Tropical Forest Healers and Habitat Preference

Tropical forests represent repositories of medicinal plant species and indigenous ethnomedical knowledge. These biotic and cognitive resources are threatened by forest removal and culture change. It has, however, yet to be demonstrated quantitatively that tropical pharmacopoeias are concentrated in primary as opposed to disturbed forests, nor that folk ethnomedical knowledge is disappearing. I examined these questions by means of a useful species enumeration of 1-hectare primary and secondary forest plots, and a survey of the regional plant pharmacopoeia of the Atlantic forests of Bahia, Brazil, a region that has witnessed significant human and biological modification. Healers demonstrated a strong preference for disturbed over primary forest. Second growth forest plots yielded 2.7 times the number of medicinal species identified in primary forest plots. The regional survey likewise elicited an ethnoflora characterized by herbaceous, weedy, cultivated, and exotic taxa. These results may reflect the availability and intrinsic medicinal value of disturbance species, as well as the increasing rarity of the region’s primary forests. They may also represent the long term outcome of culture change, cognitive erosion, and reformulation of the region’s perceived healing flora.     

基于Sentinel-2的丛生竹林信息提取方法比较及分布特征

滇西南地区拥有丰富的丛生竹林景观和珍稀特有竹种资源,但竹资源分布储量不清、监测技术缺乏等问题很大程度限制了竹资源开发与利用。基于Sentinel-2A影像数据,采用反向传播神经网络、支持向量机、随机森林三种机器学习分类方法进行沧源县丛生竹林信息提取及精度评价,利用Google Earth影像和DEM数据对竹资源分布的空间和地形特征进行了分析。结果表明,随机森林分类精度优于支持向量机和反向传播神经网络,分类总体精度达90%,Kappa系数达0.87,竹林用户精度达81%。沧源县共有竹林138.07 km2,主要分布于城镇村庄、道路、水系和耕地周边,以四旁竹和防护竹林为主,采用Sentinel-2A10 m的分辨率很好地提取了空间上分布分散的丛生竹林。沧源县竹林主要分布在海拔900~2000 m,坡度范围大都位于缓坡和斜坡。研究结果可为沧源县竹资源开发利用提供数据支持,研究方法可作为大型丛生竹遥感监测的参考。     

The effects of soil phosphorus on aboveground biomass are mediated by functional diversity in a tropical cloud forest

Plant and Soil - Soil phosphorus is a key driver of plant biodiversity and aboveground biomass (AGB) in tropical forests. A plant community’s ability to exploit such limiting resources may be...     

Diversity and protection of Korean pine broad-leaved forests in the Manchurian Natural Area

Methods for the ecological-geographical analysis of the Manchurian Natural Area are discussed to perform estimation of the contemporary state, monitoring, and conservation of the biodiversity of Korean pine broad-leaved forests. The models used for conservation of the mountain Korean pine broad-leaved forests in the transboundary areas of Russia, China, the Democratic People’s Republic of Korea (DPRK), and the Republic of Korea should be based on the coordinated management of national resources. Estimating the ecological potential of Korean pine broad-leaved forests and the state and role played by forest ecosystems in the contemporary structure of the vegetation cover of the Manchurian Natural Area is significant for a more successful management of forests and scientifically grounded distribution of the nature reserves to conserve biodiversity. The united ecological-geographical system taking into account the regional peculiarities of forests can serve as a key in the development of the conservation of the biome.     

中国主要森林生态系统公益的评估

 为生态系统管理提供科学的量化指标，以我国森林为研究对象，根据全国第3次森林资源清查资料(1984～1988)及Costanza等(1997)的森林生态系统公益资料计算了我国38种主要森林类型生态系统公益的总价值约为117.401亿美元，其中以森林营养循环的贡献最大(约占40％)，而原材料(包括木材、燃料、饲料)的贡献仅占15％，反映出森林生态系统公益的显著性。 研究发现，各森林类型的生态系统公益(Va)与其总生产力(Tp)具有良好的相关关系：Ln(Va)＝108.21(Tp)0.93，R2＝0.844。这对于简化生态系统公益的评估具有重要意义。本研究为合理保护和可持续利用森林资源提供了科学的量化依据。     

Forest recovery in an Australian amenity landscape: implications for biodiversity conservation on small-acreage properties

