共查询到20条相似文献，搜索用时 15 毫秒
1.
An analysis is undertaken to examine the potential impacts of a global climate change on patterns of potential terrestrial C storage and resulting fluxes between terrestrial and atmospheric pools. A bioclimatic model relating the current distribution of vegetation to global climate patterns is used to examine the potential impacts of a global climate change on the global distribution of vegetation. Climate change scenarios are based on the predictions of two general circulation model equilibrium simulations for a 2XCO2 atmosphere. Current estimates of C reserves in the vegetation types and associated soils are then used to calculate changes in potential terrestrial C storage under the two climate change scenarios. Results suggest a potential negative feedback to increasing atmospheric concentrations of CO2, with the potential for terrestrial C storage increasing under both scenarios. These results represent an equilibrium analysis, assuming the vegetation and soils have tracked the spatial changes in climate patterns. An approach for providing an estimate of the transient response between the two equilibria (i.e., current and 2XCO2 climates) is presented. The spatial transitions in vegetation predicted by the equilibrium analyses are classified as to the processes controlling the transition (eg., succession, dieback, species immigration). Estimates of the transfer rates related to these processes are then used to estimate the temporal dynamics of the vegetation/soils change and the associated C pools. Results suggest that although the equilibrium analyses show an increased potential for C storage under the climate change, in the transient case the terrestrial surface acts as a source of CO2 over the first 50 to 100 yrs following climate change. 相似文献
2.
Ronald P. Neilson 《Water, air, and soil pollution》1993,70(1-4):659-673
A new biogeographic model, MAPSS, predicts changes in vegetation leaf area index (LAI), site water balance and run off, as well as changes in Biome boundaries. Potential scenarios of equilibrium vegetation redistribution under 2 × CO2 climate from five different General Circulation Models (GCMs) are presented. In general, large spatial shifts in temperate and boreal vegetation are predicted under the different scenarios; while, tropical vegetation boundaries are predicted (with one exception) to experience minor distribution contractions. Maps of predicted changes in forest LAI imply drought-induced losses of biomass over most forested regions, even in the tropics. Regional patterns of forest decline and dieback are surprisingly consistent among the five GCM scenarios, given the general lack of consistency in predicted changes in regional precipitation patterns. Two factors contribute to the consistency among the GCMs of the regional ecological impacts of climatic change: 1) regional, temperature-induced increases in potential evapotranspiration (PET) tend to more than offset regional increases in precipitation; and, 2) the unchanging background interplay between the general circulation and the continental margins and mountain ranges produces a fairly stable pattern of regionally specific sensitivity to climatic change. Two areas exhibiting among the greatest sensitivity to drought-induced forest decline are eastern North America and eastern Europe to western Russia. Drought-induced vegetation decline (losses of LAI), predicted under all GCM scenarios, will release CO2 to the atmosphere; while, expansion of forests at high latitudes will sequester CO2. The imbalance in these two rate processes could produce a large, transient pulse of CO2 to the atmosphere. 相似文献
3.
FORSUM, a forest succession model of the JABOWA/FORET type was applied to simulate possible impacts of environmental changes on subalpine forest ecosystems and compared with the model FORECE (Kienast, 1987). The model used is based on approaches of Botkin et al. (1972), Shugart (1984) and Kienast (1987) and has been improved by implementing soil water movement calculations based on a user-defined one-dimensional nonhomogeneous soil profile. The influence of a possible climatic change on subalpine ecosystems was investigated for three different sites in the Grisons (Switzerland). The scenarios used are based on climate change predictions of General Circulation Models. A temperature increase of 3? C would cause important changes in species composition. Deciduous trees would invade today's subalpine belt causing a displacement of various conifers in this zone. Some coniferous species might eventually migrate into today's alpine zone which would consequently become afforested. Comparing the vegetation changes as predicted by the model FORSUM and FORECE we found that the models generate the main general patterns. However under global warming and a concurrent precipitation decrease total biomass production seems to be overestimated by FORECE. Information about seed dispersal rates (horizontal and vertical), seed availability and soil formation processes should be implemented in these models to improve the reliability of the predictions. 相似文献
4.
