Dendroclimatology method was used to study the relationship between ring index of Pinus massoniana and three climate factors in Dinghushan, South China. The ring indices were negatively correlated with the average tem...Dendroclimatology method was used to study the relationship between ring index of Pinus massoniana and three climate factors in Dinghushan, South China. The ring indices were negatively correlated with the average temperature in June, August and September, and positively correlated with the average temperature of March, whereas no statistically significant correlation was found with monthly precipitation, showing that high summer temperature could limit the radial growth of the species. Meanwhile, tree ring indices showed a strong positive correlation with the relative humidity of April, June, August, September, October and November, and also with the average humidity of the whole year, indicating that atmospheric moisture could not fully satisfy the growth of Pinus massoniana despite of abundant rainfall. The possible impact of climate change on the growth of Pinus massoniana was discussed accordingly.展开更多
Sichuan Basin is located in southwestern China and affected by a complex water vapor （WV） sources. Here, the spatial and temporal patterns of precipitation and extreme events are investigated by six indices of World...Sichuan Basin is located in southwestern China and affected by a complex water vapor （WV） sources. Here, the spatial and temporal patterns of precipitation and extreme events are investigated by six indices of World Meteorology Organization Commission, including annual precipitation total （AP）, maximum daily precipitation （Maxld）, intensity of rainfall over 1 mm/d （IR1）, maximum and mean consecutive dry days （Max CDD, Mean CDD） and coefficient of variance. Based on 24 daily precipitation time series from 1951 to 2o11, Mann-Kendall test is employed to quantify the significant level of these indices, from which the classification of precipitation change and its spatial patterns are obtained. Meanwhile, the probability distributions of these indices are identified by L-moment analysis and the Goodness-of-fit test, and the corresponding values are calculated by theoretical model at different return periods. The results reveal that the western basin displays normal drought： less AP and precipitation intensity while longer drought. The southern basin shows normal increase： larger AP and precipitation intensity but shorter CDD. However, in hilly region of the central basin and the transition zone between basin and mountains, precipitation changes abnormally： increasing both drought （one or both of Mean CDD and MaxCDD） and precipitation intensity （one or both of Maxld and trend of AP is. Probability IR1） no matter what the distribution models also demonstrate the complex patterns： a negative correlation between Maxld and Max CDD in the west （R2≥0.61） while a positive correlation in the east （R2≥0.41） at all return periods. These patterns are induced by the changes in WV sources and the layout of local terrain. The increase of WV in summer and decrease in spring leads to the heavier rainfall and longer drought respectively. The large heat island effect of the basin contributes to a lower temperature in transition zones and more precipitation in the downwind area. These results are helpful in reevaluating the risk regionally and making better decisions on water resources management and disaster prevention.展开更多
Elevation is one of key factors to affect changes in the environment, particularly changes in conditions of light, water and heat. Studying the soil physicochemical properties and vegetation structure along an elevati...Elevation is one of key factors to affect changes in the environment, particularly changes in conditions of light, water and heat. Studying the soil physicochemical properties and vegetation structure along an elevation gradient is important for understanding the responses of alpine plants andtheir growing environment to climate change. In this study, we studied plant coverage, plant height, species richness, soil water-holding capacity, soil organic carbon(SOC) and total nitrogen(N) on the northern slopes of the Qilian Mountains at elevations from2124 to 3665 m. The following conclusions were drawn:(1) With the increase of elevation, plant coverage and species richness first increased and then decreased, with the maximum values being at 3177 m.Plant height was significantly and negatively correlated with elevation(r=–0.97, P<0.01), and the ratio of decrease with elevation was 0.82 cm·100 m-1.(2) Both soil water-holding capacity and soil porosity increased on the northern slopes of the Qilian Mountains with the increase of elevation. The soil saturated water content at the 0-40 cm depth first increased and then stabilized with a further increase of elevation, and the average ratio of increase was2.44 mm·100 m-1. With the increase of elevation, the average bulk density at the 0-40 cm depth first decreased and then stabilized at 0.89 g/cm3.(3) With the increase of elevation, the average SOC content at the 0-40 cm depths first increased and then decreased,and the average total N content at the 0-40 cm depth first increased and then stabilized. The correlation between average SOC content and average total N content reached significant level. According to the results of this study, the distribution of plants showed a mono-peak curve with increasing elevation on the northern slopes of the Qilian Mountains. The limiting factor for plant growth at the high elevation areas was not soil physicochemical properties, and therefore,global warming will likely facilitate the development of plant at high elevation areas in the Qilian Mountains.展开更多
