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1.
Jun Wang Daniel G. Brown Rick L. Riolo Scott E. Page Arun Agrawal 《Global Environmental Change》2013,23(5):1266-1276
There has been a decrease in grazing mobility in the Mongolian grasslands over the past decades. Sedentary grazing with substantial external inputs has increased the cost of livestock production. As a result, the livelihoods of herders have become more vulnerable to climate variability and change. Sedentary grazing is the formal institutional arrangement in Inner Mongolia, China. However, this may not be an efficient institutional arrangement for climate change adaptation. Self-organized local institutions for climate change adaptation have emerged and are under development in the study area. In this study, we did exploratory analyses of multiple local institutions for climate change adaptation in the Mongolian grasslands, using an agent-based modeling approach. Empirical studies from literature and our field work show that sedentary grazing, pasture rental markets, and reciprocal pasture-use groups are three popular institutional arrangements in the study area. First, we modeled the social–ecological performance (i.e., livelihood benefits to herders and grassland quality) of these institutions and their combinations under different climate conditions. Second, we did exploratory analyses of multiple social mechanisms for facilitating and maintaining cooperative use of pastures among herders. The modeling results show that in certain value-ranges of some model parameters with assumed values, reciprocal pasture-use groups had better performance than pasture rental markets; and the comparative advantage of cooperative use of pastures over sedentary grazing without cooperation becomes more evident with the increase in drought probability. Agent diversity and social norms were effective for facilitating the development of reciprocal pasture-use groups. Kin selection and punishments on free-riders were useful for maintaining cooperation among herders. 相似文献
2.
Environmental change in grasslands: Assessment using models 总被引：7，自引：0，他引：7
Modeling studies and observed data suggest that plant production, species distribution, disturbance regimes, grassland biome boundaries and secondary production (i.e., animal productivity) could be affected by potential changes in climate and by changes in land use practices. There are many studies in which computer models have been used to assess the impact of climate changes on grassland ecosystems. A global assessment of climate change impacts suggest that some grassland ecosystems will have higher plant production (humid temperate grasslands) while the production of extreme continental steppes (e.g., more arid regions of the temperate grasslands of North America and Eurasia) could be reduced substantially. All of the grassland systems studied are projected to lose soil carbon, with the greatest losses in the extreme continental grassland systems. There are large differences in the projected changes in plant production for some regions, while alterations in soil C are relatively similar over a range of climate change projections drawn from various General Circulation Models (GCM's). The potential impact of climatic change on cattle weight gains is unclear. The results of modeling studies also suggest that the direct impact of increased atmospheric CO2 on photosynthesis and water use in grasslands must be considered since these direct impacts could be as large as those due to climatic changes. In addition to its direct effects on photosynthesis and water use, elevated CO2 concentrations lower N content and reduce digestibility of the forage. 相似文献
3.
多年冻土对青藏高原草地生态承载力的贡献研究 总被引：1，自引：0，他引：1
草地生态系统是一个复杂的社会、经济、生态系统,多年冻土作为高寒草地生态系统结构和功能维系的重要因素,是客观刻画高寒草地生态承载力不容忽视的重要方面。文中采用结构动力学方法,从草地质量、草地干预、草地潜力、草地压力4个维度建立高寒草地生态承载力结构动力学模型,分析青藏高原多年冻土区草地生态承载力的变化以及主要结构要素,量化多年冻土变化对青藏高原高寒草地生态承载力的贡献率,结果表明：(1)多年冻土区草地生态承载力呈增加趋势,尤其是1998年以后上升显著,这主要归因于草地生长季节降水增加、气温升高、净初级生产力增幅驱动以及生态保护工程建设的共同作用。(2)多年冻土活动层厚度变化与草地生态承载力呈负相关,多年冻土活动层厚度对草地生态承载力的贡献率约为10%,即多年冻土活动层厚度每增加1个单位,将导致草地生态承载力下降0.1个单位。由于青藏高原空间差异显著,加之气候变化的不确定性,这一贡献水平只是一个粗略的参照值。 相似文献
4.
