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1.
Investigations of the ecological, atmospheric chemical, and climatic impacts of contemporary fires in tropical vegetation have received increasing attention during the last 10 years. Little is known, however, about the impacts of climate changes on tropical vegetation and wildland fires. This paper summarizes the main known interactions of fire, vegetation, and atmosphere. Examples of predictive models on the impacts of climate change on the boreal and temperate zones are given in order to highlight the possible impacts on the tropical forest and savanna biomes and to demonstrate parameters that need to be involved in this process. Response of tropical vegetation to fire is characterized by degradation towards xerophytic and pyrophytic plant communities dominated by grasses and fire-tolerant tree and bush invaders. The potential impacts of climate change on tropical fire regimes are investigated using a GISS GCM-based lightning and fire model and the Model for the Assessment of Greenhouse Gas-Induced Climate Change (MAGICC). 相似文献
2.
André Lyra Pablo Imbach Daniel Rodriguez Sin Chan Chou Selena Georgiou Lucas Garofolo 《Climatic change》2017,141(1):93-105
Tropical rainforest plays an important role in the global carbon cycle, accounting for a large part of global net primary productivity and contributing to CO2 sequestration. The objective of this work is to simulate potential changes in the rainforest biome in Central America subject to anthropogenic climate change under two emissions scenarios, RCP4.5 and RCP8.5. The use of a dynamic vegetation model and climate change scenarios is an approach to investigate, assess or anticipate how biomes respond to climate change. In this work, the Inland dynamic vegetation model was driven by the Eta regional climate model simulations. These simulations accept boundary conditions from HadGEM2-ES runs in the two emissions scenarios. The possible consequences of regional climate change on vegetation properties, such as biomass, net primary production and changes in forest extent and distribution, were investigated. The Inland model projections show reductions in tropical forest cover in both scenarios. The reduction of tropical forest cover is greater in RCP8.5. The Inland model projects biomass increases where tropical forest remains due to the CO2 fertilization effect. The future distribution of predominant vegetation shows that some areas of tropical rainforest in Central America are replaced by savannah and grassland in RCP4.5. Inland projections under both RCP4.5 and RCP8.5 show a net primary productivity reduction trend due to significant tropical forest reduction, temperature increase, precipitation reduction and dry spell increments, despite the biomass increases in some areas of Costa Rica and Panama. This study may provide guidance to adaptation studies of climate change impacts on the tropical rainforests in Central America. 相似文献
3.
Tree Species Composition in European Pristine Forests: Comparison of Stand Data to Model Predictions 总被引：1，自引：0，他引：1
Franz-W. Badeck Heike Lischke Harald Bugmann Thomas Hickler Karl Hönninger Petra Lasch Manfred J. Lexer Florent Mouillot Jörg Schaber Benjamin Smith 《Climatic change》2001,51(3-4):307-347
The degree of general applicability across Europe currently achieved with several forest succession models is assessed, data needs and steps for further model development are identified and the role physiology based models can play in this process is evaluated. To this end, six forest succession models (DISCFORM, ForClim, FORSKA-M, GUESS, PICUS v1.2, SIERRA) are applied to simulate stand structure and species composition at 5 European pristine forest sites in different climatic regions. The models are initialized with site-specific soil information and driven with climate data from nearby weather stations. Predicted species composition and stand structure are compared to inventory data. Similarity and dissimilarity in the model results under current climatic conditions as well as the predicted responses to six climate change scenarios are discussed. All models produce good results in the prediction of the right tree functional types. In about half the cases, the dominating species are predicted correctly under the current climate. Where deviations occur, they often represent a shift of the species spectrum towards more drought tolerant species. Results for climate change scenarios indicate temperature driven changes in the alpine elevational vegetation belts at humid sites and a high sensitivity of forest composition and biomass of boreal and temperate deciduous forests to changes in precipitation as mediated by summer drought. Restricted generality of the models is found insofar as models originally developed for alpine conditions clearly perform better at alpine sites than at boreal sites, and vice versa. We conclude that both the models and the input data need to be improved before the models can be used for a robust evaluation of forest dynamics under climate change scenarios across Europe. Recommendations for model improvements, further model testing and the use of physiology based succession models are made. 相似文献
4.