Some urbanising rural (i.e. ‘amenity’) landscapes have seen an increase in forest cover over recent decades. Small-acreage landowners are key stakeholders in this forest recovery and its future ecological trajectory. Using 17 qualitative case-studies of small-acreage properties located in the Noosa hinterland in south-east Queensland, this study explores the types and condition of forests on these properties, the landholder’s differing forest management perspectives, practices and outcomes, and the implications for local biodiversity conservation. The properties contained a diverse mix of managed and un-managed natural and planted forests. Invasive weed species were a common component. Protecting and enhancing the ecological values of amenity landscapes will require an increase in active, best-practice forest management on small-acreage properties. Small-acreage landowners will require greater access to labour support and other subsidised resources to implement recommended practices. Such practices include controlling and reducing the spread of invasive weeds and soil erosion, reducing fire hazards, and positively influencing the rate and pathway of succession in regrowth forests. Peer-mentoring programs incorporating guided tours of ‘model’ small-acreage forests, and supporting landowners to establish their own small native plant nurseries and engage with local community nurseries (i.e. supplying seeds, volunteering labour), could help to increase small-acreage landowners’ forest management interests, knowledge, skills and activity. Long-term cooperative, cross-boundary forest management projects with on-going monitoring and adaptive management guided or implemented by skilled professionals are needed in amenity landscapes, particularly to increase the success of restoration interventions in weed-dominated regrowth forests. There is also a need for long-term socio-ecological analyses of amenity landscapes’ diverse and evolving small-acreage forests to better inform their future management.     

Mixed effects of climate variation on the scots pine forests: Age and species mixture matter

Understanding and unravelling the direct and indirect effects of ongoing and predicted climate change on the vitality and productivity of Scots pine forests is particularly important for Romania and other parts of eastern Europe, where the species represents an essential ecological and economic value. Here, we introduce the first nation-wide network of 34 Scots pine chronologies of basal area increment (BAI), and assess the species’ vulnerability to climate change. Temperatures of the previous autumn, as well as current year spring and summer warmth are found to be most critical for the productivity of Romania’s Scots pine forests. Negative growth anomalies after hot and dry August conditions are most severe in young (<50 years) Scots pine monocultures (>70% dominance) at lower elevations (<1000 m a.s.l.) across western Romania. Our findings emphasise the relevance and timeliness of carefully adapting sylvicultural management strategies to enhance the ecological and economic resilience of Romania’s widespread forest areas under a warmer and drier future climate.     

Biological invasions in forest ecosystems: a global problem requiring international and multidisciplinary integration

The world’s forests are crucial biological resources that provide a variety of ecosystem services such as nutrient cycling and provisioning of resources to society. But forests are particularly affected by biological invasions, with regions around the world experiencing invasions by species from virtually every kingdom. Many of these species have severely disrupted forest ecosystem processes, thereby interrupting the provisioning of ecosystem services that societies depend upon. The problem of biological invasion in forests has many facets, and a large diversity of scientific disciplines addresses these issues. To make progress in solving the problems forest invasions pose, developing interdisciplinary collaborations is crucial because the causes of invasions and many of the measures for prevention or management require expertise in biology, economics, and social sciences. The goal of this special issue is to compile a series of articles summarizing various biological, sociological, and policy subject areas associated with forest invasions from a global perspective. These papers were prepared by the task force, “Forests and Biological Invasions,” organized by the International Union of Forest Research Organizations. Publication of this special issue is intended to advance the integration of scientific knowledge and development of solutions to this very serious and growing problem.     

Effects of fragmentation and landscape variation on tree diversity in post-logging regrowth forests of the Southern Philippines

The conservation value of forest fragments remains controversial. An extensive inventory of rainforest trees in post-logging regrowth forest in the southern Philippines provided a rare opportunity to compare stem density, species richness, diversity and biotic similarity between two types of post-logging forests: broken-canopy forest fragments and adjacent tracts of closed-canopy ‘contiguous’ forest. Tree density was much lower in the fragments, but rarefied species richness was higher. ‘Hill’ numbers, computed as the exponential of Shannon’s diversity index and the inverse of Simpson’s diversity index, indicated that fragments have higher numbers of typical and dominant species compared to contiguous forest. Beta diversity (based on species incidence) and the exponential of Shannon’s diversity index was higher in fragmented forest, indicating higher spatial species turnover than in contiguous forest samples. Lower mean values of the Chao-Jaccard index in fragmented forest compared to contiguous forest also indicated a lower probability of shared species across fragments. The high species richness of contiguous forest showed that an earlier single logging event had not caused biodiversity to be degraded leaving mostly generalist species. Fragmentation and further low-level utilisation by local farmers has also not caused acute degradation. Post-logging regrowth forest fragments present a window of opportunity for conservation that may disappear in a few years as edge effects become more apparent. For the conservation of trees in forests in south-east Asia generally, our findings also suggest that while conservation of remaining primary forest may be preferable, the conservation value of post-logging regrowth forests can also be high.     