A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochast...A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined （DSC） approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average （SARIMA） models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term （10-year） environmental planning and decision making.展开更多
Coccolithophorid is unicellular marine microalgae with a global distribution in temperate and sub-temperate oceanic regions and has the ability to produce ＇the coccoliths＇. It is considered to be the second most pro...Coccolithophorid is unicellular marine microalgae with a global distribution in temperate and sub-temperate oceanic regions and has the ability to produce ＇the coccoliths＇. It is considered to be the second most productive calcifying organism on earth and becoming an important factor in the global carbonate cycle. Emiliania huxleyi is one of the only two bloom-forming coccolithophores and becomes a species crucial to the study of global biogeochemical cycles and climate modeling. Coccolithoviruse is a recently discovered group of viruses infecting the marine coceolithophorid E. huxleyi. They are a major cause of coceolithophore bloom termination, and DMSP concentration is increasing in the process of viral lysis. Phylogenetic evidences support that some genes are functional both in E. huxleyi and its virus （EhV）. Horizontal gene transfer （HGT） of multiple functionally coupled enzymes occurs in E. huxleyi and its DNA virus EhV has been confirmed, which contributes to the diversification and adaptation of plankton in the oceans and also critically regulates virus-host infection by allowing viruses to control host metabolic pathways for their repli- cation. Therefore, it is of particular interest to understand this host-virus interaction. On this issue, we have made a minireview of coeeolithoviruses focusing on the basic characteristics, phylogenesis, horizontal gene transfer and the interaction between the host and its viruses, as well as its important role in global biogeochemical cycling.展开更多
Climate change adaptation is an important part of addressing climate warming. Inner Mongolia grassland is a sensitive and vulnerable area of climate and an important region for adaptation to climate change. New climat...Climate change adaptation is an important part of addressing climate warming. Inner Mongolia grassland is a sensitive and vulnerable area of climate and an important region for adaptation to climate change. New climate change adaptation approaches with nomadic culture characteristics should be exploded in the context of climate warming. In this paper, the different utilization pattern of grassland in different regions, the different modes of production and management and historical culture were analyzed first in Nenjiang-West Liaohe plain and Ke'erqin region, Inner Mongolia Plateau and Ordos Plateau. Then, nomadic culture on the grassland was discussed from the productivity to biodiversity, from local livestock variety to resource-used system. Finally, new approaches of climate change adaptation with inheriting the essence of nomadic culture were proposed, including protecting biodiversity and using resources reasonably, performing a practice of grazing suspension-rotational grazing system,fencing degenerated grassland to facilitate its growth, founding new farming and husbandry system on the grassland, and establishing an incentive mechanism favorable to grassland and ethical cultural protection.展开更多
The present study was conducted in Solan Forest Division of Himachal Pradesh covering an area of about 57,158 ha. The aim was to estimate and assess the temporal change in carbon stock of the Chil Working Circle, in t...The present study was conducted in Solan Forest Division of Himachal Pradesh covering an area of about 57,158 ha. The aim was to estimate and assess the temporal change in carbon stock of the Chil Working Circle, in two forest ranges of the Division, Solan and Dharampur, over the period of 1956-2011. The inventory data of the working plans of Solan Forest Division from 1956-1957, 1984-1985 and 2002-2003 were used in the present study while field data for biomass estimation was collected for the year 2011.The results showed a declining trend in carbon stock over 1956-1984 period, however, an increasing trend over 1984-2002 was observed, which showed a further increase for the period 2002-2011. These fluctuating trends in the forest carbon stock can be related to increasing anthropogenic pressure on forests and the subsequent introduction of a ban on green felling envisaging efficient forest management, both of which affect the forest carbon pool significantly.展开更多
The fact of, present is the key of the past, will help us to use paleosols properties as indicators of the ecological characteristics of past .time, particularly the paleoclimate. In this respect the micro- morphologi...The fact of, present is the key of the past, will help us to use paleosols properties as indicators of the ecological characteristics of past .time, particularly the paleoclimate. In this respect the micro- morphological properties showed to be a very good indicator. Therefore, for investigating of climate change in Ardakan-Yazd plain, Central Iran 9 pedons were digged and described. Yazd has an arid climate with less than 100 mm annual precipitation and more than 22℃ mean annual temperature （Aridic-hyper thermic soil moisture and temperature regions, respectively）. Based on the morphological and physicochemical analysis Arglic, Calcic and Gypsic diagnostic horizons have been distinguished in these soils. Thin section studied showed that the illuviated form of clay includes, infillings on channel, coating on pendant, on nodules and on grains, at lower depths and also juxtaposed calcite needles on void argillan at upper part of the profiles. Mineralogical result showed fine clay in arglic horizon, too. Considering depth and forms of these pedofeatures, we concluded that, the observed illuviated clays at lower depth must be the result of the more humid climate of the past, where the carbonates have been removed completely as pendant, nodules or coating to considerable depth, following processes, clay has been dispersed and also trans located to these depths. In contrast to these features, the juxtaposed needle calcite at the shallower depth is probably the result of drier climate of today.展开更多
