Fuelwood Use and Availability in Bhutan: Implications for National Policy and Local Forest Management

Fuelwood is the principal energy resource for millions of households around the world, yet its use, availability and management remain poorly understood in many areas. We document fuelwood consumption, growth/yield and standing biomass in a Bhutanese village and alpine area used seasonally by villagers where the government is concerned about harvesting in a recently designated national park. Pinus wallichiana was the only fuelwood used in the village and assessments suggest 52 ha could sustain local needs at current consumption levels (54 m3/household/yr). In contrast, Rhododendron aeruginosum was used in the alpine site and at current consumption rates all will be consumed by 2023. Our findings emphasize the need to manage fuelwood based on site-specific consumption, growth and standing biomass criteria rather than single, nation-wide regulations. We provide methods to develop sustainable fuelwood harvesting and forest management guidelines that are applicable to government and community-managed forests in Bhutan and elsewhere.     

Spatial ecology of arboreal snakes (Hoplocephalus stephensii,Elapidae) in an eastern Australian forest

Abstract Stephens' Banded Snakes (Hoplocephalus stephensii Krefft 1869) are large (to 1 m), highly arboreal elapid snakes, restricted to mesic forested areas along the eastern coast of Australia. Radiotelemetric monitoring of 16 individuals at Whian Whian State Forest in north‐eastern New South Wales over 25 months provided the first data on spatial ecology of this threatened taxon. Two major influences on movements by Stephens' Banded Snakes were identified: the distribution of large hollow‐bearing trees, and the avoidance of conspecifics. Radiotracked snakes were sedentary inside tree hollows for extended periods (mean = 8 days) during their active season, interrupted by occasional long (mean = 124 m) nocturnal movements to another shelter tree. Snakes travelled on the ground rather than within the canopy, and thus were potentially exposed to terrestrial predators. Although the home ranges of the radiotracked snakes overlapped substantially (mean = 27%), simultaneous occupancy of ‘shared’ shelter trees was less common than expected by chance. Hence, we conclude that adult Stephens' Banded Snakes generally avoid the presence of conspecifics. Snakes used from five to 30 shelter trees and home ranges of male snakes were larger than those of females (mean = 20.2 vs 5.4 ha). The large spatial scale of these movements, and limited overlap among individuals, means that a viable population of this taxon requires a large area of contiguous forest. This requirement may explain why the species has not persisted in small forest fragments.     

Estimating Long-Term Changes in China’s Village Landscapes

Over the past 50 years, China’s ancient agricultural village landscapes have been transformed by unprecedented social, technological, and ecological changes. Although these dense anthropogenic mosaics of croplands, settlements, and other used lands cover more than 2 million square kilometers across China, the nature of these changes and their environmental impacts remain poorly understood because their spatial scale is generally too small to measure accurately using conventional land-change methods. Here, we investigate the regional consequences of fine-scale landscape changes across China’s village regions from 1945 to 2002 using high-resolution, field-validated ecological mapping of a regionally stratified sample of village landscapes at five sites across China, with uncertainties estimated using model-based resampling and Monte Carlo methods. From 1945 to 2002, built surface areas increased by about 7% (90% credible interval = 2–17%) across China’s village regions, an increase equivalent to about three times the total urban area of China in 2000. Although this striking result is explained by a near doubling of already large village populations and by lower housing density per capita in rural areas, two unexpected changes were also observed: a 9% net increase (−4% to +21%) in regional cover by closed canopy trees and an 11% net decline (−30% to +3%) in annual crops. These major regional changes were driven primarily by intensive fine-scale land-transformation processes including tree planting and regrowth around new buildings, cropland abandonment, and by the adoption of perennial crops and improved forestry practices. Moreover, the fragmentation, heterogeneity, and complexity of village landscapes increased over time. By coupling regional sampling and upscaling with observations in the field, this study revealed that fine-scale land-change processes in anthropogenic landscapes have the potential for globally significant environmental consequences that are not anticipated, measured, or explained by conventional coarser resolution approaches to global and regional change measurement or modeling. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. E. C. Ellis conceived and managed research, and wrote the article; K. Peng, H. S. Xiao, H. Wang, S. C. Li, J. X. Wu, and J. G. Jiao conducted research; H. Ouyang, X. Cheng, and L. Z. Yang managed research; N. Neerchal and Y. Zhuang contributed methods and models.     