The interactions among China's economic growth and its energy consumption and emissions during 1978–2007

This paper analyzes the interactions among China's economic growth and energy consumption and emissions during 1978–2007. Conventional energy and emergy are applied to quantify energy consumption and emissions’ impact respectively. Several indicators, based on emergy, energy and monetary units, are applied to depict the relationships among economic growth and energy consumption and emissions’ impact. The results show that energy consumption and emissions’ impact rise simultaneously. Therein, nonrenewable energy resources possess absolute share in total energy consumption and undertake primary responsibility for increasing emissions’ impact, and NH₃–N in wastewater leads to the most emissions’ impact on environment. Energy mix and energy efficiency and pollution control make some achievements, but their improvements fall far behind economic growth rate. As a result, the structure of China's economy has been obviously optimized; however, the improvement of the relationship between China's economy, energy and environment is far behind that of its economic structure in this period. Therefore, China will continue to face huge pressure on resources and environment its rapid economic growth brings about in future. Those study results imply that enhancing energy efficiency, optimizing economic structure and strengthening pollution control will still be the main tasks for China's governments in future.     

Persistence of the threatened Knysna warbler Bradypterus sylvaticus in an urban landscape: do gardens substitute for fire?

Food resources can limit populations of insectivorous birds. Previous studies have shown strong correlations between bird population densities and their invertebrate food, with declining populations being attributed to loss of prey. This might also be the case for the threatened Knysna warbler (Bradypterus sylvaticus), which in the last 20 years has declined precipitously on the Cape Peninsula, South Africa. The bird is abandoning natural, protected forests, retreating to narrow belts of suburban, riverine woodland with dense, tangled understoreys. The potential invertebrate food availability in natural forests and suburban woodland was assessed against what is known of the bird’s preferred prey. The invertebrate food resource spectrum and abundance were determined using three sampling techniques in both natural forest and suburban woodland. Despite greater overall abundance of invertebrates in suburban woodland, the warbler’s preferred prey items were equally abundant in both habitats. This suggests that reduced food supply does not explain abandonment of natural forests by the warbler. Rather, it is concluded that the availability of suitable nesting substrata, which are more abundant in suburban woodland, has driven the biotope shift. This is an unusual case of a localized and threatened bird species faring better under transformed conditions than in natural habitats.     

Role of non-timber forest products in the economy of peripheral communities of knuckles national wilderness area of Sri Lanka: A farming systems approach

The Knuckles range of forests has been identified as a unique biological resource in Sri Lanka with much biodiversity. It is also important as a watershed which feeds the Mahaweli reservoir system. Having considered the present hazardous land-use practices such as cardamum production and shifting cultivation, the Knuckles range has been declared a national wilderness area. The Forest Department is in the process of preparing the management plan for the area. There are about 48 villages in the vicinity of the forest. This study attempts to estimate the composition of income in the peripheral communities, ticularly the extraction of non-timber forest products (NTFP) from this range of forests. Data were collected using structured questionnaires from 60 households in three villages in the vicinity of the forest. The rural economy is described using a farming systems approach and the net income contributed by each activity in the farming system was estimated. Results show that nine components of the farming system use resources from the village and the forest, with at least 47 plant species used by the villagers for different purposes. Cardamum production and shifting cultivation contribute significantly to the total income of the household, but the majority of households in the study depend upon forest resources to supply some portion of their income. Nevertheless, the monetary value of the annual income generated by NTFP is much lower than income from either cardamum production or shifting cultivation. If cardamum production and shifting cultivation are to be restricted under the conservation program, there could be additional pressure put on NTFP. Therefore, we suggest a study of the natural regen-eration capacity of selected NTFP; such information should be used in finalizing the management plan in the Knuckles range of forests.     

