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1.
Throughout history, humans have transformed natural forests into agricultural land, settlement areas and managed forests. Studies on the dynamics of forest change are one of the mainstays in land change science. The forest transition theory offers a powerful tool to analyze changes in human interference with forests. At the national level, a range of factors have been found to influence a country's forest change. The role of international wood product trade has, however, rarely been studied based on empirical data. We offer a global assessment of how this trade helps shape observed forest change, by relating forest stock change to net trade of wood products for the period 1997-2007 and by localizing the origin of wood consumed in a given nation. For many nations, traded wood products have a relevant impact on the course of ongoing forest transitions. We develop a general typology of how wood product trade can influence forest change and place various nations within this framework. We find that many wealthy nations with returning forests seem to accelerate this return by importing wood products. These imports appear to be provided by two main types of wood exporters: (a) by wealthy countries with low population densities and stable forests and (b) by relatively poor countries with declining forests, employing increasing population and welfare levels. We discuss these findings in the light of general theories on land use transitions and forest change and conclude by highlighting implications for national forest policies and global environmental governance, aiming at reducing negative impacts of wood products and enhancing the positive role they can play in replacing more fossil fuel intensive products. 相似文献
2.
Potential impact of albedo incorporation in boreal forest sector climate change policy effectiveness
Forests have an important role to play in climate change mitigation through carbon sequestration and wood supply. However, the lower albedo of mature forests compared to bare land implies that focusing only on GHG accounting may lead to biased estimates of forestry's total climatic impacts. An economic model with a high degree of detail of the Norwegian forestry and forest industries is used to simulate GHG fluxes and albedo impacts for the next decades. Albedo is incorporated in a carbon tax/subsidy scheme in the Norwegian forest sector using a partial, spatial equilibrium model. While a price of EU€100/tCO2e that targets GHG fluxes only results in reduced harvests, the same price including albedo leads to harvest levels that are five times higher in the first five years, with 39% of the national productive forest land base being cleared. The results suggest that policies that only consider GHG fluxes and ignore changes in albedo will not lead to an optimal use of the forest sector for climate change mitigation.Policy relevanceBare land reflects a larger share of incoming solar energy than dense forest and thus has higher albedo. Earlier research has suggested that changes in albedo caused by management of boreal forest may be as important as carbon fluxes for the forest's overall global warming impacts. The presented analysis is the first attempt to link albedo to national-scale forest climate policies. A policy with subsidies to forest owners that generate carbon sequestration and taxes levied on carbon emissions leads to a reduced forest harvest. However, including albedo in the policy alongside carbon fluxes yields very different results, causing initial harvest levels to increase substantially. The inclusion of albedo impacts will make harvests more beneficial for climate change mitigation as compared to a carbon-only policy. Hence, it is likely that carbon policies that ignore albedo will not lead to optimal forest management for climate change mitigation. 相似文献
3.
The forest model ForClim was used to evaluate the applicability of gap models in complex topography when the climatic input data is provided by a global database of 0.5° resolution. The analysis was based on 12 grid cells along an altitudinal gradient in the European Alps. Forest dynamics were studied both under current climate as well as under four prescribed 2 × CO2 scenarios of climatic change obtained from General Circulation Models, which allowed to assess the sensitivity of mountainous forests to climatic change.Under current climate, ForClim produces plausible patterns of species composition in space and time, although the results for single grid cells sometimes are not representative of reality due to the limited precision of the climatic input data.Under the scenarios of climatic change, three responses of the vegetation are observed, i.e., afforestation, gradual changes of the species composition, and dieback of today's forest. In some cases widely differing species compositions are obtained depending on the climate scenario used, suggesting that mountainous forests are quite sensitive to climatic change. Some of the new forests have analogs on the modern landscape, but in other cases non-analog communities are formed, pointing at the importance of the individualistic response of species to climate.The applicability of gap models on a regular grid in a complex topography is discussed. It is concluded that for their application on a continental scale, it would be desirable to replace the species in the models by plant functional types. It is suggested that simulation studies like the present one must not be interpreted as predictions of the future fate of forests, but as means to assess their sensitivity to climatic change. 相似文献
4.