On 1 April 2017 China established Xiongan New Area in Hebei Province, which was described as ‘a strategy crucial for a millennium to come＇. A point of interest for the public is to be aware of the historical climate...On 1 April 2017 China established Xiongan New Area in Hebei Province, which was described as ‘a strategy crucial for a millennium to come＇. A point of interest for the public is to be aware of the historical climate change in this new area; however, results from previous global-scale or largerregional-scale averages provide relatively limited information because of the distinct regional differences in climate change. This study analyzes the changes in mean and extreme temperature in this area, based on homogenized daily temperature data for the period 1960–2016. The results show a significant warming in the indices of annual, summer, and winter mean temperature（Tmean）, maximum temperature（Tmax）, and minimum temperature（Tmin）. The linear rate of annual Tmean is 0.34 °C/decade. Temperatures on the hottest day, the warmest night, the coldest day, and the coldest night, every year, all show increasing trends, with the trends in the two nighttime-related indices being significant. An increasing occurrence of warm days, warm nights, hot days, and tropical nights, but a decreasing occurrence of cold days, cold nights, icing days, and frost days, are found, all of which are significant, except for the occurrences of hot days and icing days. A significant extension of the length of the thermal growing season is also found. The magnitudes of change in most of the temperature indices in Xiongan New Area are larger than those of the adjacent Jing-Jin-Ji and North China regional mean. These results could provide valuable information for policymakers, city planners, engineers, and migrants to this new area.展开更多
With trends indicating increase in temperature and decrease in winter precipitation, a significant negative trend in snow-covered areas has been identified in the last decade in the Himalayas. This requires a quantita...With trends indicating increase in temperature and decrease in winter precipitation, a significant negative trend in snow-covered areas has been identified in the last decade in the Himalayas. This requires a quantitative analysis of the snow cover in the higher Himalayas. In this study, a nonlinear autoregressive exogenous model, an artificial neural network （ANN）, was deployed to predict the snow cover in the Kaligandaki river basin for the next 30 years. Observed climatic data, and snow covered area was used to train and test the model that captures the gross features of snow under the current climate scenario. The range of the likely effects of climate change on seasonal snow was assessed in the Himalayas using downscaled temperature and precipitation change projection from - HadCM3, a global circulation model to project future climate scenario, under the AIB emission scenario, which describes a future world of very rapid economic growth with balance use between fossil and non-fossil energy sources. The results show that there is a reduction of 9% to 46% of snow cover in different elevation zones during the considered time period, i.e., 2Oll to 2040. The 4700 m to 52oo m elevation zone is the most affected area and the area higher than 5200 m is the least affected. Overall, however, it is clear from the analysis that seasonal snow in the Kaligandaki basin is likely to be subject to substantialchanges due to the impact of climate change.展开更多
This study investigates the influence of interannual vegetation variability. Two sets of offline and online simulations were performed using the Community Earth System Model. The interannual Global LAnd Surface Satell...This study investigates the influence of interannual vegetation variability. Two sets of offline and online simulations were performed using the Community Earth System Model. The interannual Global LAnd Surface Satellite(GLASS) leaf area index(LAI) dataset from 1985 to 2000 and its associated climatological LAI were used to replace the default climatological LAI data in version 4 of the Community Land Model(CLM4). The results showed that on a global scale, canopy transpiration and evaporation, as well as total evapotranspiration in offline simulations were significantly positively correlated with LAI, whereas ground evaporation and ground temperature showed significant negative correlation with LAI. However, the correlations in online simulations were reduced markedly because of interactive feedbacks between albedo, changed climatic factors and atmospheric variability. In the offline simulations, the fluctuations of differences in interannual variability of evapotranspiration and ground temperature focused on vegetation growing regions and the magnitudes were smaller. Those in online simulations spread over more regions and the magnitudes were larger. These results highlight the influence of interannual vegetation variability, particularly in online simulations, an effect that deserves consideration and attention when investigating the uncertainty of climate change.展开更多