Climate change is projected to be particularly strong in the northern latitudes. Thus, boreal or arctic species are especially susceptible to the effects of climate warming. In this work we forecasted changes in the distributions of 27 northern land bird species in the 21st century, based on predicted rates of climate change. We used climate and bird atlas data of Finland and northern Norway from 1971-1990 to establish bioclimatic envelope models for each species. Next, these models were applied to two climate scenarios (A2 and B1) from the general circulation model HadCM3 to forecast potential future distributions of the study species over a larger area also covering parts of nearby Sweden and Russia. This area stretches through the boreal and continental arctic zone in northern Europe. In the A2 scenario the predicted global change in mean temperature is 3.8 °C by 2100 and in the B1 scenario 2.0 °C. Our results suggest that most of the northern land bird species will lose most of their climatic space by 2080 both in the more severe (A2, average predicted range decline: -83.6%) and in the less severe scenario (B1, average change: -73.6%). A large proportion (over two thirds) of the species considered here is thus susceptible to major range contractions in this geographical region. These climate change-induced threats are of importance because the Arctic Ocean represents a natural barrier for northward movement of species. To reduce the negative effects of climate change on the northern species, relatively large areas of continuous habitats in a connected reserve network should be preserved. 相似文献
5.
基于ISI-MIP推荐的5个气候模式在4个RCP情景下的模拟结果,筛选21世纪末全球升温最接近1.5℃和2.0℃的气候数据,运用作物模型DSSAT,模拟升温1.5℃和2.0℃背景下中国玉米产量相对于基准时段1985-2006年的变化,揭示了1.5℃与2.0℃升温背景下中国玉米产量变化的空间分布。结果表明：升温2.0℃背景下玉米减产风险明显高于升温1.5℃,未来升温2.0℃背景下中国玉米减产面积比升温1.5℃背景下多6.2%,升温1.5℃和2.0℃背景下中国玉米平均减产幅度分别为3.7%和11.5%;从空间分布来看,升温1.5℃与2.0℃背景下未来中国玉米产量变化在区域分布上大致相似,但未来玉米增产和减产的面积和幅度不尽相同,在北方与西南玉米种植区都有一定的增产区域,其它区域大多以减产为主,其中西北部玉米种植区减幅最大;1.5℃升温背景下北方大部分地区气候条件对玉米生长有利,2.0℃升温背景下北方地区玉米减产也不明显,说明从近期到未来一段时间内,将全球升温控制在1.5℃以内,北方地区玉米仍具有一定增产潜力。 相似文献
6.
Studies in the response of vegetation to predicted future climate change have focussed on vascular plants and are therefore largely unrepresentative of wider botanical diversity (i.e. comprising cryptogams; algae, mosses, liverworts and fungi including lichens). This paper presents a study to predict the response of a cryptogam species, the epiphytic lichen Lecanora populicola, to climate change scenarios. L. populicola is an easily dispersed species that occurs predictably in a widespread habitat, i.e. aspen stands. The study area was geographically constrained to a clean-air region of northern Britain. Thus, using the popular bioclimatic envelope approach, the projected climatic response of L. populicola is not expected to be confounded by air-borne pollution effects, or dispersal and habitat limitation. Non-parametric multiplicative regression was used to describe the response of L. populicola to seven climate variables, and an optimum model projected using UKCIP02 scenarios, comprising two time-frames (2020 s and 2050 s) and two greenhouse gas emission levels (low and high). Model predictions suggest an overall increase in the potential range of L. populicola, and, by association, several other ‘Boreal’ lichen epiphytes. Projected increases in the occurrence of L. populicola are associated with predicted summer drying, and indicate a putative threat to negatively associated ‘oceanic’ lichens. 相似文献
7.
基于遥感的黄土高原植被物候监测及其对气候变化的响应 总被引：9，自引：0，他引：9
为了分析黄土高原地区植被物候特征,该文基于AVHRR传感器获取的陆地长期数据记录(land long term data record,LTDR)V4 NDVI数据,对黄土高原1982-2011年间植被物候的时空变化进行分析,并借助偏相关分析方法对物候与气温和降雨的关系进行量化分析。结果表明:黄土高原近30 a间春季物候提前显著(0.54 d/a,P0.001),主要集中在北部草地和灌木植被;秋季物候推迟显著(0.74 d/a,P0.001),主要分布在甘肃、陕北、内蒙古和山西北部等地。不同植被的春秋物候稍有差异,稀疏灌木林春季物候提前趋势最多(1.31 d/a),常绿针叶林最小(0.19 d/a);秋季物候推迟最多的为乔木园地(1.18 d/a),最少的是水田(0.17 d/a)。黄土高原植被物候主要受气温影响,降雨的变化也会对物候产生一定影响。冬季和前年秋季气温上升是春季物候提前的主要驱动因子;夏季和秋季降雨则对秋季物候休眠期延迟起着重要作用。该研究可为黄土高原生态环境评价及气候变化预测模型提供一定依据。 相似文献
8.