Agricultural insurance programs are currently being championed by international donors in many developing countries. They are acclaimed as promising instruments for coping with climate risk. However, research on their impacts has mainly focused on economic considerations. Studies on broader social and ecological consequences are sparse and have produced ambiguous and inconclusive results. We address this knowledge deficit by (a) advocating for a holistic view of social-ecological systems and vulnerability when considering insurance impacts; (b) offering a systematic overview highlighting the potential beneficial and adverse effects of ‘climate insurance’ in agriculture, particularly where programs target intensifying agricultural production; and (c) suggesting preliminary principles for avoiding maladaptive outcomes, including specific recommendations for designing appropriate impact studies and insurance programs. Our synopsis brings together scientific knowledge generated in both developing and developed countries, demonstrating that agricultural insurance programs shape land-use decisions and may generate serious economic, social, and ecological consequences. If insurance is to be an appropriate tool for mitigating the impacts of climate change, it needs to be carefully developed with specific local social-ecological contexts and existing risk coping strategies in mind. Otherwise, it is liable to create long-term maladaptive outcomes and undermine the ability of these systems to reduce vulnerability. 相似文献
5.
内蒙古草原气候特点与草原生态类型区域划分 总被引：6，自引：0，他引：6
为了合理开发利用气候资源，给草原畜牧业生产的分区管理提供科学依据，文章对内蒙古草原气候特点及气候对牧草生长、畜种分布和土壤环境的影响进行了分析，发现内蒙古气候湿润度的某些等值线与土壤带的分界线几乎完全重合，表明土壤带的形成与气候条件密切相关。而气候和土壤环境是草场类型及其生态系统的主要影响因素，因此以气候湿润度为主要依据，结合内蒙古土壤带的水平分布特征，进行草原生态类型区域的划分不仅具有合理性，而且具有稳定性。指出近年来的气候增暖以及由此引起的其他气候变化，虽使草原生产力有一定的提高，但并未使内蒙古草原的生态类型有所改变。 相似文献
6.
Small-scale fisheries in developing regions are particularly vulnerable to climate change, but the assessment of climate-induced changes and impacts are often hampered by the data poor-situation of these social-ecological systems. Based on 40 years of scientific and local ecological knowledge, we provide a coherent narrative about the effects of a marine hotspot of climate change on a small-scale fishery across different geographical and temporal scales. We applied a mixed-methods approach to assess biophysical changes, social-ecological impacts, and the incremental spectrum of actions implemented at multiple levels to increase the adaptive capacity of a small-scale clam fishery. The warming hotspot here analyzed was the fastest-warming region in the South Atlantic Ocean. Long-term changes in wind intensity and direction were also noticeable at a regional scale. Both sea surface temperature and winds showed a clear shifting pattern in the late 1990 s. These climate-related stressors determined ecosystem and targeted population changes (e.g. clam mass mortalities, slow stock recovery rates after ecological shocks, habitat narrowing), and favored harmful algal bloom-forming organisms. Climate-induced drivers also affected the human component of the social-ecological system, preventing fishers from securing a fulltime livelihood and limiting the fishery economic potential. Adaptive responses at multiple levels provided some capacity to address climate change effects, and transformative pathways are being taken to adapt to climate-induced changes over the long-term. Transformative changes were fostered by the local perception of environmental change, shared narratives, sustained scientific monitoring programs, and the interaction between knowledge systems, facilitated by a bridging organization within a broader process of governance transformation. The combination of autonomous adaptations (based on linking social capital and fishery leaders agency) and government-led adaptations were essential to face the challenges imposed by climate change. Our results serve as a learning platform to anticipate threats and envision solutions to a wide range of small-scale fisheries in fast-warming regions worldwide. 相似文献
7.