Global Climate Change and Tropical Forest Genetic Resources 总被引：4，自引：0，他引：4
Global climate change may have a serious impact on genetic resources in tropical forest trees. Genetic diversity plays a critical role in the survival of populations in rapidly changing environments. Furthermore, most tropical plant species are known to have unique ecological niches, and therefore changes in climate may directly affect the distribution of biomes, ecosystems, and constituent species. Climate change may also indirectly affect plant genetic resources through effects on phenology, breeding systems, and plant-pollinator and plant seed disperser interactions, and may reduce genetic diversity and reproductive output. As a consequence, population densities may be reduced leading to reduction in genetic diversity through genetic drift and inbreeding. Tropical forest plants may respond to climate change through phenotypic plasticity, adaptive evolution, migration to suitable site, or extinction. However, the potential to respond is limited by a rapid pace of change and the non-availability of alternate habitats due to past and present trends of deforestation. Thus climate change may result in extinction of many populations and species. Our ability to estimate the precise response of tropical forest ecosystems to climate change is limited by lack of long-term data on parameters that might be affected by climate change. Collection of correlative data from long-term monitoring of climate as well as population and community responses at selected sites offer the most cost-effective way to understand the effects of climate change on tropical tree populations. However, mitigation strategies need to be implemented immediately. Because many effects of climate change may be similar to the effects of habitat alteration and fragmentation, protected areas and buffer zones should be enlarged, with an emphasis on connectivity among conserved landscapes. Taxa that are likely to become extinct should be identified and protected through ex situ conservation programs. 相似文献
5.
海南尖峰岭热带山地雨林作为典型的热带雨林生态系统之一,其长期的气候动态变化研究对全球变化研究有着重要的作用。采用1980--2005年海南尖峰岭森林生态系统国家野外科学观测研究站天池气象站地面常规气象观测资料,利用累积距平法和Mann—Kendall检验法分析了尖峰岭热带山地雨林区气候突变和气候异常。结果表明：近26a来,该区年平均气温、年平均地温、年平均最高最低气温、年积温和平均水汽压在1990年前后经历一次由低到高的突变,年平均风速在1993年经历由大到小的突变。在高强度ENSO事件发生的1998年,气温、地温均出现异常偏高,这些都表明该林区的森林气候变化正是对全球气候异常的明显响应过程。 相似文献
6.
海南尖峰岭热带山地雨林作为典型的热带雨林生态系统之一,其长期的气候动态变化研究对全球变化研究有着重要的作用。采用1980—2005年海南尖峰岭森林生态系统国家野外科学观测研究站天池气象站地面常规气象观测资料,利用累积距平法和Mann-Kendall检验法分析了尖峰岭热带山地雨林区气候突变和气候异常,结果表明：该区26 a来,年平均气温、年平均地温、年平均最高最低气温、年积温和平均水汽压在1990年前后经历一次由低到高的突变,年平均风速在1993年经历由大到小的突变。在高强度ENSO事件发生的1998年,气温、地温均出现异常偏高,这些都表明该林区的森林气候变化正是对全球气候异常的明显响应过程。 相似文献
7.