Forest biodiversity gradients and the human impact in Annapurna Conservation Area, Nepal

Patterns of biodiversity, environment and human impact were studied in 57 sample plots in an 1,178 ha forest area in a rural mountain area of Nepal that is administrated by the Annapurna Conservation Area Project. Alpha-, beta- and gamma-diversity was measured or estimated for six groups of organisms: trees, shrubs, climbers, herbs, polypores and mycorrhizal fungi, and the recorded patterns were correlated with a set of environmental variables. Human impact in terms of fuelwood collection, selective cutting and grazing was found to influence species diversity patterns in all organism groups. Species richness of trees, climbers and polypores at plot level (alpha-diversity) generally responded negatively to human impact, whereas species richness of herbs and shrubs showed a positive relation. Species turnover (beta-diversity), measured as length of the DCA first axis, was significantly correlated to distance to village for all species groups. This indicates that the human impact is very important for the biodiversity patterns in the study area, and that biodiversity connected to undisturbed forest habitats are potentially threatened in the area. The results are discussed in the context of practical conservation. A proposal for future management zones addressing protection of biodiversity without limiting the local use of the forest resource is put forward.     

农户生活消费对环境影响的空间差异及其原因——基于张掖市2010年调查数据

农户是农村最主要的行为主体,其生活消费对环境有重要影响,然而农户的生活消费模式等因素的差异导致对环境的影响在空间上存在差异,为了缓解农户生活消费对环境的压力,需要研究其消费对环境影响的空间差异。基于张掖市2010年调查数据和统计资料研究了农户生活消费对环境影响空间差异,并分析了原因,研究结果显示:(1)张掖市2010年人均生态足迹为1.056hm2/人,人均生态承载力为1.705hm2/人,人均生态盈余0.649hm2/人;(2)从生态足迹的构成看,当地的生活消费主要是以生物资源和化石能源消耗为主,占总生态足迹的81%,而建筑用地和水域消耗最少,占总生态足迹的1.2%。;(3)张掖市五县(区)农户生活消费对环境的影响总体差异较小,Gini系数为0.309。但是区域间的差异远远大于区域内的差异,区域间的差异为0.442,占总差异的71.1%,区域内的差异为0.18,占总差异的28.9%。其中,甘州区农户生活消费对环境影响差异最大,Theil指数为0.078;(4)农户消费模式、家庭规模和人均年收入增多,将加剧农户对环境的压力,劳动力受教育程度、社会资本存量和非农化程度提高,将在一定程度上减缓农户对环境的影响。     

Landscape-Scale Simulation of Heterogeneous Fire Effects on Pyrogenic Carbon Emissions,Tree Mortality,and Net Ecosystem Production

Fire influences carbon dynamics from local to global scales, but many uncertainties remain regarding the remote detection and simulation of heterogeneous fire effects. This study integrates Landsat-based remote sensing and Biome-BGC process modeling to simulate the effects of high-, moderate-, and low-severity fire on pyrogenic emissions, tree mortality, and net ecosystem production. The simulation area (244,600 ha) encompasses four fires that burned approximately 50,000 ha in 2002–2003 across the Metolius Watershed, Oregon, USA, as well as in situ measurements of postfire carbon pools and fluxes that we use for model evaluation. Simulated total pyrogenic emissions were 0.732 Tg C (2.4% of equivalent statewide anthropogenic carbon emissions over the same 2-year period). The simulated total carbon transfer due to tree mortality was fourfold higher than pyrogenic carbon emissions, but dead wood decomposition will occur over decades. Immediately postfire, burned areas were a simulated carbon source (net C exchange: −0.076 Tg C y⁻¹; mean ± SD: −142 ± 121 g C m⁻² y⁻¹). As expected, high-severity, stand-replacement fire had disproportionate carbon impacts. The per-unit area effects of moderate-severity fire were substantial, however, and the extent of low-severity fire merits its inclusion in landscape-scale analyses. These results demonstrate the potential to reduce uncertainties in landscape to regional carbon budgets by leveraging Landsat-based fire products that account for both stand-replacement and partial disturbance.     

