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V. Ramón Vallejo Athanasios Smanis Esteban Chirino David Fuentes Alejandro Valdecantos Alberto Vilagrosa 《New Forests》2012,43(5-6):561-579
Reforestation efforts in dryland ecosystems frequently encounter drought and limited soil productivity, although both factors usually interact synergistically to worsen water stress for outplanted seedlings. Land degradation in drylands (e.g. desertification) usually reduces soil productivity and, especially, soil water availability. In dry sub-humid regions, forest fires constitute a major disturbance affecting ecosystem dynamics and reforestation planning. Climate change projections indicate an increase of drought and more severe fire regime in many dryland regions of the world. In this context, the main target of plantation technology development is to overcome transplant shock and likely adverse periods, and in drylands this is mostly related to water limitations. In this paper, we discuss some selected steps that we consider critical for improving success in outplanting woody plants, both under current and projected climate change conditions including: (1) Plant species selection, (2) Improved nursery techniques, and (3) Improved planting techniques. The number of plant species used in reforestation is increasing rapidly, moving from a reduced set of well-known, easy-to-grow, widely used species, to a large variety of promising native species. Available technologies allow for reintroducing native plants and recovering critical ecosystem functions for many degraded drylands. However, climate change projections introduce large uncertainties about the sustainability of current reforestation practices. To cope with these uncertainties, adaptive restoration approaches are suggested, on the basis of improved plant quality, improved techniques for optimizing rain use efficiency in plantations, and exploring native plant species, including provenances and genotypes, for their resilience to fire and water use efficiency. 相似文献
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Mapping forest dynamics under climate change: A matrix model 总被引：1，自引：0，他引：1
Jingjing Liang Mo ZhouDave L. Verbyla Lianjun ZhangAnna L. Springsteen Thomas Malone 《Forest Ecology and Management》2011,262(12):2250-2262
Global climate change may be affecting forests around the world. However, the impact of climate change on forest population dynamics, especially at the landscape or regional level, has hardly been addressed before. A new methodology was proposed to enable matrix transition models to account for climate impact on forest population dynamics. The first climate-sensitive matrix (CSMatrix) model was developed for the Alaska boreal forest based on observations from over 15 years of forest inventory. The spatially explicit model was used to map climate-induced forest population dynamics across the region. The model predicted that the basal area increment in the region under natural succession would be hindered by global warming, more so for dry upland areas than for moist wetlands. It was suggested that temperature-induced drought stress could more than offset a predicted increase of future precipitation in the region to lower overall forest productivity. At the same time, stand diversity would increase across the region through transient species redistribution. Accounting for climate conditions made the CSMatrix model more accurate than conventional matrix models. 相似文献
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Schulte Maximilian Jonsson Ragnar Hammar Torun Stendahl Johan Hansson Per-Anders 《European Journal of Forest Research》2022,141(5):845-863
European Journal of Forest Research - Climate change mitigation trade-offs between increasing harvests to exploit substitution effects versus accumulating forest carbon sequestration complicate... 相似文献
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Context
In the context of climate change, several forest adaptation options have to be advocated such as a shift to more resistant species.Aims
We provide an economic analysis of timber species change as a tool for adapting forests to climate change.Methods
We use the framework of cost–benefit analysis, taking uncertainty into account both exogenously (sensitivity analysis) and endogenously [(quasi-)option value calculations]. We apply the method to assess the economic rationale for converting Norway spruce stands to Douglas-fir in the French Black Mountain.Results
We find that the Douglas-fir conversion is land expectation value (LEV) maximizing under a wide range of a priori (subjective) probabilities attached to high mortality of Norway spruce under climate change (for probabilities higher than 0.25–0.31). If information about the impacts of climate change is expected to increase over time, and given the large sunk costs attached to conversion, a delay strategy may be preferable to transition and to status quo when the impacts of climate change on Norway spruce mortality are sufficiently ambiguous. In such cases, getting information earlier increases the LEV by €5–60/ha.Conclusion
Beyond the specifics of the case study, this paper suggests that quasi-option value is a relevant tool to provide insights to forest owners dealing with adaptation decisions in the context of climate change. 相似文献7.