Richard Condit 《Climatic change》1998,39(2-3):413-427
CO2 concentration is increasing, temperature is likely to rise, and precipitation patterns might change. Of these potential climatic shifts, it is precipitation that will have the most impact on tropical forests, and seasonal patterns of rainfall and drought will probably be more important than the total quantity of precipitation. Many tree species are limited in distribution by their inability to survive drought. In a 50 ha forest plot at Barro Colorado Island in Panama (BCI), nearly all tree and shrub species associated with moist microhabitats are declining in abundance due to a decline in rainfall and lengthening dry seasons. This information forms the basis for a simple, general prediction: drying trends can rapidly remove drought-sensitive species from a forest. If the drying trend continues at BCI, the invasion of drought-tolerant species would be anticipated, but computer models predict that it could take 500 or more years for tree species to invade and become established. Predicting climate-induced changes in tropical forest also requires geographic information on tree distribution relative to precipitation patterns. In central Panama, species with the most restricted ranges are those from areas with a short dry season (10–14 weeks): 26–39% of the tree species in these wet regions do not occur where it is drier. In comparison, just 11–19% of species from the drier side of Panama (18 week dry season) are restricted to the dry region. From this information, I predict that a four-week extension of the dry season could eliminate 25% of the species locally; a nine-week extension in very wet regions could cause 40% extinction. Since drier forests are more deciduous than wetter forests, satellite images that monitor deciduousness might provide a way to assess long-term forest changes caused by changes in drought patterns. I predict that increasing rainfall and shorter dry seasons would not cause major extinction in tropical forest, but that drying trends are a much greater concern. Longer dry seasons may cause considerable local extinction of tree species and rapid forest change, and they will also tend to exacerbate direct human damage, which tends to favor drought-adapted and invasive tree species in favor of moisture-demanding ones. 相似文献
8.
Recent temperature observations suggest a general warming trend that may be causing the range of tree species to shift to higher latitudes and altitudes. Since biotic interactions such as herbivory can change tree species composition, it is important to understand their contribution to vegetation changes triggered by climate change. To investigate the response of forests to climate change and herbivory by wild ungulates, we used the forest gap model ForClim v2.9.6 and simulated forest development in three climatically different valleys in the Swiss Alps. We used altitudinal transects on contrasting slopes covering a wide range of forest types from the cold (upper) to the dry (lower) treeline. This allowed us to investigate (1) altitudinal range shifts in response to climate change, (2) the consequences for tree species composition, and (3) the combined effect of climate change and ungulate herbivory. We found that ungulate herbivory changed species composition and that both basal area and stem numbers decreased with increasing herbivory intensity. Tree species responded differently to the change in climate, and their ranges did not change concurrently, thus causing a succession to new stand types. While climate change partially compensated for the reductions in basal area caused by ungulate herbivory, the combined effect of these two agents on the mix of the dominant species and forest type was non-compensatory, as browsing selectively excluded species from establishing or reaching dominance and altered competition patterns, particularly for light. We conclude that there is an urgent need for adaptive forest management strategies that address the joint effects of climate change and ungulate herbivory. 相似文献
9.
A dynamic global vegetation model (DGVM) coupled with a land surface model (LSM) is generally initialized using a spin-up process to derive a physically-consistent initial condition. Spin-up forcing, which is the atmospheric forcing used to drive the coupled model to equilibrium solutions in the spin-up process, varies across earlier studies. In the present study, the impact of the spin-up forcing in the initialization stage on the fractional coverages (FCs) of plant functional type (PFT) in the subsequent simulation stage are assessed in seven classic climate regions by a modified Community Land Model’s Dynamic Global Vegetation Model (CLM-DGVM). Results show that the impact of spin-up forcing is considerable in all regions except the tropical rainforest climate region (TR) and the wet temperate climate region (WM). In the tropical monsoon climate region (TM), the TR and TM transition region (TR-TM), the dry temperate climate region (DM), the highland climate region (H), and the boreal forest climate region (BF), where FCs are affected by climate non-negligibly, the discrepancies in initial FCs, which represent long-term cumulative response of vegetation to different climate anomalies, are large. Moreover, the large discrepancies in initial FCs usually decay slowly because there are trees or shrubs in the five regions. The intrinsic growth timescales of FCs for tree PFTs and shrub PFTs are long, and the variation of FCs of tree PFTs or shrub PFTs can affect that of grass PFTs. 相似文献
10.