Intercolony variation in foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period

Using GPS loggers, we examined the influence of colony, sex, and bird identity on foraging flight characteristics of black‐headed gulls Chroicocephalus ridibundus during the incubation period. We studied tracks of 36 individuals breeding in one urban and two rural colonies in Poland. Birds from both rural colonies performed the furthest flights (mean max distance 8–12 km, up to 27 km) foraging mainly in agricultural areas. Gulls from the urban colony performed shorter flights (mean 5 km, up to 17 km) visiting mainly urbanized areas and water bodies. We found that females performed longer flights and their flight parameters were less repeatable compared to males. Males from both rural colonies visited water bodies more frequently than females. In all colonies, males (but not females) used habitats unproportionally to their availability in the vicinity. Relatively low interindividual and relatively high intraindividual overlap in home ranges indicated considerable foraging site fidelity. Individuals specialized in the use of a particular type of habitat performed shorter foraging flights compared to individuals using diverse habitats during their foraging flights. Our results indicate diverse foraging strategies of black‐headed gulls, including generalists that explore various habitats and specialists characterized by high foraging site and habitat fidelity.     

Children's Television,Radio, Internet,and Computer Usage in a City and a Village of China

A first step in understanding media consumption is to understand the time people spend using media, and how usage varies across demographic groups and in response to other factors. While there is ample research from the West, research from China is less evident. Here I provide a case study of children's media usage in a rural and an urban area in China. The findings showed that a greater proportion of children in the urban sample used media such as television, Internet, and computer games, and that rural–urban residency had the most significant influence on television viewing. Further, more urban children reported their parents had concerns about media usage, whereas a greater proportion of children in the rural area had televisions in their bedrooms and ate meals while watching television. This difference was explained by differences in socio-economic levels, traditional values, and educational background. The findings show that the rural–urban difference, and other factors such as parental concern, should be considered when conducting and interpreting media consumption. There also are implications for health because a large proportion of children in the present study had televisions in their bedrooms and ate while watching television, and such behaviors in the West have been associated with unhealthy lifestyles.     

河北邢台市发现领雀嘴鹎

2019年5月6日上午8时,在河北省邢台市浆水镇香炉寨村北部,浆水川河道西岸的树上拍摄到一只领雀嘴鹎。     

Effects of population density on forest structure and species richness and diversity of trees in Kampong Thom Province, Cambodia

This study examined differences in stand structure, tree species richness, and tree species diversity in relation to population density in Kampong Thom Province, Cambodia. Tree data were obtained from a 1997 forest inventory involving 60 clusters (540 plots) systematically distributed over 30% of the provincial forest area. Spatially referenced population data were obtained from the 1998 national population census. The average number of trees per cluster was 356/ha, the average basal area, 23 m²/ha, the average stand volume, 217 m³/ha, and the average aboveground biomass, 273 Mg/ha for all trees of DBH 10 cm and larger. The average species richness per cluster was 37 species, while average species diversity was measured as 0.916 using Simpson’s index and 2.98 by Shannon’s index. Significant negative correlations were generally found between population density surrounding clusters and tree density, basal area, stand volume, aboveground biomass, and species richness and diversity for three examined diameter classes (DBH of 10–30, ≥30, and ≥10 cm). As the distance from clusters for calculating population density increased, the correlation levels increased up to 5 or 7 km, depending on the variables and diameter class, and then stayed relatively constant for stand structure variables and decreased for species richness and diversity. The results indicate that evidence of disturbance was more pronounced at higher population density up to around 5 to 7 km. We suggest that introduction of greater controls on human disturbance should be a high priority for resource management and conservation in Kampong Thom Province and, presumably, Cambodia as a whole.     