The paper looks, from a perspective of institutional economics, at a process of change of rules and organisational practises in the forestry sector, particularly drawing on a case study of small-scale private forest owners in the Allgäu, Bavaria. It is argued that the process of change may be initiated by the traditional factors mentioned by the various theories of institutional change (technological change, changes in preferences, changes in relative factor prices, etc.). However, the direction of change observed in the short run cannot be understood with the help of efficiency theories of institutional change. Denzau and North (1994) extended those theories by introducing mental models as explanatory variables. Mental models are the interpretations (half-baked theories) people use to understand their environment. As observed, mental models play a crucial role in determining the direction of change. However, the question that arose was: what determines the selection of mental models in an uncertain environment? It is observed that trust plays an important role. Therefore, an extension of the Douglas and North theory is suggested. 相似文献
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Sebastián Martinuzzi William A. Gould Ariel E. Lugo Ernesto Medina 《Forest Ecology and Management》2009
Human activities have dramatically reduced the world’s area of mangroves just as the ecological services they provide are becoming widely recognized. Improving the conservation tools available to restore lost mangroves would benefit from a better understanding of how human activities influence the conservation of these ecosystems. We took advantage of historical information and long-term landscape analyses to relate land use change with the area of mangroves in Puerto Rico. We found that mangroves experienced dramatic changes over the last 200 years, and four distinct eras of change were visible. During the agricultural era (1800–1940) the area of mangroves declined 45%. As the economy changed to industrial in the late 1940s the area of mangrove increase due to reduced land use pressure on the wetlands. Nevertheless, urban expansion between 1960s and 1970s produced another decline. Public concern for mangrove conservation resulted in the legal protection of all the mangroves in 1972, and since then their area has expanded. We found that past human activity altered the original proportion of mangrove species. The number and size of mangrove-forest fragments was impacted by land use, and urban areas had fewer and smaller fragments than vegetated areas. Uncontrolled expansion of urban areas emerged as a major threat to mangrove conservation. Mangroves are resilient and recover quickly when given an opportunity if the geomorphological and hydrological features of the habitat are not changed by their use. The key to conservation appears to be a combination of the type of human activity in mangrove watersheds combined with strong legal protection. The following steps are recommended: (1) identify the areas that satisfy the ecological requirements of mangrove development; (2) incorporate better zoning regulations to maintain these areas natural and to protect the fluxes of water, nutrients, and organisms in and out of the system; and (3) monitor results. 相似文献
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Remigijus Ozolinčius Edmundas Lekevičius Vidas Stakėnas Audronė Galvonaitė Arūnas Samas Donatas Valiukas 《European Journal of Forest Research》2014,133(1):51-60
Outputs from the HadCM3 Global Climate Circulation Model according to scenarios A2 and B1 were used for climate change predictions in Lithuania. According to scenario A2, the annual temperature will increase by approximately 4.0 °C from 2061 to 2090, while scenario B1 predicts an increase of 2.0 °C. In contrast to scenario B1, scenario A2 predicts an annual increase in precipitation of 15–20 % at the end of the century. Based on the predicted climatic data for the two scenarios and climate maps by European Food Safety Authority for the EU, we created climate analogues for Lithuania for 2031–2060 and 2061–2090. These areas were overlain by the digital map of native tree species distributions in Europe, which was created from the European Forest Genetic Resources Programme database. If climate changes occur according to scenario B1, in 2031–2060, Lithuania’s climate will become suitable for approximately five to six alien species, such as Acer campestre, Acer pseudoplatanus, Fagus sylvatica, Populus nigra, and Prunus avium. In 2061–2090, these species will be joined by Sorbus domestica and Tilia platyphyllos. If climate changes occur according to scenario A2, at the end of the twenty-first century, Castanea sativa, Quercus pubescens, and Sorbus torminalis could expand this list. With respect to species dispersal rates, there is a high probability that the species A. campestre, A. pseudoplatanus, P. nigra, and P. avium will become immigrants to Lithuanian forests at the end of the twenty-first century. Approximately 20 new species native to Europe will be suitable for cultivation (scenario A2). Climate change will affect the distributions of native species too. An increase in the proportion of deciduous tree species (except Alnus incana) and some reduction in the proportion of conifers, Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), are expected in Lithuanian forests. 相似文献