Victorine Perarnaud Bernard Seguin Eric Malezieux Michel Deque Denis Loustau 《Climatic change》2005,70(1-2):319-340
The adaptation of agriculture and forestry to the climate of the twenty-first century supposes that research projects will
be conducted cooperatively between meteorologists, agronomists, soil scientists, hydrologists, and modellers. To prepare for
it, it is appropriate first of all to study the variations in the climate of the past using extensive, homogenised series
of meteorological or phenological data. General circulation models constitute the basic tool in order to predict future changes
in climate. They will be improved, and the regionalisation techniques used for downscaling climate predictions will also be
made more efficient. Crop simulation models using input data from the general circulation models applied at the regional level
ought to be the favoured tools to allow the extrapolation of the major trends on yield, consumption of water, fertilisers,
pesticides, the environment and rural development. For this, they have to be validated according to the available agronomical
data, particularly the available phenological series on cultivated crops. In addition, climate change would have impact on
crop diseases and parasites, as well as on weeds. Very few studies have been carried out in this field. It is also necessary
to quantify in a more accurate way the stocks and fluxes of carbon in large forest ecosystems, simulate their future, and
assess the vulnerability of the various forest species to a change in climate. This is all the more important in that some
propagate species choices must be made in the course of the next ten years in plantations which will experience changed climate.
More broadly speaking, we shall have not only to try hard to research new agricultural and forestry practices which will reduce
greenhouse gas emissions or promote the storage of carbon, but it will also be indispensable to prepare the adaptation of
numerous rural communities for the climate change (with special reference to least developed countries in tropical areas,
where malnutrition is a common threat). This can be accomplished with a series of new environmental management practices suited
to the new climatic order. 相似文献
11.
Manuel Nores 《Climatic change》2009,97(3-4):543-551
The tropical and subtropical moist forests of South America have been seen as remarkable for their great wealth of animals and plants and as the world leader in bird diversity. However, a problem is apparently affecting bird populations in these habitats, to the extent that most of the sites that I have studied in the last few years were practically “ornithological deserts”. Censuses conducted in the Amazon rainforest in Ecuador and Bolivia have revealed no more than 15 species and 18 individuals in 1 day. It is evident that this is not a problem of the kind usually induced by humans at a local level, such as deforestation, hunting or pesticide use. The low diversity and activity were observed not only in disturbed habitats, but also in well-preserved national parks and reserves. If it is related to human activities, then this must be more widespread. One such possibility is global warming. For ornithological studies, this is a very severe problem that must be closely examined to see whether it is also a threat to bird survival and if it is related to climate change. 相似文献
12.
Xiongqing Zhang Yuancai Lei Yong Pang Xianzhao Liu Jinzeng Wang 《Climatic change》2014,124(1-2):179-190
Tree mortality in response to climate change induced drought has emerged as a global concern. Small changes of tree mortality rates can profoundly affect forest structure, composition, dynamics and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from natural stands (82 plots) in Beijing showed that tree mortality rates have increased significantly over the two decades from 1986 to 2006. In contrast, recruitment rates decreased significantly over this period. The increase in overall mortality rates resulted from an increase in tree deaths dominantly attributed to changes in temperature and precipitation resulting in drier conditions across latitudes, elevations, tree species, and tree sizes. In addition, the results showed that mortality rates of Chinese pine (Pinus tabuliformis) (β 1 ?=?0.0874) as a result of climate change induce drought were much smaller than oak (Quercus) (β 1 ?=?0.1583). 相似文献
13.
There is increasing evidence that the future recruitment in South-East Asian dipterocarp trees species depending on mast-fruiting events might be endangered by climate change or enhanced seed predation in forest fragments. Especially in combination with the ongoing tree harvesting in this region the recruitment threat imposes a severe danger on the species richness and forest structure of the whole area. We here assess with the process-based forest growth model FORMIND2.0 the impacts of common tree-logging strategies in those recruitment endangered forests. FORMIND2.0 is based on the calculations of the carbon balance of individual trees belonging to 13 different plant functional types. Even single logging events in those rainforests threatened by a lack of recruitment led to shifts in the abundances of species, to species loss, and to forest decline and dieback. The results show that current logging practices in South-East Asia seriously overuse the forests especially in the light of changing climate conditions. 相似文献
14.