The fate of global soil carbon stores in response to predicted climate change is a ‘hotly’ debated topic. Considerable uncertainties remain as to the temperature sensitivity of non-labile soil organic matter (SOM) to decomposition. Currently, models assume that organic matter decomposition is solely controlled by the interaction between climatic conditions and soil mineral characteristics. Consequently, little attention has been paid to adaptive responses of soil decomposer organisms to climate change and their impacts on the turnover of long-standing terrestrial carbon reservoirs. Using a radiocarbon approach we found that warming increased soil invertebrate populations (Enchytraeid worms) leading to a greater turnover of older soil carbon pools. The implication of this finding is that until soil physiology and biology are meaningfully represented in ecosystem carbon models, predictions will underestimate soil carbon turnover. 相似文献
9.
The forest cover of Thailand has been characterized according to the Holdridge Life Zone Classification, a model that correlates climatic features with vegetation distribution. Six Holdridge life zone types of forest cover are found in Thailand: subtropical dry forest, subtropical moist forest, subtropical wet forest, tropical dry forest, tropical moist forest, and tropical wet forest. Climate change scenarios were simulated by three general circulation models: two United Kingdom Meteorological Office models (the low and high resolution versions) and the Goddard Institute for Space Studies model. These scenarios were used to simulate the effects of future climate change on Thai forests. The ratios of precipitation and the absolute values of temperature changes were incorporated into a baseline climate scenario from the International Institute of Applied Systems Analysis. Under the climate change scenarios simulated by the three general circulation models, the subtropical dry forest could potentially disappear, and areas of tropical very dry forest would appear. In general, the area of subtropical life zone would decline from about 50% to 20%–12% of total cover, whereas the tropical life zone would expand its cover from 45% to 80%. All three general circulation model scenarios suggest that the tropical dry forest has the greatest potential to extend into the subtropical moist forest. This analysis suggests that global climate change would have a profound effect on the future distribution and health of Thai forests. 相似文献
10.
G. H. Kohlmaier Ch. Häger A. Nadler G. Würth M. K. B. Lüdeke 《Water, air, and soil pollution》1995,82(1-2):455-464
The response of the vegetation and soils of the higher latitude forests and tundra ecosystems to an anticipated climate change is investigated using two alternative approaches to calculate the resulting change in the total carbon content (TCC) of the vegetation and the soils: On the one hand a BGC (bio-geochemical-cycle) model, in this case the FBM (Frankfurt Biosphere Model), where the ecosystem response is entirely due to the ecophysiological response of the vegetation and the ecological response of the soils. On the other hand a biome or “rule-based” model, in this case the BIOME model, which allows for the determination of the occurrence of a specific biome type from a given climatic situation assuming equilibrium conditions. Within the FBM prognosis net primary production and TCC are reduced both for needle leaved and broad leaved forests if the CO2-fertilisation effect is not taken into account. When the CO2-fertilisation effect is taken into consideration NPP, standing biomass and soil carbon are increased in a future greenhouse climate. Although there is a considerable shift of the biomes in response to the greenhouse climate within the BIOME approach, the TCC in the investigated northern biomes stayed more or less constant. This is due to a decrease in biomass in the southern regions of today's temperate forests compensating the biomass increase by the northward shift of the taiga border. 相似文献
11.