Assessing the impact of climate change is important for ecosystem conservation and plant recovery, especially in climate sensitive regions. Various studies suggested that the KSppen classification is an effective meth...Assessing the impact of climate change is important for ecosystem conservation and plant recovery, especially in climate sensitive regions. Various studies suggested that the KSppen classification is an effective method to depict climate change. However, these studies were restricted to large scales or of limited accuracy due to uncertainties in climate model projections. In addition, the impact of elevation on the shift of climate zones, as compared with other factors, is less emphasized. To address these issues we compiled the KSppen Climate Classification （period 1961-2olo） for the study area, Sichuan Province, China. The spatial resolution was selected as x km x x km. Sichuan Province may be characterized by 3 main climate classes and 1o subtypes. The east-west gradient of the climatic regimes in Siehuan is represented by the main climate classes, warm temperate climates （C）, snow climates （D） and polar climates （E）, at which the most abundant class is C. The most abundant subtype is snow climate with dry winter and cool summer （Dwe）. Shifts in K/Sppen climate classes reflect the observed trend of increasing temperature. Finally, the elevation showed an obvious impact on the distribution and the change of climate classes in Siehuan Province. The shift of areas covered by KSppen climate classes increases with elevation.展开更多
In the setting of dealing with climate change, this article designs a matching mechanism for global public goods provision with the aggregative game approach. Given endowment and the technology of each country, we pro...In the setting of dealing with climate change, this article designs a matching mechanism for global public goods provision with the aggregative game approach. Given endowment and the technology of each country, we propose the conditions under which the matching mechanism is able to guarantee full participation and Pareto efficient provision, respectively, in the cases with certain and uncertain preference information. These conditions cannot only be adopted in international negotiation and cooperation, but also refines the theory of matching game. In comparative static analyses, we discover that: First, changes of initial stock of climate goods produce a wealth effect and the crowd-out effect is less than 1. Second, climate tax policies affect the supply and welfare of each country only when they produce wealth effects, and if tax revenue is transferred into climate goods with more advanced technology, they will produce positive wealth effects. Third, modifying matching plans dynamically and appropriately can urge countries to improve technology, and especially given a Pareto optimal mechanism, adjusting the matching plan to keep marginal rates of transformation unchanged as technology changes is still able to ensure full participation and efficient supply of climate goods.展开更多
This article analyzes the perceptions of Puerto Rican citizens of global climate change (GCC) before and after an extreme weather event, specifically Hurricane Maria (HM). The purpose of the current article is to eval...This article analyzes the perceptions of Puerto Rican citizens of global climate change (GCC) before and after an extreme weather event, specifically Hurricane Maria (HM). The purpose of the current article is to evaluate Puerto Ricans’ perceptions of the impact of extreme meteorological phenomena and of GCC before and after HM. This tropical cyclone entered the island as a category IV hurricane on September 17, 2017, causing enormous destruction, loss of life, and economic damage. In this study, two data samples were collected before and after HM struck Puerto Rico (PR) (the second sample was collected approximately six months after the hurricane). Surveyed citizens with general knowledge of GCC increased from 43% to 62%, which the researchers consider a small increase, considering the severe destruction caused by HM. This study also found that Puerto Ricans trust non-profit institutions and the scientific community more than state authorities. Furthermore, 85% of citizens believe that public policies on GCC should be directed by the state (federal, state, and municipal governments);this did not change after HM. In addition, this study found that the poor response of the federal and state governments to the destruction caused by HM increased citizens’ trust in the scientific community.展开更多
This study assesses the commonly adopted adaptation planning strategies of infrastructures in Northwest Florida(USA)based on economic analysis under different objective years.Specifically,the economic analysis conside...This study assesses the commonly adopted adaptation planning strategies of infrastructures in Northwest Florida(USA)based on economic analysis under different objective years.Specifically,the economic analysis considers both direct and indirect impacts of sea level rise by deploying the interdependence of infrastructures.We demonstrate the difference and significance of considering indirect economic impacts in the process of cost-benefit analysis under sea level rise.Based on the results,we recommend that the most effective strategy is partial protection of land use plus inundated transportation network upgrade,even though the total shoreline protection can make more benefits.Furthermore,we compare the performance of objective planning year from two criteria:total benefits and cost-effectiveness.The result indicates that the year 2080 could be the most economical if it is set as the objective year for the long-term infrastructure planning.The result also highlights that the economic analysis of infrastructure should be conducted over time since the total costs are distributed over many years.It is not to say that the farther the year is,the more effectiveness the strategy would be,although the total benefits would be greater.展开更多