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Technical change is developing rapidly in some parts of the forest sector, especially in the pulp and paper industry where wood fiber is being substituted by waste paper. In forest sector models, the processing of wood and other input into products is frequently represented by activity analysis (input–output). In this context, technical change translates in changes over time of the input–output (I–O) coefficients and of the manufacturing cost (labor, capital, and materials, excluding wood and fiber). In the case of the global forest products model, the I–O coefficients and the manufacturing costs are determined empirically from historical data, while correcting for possible reporting errors. The method consists of goal programming. The objective function is the sum of the weighted absolute value of the deviations from estimated and observed production in each country of interest. The constraints express the relationship between the multiple output (sawnwood, panels, pulp, paper) and input (wood, waste paper, other fiber) and prior knowledge on the limits of the I–O coefficients. The paper presents observed technical changes from 1993 to 2010 and projections to 2030 with their consequences for the global forest sector in terms of prices, production and consumption, value added, and carbon sequestration in forest biomass. 相似文献
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Guillermo Martínez Pastur Emilie Andrieu Louis R. Iverson Pablo Luis Peri 《Agroforestry Systems》2012,85(3):315-318
Forest ecosystems are impacted by multiple uses under the influence of global drivers, and where landscape ecology tools may substantially facilitate the management and conservation of the agroforestry ecosystems. The use of landscape ecology tools was described in the eight papers of the present special issue, including changes in forested landscapes due to agricultural and forestry activities, landscape changes due to recent intensification of agriculture, and the impacts of agroforestry as compared to natural forest ecosystems. Landscape ecology can improve the economic, environmental and social values of agroforestry, and this knowledge should help to develop new management alternatives for agroforestry. We believe that these papers will inform management at the landscape level, especially in agroforestry landscapes, offering new tools for management and conservation. 相似文献
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Sunflecks are brief, intermittent periods of high photon flux density (PFD) that can significantly improve carbon gain in shaded forest understories and lower canopies of trees. In this review, we discuss the physiological basis of leaf-level responses to sunflecks and the mechanisms plants use to tolerate sudden changes in PFD and leaf temperature induced by sunflecks. We also examine the potential effects of climate change stresses (including elevated temperatures, rising CO(2) concentrations and drought) on the ability of tree species to use sunflecks, and advocate more research to improve our predictions of seedling and tree carbon gain in future climates. Lastly, while we have the ability to model realistic responses of photosynthesis to fluctuating PFD, dynamic responses of photosynthesis to sunflecks are not accounted for in current models of canopy carbon uptake, which can lead to substantial overestimates of forest carbon fixation. Since sunflecks are a critical component of seasonal carbon gain for shaded leaves, sunfleck regimes and physiological responses to sunflecks should be incorporated into models to more accurately capture forest carbon dynamics. 相似文献
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Determining suitable locations for seed transfer under climate change: a global quantitative method 总被引：1，自引：1，他引：0
Changing climate conditions will complicate efforts to match seed sources with the environments to which they are best adapted. Tree species distributions may have to shift to match new environmental conditions, potentially requiring the establishment of some species entirely outside of their current distributions to thrive. Even within the portions of tree species ranges that remain generally suitable for the species, local populations may not be well-adapted to altered local conditions. To assist efforts to restore forests and to maximize forest productivity in the face of climate change, we developed a set of 30,000 quantitatively defined seed transfer “ecoregions” across the globe. Reflecting current and future conditions, these were created by combining global maps of potentially