Maria Nijnik 《Climate Policy》2013,13(3):319-336
Abstract This article reveals the contribution of woodland expansion in Ukraine to climate change mitigation policies. The opportunities for climate change mitigation of three policy scenarios: (1) carbon storage in forests, (2) carbon storage and additional wood-for-fuel substitution, and (3) carbon storage with additional sink policy for wood products, are investigated by using a simulation technique, in combination with cost—benefit analysis. The article concludes that the Ukraine's forests and their expansion offer a low-cost opportunity for carbon sequestration. Important factors that influence the results are the discount rate and the time horizon considered in the models. The findings provide evidence that the storage climate change mitigation forest policy scenario is most viable for the country, under the assumptions considered in this research. 相似文献
5.
Long-living wood products contribute to the mitigation of climate change in many ways. They act as a carbon pool during their service life, as they withdraw CO2 from its natural cycle. After their service life, they can stitute for fossil fuels if they are incinerated in adequate furnaces. Furthermore, wood products can stitute for more energy-intense products made of ‘conventional’ materials. This paper quantifies the stitution and pool effects of an increased use of wood in the building sector in Switzerland for the years 2000–2130. Life cycle data on greenhouse gas (GHG) emissions of 12 wood products and their stitutes are used as proxies for relevant building products; this data is linked to the forecasted wood flows for each group of building products in a cohort-model. For the political assessment, GHG effects occurring abroad and in Switzerland are distinguished. The results show that the pool effect of an increased use of long-living wood products is of minor importance, whereas the energetic and material stitution effects are much more relevant, especially on a long-term. For construction products, the Swiss share of the GHG effect related to the material stitution is relatively high, as mainly nationally produced materials are stituted for. For interior products, the Swiss share of the GHG effect related to the material stitution is rather small because mainly imports are stituted for. The results must be considered as rough estimates. Nonetheless, these calculations show that an increased use of wood in the building sector is a valid and valuable option for the mitigation of greenhouse gas emissions and for reaching GHG emission targets in a mid- to long-term. Still, the pool and stitution capacity of an increased use of wood is relatively small compared to the overall GHG emissions of Switzerland. 相似文献
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7.
T. C. Whitmore 《Climatic change》1998,39(2-3):429-438
Tropical rain forests are dynamic and continually regenerating by growth of seedlings up from the forest floor into canopy gaps that form on a cycle of usually a century of more in length. Changes in seedling establishment, survival, and release in gaps could thus change canopy species composition for a long time. Of likely climatic changes, evidence is presented that cyclone occurrence and increased rainfall seasonality could have important effects on seedling ecology. These forests and their species have lived through big Pleistocene and Holocene climatic changes, but today they are fragmented by human impact and so have less resilience to future climatic change. Management to accommodate climatic change should aim to reduce fragmentation and also canopy opening during logging operations. These are the same practices as advocated for biodiversity conservation. Tropical seasonal forests are also likely to be altered by expected climatic change, and also mainly at their regeneration stage. 相似文献
8.
Carbon sequestration in agroforestry systems 总被引：2，自引：0，他引：2
《Climate Policy》2013,13(4):367-377
Abstract Management of trees in agroecosystems such as agroforestry, ethnoforests, and trees outside forests can mitigate green house gas (GHG) emissions under the Kyoto Protocol. Agroforestry systems are a better climate change mitigation option than oceanic, and other terrestrial options because of the secondary environmental benefits such as helping to attain food security and secure land tenure in developing countries, increasing farm income, restoring and maintaining above-ground and below-ground biodiversity, corridors between protected forests, as CH4 sinks, maintaining watershed hydrology, and soil conservation. Agroforestry also mitigates the demand for wood and reduces pressure on natural forests. Promoting woodcarving industry facilitates long-term locking-up of carbon in carved wood and new sequestration through intensified tree growing. By making use of local knowledge, equity, livelihood security, trade and industry, can be supported. There is need to support development of suitable policies, assisted by robust country-wide scientific studies aimed at better understanding the potential of agroforestry and ethnoforestry for climate change mitigation and human well-being. 相似文献
9.
Providing food and other products to a growing human population while safeguarding natural ecosystems and the provision of their services is a significant scientific, social and political challenge. With food demand likely to double over the next four decades, anthropization is already driving climate change and is the principal force behind species extinction, among other environmental impacts. The sustainable intensification of production on current agricultural lands has been suggested as a key solution to the competition for land between agriculture and natural ecosystems. However, few investigations have shown the extent to which these lands can meet projected demands while considering biophysical constraints. Here we investigate the improved use of existing agricultural lands and present insights into avoiding future competition for land. We focus on Brazil, a country projected to experience the largest increase in agricultural production over the next four decades and the richest nation in terrestrial carbon and biodiversity. Using various models and climatic datasets, we produced the first estimate of the carrying capacity of Brazil's 115 million hectares of cultivated pasturelands. We then investigated if the improved use of cultivated pasturelands would free enough land for the expansion of meat, crops, wood and biofuel, respecting biophysical constraints (i.e., terrain, climate) and including climate change impacts. We found that the current productivity of Brazilian cultivated pasturelands is 32–34% of its potential and that increasing productivity to 49–52% of the potential would suffice to meet demands for meat, crops, wood products and biofuels until at least 2040, without further conversion of natural ecosystems. As a result up to 14.3 Gt CO2 Eq could be mitigated. The fact that the country poised to undergo the largest expansion of agricultural production over the coming decades can do so without further conversion of natural habitats provokes the question whether the same can be true in other regional contexts and, ultimately, at the global scale. 相似文献
10.