张永香 《沙漠与绿洲气象(新疆气象)》2015,9(1):12-16
沙漠及其边缘地区生态环境脆弱,对气候变化敏感。但沙漠地区有限的森林资源限制了区域百年到千年尺度上的历史气候变化研究。利用采自巴丹吉林南缘的青海云杉年轮宽度资料,重建了区域近191 a(1815—2005年)来的年降水(前一年7月至当年8月的总降水量)变化序列。重建的相关系数是0.636,方差解释量为40.4%,调整自由度后的解释方差R2adj为0.392。重建结果稳定可靠。分析区域过去年降水变化结果可见,19世纪该区域干湿变化频繁,20世纪前半段主要以干旱为主,干湿转变较少。20世纪20年代的干旱事件在巴丹吉林南缘的干旱持续时间更长。周期分析的结果表明,区域年降水量变化有2 a、4 a、64 a等周期。 相似文献
15.
European forests are facing multiple natural and anthropogenic pressures that are expected to become more severe in the next decades. Tree diversity is projected to decline in many areas across the continent. How this will affect the provision of forest services remains an open question, whose answer depends, among others, on the practical and theoretical challenges of incorporating assisted migration into climate adaptation strategies. Here, we tackle the issue by combining a large dataset of tree species occurrences, future climatic projections, and data on tree functional traits and tree-specific forest services into a novel modelling framework. We estimate that, by the end of the century and under a natural dispersal scenario, the provision of forest services would decrease on average by 15% in Europe (for RCP 4.5; 23% for RCP 8.5), and up to 52% (70% for RCP 8.5) in the Mediterranean. To explore if and how management could reduce the projected losses, we simulated a suite of alternative assisted migration strategies aimed at identifying, for each locality, the tree species communities offering the best compromise in terms of resilience to climate change and delivery of specific combinations of ecosystem services. Such strategies could reduce losses of services by 10% (15%) on average in Europe, and even increase service availability in the Alpine and Boreal regions but not in the Mediterranean, where losses will remain as high as 33% (54% for RCP 8.5). Our findings highlight how science-driven management strategies could be vital to reduce an otherwise dramatic, European-wide decline of forest services. Our results are qualitatively robust to different assumptions on future carbon emissions and related climate trajectories. That is, our simulated assisted migration strategies identify similar tree species communities under different pathways (RCP 4.5 vs RCP 8.5). This makes our approach a powerful tool for forest management, as it generates advice that is valid regardless of whether, and to what extent, human society will steer away from business-as-usual emission trajectories. 相似文献
16.
F. A. Bazzaz 《Climatic change》1998,39(2-3):317-336
Tropical forest ecosystems are large stores of carbon which supply millions of people with life support requirements. Currently tropical forests are undergoing massive deforestation. Here, I address the possible impact of global change conditions, including elevated CO2, temperature rise, and nitrogen deposition on forest structure and dynamics. Tropical forests may be particularly susceptible to climate change for the following reasons: (1) Phenological events (such as flowering and fruiting) are highly tuned to climatic conditions. Thus a small change in climate can have a major impact on the forest, its biological diversity and its role in the carbon cycle. (2) There are strong coevolutionary interactions, such as pollination seed dispersal, with a high degree of specialization, i.e., only certain animals can effect these activities for certain species. Global change can decouple these tight coevolutionary interactions. (3) Because of high species diversity per unit area, species of the tropical rain forest must have narrow niches. Thus changes in global climate can eliminate species and therefore reduce biological diversity. (4) Deforestation and other forms of disturbance may have significant feedback on hydrology both regionally and globally. The predicted decline in the rainfall in the Amazon Basin and the intensification of the Indian monsoon can have a large effect on water availability and floods which are already devastating low-lying areas. It is concluded that tropical forests may be very sensitive to climate change. Under climatic change conditions their structure and function may greatly change, their integrity may be violated and their services to people may be greatly modified. Because they are large stores of great biological diversity, they require immediate study before it is too late. The study requires the collaboration of scientists with a wide range of backgrounds and experiences including biologists, climate modellers, atmospheric scientists, economists, human demographers and sociologists in order to carry out holistic and urgently needed work. Global climatic change brings a great challenge to science and to policy makers. 相似文献
17.