important environmental characteristics using a large-scale statistical clustering technique. This approach assigns every 4?km2 terrestrial raster cell into an ecoregion using non-hierarchical clustering of the cells in multivariate space based on 16 environmental variables. Two cells anywhere on the map with similar combinations of environmental characteristics are located near each other in this data space; cells are then classified into relatively homogeneous ecoregion clusters. Using two global circulation models and two emissions scenarios, we next mapped the predicted environmentally equivalent future locations of each ecoregion in 2050 and 2100. We further depicted areas of decreasing environmental similarity to given ecoregions, both in current time and under climate change. This approach could help minimize the risk that trees used for production, restoration, reforestation, and afforestation are maladapted to their planting sites. 相似文献
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Nophea Sasaki 《Journal of Forest Research》2006,11(6):397-403
Land-use change and forestry in the tropics have caused huge carbon emissions to the atmosphere. The magnitude of these emissions,
however, remains debatable. Therefore, there is a need to further develop appropriate methods that would reduce the estimation
uncertainties. From a modeling perspective, this report is aimed at estimating carbon emissions from deforestation and logging
activities in Cambodia just after it opened its door to the world. Recently available land-use and forest inventory data were
used to develop simple models capable of estimating the change of carbon stocks in, and carbon emissions from, dryland and
edaphic forests. This study estimated the annual deforestation rate to be 0.1 million ha between 1973 and 2003, or about 0.7%.
Between 1993 and 2003, annual carbon emissions amounted to about 13.7 TgC, owing to deforestation and logging. The emissions
calculated here are higher than those reported by the Cambodian government, which claimed that Cambodia was once a net sink
of carbon. The models developed in this study will be a useful tool for further study of carbon emissions in tropical countries
where selective logging is practiced.
Part of this article was presented at the International Symposium on the Role of Forests for Coming Generations: Philosophy
and Technology for Forest Resource Management, October 2004, Utsunomiya, Japan 相似文献
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S. Dabbert 《Agroforestry Systems》1995,31(2):157-168
The paper describes the changes in agricultural structure and land use in northeastern Germany that were triggered by reunification. It projects possible effects of the recent EU-agricultural policy reform with the help of a simulation model. It is concluded that a considerable part of land (especially permanent grassland) might not have a productive use in the mediumrun. Agroforestry systems relevant for Central Europe are discussed and problems identified. Agroforestry systems are evaluated as one land-use option among others (afforestation, natural succession, new agricultural systems) and their possible impact is assessed. 相似文献
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Dante Castellanos-Acuña Kenneth W. Vance-Borland J. Bradley St. Clair Andreas Hamann Javier López-Upton Erika Gómez-Pineda Juan Manuel Ortega-Rodríguez Cuauhtémoc Sáenz-Romero 《New Forests》2018,49(3):297-309
Seed zones for forest tree species are a widely used tool in reforestation programs to ensure that seedlings are well adapted to their planting environments. Here, we propose a climate-based seed zone system for Mexico to address observed and projected climate change. The proposed seed zone classification is based on bands of climate variables often related to genetic adaptation of tree species: mean coldest month temperature (MCMT) and an aridity index (AHM). The overlay of the MCMT and AHM for the 1961–1990 period resulted in 63 climate-based zones. Climate change observed over the last three decades has resulted in an increase of + 0.74 °C for MCMT and a shift toward overall drier conditions across Mexico. By the 2050s, MCMT is expected to increase by + 1.7 °C and AHM shifts further towards drier conditions. We recommend moving seed sources from warm, dry locations towards currently wetter and cooler planting sites, to compensate for climate change that has already occurred and is expected to continue for the next decades. We contribute a straight-forward climate-based seed zone system that allows practitioners to match seed procurement regions with planting regions under observed and anticipated climate change. Our transfer recommendations using climate-based zones can be implemented within the existing seed zone system, which often span large climate gradients. 相似文献
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周少舟 《绿色中国(A版)》2002,(10):37-39
当前,我国林业的外部环境和内部条件已经发生了深刻的变化。加入WTO要求减少政府对经济活动的干预;社会对林业主导需求的变化使林业自身社会公益事业的性质更为突出;非公有制林业广泛兴起,全社会办林业方兴未艾。 相似文献