Confessions of solitary oaks: We grow fast but we fear the drought

Competition effects and management related disturbances can contribute to strong non-climatic signals in ring-width trends of trees from closed canopy forests. Removing this noise comes at the price of losing a considerable amount of (climatic) information on decadal and centennial time scales. Alternatively, open grown solitary trees, which never competed for light or other resources could function as less biased climate proxies. To explore this potential we analysed individual growth trends and climate-growth relationships of solitary oaks, potentially representative of former, open forests, and compared it to those of trees growing in adjacent closed canopy forests. Solitary oaks show differing tree allometry with bigger crowns and lower absolute heights. Their radial growth was significantly higher compared to forest trees. Contrary to our expectations, these solitary oaks show highly individualistic decadal growth trends. Their inter-annual variations are nevertheless in good agreement between individuals and stronger compared to trees from closed canopy forests. Climate –growth analysis revealed a significantly higher drought sensitivity of solitary oaks. Given the typical open medieval forest structure of large trees with extensive crowns growing in a mosaic of grazed woodlands and grasslands, it is likely that these trees contribute to the historical part of tree-ring collections. When trees from today’s denser forests forming the recent parts of the collections are used to calibrate reconstruction models, the differing drought sensitivity might therefore lead to an overestimation of historical droughts.     

Development policy,forests, and peasant farms: Reflections on Huastec-managed forests’ contributions to commercial production and resource conservation

The Huastec Indians of northeastern Mexico manage their forests in an indigenous system that integrates commercial and subsistence production. Elements of primary and secondary forest coexist with introduced species in this diverse silvicultural structure which complements the swidden and permanent agriculture fields of the Huastec farmstead. The forest’s direct production of the food, timber, and fuel resources discussed here buffers the Huastec peasant family against market fluctuations and the failed harvest of a single crop. The Huastec system of forest management offers an alternative pattern to the agroforestry and plantation schemes now being suggested for development in the tropics. It is an alternative that provides protection for wild genetic resources while it contributes to the combination of commercial and subsistence agriculture so important for the successful modernization of peasant agriculture. The documentation of this system demonstrates that ethnobotanists and economic botanists have an important but unrealized role to play in the protection of biotic resources and in the development of sustained yield agroecosystems for peasants. The contributions of ethnobotanists are particularly valuable because they can find where and why useful wild species persist in agroecosystems. A greater effort to direct the attentions of policy makers to the value of ethnobotanical knowledge is needed.     

Global environmental change effects on plant community composition trajectories depend upon management legacies

The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land‐use legacies given different community trajectories initiated by prior management, and subsequent responses to altered resources and conditions. We tested this expectation for species richness and functional traits using 1814 survey‐resurvey plot pairs of understorey communities from 40 European temperate forest datasets, syntheses of management transitions since the year 1800, and a trait database. We also examined how plant community indicators of resources and conditions changed in response to management legacies and environmental change. Community trajectories were clearly influenced by interactions between management legacies from over 200 years ago and environmental change. Importantly, higher rates of nitrogen deposition led to increased species richness and plant height in forests managed less intensively in 1800 (i.e., high forests), and to decreases in forests with a more intensive historical management in 1800 (i.e., coppiced forests). There was evidence that these declines in community variables in formerly coppiced forests were ameliorated by increased rates of temperature change between surveys. Responses were generally apparent regardless of sites’ contemporary management classifications, although sometimes the management transition itself, rather than historic or contemporary management types, better explained understorey responses. Main effects of environmental change were rare, although higher rates of precipitation change increased plant height, accompanied by increases in fertility indicator values. Analysis of indicator values suggested the importance of directly characterising resources and conditions to better understand legacy and environmental change effects. Accounting for legacies of past disturbance can reconcile contradictory literature results and appears crucial to anticipating future responses to global environmental change.     

北京市房山区野生植物资源及濒危植物保护策略

北京市房山区植被丰富,以暖温带落叶阔叶林为主,并混生温带针叶林,表现出明显的垂直地带性分布。通过对北京市房山区进行野生植物资源调查,统计出共有野生植物80科,259属,409种,同时分析了房山区野生植物资源在园林中的潜在应用价值;另外,通过对比相关濒危植物资料,总结出房山区的濒危植物21种,并就重点保护植物保护策略进行探讨。     

Sustainable management of planted landscapes: lessons from Japan

In Japan, 42?% of forests are planted forests, and most of them were established after World War II (1950–1980) to meet increased wood demands. Although Japanese planted forests are now reaching their planned harvest age, they have not been managed, and their restoration is now being discussed. Japanese foresters have not cut their own forests, and the country’s high wood demands have been met by imports during recent decades. The decline of young forests due to the stagnation of forestry activity is suggested to be partly responsible for the nation-wide decline in early-successional species, which is referred to as the “second crisis of biodiversity.” As a timber-importing nation, it is suggested that Japan has underused the nation’s own forests and has overused forests elsewhere. A revival of Japanese plantation forestry may contribute to the restoration of early-successional species because young planted forests are likely to provide suitable habitats. Furthermore, only 30?% of the current planted forests in Japan will be needed to meet the expected future domestic demand for lumber and plywood without imports. The remaining 70?% of the current planted forests may be restored to natural forests with or without harvesting. The history of Japanese planted forests suggests that some natural trees/forests should be retained, even in the landscapes that specialize in wood production, because part of the planted forests may be economically marginalized in the future, and their restoration to natural forests would then be needed.     