The tree species composition of a forested landscape may respond to climate change through two primary successional mechanisms: (1) colonization of suitable habitats and (2) competitive dynamics of established species. In this study, we assessed the relative importance of competition and colonization in forest landscape response (as measured by the forest type composition change) to global climatic change. Specifically, we simulated shifts in forest composition within the Boundary Waters Canoe Area of northern Minnesota during the period 2000–2400?AD. We coupled a forest ecosystem process model, PnET-II, and a spatially dynamic forest landscape model, LANDIS-II, to simulate landscape change. The relative ability of 13 tree species to colonize suitable habitat was represented by the probability of establishment or recruitment. The relative competitive ability was represented by the aboveground net primary production. Both competitive and colonization abilities changed over time in response to climatic change. Our results showed that, given only moderate-frequent windthrow (rotation period = 500?years) and fire disturbances (rotation period = 300?years), competition is relatively more important for the short-term (<100?years) compositional response to climatic change. For longer-term forest landscape response (>100?years), colonization became relatively more important. However, if more frequent fire disturbances were simulated, then colonization is the dominant process from the beginning of the simulations. Our results suggest that the disturbance regime will affect the relative strengths of successional drivers, the understanding of which is critical for future prediction of forest landscape response to global climatic change. 相似文献
18.
Thomas Van Der Hammen 《Climatic change》1991,19(1-2):37-47
19.
T. Nuutinen J. Matala H. Hirvelä K. Härkönen H. Peltola H. Väisänen S. Kellomäki 《Climatic change》2006,79(3-4):315-333
The purpose of this study was to optimize forest management for a forest region (the total area of forest and scrub land 1.54
mill. ha) under changing climate by using the large-scale forestry scenario model MELA and sample plot data from the geo-referenced
National Forest Inventory (NFI). The MELA model is based on integrated simulation and optimisation; in the simulation it utilises
empirical tree-level models into which the impacts of climate change were introduced by transfer variables derived by using
the physiological model FinnFor. Six scenarios with differences in climate and forest management were defined. In simulations,
the accelerating tree growth caused by climate change resulted in an increase in maximum sustainable removal of trees at regional
level. Changes in regionally optimized forest management were also detected during the analysis period of 30 years; the proportion
of thinnings increased because the stands fulfilled the thinning requirements earlier than in the current climate. This study
was the first attempt to solve endogenously maximum sustainable timber production and corresponding forest management at the
regional level under different climate scenarios. When implemented in the MELA system, which is widely used in Finnish forestry,
the transfer variables offer means of disseminating the results from physiological studies to planning of adjustment and mitigation
measures under changing climate. 相似文献
20.
SiB3对不同下垫面的模拟试验与验证 总被引：3，自引：1，他引：2
首先介绍简单生物圈模式版本3(Simple Biosphere Model 3,SiB3)相比SiB2的改进之处以及相应的参数化方案。为了检验SiB3模式能否模拟不同下垫面的地气之间水分和能量交换,本文在全球选择3个代表高、中、低纬度的典型实验站点(青藏高原安多站点、亚马逊流域的Km34站点和美国中西部的WLEF站点),利用SiB3进行模拟分析和实验验证。研究结果表明,SiB3能够较好地模拟出不同下垫面的地表感热通量、潜热通量和净辐射通量随时间的变化率以及变化趋势,模式模拟值和测量值的相关系数达到080左右。但与实测相比,SiB3模拟的感热通量值仍偏高。在安多站点,模式模拟的地表土壤水分比较干燥,且模拟的地表温度较测量值偏高。 相似文献