Trevor H. Booth 《Climatic change》1994,27(1):93-102
After fossil fuel burning, clearing of forests for agriculture is the second most significant factor increasing levels of atmospheric carbon dioxide. Replanting trees on previously cleared land around the world could reduce the buildup of atmospheric carbon dioxide. However, forests were usually cleared to grow crops or graze animals, so there is no possibility of completely restoring forests on most cleared lands. There is a need to develop agroforestry systems, which integrate trees with agricultural activities.One of the key problems in developing successful agroforestry systems is identifying which trees can be successfully grown in different areas. This problem will become even greater as tree breeding produces a wider variety of genotypes available for planting. General methods are described to identify where a particular tree (species, provenance or clone) with potential for use in agroforestry systems can be grown. The methods also help to identify locations where particular trees are growing under relatively extreme climatic conditions for that taxa. Conditions at these locations should be carefully evaluated as more reliable future climatic scenarios are developed. In the meantime they could be monitored to provide early warning of the effects of climatic and atmospheric change. 相似文献
11.
Thomas Knoke Baltazar Calvas Santiago Ochoa Moreno Jonathan C. Onyekwelu Verena C. Griess 《Global Environmental Change》2013,23(5):1064-1072
Approaches to reconciling food production with climatic and environmental protection often require agricultural intensification. The production of more food per unit of agricultural land through “sustainable intensification” is intended to enable the protection of natural ecosystems elsewhere (land sparing). However, there are problems associated with agricultural intensification; such as soil erosion, eutrophication or pollution of water bodies with chemicals, landscape homogenization and loss of biodiversity; for which solutions have not yet been found. Reuse of abandoned agricultural lands – which are abundant throughout the world – to address the rising demand for food is a potentially important alternative, which up to now has been widely ignored. To test the power of this alternative, equilibrium economic land allocation to various land-use practices by risk-avoiding tropical farmers in Ecuador was simulated. The reestablishment of pastures on abandoned cattle lands lowered prices for pasture products, and also triggered conversion of existing pasture into cropland. The resulting land-use change increased total annual food production in a moderate scenario from the current level of 17.8–23.1 petacalories (1015 calories), which amounted to a production increase of 30%. At the same time, there was a 19% reduction in the amount of payments to farmers required to preserve tropical forests – one of the world's greatest terrestrial carbon stores. 相似文献
12.
Kaysara Khatun 《Climate Policy》2013,13(3):384-402
Policy initiatives in India, such as the Social Forestry Program and later the Joint Forest Management, were introduced for their co-benefits, including forest protection, employment opportunities, and added income for communities living in and around the forests. The evolution of these forest policies is critically reviewed. It is argued that India is perfectly positioned to benefit from climate change mitigation efforts, due to a rich, albeit chequered, history in forest management. National forestry policies are examined to assess how they can complement international climate change mitigation instruments, such as the Clean Development Mechanism (CDM) and the more recent Reduced Emissions from Deforestation and Forest Degradation (REDD or REDD+ with conservation, sustainable management of forests, and enhancement of forest carbon stocks) and aid national sustainable development objectives. There is a need to heed the experiences from India's evolving forest policies, particularly those concerning land tenure and resource rights, which lack specificity within international mechanisms. The active engagement of rural communities must be integral to any programmes that make any claim to development and to environmental integrity as a whole. Policy relevance India's forestry programmes are examined for their effectiveness in informing international initiatives such as the CDM and REDD+. Forestry policies in India can evolve to complement international climate mitigation tools. By examining current and historical forest legislation, and their subsequent impacts, it is shown how communities can sustain their system of forest management and retain/obtain rights to land and resources under the CDM and REDD+. Looking for such synergies within existing national policies to implement newer international initiatives can greatly facilitate and increase the momentum of global environmental change. 相似文献
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14.