Impact of the invasive ant Wasmannia auropunctata (Formicidae: Myrmicinae) on local ant diversity in southern Cameroon

The little fire ant, Wasmannia auropunctata Roger, is one of the world's most destructive invasive ants. It has been present in Cameroon for more than four decades, but its impact on local ant diversity is not known. We studied impact of W. auropunctata in three disturbed habitats located in rural and urban areas. We monitored ant diversity in both invaded and noninvaded zones in each area using a combination of three sampling methods: bait, pitfall traps and visual catch in quadrat. We collected 28 species in urban area and 64 in rural area. In invaded zone, W. auropunctata made up 97.72% and 99.96% of all ant fauna and ant species richness decreased to 7 and 2 in urban and rural area, respectively. In accordance with others findings in introduced environments, the presence of W. auropunctata has severely reduced abundance and richness of local ant species in both urban and rural environments in Cameroon. Measures should therefore be put in place to prevent its introduction in natural environment as forest reserves and natural parks.     

Twelve years on: Ecological restoration and rehabilitation at Sydney Olympic Park

When Sydney's 760 ha Homebush Bay industrial site was rezoned for urban renewal and staging the Olympic Games in 2000, massive investment was made to remediate past damage and develop a future public park containing active recreation and natural areas. Since that date, endangered forest and wetland communities, along with threatened fauna species, have received priority treatments to improve the ecological function of the Park's natural areas. Evaluation of progress 12 years on reveals substantial achievements and multiple lessons.     

Impact of environmental conditions on fruit production patterns of shea tree (Vitellaria paradoxa C.F.Gaertn) in West Africa

A better knowledge of the impact of environmental conditions on shea tree’s fruit production is critical to improve the species management. Fruit production of 237 shea trees was monitored over five successive years (2014–2018) to understand how climatic variables, shea tree population and land use could affect fruit production patterns of the species in Burkina Faso. Data were collected in 12 shea tree populations distributed in three climatic zones with two contrast land use systems. The results showed that fruit production was negatively correlated with mean annual temperature, temperature seasonality, rainfall seasonality and solar radiation, while it was positive with annual rainfall. Therefore, fruiting modelling is needed to predict the impact of future climate change on reproductive ability of the species. In each climatic zone, fruit production was significantly different among shea tree populations (p < 0.05). Within populations, fruit production greatly varies among years with specific patterns of variation. Land use had significant effect on fruit production of shea tree (p < 0.05). Annually, shea trees produced about 12 times more in agroforestry parklands than in protected areas. Interannual variation in fruit production at individual tree level was higher in protected areas. The cultivation of shea tree is recommended to improve its fruit productivity.     

Impacts of Urbanization on Ecosystem Goods and Services in the U.S. Corn Belt

In this study, three cities located in the U.S. Corn Belt are evaluated for impacts of past (1992–2001) and projected (2001–2030) urban expansion on ecosystem goods and services, with a specific focus on changes in energy balance, hydrology, and productivity. Scenarios for high-, medium- and low-density urban areas are simulated using a dynamic agro-ecosystem model (Agro-IBIS), by incorporating new parameterizations for impervious surfaces and turf grass. Moderate Resolution Imaging Spectroradiometer (MODIS) 500-m albedo data and remote sensing-derived 30-m resolution maps from the U.S. National Land Cover Database are used as model input to simulate biogeochemical, thermodynamic, and hydrological cycles for a range of land-cover types in each region. The results show that the expanding urban areas have a significant impact on each city’s capacity to regulate climate and flooding. High-density urban areas, for instance, have soil surface temperatures up to 6°C higher than soils within natural and managed ecosystems. Expansion of turf grass in residential areas could require an additional 8–105 million m³ of water use annually, which increases runoff by 15–48% and reduces the capacity to respond/adapt to flooding. Finally, the analysis shows that net primary productivity (NPP) decreases as expected due to the removal of cropland, forests, and grasslands in favor of development, but increased urban turf grass provides an annual offset of 40–210 g C m⁻². Urban expansion through 2030 is estimated to lower total annual crop production by 8.1, 8.6, and 16.7% for the Madison, Peoria, and Indianapolis regions, respectively. Given current projections for city growth to exceed 2–3% per year in the north-central U.S., urban expansion across a nine-state region in the Corn Belt could potentially take an additional 210,000–310,000 ha of farmland out of production annually at a time when demand for food, fuel, and fiber is increasing. Because conversion of cropland to urban uses is nearly always unidirectional, any changes to ecosystem goods and services due to urbanization are likely to be permanent and irreversible.     