Critical to improving environmental governance is understanding the fit (alignment) between institutional arrangements and key ecological processes. This is particularly true for biodiversity hotpots and ecologically sensitive areas that are subject to significant impacts from human activities. Here, we have developed an innovative approach to quantify ecological-institutional alignment across an environmentally and politically complex large-scale marine social-ecological system. We mapped the trans-boundary networks of marine population dispersal corridors, and intersected these with estimates of cross-country institutional linkages related to marine management and conservation. In integrating large-scale ecological-institutional networks, we identify geopolitical fit and misfit between a region's ecological processes and its governance. We have demonstrated this approach in the Indo-West Pacific region, a global marine biodiversity hotpot in the Indo-West Pacific. We present region-specific institutional and ecological networks, highlight current challenges, and suggest future directions to refine the proposed approach to quantify alignment between ecological processes and governance arrangements. Ultimately, our method has the potential to assist management efforts in prioritizing and strengthening governance to effectively safeguard ecological processes across multiple jurisdictions. 相似文献
8.
Understanding the linkages between social and ecological systems is key to developing sustainable natural resource management (NRM) institutions. Frequently, however, insufficient attention is paid to the historical development of NRM institutions. Instead, discussion largely focuses on models of economic efficiency at the expense of the cultural, historical, and ecological contexts within which institutions develop. Here we use the research program of historical ecology to explore the development, maintenance, and change of two contemporary fire management institutions in northern Australia and Colorado, USA, to demonstrate how social institutions and ecological systems change and resist change over time and how institutions interact across scales to negotiate contrasting goals and motivations. We argue that these NRM institutions are not strictly speaking evolutionary or adaptive, and that historical context is critical when evaluating how and why particular institutions and institutional relationships develop. As with ecosystems, the present characteristics of the NRM institutions are dependent on what has happened before and their efficacy can only be evaluated retrospectively. Therefore, an understanding of history is essential to questions of the desirability and feasibility of institutional change where such shifts are required from an ecological, social, or economic perspective. We further propose that institutional conflict arises from the differing goals and motives of resource management institutions at different scales. Our cases reveal that larger-scale institutions can be successful at achieving narrowly defined goals but often fall short of achieving socially desirable sustainable outcomes. Our findings support the use of narratives of community history, place, and being in considering the resilience and sustainability of social-ecological systems. We offer that historical ecology is complementary with institutional and economic approaches to the analysis of NRM institutions, and possesses a particular strength in linking ecology to the values and norms of small social groups. 相似文献
9.
Summary Recent climate change scenarios resulting from elevated trace gasses may alter environmental temperature and moisture. The ecological consequences, however, are uncertain requiring an understanding of how soil-plant systems will respond to different conditions. This study examines the temporal characteristics of soil water retention in a temperate grassland following natural and simulated summer showers. We have used weighting lysimeters located in grassland stands of 360 m2, 2.25 m2 and lone lysimeters measuring 0.07 m2. Water deposited from natural summer rainfall on these grasslands is likely to be lost in less than two days because 92% of the rainshowers are < 10 mm having residence times of less than two days. Showers > 10 mm did, however, consistently remain in the soil-plant system for periods longer than light showers. When the largest plots (360 m2) were wetted by small (< 3 mm) natural rainfall events covering a portion of the entire valley (30–70 km2), soil water depletion rates were not significantly different than if just the 360 m2 plots were wetted by irrigations of the same size. If anthopogenetic changes occur in the rainfall amounts of summer showers in the Northern Great Plains, our results support the contention that soil water retention and associated ecosystem processes may be significantly altered inAgropyron smithii (Rybd.) grasslands.With 1 Figure 相似文献
10.
Effects of climate on numbers of northern prairie wetlands 总被引：4，自引：1，他引：4
Diane L. Larson 《Climatic change》1995,30(2):169-180
The amount of water held in individual wetland basins depends not only on local climate patterns but also on groundwater flow regime, soil permeability, and basin size. Most wetland basins in the northern prairies hold water in some years and are dry in others. To assess the potential effect of climate change on the number of wetland basins holding water in a given year, one must first determine how much of the variability in number of wet basins is accounted for by climatic variables. I used multiple linear regression to examine the relationship between climate variables and percentage of wet basins throughout the Prairie Pothole Region of Canada and the United States. The region was divided into three areas: parkland, Canadian grassland, and United States grassland (i.e., North Dakota and South Dakota). The models - which included variables for spring and fall temperature, yearly precipitation, the previous year's count of wet basins, and for grassland areas, the previous fall precipitation - accounted for 63 to 65% of the variation in the number of wet basins. I then explored the sensitivities of the models to changes in temperature and precipitation, as might be associated with increased greenhouse gas concentrations. Parkland wetlands are shown to be much more vulnerable to increased temperatures than are wetlands in either Canadian or United States grasslands. Sensitivity to increased precipitation did not vary geographically. These results have implications for waterfowl and other wildlife populations that depend on availability of wetlands in the parklands for breeding or during periods of drought in the southern grasslands.The U.S. Government right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
11.