Policy efforts to address climate change are increasingly focused on adaptation, understood as adjustments in human systems to moderate the harm, or exploit beneficial opportunities, related to actual or expected climate impacts. We examine individual-level determinants of support for climate adaptation policies, focusing on whether individuals’ exposure to extreme weather events is associated with their support for climate adaptation policies. Using novel public opinion data on support for a range of adaptation policies, coupled with high resolution geographic data on extreme weather events, we find that individuals experiencing recent extreme weather activity are more likely to support climate change adaptation policy in general, but that the relationship is modest, inconsistent across specific adaptation policies, and diminishes with time. The data thus suggest that experiencing more severe weather may not appreciably increase support for climate adaptation policies. 相似文献
15.
The response of plant species to future climate conditions is probably dependent on their ecological characteristics, including climatic niche, demographic rates and functional traits. Using forest inventory data from 27 dominant woody species in Spanish forests, we explore the relationships between species characteristics and projected changes in their average climatic suitability (occurrence of suitable climatic conditions for a species in a given territory) obtained by empirical niche-based models, under a business-as-usual climate change scenario (A1, HadCM3, 2001–2100). We hypothesize that most species will suffer a decline in climatic suitability, with a less severe for species (i) currently living in more arid climates or exhibiting a broader current climatic niche; (ii) with higher current growth rates; (iii) with functional traits related to resistance to water deficits. The analysis confirm our hypothesis since apart from a few Mediterranean species, most species decrease their climatic suitability in the region under future climate, characterized by increased aridity. Also, species living in warmer locations or under a wider range of climatic conditions tend to experience less decrease in climatic suitability. As hypothesized, a positive relationship was detected between current relative growth rates and increase in future climatic suitability. Nevertheless, current tree mortality did not correlate with changes in future climatic suitability. In contrast with our hypothesis, functional traits did not show a clear relationship with changes in climate suitability; instead species often presented idiosyncratic responses that, in some cases, could reflect past management. These results suggest that the extrapolation of species performance to future climatic scenarios based on current patterns of dominance is constrained by factors other than species autoecology, particularly human activity. 相似文献
16.
The Russian Federation contains approximately 20% of the world's timber resources and more than half of all boreal forests. These forests play a prominent role in environmental protection and economic development at global, national, and local levels, as well as, provide commodities for indigenous people and habitat for a variety of plant and animal species. The response and feedbacks of Russian boreal forests to projected global climate change are expected to be profound. Large shifts in the distribution (up to 19% area reduction) and productivity of boreal forests are implied by scenarios of General Circulation Models (GCMs). Uncertainty regarding the potential distribution and productivity of future boreal forests complicates the development of adaptation strategies for forest establishment, management, harvesting and wood processing. Although a low potential exists for rapid natural adaptation of long-lived, complex boreal forests, recent analyses suggest Russian forest management and utilization strategies should be field tested to assess their potential to assist boreal forests in adaptation to a changing global environment. Current understanding of the vulnerability of Russian forest resources to projected climate change is discussed and examples of possible adaptation measures for Russian forests are presented, including: (1) artificial forestation techniques that can be applied with the advent of failed natural regeneration and to facilitate forest migration northward; (2) silvicultural measures that can influence the species mix to maintain productivity under future climates; (3) identifying forests at risk and developing special management adaptation measures for them; (4) alternative processing and uses of wood and non-wood products from future forests; and (5) potential future infrastructure and transport systems that can be employed as boreal forests shift northward into melting permafrost zones. Current infrastructure and technology can be employed to help Russian boreal forests adapt to projected global environmental change, however many current forest management practices may have to be modified. Application of this technical knowledge can help policymakers identify priorities for climate change adaptation. 相似文献
17.
Investigating the Balance between Timber Harvest and Productivity of Global Coniferous Forests under Global Change 总被引：2，自引：0，他引：2
A widely used assumption in forestry is that thedemand for timber will exceed the maximum levelavailable from forests on a sustainable basis. In thisstudy, measurements of extracted timber and modeledforest productivity were used to investigate therelationship between harvested timber and naturalforest productivity for current conditions, and underglobal change scenario. The analysis was confined toconiferous forests and countries that have coniferousforests within their territories. Annual roundwoodproduction from the database of Food and AgricultureOrganization was used as an approximation of annualtimber harvest for each country. Annual stem primaryproductivity of coniferous forests was estimated usingthe BIOME-BGC model. Based on the current rates,annual timber extraction was extrapolated for eachcountry for the next 80 years. Then, on a countrybasis, the timber harvest was related to the modeledforest stem productivity, assuming that the area ofconiferous forest would stay unchanged for the next 80years.The results of this study suggest that globalconiferous forests currently produce more wood thanpeople consume, but that this gap will narrow in thefuture. The results also suggest that wood extractionmay reach forest regrowth by the middle of the nextcentury, even though most coniferous forests arelocated in high latitudes and may have an acceleratedstem growth associated with the joint effect ofclimate change and elevated carbon dioxideconcentration in the atmosphere. 相似文献
18.