Reconciling Forest Conservation and Logging in Indonesian Borneo

Combining protected areas with natural forest timber concessions may sustain larger forest landscapes than is possible via protected areas alone. However, the role of timber concessions in maintaining natural forest remains poorly characterized.An estimated 57% (303,525 km²) of Kalimantan''s land area (532,100 km²) was covered by natural forest in 2000. About 14,212 km² (4.7%) had been cleared by 2010. Forests in oil palm concessions had been reduced by 5,600 km² (14.1%), while the figures for timber concessions are 1,336 km² (1.5%), and for protected forests are 1,122 km² (1.2%). These deforestation rates explain little about the relative performance of the different land use categories under equivalent conversion risks due to the confounding effects of location.An estimated 25% of lands allocated for timber harvesting in 2000 had their status changed to industrial plantation concessions in 2010. Based on a sample of 3,391 forest plots (1×1 km; 100 ha), and matching statistical analyses, 2000–2010 deforestation was on average 17.6 ha lower (95% C.I.: −22.3 ha–−12.9 ha) in timber concession plots than in oil palm concession plots. When location effects were accounted for, deforestation rates in timber concessions and protected areas were not significantly different (Mean difference: 0.35 ha; 95% C.I.: −0.002 ha–0.7 ha).Natural forest timber concessions in Kalimantan had similar ability as protected areas to maintain forest cover during 2000–2010, provided the former were not reclassified to industrial plantation concessions. Our study indicates the desirability of the Government of Indonesia designating its natural forest timber concessions as protected areas under the IUCN Protected Area Category VI to protect them from reclassification.     

Homestead tree holdings: Composition,uses and challenges in Checheche Growth Point,South East Lowveld,Zimbabwe

Understanding homestead tree holdings is important for developing local conservation and livelihood strategies. However, relative to urban homesteads, tree holdings in rural African homesteads remain little studied, especially in semi-arid settings. Using ecological and household surveys, this paper examines homestead tree composition, uses and challenges in Checheche, Zimbabwe. In total, 1,594 trees were encountered across 147 homesteads. Nearly, all homesteads (99%) had trees, and most of them were primarily planted for fruits and shade. Fuelwood, traditional medicines, windbreak and homestead decoration were considered as secondary benefits. Overall, tree density was approximately 112 trees/ha, with an average of 11 ± 7.1 trees per homestead. Homestead tree holdings were explained by age and gender of respondent, homestead ownership and importance attached to and knowledge of trees. Challenges to tree planting mentioned include termites, diseases, livestock damage, high temperatures, water shortages and poor quality soils. Overall, this study shows that homestead tree planting is widespread in semi-arid rural settings but constraints to tree planting ought to be addressed to optimise the benefits from trees. Further research is needed to fully understand the socioecological context that explains tree survival, as a basis for developing interventions for enabling homestead tree planting.     

Forests for Energy and the Role of Planted Trees

Woodfuels currently supply 7 percent of worldwide energy use and are much more important in developing than developed countries. Worldwide fuelwood use may be slowly declining, while charcoal production is increasing. In developing countries, woodfuel comes from natural forests, woodlands, shrublands, plantations and trees outside forests; the last is often the most important source. In developed countries, woodfuels are largely from industrial roundwood processing where up to 50 percent of logs may be used for energy. In urban areas, of both developing and developed countries, woodfuels also arises from wood processing and construction and other urban residues including tree trimming. Currently, apart from some nonindustrial plantations and the small areas of energy plantations, woodfuel largely results from by-products and residues.