中国森林生态资产价值评估

森林资源是支撑人类社会发展的重要生态资产,探索森林生态资产价值的评估方法,对合理利用和有效保护森林资源具有重要意义。运用净现值法计算了中国森林生态资产总价值为698.5万亿元,其中直接价值为7.5万亿元,包括林木价值4.5万亿元和林下产品价值3.0万亿元;间接价值为691万亿元,其中,气候调节价值量最高,占间接价值的48%;水源涵养价值量次之,占间接价值的27%。从森林生态资产总价值的分布来看,广西省、广东省和云南省位于全国前列,分别占森林生态资产总价值的10%、9%和9%。单位面积森林生态资产价值表现为海南省、浙江省和广东省较高,分别为954万元/hm2,915万元/hm2和888万元/hm2。森林生态资产价值研究为我国编制自然资源资产负债表提供理论依据,因此全面的估算中国森林生态资产价值很有意义。     

Why are leaf‐cutting ants more common in early secondary forests than in old‐growth tropical forests? An evaluation of the palatable forage hypothesis

I evaluated the hypothesis that leaf‐cutting ants are more common in early successional forests than in old‐growth forests because pioneer species, which dominate in early successional habitats, appear more susceptible to leafcutters than shade‐tolerant species, which dominate primary forests (palatable forage hypothesis). The relative importance of pioneer and shade‐tolerant species as plant resources for leaf‐cutting ant colonies was evaluated (1) by literature review of leaf‐cutting ants’ diet, and (2) experimentally, using field assays to determine leafcutter's selectivity. Pioneer species were harvested three times more frequently than shade‐tolerant species and made up the largest component of the diet in all the studies reviewed. The amount harvested was not correlated with the plant species abundance. In addition, leaves from pioneer plants were selected eight times more than leaves from shade‐tolerant species in the field assays. These results support the palatable forage hypothesis. Leafcutters probably select pioneer leaves because of their low level of chemical defenses and high nutrient content. The high availability of pioneer species in early successional forest probably decreases the cost to locate palatable resources. Therefore, early successional habitats support more ant colonies than old‐growth forests. On the other hand, the effective defense mechanisms of mature plant species and the high dispersion of palatable plants could explain the low density of leaf‐cutting ant colonies in old‐growth forests. The palatable forage hypothesis is compared with other hypotheses that explain leaf‐cutting ant density. The preference of foundress queens for forest clearings, the dependence of small colonies on herbs, and the importance of pioneer plant species for mature colonies (palatable forage hypothesis) can be considered complementary, because they focus on different stages of the colony's life history. Consequently, the availability of pioneer plants appears to be one of the most influential factors determining mature leaf‐cutting ant nest densities in Neotropical forests.     

Ecological considerations for using dipterocarps for restoration of lowland rainforest in Southeast Asia

The lowland dipterocarp forests of Southeast Asia support a substantial proportion of the world’s biodiversity. They are of considerable environmental and economic value at the local, regional and global scale, providing many goods and services to a growing population. The forests of this region are among the fastest disappearing in the world and restoration is urgently required. This paper provides a review of the ecological constraints to restoration of lowland dipterocarp forest in Southeast Asia. It focuses on the production of planting stock, the significance of site-species matching and post-planting site maintenance. It identifies gaps in our knowledge and highlights priority areas of research. Adopting a long-term view is essential for restoring as well as conserving the dipterocarp forests of Southeast Asia. An immediate strategy for the conservation and management of dwindling genetic resources of these important timber species is essential. This will provide the foundations for sourcing seed and production of planting material for longer term restoration. The importance of species-site matching, mycorrhizal fungi and post-planting maintenance for restoration are apparent. Financing is a major limiting factor to dipterocarp forest restoration. Trading in carbon, private finance and environmental markets afford considerable opportunities for restoring these forests providing their total value is recognised. Despite the wealth of ecological knowledge we already have for scientifically-informed forest restoration, without the backing of governments and corporate stakeholders, forest restoration will not gain the urgently required momentum.