This paper presents a concise summary of the studies on interdecadal variability of the East Asian winter monsoon （EAWM） from three main perspectives. （1） The EAWM has been significantly affected by global climate...This paper presents a concise summary of the studies on interdecadal variability of the East Asian winter monsoon （EAWM） from three main perspectives. （1） The EAWM has been significantly affected by global climate change. Winter temperature in China has experienced three stages of variations from the beginning of the 1950s： a cold period （from the beginning of the 1950s to the early or mid 1980s）, a warm period （from the early or mid 1980s to the early 2000s）, and a hiatus period in recent 10 years （starting from 1998）. The strength of the EAWM has also varied in three stages： a stronger winter monsoon period （1950 to 1986/87）, a weaker period （1986/87 to 2004/05）, and a strengthening period （from 2005）. （2） Corresponding to the interdecadal variations of the EAWM, the East Asian atmospheric circulation, winter temperature of China, and the occurrence of cold waves over China have all exhibited coherent interdecadal variability. The upper-level zonal circulation was stronger, the mid-tropospheric trough over East Asia was deeper with stronger downdrafts behind the trough, and the Siberian high was stronger during the cold period than during the warm period. （3） The interdecadal variations of the EAWM seem closely related to major modes of variability in the atmospheric circulation and the Pacific sea surface temperature. When the Northern Hemisphere annular mode/Arctic Oscillation and the Pacific decadal oscillation were in negative （positive） phase, the EAWM was stronger （weaker）, leading to colder （warmer） temperatures in China. In addition, the negative （positive） phase of the Atlantic multi decadal oscillation coincided with relatively cold （warm） temperatures and stronger （weaker） EAWMs. It is thus inferred that the interdecadal variations in the ocean may be one of the most important natural factors influencing long-term variability in the EAWM, although global warming may have also played a significant role in weakening the EAWM.展开更多
China harbors a rich variety of forest types and forest-associated biodiversity, linked to both historical and contemporary environmental factors. However, being a country with a large population and rapid economic de...China harbors a rich variety of forest types and forest-associated biodiversity, linked to both historical and contemporary environmental factors. However, being a country with a large population and rapid economic development, its diverse forest is facing unprecedent challenges. The Chinese Forest Biodiversity Network （CForBio） was initiated 12 years ago to study the mainte- nance of biodiversity in China＇s forest ecosystems. In this review, we first summarize research progress in CForBio, and then give suggestions for future research. In the past 12 years, the research based on CForBio mainly focused on local ecological factors, such as environment filtering, biotic interactions and small-scale dispersal limitation. We suggest that future studies in CForBio should （1） continue research on trees, but expand more on insects, birds, mammals, microbes and other organism groups; （2） investigate the effects of widespread defaunation on forest biodiversity, structure and functioning; （3） evaluate the diverse effects of climate change on forest composition,structure and functioning; （4） include new technologies, such as remote sensing, to better monitor and study forest biodiversity change and maintenance.展开更多
Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and...Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM ＋ images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06km^2 in 1975 to 46049.23 km^2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate wanning, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of fiver runoff. Consequently, thearea of inland lakes in Central Asia shrank over the past 32 years.展开更多
文摘Dendroclimatology method was used to study the relationship between ring index of Pinus massoniana and three climate factors in Dinghushan, South China. The ring indices were negatively correlated with the average temperature in June, August and September, and positively correlated with the average temperature of March, whereas no statistically significant correlation was found with monthly precipitation, showing that high summer temperature could limit the radial growth of the species. Meanwhile, tree ring indices showed a strong positive correlation with the relative humidity of April, June, August, September, October and November, and also with the average humidity of the whole year, indicating that atmospheric moisture could not fully satisfy the growth of Pinus massoniana despite of abundant rainfall. The possible impact of climate change on the growth of Pinus massoniana was discussed accordingly.