Forest plantation may currently provide 15 to 20 percent of all fuelwood and this contribution will rise due to continued tree planting plus the rapidly increasing industrial plantation harvest. However, forest and woodfuel-use data are of uneven quality, making estimates tenuous.

There is potential to increase the amount of woodfuels in developed countries but its use will depend on fossil fuel price increases, and on ecological and social issues. In Nordic countries, forest residue use has grown, being underpinned by carbon taxes and research and development. Site nutrient conservation is assisted by leaving foliage on site and by returning the ash after burning. Leaving bark on site may be important for eucalypts.

In developing countries participatory programmes are critical for encouraging tree planting. Farmers seldom plant for fuelwood alone. Large-scale fuelwood plantations programs have not always been successful. Agroforestry practices are often practiced as they provide multiple benefits, including the provision of woodfuel. Silviculture should be readily adoptable, with special attention being given to species selection, high-quality planting stock, establishment methods and protection from animals.

Because of woodfuel's low relative value, energy is seldom a management objective of industrial plantations. However, often silviculture could be altered to increase bioenergy output, particularly with those sawlog regimes based on low stockings and non-extraction thinnings, and through more intensive silviculture. As a supplement to current silvicultural decision-making tools, energy analysis of silvicultural options would assist in efficient allocation of fossil fuels.     

Urban forest fragments as unexpected sanctuaries for the rare endemic ghost butterfly from the Atlantic forest

Anthropogenic land expansion, particularly urbanization, is pervasive, dramatically modifies the environment and is a major threat to wildlife with its associated environmental stressors. Urban remnant vegetation can help mitigate these impacts and could be vital for species unable to survive in harsh urban environments. Although resembling nonurban habitats, urban vegetation remnants are subject to additional environmental stresses. Here, we evaluate the occurrence and density of the endemic ghost butterfly (Morpho epistrophus nikolajewna) that was once common, in the highly fragmented Atlantic forest of NE Brazil. We tested whether this butterfly would be found at lower densities in urban forest fragments of contrasting sizes as opposed to rural ones, given the number of environmental stressors found in urban areas. We surveyed 14 forest fragments (range 2.8 to over 3,000 ha) of semideciduous Atlantic forest in rural and urban locations using transect based distance sampling. The ghost butterflies showed strong seasonality; flying only from April to June. They were only identified in an urban fragment (515 ha), with an estimate of 720 individuals and a density 1.4 ind/ha. All forest fragments had experienced some level of logging in the past, which might have had an effect in the butterfly population. Nevertheless, rural forest fragments were subject to increased particulate matter concentrations, associated to biomass burning that we suggest might have had a more influential role driving the collapse of rural populations. Our findings show the importance of urban forest remnants to sustain population of this endangered species.     

Methane emissions from contrasting urban freshwaters: Rates,drivers, and a whole‐city footprint

Global urbanization trends impose major alterations on surface waters. This includes impacts on ecosystem functioning that can involve feedbacks on climate through changes in rates of greenhouse gas emissions. The combination of high nutrient supply and shallow depth typical of urban freshwaters is particularly conducive to high rates of methane (CH₄) production and emission, suggesting a potentially important role in the global CH₄ cycle. However, there is a lack of comprehensive flux data from diverse urban water bodies, of information on the underlying drivers, and of estimates for whole cities. Based on measurements over four seasons in a total of 32 water bodies in the city of Berlin, Germany, we calculate the total CH₄ emission from various types of surface waters of a large city in temperate climate at 2.6 ± 1.7 Gg CH₄/year. The average total emission was 219 ± 490 mg CH₄ m^?2 day^?1. Water chemical variables were surprisingly poor predictors of total CH₄ emissions, and proxies of productivity and oxygen conditions had low explanatory power as well, suggesting a complex combination of factors governing CH₄ fluxes from urban surface waters. However, small water bodies (area <1 ha) typically located in urban green spaces were identified as emission hotspots. These results help constrain assessments of CH₄ emissions from freshwaters in the world's growing cities, facilitating extrapolation of urban emissions to large areas, including at the global scale.