This paper presents one of the first integrated analyses of acidification and climate change on a geographically-detailed basis, and the first linkage of integrated models for acid deposition (RAINS) and for climate change (IMAGE 2). Emphasis in this paper is on Europe. Trends in driving forces of emissions are used to compute anthropogenic SO2 emissions in 13 world regions. These emissions are translated into regional patterns of sulfur deposition in Europe and global patterns of sulfate aerosols using source-receptor matrices. Changes in climate are then computed based on changes in sulfate and greenhouse gases. Finally, we compute ecosystem areas affected by acid deposition and climate change based on exceedances of critical loads and changes in potential vegetation. Using this framework, information from global and regional integrated models can be used to link sulfur emissions with both their global and regional consequences. Preliminary calculations indicate that the size of European area affected by climate change in 2100 (58%) will be about the same as that affected by acid deposition in 1990. By the mid 21st century, about 14% of Europe's area may be affected by both acid deposition and climate change. Also, reducing sulfur emissions in Europe will have both the desirable impact of reducing the area affected by acid deposition, and the undesirable impact of enhancing climate warming in Europe and thus increasing the area affected by climate change. However, for the scenarios in this paper, the desirable impact of reducing sulfur emissions greatly outweighs its undesirable impact. 相似文献
12.
Fatemeh Karandish Mahdi Kalanaki Seyyed Farhad Saberali 《Archives of Agronomy and Soil Science》2017,63(1):1-13
In this research, the influence of climate change on maize cultivation was investigated and then, the possible solutions for adopting this natural hazard in the coasts of Caspian Sea in Iran was assessed. Weather data were generated for the 2011–2100 period using a statistical downscaling model under different climatic scenarios. Reference evapotranspiration (ETo) was calculated using a Neuro-fuzzy inference system. Cop water requirement was calculated by multiplying ETo by crop coefficients. Increased cardinal temperatures during 2011–2100 led to shifting in the planting date backward by 10–26 days. In addition, the projected global warming has a considerable effect on the duration of the vegetative growth stage resulting in earlier harvesting. However, the duration of the reproductive stage is less affected. Despite the obvious reduction in the length of the growing season, crop water requirement will increase by 10.6–15.3% in the future due to 1.64–28.4% increase in ETo. However, changing the cultivation time may lead to 11.2–264.5 m3 ha?1 water saving during the whole cropping cycle through affecting both ETo and the crop growth cycle. This result demonstrates that management of the maize cropping calendar can be an effective way to achieve sustainable agriculture under future climate conditions in the study area. 相似文献
13.
Soil erosion from sugar beet in Central Europe in response to climate change induced seasonal precipitation variations 总被引：2，自引：0，他引：2
This study estimates the implications of projected seasonal variations in rainfall quantities caused by climate change for water erosion rates by means of a modeling case study on sugar beet cultivation in the Central European region of Upper-Austria. A modified version of the revised Morgan–Morgan–Finney erosion model was used to assess soil losses in one conventional and three conservation tillage systems. The model was employed to a climatic reference scenario (1960–89) and a climate change scenario (2070–99). Data on precipitation changes for the 2070–99 scenario were based on the IPCC SRES A2 emission scenario as simulated by the regional climate model HadRM3H. Weather data in daily time-steps, for both scenarios, were generated by the stochastic weather generator LARS WG 3.0. The HadRM3H climate change simulation did not show any significant differences in annual precipitation totals, but strong seasonal shifts of rainfall amounts between 10 and 14% were apparent. This intra-annual precipitation change resulted in a net-decrease of rainfall amounts in erosion sensitive months and an overall increase of rainfall in a period, in which the considered agricultural area proved to be less prone to erosion. The predicted annual average soil losses under climate change declined in all tillage systems by 11 to 24%, which is inside the margins of uncertainty typically attached to climate change impact studies. Annual soil erosion rates in the conventional tillage system exceeded 10 t ha− 1 a− 1 in both climate scenarios. Compared to these unsustainably high soil losses the conservation tillage systems show reduced soil erosion rates by between 49 and 87%. The study highlights the importance of seasonal changes in climatic parameters for the discussion about the impacts of global climate change on future soil erosion rates in Central Europe. The results also indicate the high potential of adaptive land-use management for climate change response strategies in the agricultural sector. 相似文献
14.