基金funded by open funding of Guizhou Provincial Key Laboratory of Public Big Data(Guizhou University, Grant No.2017BDKFJJ021)Special Science and Technology Funding of Guizhou Province Water Resources Department (KT201707)+1 种基金Guizhou Province Science and Technology Joint Founding (LH [2017]7617)China Postdoctoral Science Foundation (Grant No.2016M5 92671)
文摘Sichuan Basin is located in southwestern China and affected by a complex water vapor （WV） sources. Here, the spatial and temporal patterns of precipitation and extreme events are investigated by six indices of World Meteorology Organization Commission, including annual precipitation total （AP）, maximum daily precipitation （Maxld）, intensity of rainfall over 1 mm/d （IR1）, maximum and mean consecutive dry days （Max CDD, Mean CDD） and coefficient of variance. Based on 24 daily precipitation time series from 1951 to 2o11, Mann-Kendall test is employed to quantify the significant level of these indices, from which the classification of precipitation change and its spatial patterns are obtained. Meanwhile, the probability distributions of these indices are identified by L-moment analysis and the Goodness-of-fit test, and the corresponding values are calculated by theoretical model at different return periods. The results reveal that the western basin displays normal drought： less AP and precipitation intensity while longer drought. The southern basin shows normal increase： larger AP and precipitation intensity but shorter CDD. However, in hilly region of the central basin and the transition zone between basin and mountains, precipitation changes abnormally： increasing both drought （one or both of Mean CDD and MaxCDD） and precipitation intensity （one or both of Maxld and trend of AP is. Probability IR1） no matter what the distribution models also demonstrate the complex patterns： a negative correlation between Maxld and Max CDD in the west （R2≥0.61） while a positive correlation in the east （R2≥0.41） at all return periods. These patterns are induced by the changes in WV sources and the layout of local terrain. The increase of WV in summer and decrease in spring leads to the heavier rainfall and longer drought respectively. The large heat island effect of the basin contributes to a lower temperature in transition zones and more precipitation in the downwind area. These results are helpful in reevaluating the risk regionally and making better decisions on water resources management and disaster prevention.
基金funded by National Key R&D Program of China(2017YFA0604801,2016YFC0501802)Natural Science Foundation of Qinghai Province(Grant No.2016-ZJ-910)+1 种基金CAS“Light of West China”Program(2016):Study on the soil moisture with the restoration process of degraded alpine meadows in the Three-River Headwater Region,ChinaQinghai innovation platform construction project(2017-ZJ-Y20)supported this work
文摘Elevation is one of key factors to affect changes in the environment, particularly changes in conditions of light, water and heat. Studying the soil physicochemical properties and vegetation structure along an elevation gradient is important for understanding the responses of alpine plants andtheir growing environment to climate change. In this study, we studied plant coverage, plant height, species richness, soil water-holding capacity, soil organic carbon(SOC) and total nitrogen(N) on the northern slopes of the Qilian Mountains at elevations from2124 to 3665 m. The following conclusions were drawn:(1) With the increase of elevation, plant coverage and species richness first increased and then decreased, with the maximum values being at 3177 m.Plant height was significantly and negatively correlated with elevation(r=–0.97, P<0.01), and the ratio of decrease with elevation was 0.82 cm·100 m-1.(2) Both soil water-holding capacity and soil porosity increased on the northern slopes of the Qilian Mountains with the increase of elevation. The soil saturated water content at the 0-40 cm depth first increased and then stabilized with a further increase of elevation, and the average ratio of increase was2.44 mm·100 m-1. With the increase of elevation, the average bulk density at the 0-40 cm depth first decreased and then stabilized at 0.89 g/cm3.(3) With the increase of elevation, the average SOC content at the 0-40 cm depths first increased and then decreased,and the average total N content at the 0-40 cm depth first increased and then stabilized. The correlation between average SOC content and average total N content reached significant level. According to the results of this study, the distribution of plants showed a mono-peak curve with increasing elevation on the northern slopes of the Qilian Mountains. The limiting factor for plant growth at the high elevation areas was not soil physicochemical properties, and therefore,global warming will likely facilitate the development of plant at high elevation areas in the Qilian Mountains.
基金This research was supported by the Ministry of Science and Technology of China，National Basic Research Program of China (Grant No.2010CB951504).The authors acknowledge support from the Flemish Interuniversity Council，the Ghent University Laboratory of Soil Science for the writing of this paper
文摘A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined （DSC） approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average （SARIMA） models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term （10-year） environmental planning and decision making.