Jianglin Wang Bao Yang Chun Qin Shuyuan Kang Minhui He Zhangyong Wang 《Climate Dynamics》2014,43(3-4):627-640
We present two tree-ring chronologies for the southeastern Tibetan Plateau (TP), established by applying the signal-free regional curve standardization and standard dendrochronological methodologies to a set of ring-width series of Tibetan juniper. The relationship between tree growth and climate shows that temperature variability in the previous year is the primary factor controlling tree growth at the upper portion of the forest belt. Accordingly, we developed a mean annual temperature reconstruction covering the period A.D. 984–2009 and explaining 50 % of the instrumental variance. The spatial correlation patterns suggest that our temperature reconstruction is a reasonable proxy for temperature change over the TP. At long time scales, the temperature reconstruction shows similar warm-cold patterns to those in temperature records from other regions of the TP, indicating that decadal and multidecadal temperature variations were generally synchronous across the TP during the past millennium. The periods 1140–1350 and 1600–1800 were common warm and cold episodes over the TP, respectively. Comparison of our reconstruction with four Northern Hemisphere (NH) temperature series indicates that temperature changes on the southeastern TP have generally followed the NH temperature patterns during the past millennium. Our results also suggest that temperature variability over the TP is affected by the Atlantic Multidecadal Oscillation (AMO), with the warm (cool) phases of the AMO associated with above-average (below-average) temperatures over the TP. 相似文献
12.
Matthew Bunce Laurence Mee Lynda D. Rodwell Richard Gibb 《Global Environmental Change》2009,19(2):213-226
Few studies consider how social-ecological systems recover from disturbance. We consider the small semi-autonomous island of Rodrigues (Indian Ocean). Based on semi-structured interviews (n = 70), a fisher survey (n = 73), weather data and official records we build a timeline of key events. We tabulate local perceptions (5+ mentions) of changes (social, economic and natural capital) and look for signs of adaptive cycles in the island's social-ecological past. Rising human pressure and extreme weather event impacts are reported since first settlement. We propose a recent “collapse” phase catalysed in the 1970s by severe drought, based on respondents’ perceptions of still-ongoing changes in farming and fishing, water, external dependence, migration and inter-island political change. Connectivity (flows of people, goods, information, money, power) appear to have strengthed local island recovery, but degradation continued, not least due to water scarcity and a lack of shared political vision as Rodrigues became more tied into the wider world.Overall, our findings suggest social-ecological systems may get stuck in a post-collapse recovery without any new structure emerging, presuming adaptive cycles can even be detected. Data gaps and global change redefining spatial and temporal scales could mean the adaptive cycle's usefulness is limited in development policy-making contexts. 相似文献
13.