[目的]揭示台湾省陆地植被生态系统随海拔高度的变化趋势及其响应程度,为区域可持续发展、生态环境保护提供理论依据。[方法]基于台湾省1998—2018年SPOT/VEGETATION NDVI卫星遥感数据、气象及DEM数据,结合相关分析法、回归分析法等数理统计方法,对气候变化下的台湾省植被归一化植被指数(NDVI)变化趋势及区域响应进行了分析。[结果] 1998—2018年台湾省植被NDVI均值增长率为5.09%;台湾省不同高程范围所占的面积比例差异较大,500 m区域的面积比例高达52.49%,3 600 m区域的面积比例仅为0.01%,且NDVI均呈现较低值,分别为0.72和0.73;1998—2018年台湾省海拔除3 600 m外,其他海拔高程范围NDVI均值增长明显(p0.001);在500～3 600 m高程范围内,NDVI年均值与气温、降雨相关关系显著(p0.05)。[结论]海拔越高,植被生长状况对降雨的变化较气温更为敏感。 相似文献
15.
16.
气候变暖对甘肃省不同气候类型区主要作物需水量的影响 总被引：6，自引：0，他引：6
作物需水量是农田水分循环系统中最重要的因素之一。在未来温度上升1~4 ℃的情景下, 研究了气候变暖对我国甘肃省不同气候类型区主要作物需水量的影响。结果表明, 气候变暖对不同作物需水量的影响程度不同。其中对冬小麦需水量的影响最大, 对玉米和春小麦次之。当生长期内温度上升1~4 ℃时, 冬小麦需水量将增加3.05%~12.90%, 相当于13.2~81.2 mm; 玉米需水量将增加2.49%~10.80%, 相当于9.9~60.6 mm;春小麦需水量将增加2.74%~11.69%, 相当于6.7~40.0 mm。气候变暖对作物需水量的影响存在一定地域性差异。对干旱区的作物需水量影响最大, 半干旱区次之, 其次是半湿润区, 对湿润区影响不大。根据甘肃省目前的种植结构, 据此估算, 当温度上升1~4 ℃时, 将使甘肃省冬小麦的灌溉需水量增加12.43×108 m3、13.02×108 m3、13.74×108 m3 和14.65×108 m3, 玉米的灌溉需水量增加7.94×108 m3、8.32×108 m3、8.78×108 m3 和9.30×108 m3, 春小麦的灌溉需水量增加4.97×108 m3、5.16×108 m3、5.42×108 m3 和5.76×108 m3。 相似文献
17.
Although an increasing frequency of forest fires has been suggested as a consequence of global warming, there are no empirical data that have shown climatically driven increases in fire frequency since the warming that has followed the end of the “Little Ice Age” (～1850). In fact, a 300-year fire history (AD 1688–1988) from the Lac Duparquet area (48°28′N, 79°17′W) shows a significant decrease both in the number and extent of fires starting 100 years ago during a period of warming. To explore this relationship between climatic change and fire frequency we used daily data from the Canadian Atmospheric Environment Service's General Circulation Model to calculate components of the Canadian Forest Fire Weather Index (FWI) System for the 1xCO2 and 2xCO2 scenarios. The average FWI over much of eastern Canada, including the Lac Duparquet region, decreased under the 2xCO2 simulation, whereas FWI increased dramatically over western Canada. According to these results, fire frequency would decrease over the southeastern boreal forest which is in agreement with the empirical data from the fire history. Our results stress the importance of large regional variability and call into question previous generalisations suggesting universal increases in the rate of disturbance with climate warming. 相似文献
18.
Our failure to understand or predict evolutionary dynamics under climatic change precludes much conservation planning. Evolution may reduce extinction under global warming, but few studies have explored how genetic covariation, the norm for most quantitative traits, will affect the course of evolution under rapid climatic change. To draw attention to and begin to fill this gap, we draw from the population genetics literature and explore climate-driven evolution using a multi-trait model under two qualitative scenarios of climate change. Under a monotonic change in the mean environment and a change in the amplitude and frequency of a periodic environment, we show that the angle between the direction of the largest genetic covariation and the selection gradient is important in determining a population’s fitness decline, or lag load. When the environment changes monotonically in the direction of the greatest covariation, the population is able to more closely track the changing environment resulting in a lower lag load. In contrast, when the environment changes in a direction of low covariation, the ability of the population to track the changing environment is lower, and the population experiences a higher lag load. In a periodic environment, populations suffer a higher lag load under increased environmental amplitude than under increased frequency. These observations suggest that populations where the angle between the largest genetic covariation and the selection gradient is large, as well as populations experiencing an increased magnitude of environmental extremes, may be vulnerable to extinctions and genetic bottlenecks and may benefit from conservation efforts that enhance the preservation of genetic diversity. To make specific predictions of evolutionary trajectories and obtain estimates of lag loads for natural populations, climatic changes have to be quantified in terms of fitness landscapes and genetic covariation among climate-related traits must be measured. We performed an extensive review of the literature and found only 24 studies that quantify covariation in traits involving climate. 相似文献
19.
