Climate Change, Elevational Range Shifts, and Bird Extinctions

Abstract:  Limitations imposed on species ranges by the climatic, ecological, and physiological effects of elevation are important determinants of extinction risk. We modeled the effects of elevational limits on the extinction risk of landbirds, 87% of all bird species. Elevational limitation of range size explained 97% of the variation in the probability of being in a World Conservation Union category of extinction risk. Our model that combined elevational ranges, four Millennium Assessment habitat-loss scenarios, and an intermediate estimate of surface warming of 2.8° C, projected a best guess of 400–550 landbird extinctions, and that approximately 2150 additional species would be at risk of extinction by 2100. For Western Hemisphere landbirds, intermediate extinction estimates based on climate-induced changes in actual distributions ranged from 1.3% (1.1° C warming) to 30.0% (6.4° C warming) of these species. Worldwide, every degree of warming projected a nonlinear increase in bird extinctions of about 100–500 species. Only 21% of the species predicted to become extinct in our scenarios are currently considered threatened with extinction. Different habitat-loss and surface-warming scenarios predicted substantially different futures for landbird species. To improve the precision of climate-induced extinction estimates, there is an urgent need for high-resolution measurements of shifts in the elevational ranges of species. Given the accelerating influence of climate change on species distributions and conservation, using elevational limits in a tested, standardized, and robust manner can improve conservation assessments of terrestrial species and will help identify species that are most vulnerable to global climate change. Our climate-induced extinction estimates are broadly similar to those of bird species at risk from other factors, but these estimates largely involve different sets of species.     

Environmental implications of tropical deforestation

SUMMARY

Forests are fundamental and vital components of the world ecosystems. The essential links between forest and man are now receiving renewed and urgent attention, and there is increasing awareness that the value of forests to life on Earth is beyond economic value, and should be above political considerations. Tropical forests, generally marked out by richness in species, are found in more than 80 countries and account for roughly one-third of the world's forest cover. They encompass a wide variety of forest types found under diverse environmental conditions — from lush, constantly wet rain forests to arid thorn woodlands. These forests have been estimated to cover about 1715 million hectares in Africa alone. They have provided habitats for wildlife and wood, fibre, food and many other products to generations of mankind and are invaluable genetic resources of plants. Rapid population growth has, however, resulted in increasing the pressure on these forests, with a consequent decline in their qualitative and quantitative values. Throughout the world, forest lands have been cleared extensively for agriculture, and deforestation continues today. In the tropics, 10–25 million ha are being lost each year, with Africa alone losing 4–5 million ha annually. It has been estimated that, at this rate, the remaining tropical forest would disappear in 60–80 years; thereby leading to catastrophic environmental changes. The serious impact of these changes on the environment and on human needs is awakening world attention, and alarming consequences have sometimes been suggested. This paper highlights the major causes of tropical deforestation and its environmental consequences. Possible efforts to arrest the unpleasant trend are discussed.     

Land-use planning for sustainable resource development in Kumaon Lesser Himalaya—a study of the Gomti watershed

SUMMARY

The Lesser Himalaya, as the most densely populated part of the tectonically active and ecologically sensitive Himalayan mountain ranges, deserves specific attention to the conservation of the environment and the sustainable development of natural resources. Rapid growth of the human population during recent years, and the absence of any viable means of livelihood other than uneconomic crop farming have led to the uncontrolled exploitation of land areas and the consequent degradation and depletion of critical biophysical resources in the region. The need for sustainable development in Himalaya, therefore, makes it imperative to adopt a comprehensive land-use policy based on land capacity analysis that is scientific and practical. The main objective of this paper is to evolve an optimal land-use framework for the Gomti Watershed, situated in Kumaon, Lesser Himalaya. A detailed study of the traditional land use, regional agricultural system and the areas prone to environmental hazards was made throughout the watershed, through the preparation of large scale topographical forest and land record maps, field surveys and mapping. The average slope was considered as the principal parameter of land capacity, the potential for landslides and the intensity of erosion. Recognising the drastic changes that have taken place in the traditional land use, the watershed area has been proposed to be defined as protected forests (33.41%), community forests (32.86%), cultivation (23.33%) and horticulture (8.30%).     

广州市南沙区海岸防护林群落构建技术研究

森林是稳固和改善生态环境的重要载体,因其能提供巨大的生态服务功能而备受各国政府和学界的关注。珠江三角洲地区城市化进程的步伐逐渐加快,带来一系列环境问题。以广州市南沙区海岸景观防护林（也即河涌水网林、公路隔离林、海岸防风林）建设为例,主要研究了防护林的关键构建模式、林分群落结构等方面内容。结果显示,采用多层次的乔灌草配置,遵循适地适树的原则,以本土树种为主,搭配部分优良的引进树种,采取适合的营林措施,可构建出具有一定防护功能的人工林群落。广州南沙防护林建设是珠三角地区城市森林建设的一个缩影和代表,为我国南方城市森林建设理论的创建提供了一定的参考经验。破解城市化危机,创建宜居城市环境,实现城市可持续发展,应综合考虑城市的人口集中程度,经济发展规模,环境污染模式,针对具体的水分、气候和土壤等要素,运用多学科理论和技术,制定合适的森林构建模式,并需要政府、社会组织、以及公众的协同努力。     

Could Peace be Worse than War for Colombia's Forests?

The forests of Colombia are influenced by the actions of armed groups and, in many cases, their settlers are economically dependent on illicit crops. Up to the present armed conflict has simultaneously discouraged organized exploitation in some frontier areas, and encouraged unsustainable use of natural resources therein. The Colombian government seeks to end the conflict by pursuing peace negotiations, and to eradicate illicit crops. How will these policies affect the forests? The environmental consequences of these policies are not only dependent on the unlikely economic success of alternative development, but on making informed decisions about infrastructure development in affected areas.     