Large wildfire events (e.g. >100 square km) highlight the importance of governance systems that address wildfire risk at landscape scales and among multiple land owners and institutions. A growing body of empirical work demonstrates that environmental governance outcomes depend upon how well patterns of interaction among actors align with patterns of ecological connectivity, such as wildfire transmission. However, the factors that facilitate or inhibit this alignment remain poorly understood. It is crucial to improve understanding of the conditions under which actors establish or maintain linkages with other actors with whom they are interdependent because of ecological linkages. To this end, we introduce the concept of “risk interdependence archetypes” based on the spatial configurations by which one actor (i.e. a particular organization) is exposed to risk via the actions of another actor. We then develop a set of hypotheses to explore how different sets of conditions associated with each spatial configurations of risk interdependence may shape the likelihood that an actor coordinates with another actor in ways that promote social-ecological alignment. We test these hypotheses using network analysis of a wildfire transmission network developed through simulation of wildfires over several thousand fire seasons and a governance network created from interviews with 154 representatives of 87 organizations involved in efforts to mitigate wildfire risk in the Eastern Cascades Ecoregion, USA. Results indicate that social-ecological alignment is more likely when actors have opportunities to influence forest management practices on ignition-prone lands that they do not manage themselves, and when actors bear greater responsibility for averting losses from wildfires that spread to lands they manage independently. Importantly, not all forms of risk interdependence increase the likelihood of alignment, implying that organizations have limited capacity for interaction and may prioritize certain risk mitigation partnerships over others. While the performance of risk governance systems may hinge on the alignment of social and ecological networks, our results suggest that alignment in turn may depend on actor-level strategies for interaction with other actors. 相似文献
14.
A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium 总被引：1，自引：0，他引：1
To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June–July–August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 % confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 % confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400. 相似文献
15.
Research on the governance of social-ecological systems often emphasizes the need for self-organized, flexible and adaptive arrangements to deal with uncertainty, abrupt change and surprises that are characteristic of social-ecological systems. However, adaptive governance as well as transitions toward alternative forms of governance are embedded in politics and it is often the political processes that determine change and stability in governance systems and policy. This paper analyses five established theoretical frameworks of the policy process originating in political science and public policy research with respect to their potential to enhance understanding of governance and complex policy dynamics in social-ecological systems. The frameworks are found to be divergent in their conceptualization of policy change (focusing on incremental or large-scale, major changes), highlighting different aspects of bounded rationality in their model of individual behavior and focusing their attention on different aspects of the policy process (role of information, attention, beliefs, institutional structure, particular actors, etc.). We discuss the application of these frameworks and their potential contribution to unravelling the political dimension in adaptive governance and transformations. 相似文献
16.
Giles H. F. Young Danny McCarroll Neil J. Loader Mary H. Gagen Andreas J. Kirchhefer Joanne C. Demmler 《Climate Dynamics》2012,39(1-2):495-507
Cloud cover currently represents the single greatest source of uncertainty in General Circulation Models. Stable carbon isotope ratios (δ13C) from tree-rings, in areas of low moisture stress, are likely to be primarily controlled by photosynthetically active radiation (PAR), and therefore should provide a proxy record for cloud cover or sunshine; indeed this association has previously been demonstrated experimentally for Scots pine in Fennoscandia, with sunlight explaining ca 90% of the variance in photosynthesis and temperature only ca 4%. We present a statistically verifiable 1011-year reconstruction of cloud cover from a well replicated, annually-resolved δ13C record from Forfjord in coastal northwestern Norway. This reconstruction exhibits considerable variability in cloud cover over the past millennium, including extended sunny periods during the cool seventeenth and eighteenth centuries and warm cloudy periods during the eleventh, early fifteenth and twentieth centuries. We find that while a generally positive relationship persists between sunshine and temperature at high-frequency, at lower (multi-decadal) frequencies the relationship is more often a negative one, with cool periods being sunny (most notably the Little Ice Age period from 1600 to 1750 CE) and warm periods more cloudy (e.g. the mediaeval and the twentieth century). We conclude that these long-term changes may be caused by changes in the dominant circulation mode, likely to be associated with the Arctic Oscillation. There is also strong circumstantial evidence that prolonged periods of high summer cloud cover, with low PAR and probably high precipitation, may be in part responsible for major European famines caused by crop failures. 相似文献
17.