基金funded by the Chinese Public Science and Technology Research Funds Projects of Ocean (No. 201305027)the National Natural Science Foundation of China (Nos. 40930847, 41376119)+1 种基金Funds of China Southern Oceano-graphic Research Center (No. 14GZP71NF35)Funds of Provincial Key Laboratory of Food Microbiology and Enzyme Engineering (No. M20140910)
文摘Coccolithophorid is unicellular marine microalgae with a global distribution in temperate and sub-temperate oceanic regions and has the ability to produce ＇the coccoliths＇. It is considered to be the second most productive calcifying organism on earth and becoming an important factor in the global carbonate cycle. Emiliania huxleyi is one of the only two bloom-forming coccolithophores and becomes a species crucial to the study of global biogeochemical cycles and climate modeling. Coccolithoviruse is a recently discovered group of viruses infecting the marine coceolithophorid E. huxleyi. They are a major cause of coceolithophore bloom termination, and DMSP concentration is increasing in the process of viral lysis. Phylogenetic evidences support that some genes are functional both in E. huxleyi and its virus （EhV）. Horizontal gene transfer （HGT） of multiple functionally coupled enzymes occurs in E. huxleyi and its DNA virus EhV has been confirmed, which contributes to the diversification and adaptation of plankton in the oceans and also critically regulates virus-host infection by allowing viruses to control host metabolic pathways for their repli- cation. Therefore, it is of particular interest to understand this host-virus interaction. On this issue, we have made a minireview of coeeolithoviruses focusing on the basic characteristics, phylogenesis, horizontal gene transfer and the interaction between the host and its viruses, as well as its important role in global biogeochemical cycling.
基金supported by the National Key Technology R&D Program:[Grant Number 2013BAC09B04]
文摘Climate change adaptation is an important part of addressing climate warming. Inner Mongolia grassland is a sensitive and vulnerable area of climate and an important region for adaptation to climate change. New climate change adaptation approaches with nomadic culture characteristics should be exploded in the context of climate warming. In this paper, the different utilization pattern of grassland in different regions, the different modes of production and management and historical culture were analyzed first in Nenjiang-West Liaohe plain and Ke'erqin region, Inner Mongolia Plateau and Ordos Plateau. Then, nomadic culture on the grassland was discussed from the productivity to biodiversity, from local livestock variety to resource-used system. Finally, new approaches of climate change adaptation with inheriting the essence of nomadic culture were proposed, including protecting biodiversity and using resources reasonably, performing a practice of grazing suspension-rotational grazing system,fencing degenerated grassland to facilitate its growth, founding new farming and husbandry system on the grassland, and establishing an incentive mechanism favorable to grassland and ethical cultural protection.
文摘The present study was conducted in Solan Forest Division of Himachal Pradesh covering an area of about 57,158 ha. The aim was to estimate and assess the temporal change in carbon stock of the Chil Working Circle, in two forest ranges of the Division, Solan and Dharampur, over the period of 1956-2011. The inventory data of the working plans of Solan Forest Division from 1956-1957, 1984-1985 and 2002-2003 were used in the present study while field data for biomass estimation was collected for the year 2011.The results showed a declining trend in carbon stock over 1956-1984 period, however, an increasing trend over 1984-2002 was observed, which showed a further increase for the period 2002-2011. These fluctuating trends in the forest carbon stock can be related to increasing anthropogenic pressure on forests and the subsequent introduction of a ban on green felling envisaging efficient forest management, both of which affect the forest carbon pool significantly.
基金supported by the Soil Science department, faculty of Soil & Water, University College of Agriculture & Natural Resources, University of Tehran
文摘The fact of, present is the key of the past, will help us to use paleosols properties as indicators of the ecological characteristics of past .time, particularly the paleoclimate. In this respect the micro- morphological properties showed to be a very good indicator. Therefore, for investigating of climate change in Ardakan-Yazd plain, Central Iran 9 pedons were digged and described. Yazd has an arid climate with less than 100 mm annual precipitation and more than 22℃ mean annual temperature （Aridic-hyper thermic soil moisture and temperature regions, respectively）. Based on the morphological and physicochemical analysis Arglic, Calcic and Gypsic diagnostic horizons have been distinguished in these soils. Thin section studied showed that the illuviated form of clay includes, infillings on channel, coating on pendant, on nodules and on grains, at lower depths and also juxtaposed calcite needles on void argillan at upper part of the profiles. Mineralogical result showed fine clay in arglic horizon, too. Considering depth and forms of these pedofeatures, we concluded that, the observed illuviated clays at lower depth must be the result of the more humid climate of the past, where the carbonates have been removed completely as pendant, nodules or coating to considerable depth, following processes, clay has been dispersed and also trans located to these depths. In contrast to these features, the juxtaposed needle calcite at the shallower depth is probably the result of drier climate of today.
