was applied for analyzing the response of pine forest ecosystem to PWN disturbance. The result showed that a five-degree multi-stage hierarchical system affected the response of the pine forest ecosystem to PWN disturbance, in which direct affecting factors are resistance and resilience. Furthermore, the analysis to the 2nd, 3rd and 4th degree factors showed that not only does distribution pattern of plant species and pine’s ecological features affect the resistance of pine forests’ ecosystem, but removal of attacked trees and other measures also influence the resistance through indirectly affecting the damage degree of Monochamus alternatus and distribution pattern of plant species. As for resilience, it is influenced directly by soil factors, hydrology, surrounding species provenance and biological characteristics of the second and jointly dominant species, and the climate factors can also have a direct or indirect effect on it by affecting the above factors. Among the fifth elements, the elevation, gradient and slope direction, topographical factors, diversity of geographical location and improvement of prevention technology all influence the response of pine forest ecosystem to PWN disturbance. __________ Translated from Scientia Silvae Sinicae, 2007, 43(8): 85–90 [译自: 林业科学]     

Ecology and regeneration of tropical dry forests in the Americas: Implications for management

Dry forests represent the most endangered ecosystem in tropical regions and continue to be one of the most sought after environments for human colonization, development and production. In spite of this, dry forests are one of the least well studied tropical habitats. This special issue is dedicated to reviewing much of the information that exists about tropical dry forest in the Americas. The introduction summarizes the articles presented herein, highlighting management strategies that are suggested throughout the special issue that may be useful for conserving tropical dry forest environments.