Insect populations have a substantial impact on Canada's forest. They are a dominating disturbance factor and during outbreaks they can cause tree mortality over vast areas of forest. If the predicted climate changes take effect, the damage patterns caused by insects may be drastically altered, especially for the many insects whose occurrence in time and space is severely limited by climatic factors. This possibility substantially increases the uncertainties associated with the long-term planning of pest control requirements, with hazard rating models, with depletion forecasts, and with projections for the sustainability of future timber supplies. Moreover, because insect damage affects the rates of various processes in nutrient and biogeochemical cycling, potential changes in damage patterns can affect ecosystem resilience. This paper presents a number of plausible scenarios that describe how some key processes in the boreal forest's insect defoliator outbreak systems may respond to climate change. The spruce budworm,Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used as an illustrative case study throughout. The potential importance of phonological synchrony in the dynamical interactions between species is emphasised. It is argued that natural selection may be a particularly important process in the response of insects to climate change and that climate change may already be influencing some insect lifecycles. The importance of threshold effects, rare but extreme events, and transient dynamics is emphasised, and the inadequacy of ‘equilibrium’ models for forest:pest systems noted. We conclude by discussing approaches to developing forecasts of how one of the boreal forest's insect defoliator-based disturbance regimes, as a whole, might respond to climate change. 相似文献
20.
顾及时滞效应的西南地区植被NPP变化归因分析 总被引：3，自引：3，他引：0
随着社会经济的不断发展,近年来西南地区部分区域生态环境日益脆弱。研究气候变化和人类活动影响下植被净初级生产力（Net Primary Productivity,NPP）时空演变特征,可为监测区域植被生长状况及其对驱动因素的响应机制提供理论依据。该研究以2000－2020年MOIDS NPP数据为基础,结合气象、人口密度、夜间灯光和土地利用类型等数据,使用Theil-Sen Median趋势分析、多重共线性检验、多元回归分析、残差分析和偏相关分析等研究方法,分析2000－2020年西南地区及各地貌单元植被NPP时空变化特征及对气候变化和人类活动的响应特征。结果表明：1）2000－2020年,除青藏高原植被NPP、气候影响下的植被NPP预测值（Predicted Net Primary Productivity,NPPPre,）和人类活动影响下的植被NPP残差值（Residual Net Primary Productivity,NPPRes）呈微弱波动下降外,其余地貌单元植被NPP、NPPPre和NPPRes均呈较明显的波动上升趋势,其中,四川盆地植被NPP、NPPPre和NPPRes波动上升趋势尤为显著,上升斜率分别为7.14、3.72和3.44 g/(m2·a)。2）研究时段内西南地区气候变化对植被NPP上升的影响整体强于人类活动。气候变化影响下,西南地区约45.18%的区域植被NPP呈显著和极显著上升趋势,而人类活动影响下,该占比仅为18.55%。地貌单元上,气候变化和人类活动影响下,四川盆地植被NPP呈极显著上升和显著上升的比例最高,分别为69.42%和50.75%。3）西南地区整体及各地貌单元植被NPP变化主要受温度类因子的主导,相对湿度和大气压强对西南地区植被生长整体具有抑制作用。4）耕地转化为城镇用地是植被NPP下降的重要原因,而非耕地转化为耕地和非林地转化为林地是植被NPP上升的重要原因。整体上,西南地区植被NPP与人口密度和夜间灯光呈不显著相关关系。地貌单元上,四川盆地植被NPP与人口密度和夜间灯光的相关性最高,即四川盆地植被生长受人为活动的影响强于其他地貌单元。研究结果可为区域植被生长监测、生态环境质量评价和林业生态工程效益评估提供理论依据。 相似文献