Problems of scale abound in the governance of complex social-ecological systems. Conservation governance, for example, typically occurs at a single scale, but needs to inform governance and action at other scales to be truly effective at achieving social and ecological outcomes. This process is conventionally conceived as unidirectional – either scaling down or scaling up – in the way it both exploits and creates the natural, social, human, institutional, and financial resources and benefits that are collectively known as conservation ‘capital’. Here we analyse multiscale conservation governance and the different types of capital that impede or facilitate its effectiveness. Comparative analysis of conservation planning in Papua New Guinea and the Solomon Islands, through in-depth document review, key informant interview, and participant observation, reveals limited evidence of unidirectional processes. Instead, we observe multidirectional scaling pathways, cultivated by the following six scale-explicit characteristics of effective conservation governance: 1) multiscale understanding, 2) scale jumping, 3) scaled leadership characteristics, 4) scaled stakeholder engagement, 5) scaled policy frameworks, and 6) scaled institutional settings. While the latter four are familiar concepts, though not always recognised as explicitly scalar, we know little about the first two attributes of conservation governance. Based on this novelty and relevance, we propose a new form of capital – ‘scalar capital’ – to complement natural, social, human, institutional, and financial capitals as both input and outcome of effective conservation governance. We find that scalar capital facilitates flows of different resources (data, conservation objectives, practitioner experience, institutional support, and funding) in multiple directions. Critically, we present empirical evidence that conservation governance can foster scalar capital to improve outcomes across multiple scales. 相似文献
18.
Elin Enfors 《Global Environmental Change》2013,23(1):51-60
Recent efforts to achieve a much needed productivity increase in farming systems across semi-arid and dry sub-humid sub-Saharan Africa have highlighted the potential of small-scale water system innovations (SWSIs). This paper takes a social–ecological resilience approach to investigate how this type of water management technology would influence agro-ecosystem dynamics, using a catchment in northeastern Tanzania as an example. The analysis finds that three external drivers (increasing dryspell frequency, population growth, and institutional changes) have interacted with a set of key variables in the studied system to shape a development trajectory over the past half-century where off-farm ecosystem services are being degraded while agricultural yields remain low and people remain poor. The analysis further finds that the evaluated SWSIs have the potential to destabilize feedbacks maintaining this social–ecological trap through several different mechanisms, and thereby open up for new development trajectories. A concluding discussion identifies a number of challenges to this type of transformation in sub-Saharan Africa, and outlines the type of investment approaches that would be needed to go from potential to reality. 相似文献
19.
Ecological and social constraints are key for voluntary investments into renewable natural resources
Encouraging pro-environmental behavior is an urgent global challenge. An interdisciplinary framework covering governance, economic, social, ecological, and psychological dimensions is required to understand the salient features that encourage pro-environmental outcomes within and across contexts. We apply the Ostrom social-ecological systems framework to model voluntary investments by members of civil society into the aquatic environment. Using a data set of 1,809 angling clubs managing water bodies for fish stocking and habitat management in Germany and France, we show that a small set of factors, most crucially social-ecological and governance context as well as social norms and other bottom-up social pressures, drive environmental investments. These factors appear to override behavioral influences from psychological variables of the decision-maker. By contrast, the contextual setting related to property rights, size of the resource system, and social expectations were found to be strongly related to behavioral decisions, highlighting that the social-ecological context as well as incentives may be more important than knowledge and cognitions in driving certain pro-environmental actions. 相似文献
20.
中国近代土地利用变化对区域气候影响的数值模拟 总被引：26，自引：1，他引：26
利用国家气候中心改进的高分辨率区域气候模式(RegCM-NCC)模拟研究了中国近代历史时期土地利用/覆盖变化对中国区域气候的影响,模拟结果显示,1700年以来,以森林砍伐、草地退化及相应耕地面积扩大为主的土地利用变化可能对中国区域降水、温度产生了显著影响。1700—1900年期间,由于土地利用的变化使华北、西南等地区降水呈减少趋势,其他区域变化不明显,但近50年来却使长江中下游地区、西北、东北部分地区降水有所增加。1700—1800年间的土地利用变化使得除东北及长江流域地区外的大部分地区温度呈下降趋势,1900年以后有所升高,特别是近50年来中国大部分区域平均气温升高,与这一时期由于大气中温室气体排放浓度增加造成的温度升高相一致。另外,土地利用变化不仅使大气温度、湿度发生变化,还可引起基本流场的变化,使东亚冬、夏季风气流有所增强,这主要是由于植被变化改变了地面温度,使海、陆温差进一步增大的结果。因此,土地利用变化对区域尺度气候变化的影响是不容忽视的。 相似文献