Discourses of Place: Environmental Interpretation about Vermont Forests

Motivated by a lack of scholarly attention to the substance of interpretive messages and materials, this study examines discursive aspects of interpretative brochures available at forest recreation and tourism sites in Vermont, United States. Directive statements that instruct and guide visitor experiences—and the discourses to which they contribute—were analyzed for content, form, and meaning. Across the interpretive brochures, four broad discourses were identified: the natural forest, the recreational forest, the productive forest, and the dependent forest. Consideration of intertextuality revealed a fifth, hybrid discourse that linked forests to meanings of Vermont as a distinctive place. The convergence of these discourses across the set of brochures gives insight into the ways interpretation serves to both direct individual visitor experiences at particular sites, and to influence the development of larger-scale place meanings.     

Impact of forest policies on timber production in India: a review

Until the 20th century, forest policies across the globe focused primarily on effective forest utilization for timber production. Subsequent loss of forest land prompted many countries to review and amend such policies, in an attempt to incorporate the principles of conservation and sustainable forest management. One of the countries to implement such changes was India, which introduced new policies, acts and programmes to regulate forest conversion and degradation, beginning in the 1980s. These policies, acts, and programmes included the Forest Conservation Act of 1980, the National Forest Policy of 1988 and the Hon. Supreme Court Order of 1996. All of these regulations affected the timber supply from government forest areas, and created a huge gap in timber supply and demand. Currently, this deficit is met through imports and trees outside forests (TOFs). Timber production from government forest areas is abysmally low (3.35% of total demand) compared to potential timber production from TOFs, which fulfil 45% of the total timber demand in India. This implies that TOFs have immense potential in meeting the growing timber demand; however, they have not been fully utilized due to discrepancies in state level TOFs’ policies. The present paper provides a review of different forest policies, acts and guidelines in relation to timber production in India, and provides specific recommendations in order to maximize timber production in the context of increasing demand for timber products.     

Uptake of Cs by berries, mushrooms and needles of Scots pine in peatland forests after wood ash application

Increasing use of wood fuels for energy production in Finland since the 1990s implies that large quantities of the generated ashes will be available for forest fertilization. The aim of this study was to analyse the effect of wood ash application on ¹³⁷Cs activity concentrations in Scots pine (Pinus sylvestris L.) needles and certain berries and mushrooms on drained peatlands. The study was based on field experiments carried out on two mires in Finland in 1997-1998. Two different types of wood ash were applied at dosages of 3500, 3700, 10 500 and 11 100 kg ha⁻¹. Wood ash did not increase ¹³⁷Cs activity concentration in plants in the second growing season following application. On the contrary, a decrease in ¹³⁷Cs activity concentration was seen in the plants of the ecosystem on drained peatlands. This result is of importance, for instance, when recycling of ash is being planned.     

Hydrologic Calibration and Validation of SWAT in a Snow‐Dominated Rocky Mountain Watershed,Montana, U.S.A.1

Abstract: The Soil and Water Assessment Tool (SWAT) has been applied successfully in temperate environments but little is known about its performance in the snow‐dominated, forested, mountainous watersheds that provide much of the water supply in western North America. To address this knowledge gap, we configured SWAT to simulate the streamflow of Tenderfoot Creek (TCSWAT). Located in central Montana, TCSWAT represents a high‐elevation watershed with ～85% coniferous forest cover where more than 70% of the annual precipitation falls as snow, and runoff comes primarily from spring snowmelt. Model calibration using four years of measured daily streamflow, temperature, and precipitation data resulted in a relative error (RE) of 2% for annual water yield estimates, and mean paired deviations (Dv) of 36 and 31% and Nash‐Sutcliffe (NS) efficiencies of 0.90 and 0.86 for monthly and daily streamflow, respectively. Model validation was conducted using an additional four years of data and the performance was similar to the calibration period, with RE of 4% for annual water yields, Dv of 43% and 32%, and NS efficiencies of 0.90 and 0.76 for monthly and daily streamflow, respectively. An objective, regression‐based model invalidation procedure also indicated that the model was validated for the overall simulation period. Seasonally, SWAT performed well during the spring and early summer snowmelt runoff period, but was a poor predictor of late summer and winter base flow. The calibrated model was most sensitive to snowmelt parameters, followed in decreasing order of influence by the surface runoff lag, ground water, soil, and SCS Curve Number parameter sets. Model sensitivity to the surface runoff lag parameter reflected the influence of frozen soils on runoff processes. Results indicated that SWAT can provide reasonable predictions of annual, monthly, and daily streamflow from forested montane watersheds, but further model refinements could improve representation of snowmelt runoff processes and performance during the base flow period in this environment.     

Carbon Sequestration Potential of Indian Forests

The forestry sector can not only sustain its carbon but also has the potential to absorb carbon from the atmosphere. India has maintained approximately 64 Mha of forest cover for the last decade. The rate of afforestation in India is one of the highest among the tropical countries, currently estimated to be 2 Mha per annum. The annual productivity has increased from 0.7 m³ per hactare in 1985 to 1.37 m³ per hectare in 1995. Increase in annual productivity directly indicates an increase in forest biomass and hence higher carbon sequestration potential. The carbon pool for the Indian forests is estimated to be 2026.72 Mt for the year 1995. Estimates of annual carbon uptake increment suggest that our forests and plantations have been able to remove at least 0.125 Gt of CO₂ from the atmosphere in the year 1995. Assuming that the present forest cover in India will sustain itself with a marginal annual increase by 0.5 Mha in area of plantations, we can expect our forests to continue to act as a net carbon sink in future.