Aboveground Growth and Competition in Forest Gap Models: An Analysis for Studies of Climatic Change 总被引：2，自引：0，他引：2
Richard J. Norby Kiona Ogle Peter S. Curtis Franz-W. Badeck Andreas Huth George C. Hurtt Takashi Kohyama Josep Peñuelas 《Climatic change》2001,51(3-4):415-447
Gap models have been used extensively in ecological studies of forest structure and succession, and they should be useful tools for studying potential responses of forests to climatic change. There is a wide variety of gap models with different degrees of physiological detail, and the manner in which the effects of climatic factors are analyzed varies across that range of detail. Here we consider how well the current suite of gap models can accommodate climatic-change issues, and we suggest what physiological attributes and responses should be added to better represent responses of aboveground growth and competition. Whether a gap model is based on highly empirical, aggregated growth functions or more mechanistic expressions of carbon uptake and allocation, the greatest challenge will be to express allocation correctly. For example, incorporating effects of elevated CO2 requires that the fixed allometry between stem volume and leaf area be made flexible. Simulation of the effects of climatic warming should incorporate the possibility of a longer growing season and acclimation of growth processes to changing temperature. To accommodate climatic-change factors, some of the simplicity of gap models must be sacrificed by increasing the amount of physiological detail, but it is important that the capability of the models to predict competition and successional dynamics not be sacrificed. 相似文献
19.
Attack of decay fungi on wood-based material depends primarily on the natural durability of wood, the local climatic conditions, and the likely climatic change. This study investigates the vulnerability of wood and structural timber in ground contact to decay fungi under high and medium emissions scenarios specified by the Intergovernmental Panel on Climate Change, and a future scenario in which the global emissions have been limited to 550?ppm through a range of successful intervention schemes. Nine general circulation models are applied to project the local climates of Brisbane, Sydney, and Melbourne in Australia. It was found that, under the three emissions scenarios, the median decay rate of wood by 2080, relative to that in 2010, could increase up to 10?% in Brisbane and Sydney, but could decrease by 12?% in Melbourne. For timber of less durable wood species 50?years after installation, the residual strength under climate change could be almost 25?% less than that without climate change. The coefficients of variation (COVs) of decay rate of wood are in the vicinity of 1.0 regardless of wood species. For residual strength of timber pole after 50?years of installation, the COVs range from 0.2 to 1.1, depending on the natural durability of timber and the site location. The high COVs due to the variability of natural durability of wood and of climate change, in combination with the likely changes in median residual strength of structural elements, will cause significant structural reliability issues of wood construction and need to be addressed in engineering design codes. 相似文献
20.
Lorenzo Marini Matthew P. Ayres Andrea Battisti Massimo Faccoli 《Climatic change》2012,115(2):327-341
Temperature warming and the increased frequency of climatic anomalies are expected to trigger bark beetle outbreaks with potential severe consequences on forest ecosystems. We characterized the combined effects of climatic factors and density-dependent feedbacks on forest damage caused by Ips typographus (L.), one of the most destructive pests of European spruce forests, and tested whether climate modified the interannual variation in the altitudinal outbreak range of the species. We analyzed a 16-year time-series from the European Alps of timber loss in Picea abies Karsten forests due to I. typographus attacks and used a discrete population model and an information theoretic approach to compare multiple competing hypotheses. The occurrence of dry summers combined with warm temperatures appeared as the main abiotic triggers of severity of outbreaks. We also found an endogenous negative feedback with a 2-year lag suggesting a potential important role of natural enemies. Forest damage per hectare averaged 7-fold higher where spruce was planted in sites warmer than those within its historical climatic range. Dry summers, but not temperature, was related to upward shifts in the altitudinal outbreak range. Considering the potential increased susceptibility of spruce forests to insect outbreaks due to climate change, there is growing value in mitigating these effects through sustainable forest management, which includes avoiding the promotion of spruce outside its historical climatic range. 相似文献