基金sponsored by the National Key R&D Programof China(grant number 2016YFA0600404)Key Technology of Integration of Meteorological and Application Projects(grant number CMAGJ2015Z16)+1 种基金the Youth Innovation Promotion Association of CAS(grant number 2016075)the Jiangsu Collaborative Innovation Center for Climate Change
文摘On 1 April 2017 China established Xiongan New Area in Hebei Province, which was described as ‘a strategy crucial for a millennium to come＇. A point of interest for the public is to be aware of the historical climate change in this new area; however, results from previous global-scale or largerregional-scale averages provide relatively limited information because of the distinct regional differences in climate change. This study analyzes the changes in mean and extreme temperature in this area, based on homogenized daily temperature data for the period 1960–2016. The results show a significant warming in the indices of annual, summer, and winter mean temperature（Tmean）, maximum temperature（Tmax）, and minimum temperature（Tmin）. The linear rate of annual Tmean is 0.34 °C/decade. Temperatures on the hottest day, the warmest night, the coldest day, and the coldest night, every year, all show increasing trends, with the trends in the two nighttime-related indices being significant. An increasing occurrence of warm days, warm nights, hot days, and tropical nights, but a decreasing occurrence of cold days, cold nights, icing days, and frost days, are found, all of which are significant, except for the occurrences of hot days and icing days. A significant extension of the length of the thermal growing season is also found. The magnitudes of change in most of the temperature indices in Xiongan New Area are larger than those of the adjacent Jing-Jin-Ji and North China regional mean. These results could provide valuable information for policymakers, city planners, engineers, and migrants to this new area.
文摘With trends indicating increase in temperature and decrease in winter precipitation, a significant negative trend in snow-covered areas has been identified in the last decade in the Himalayas. This requires a quantitative analysis of the snow cover in the higher Himalayas. In this study, a nonlinear autoregressive exogenous model, an artificial neural network （ANN）, was deployed to predict the snow cover in the Kaligandaki river basin for the next 30 years. Observed climatic data, and snow covered area was used to train and test the model that captures the gross features of snow under the current climate scenario. The range of the likely effects of climate change on seasonal snow was assessed in the Himalayas using downscaled temperature and precipitation change projection from - HadCM3, a global circulation model to project future climate scenario, under the AIB emission scenario, which describes a future world of very rapid economic growth with balance use between fossil and non-fossil energy sources. The results show that there is a reduction of 9% to 46% of snow cover in different elevation zones during the considered time period, i.e., 2Oll to 2040. The 4700 m to 52oo m elevation zone is the most affected area and the area higher than 5200 m is the least affected. Overall, however, it is clear from the analysis that seasonal snow in the Kaligandaki basin is likely to be subject to substantialchanges due to the impact of climate change.
基金supported by Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05110103)the National High Technology Research and Development Program of China (863 Program, Grant No. 2009AA122100)
文摘This study investigates the influence of interannual vegetation variability. Two sets of offline and online simulations were performed using the Community Earth System Model. The interannual Global LAnd Surface Satellite(GLASS) leaf area index(LAI) dataset from 1985 to 2000 and its associated climatological LAI were used to replace the default climatological LAI data in version 4 of the Community Land Model(CLM4). The results showed that on a global scale, canopy transpiration and evaporation, as well as total evapotranspiration in offline simulations were significantly positively correlated with LAI, whereas ground evaporation and ground temperature showed significant negative correlation with LAI. However, the correlations in online simulations were reduced markedly because of interactive feedbacks between albedo, changed climatic factors and atmospheric variability. In the offline simulations, the fluctuations of differences in interannual variability of evapotranspiration and ground temperature focused on vegetation growing regions and the magnitudes were smaller. Those in online simulations spread over more regions and the magnitudes were larger. These results highlight the influence of interannual vegetation variability, particularly in online simulations, an effect that deserves consideration and attention when investigating the uncertainty of climate change.
基金partly funded by The national ecological environment ten years (2000-2010) change remote sensing survey and evaluation project--Chengdu-Chongqing urban agglomeration ecological environment situation and ten years change investigation and assessment (Project No. STSN-12-05)Sino-Norwegian Biodiversity and Climate Change Project (Grant No. C/IV/S//11/242-02)
文摘Assessing the impact of climate change is important for ecosystem conservation and plant recovery, especially in climate sensitive regions. Various studies suggested that the KSppen classification is an effective method to depict climate change. However, these studies were restricted to large scales or of limited accuracy due to uncertainties in climate model projections. In addition, the impact of elevation on the shift of climate zones, as compared with other factors, is less emphasized. To address these issues we compiled the KSppen Climate Classification （period 1961-2olo） for the study area, Sichuan Province, China. The spatial resolution was selected as x km x x km. Sichuan Province may be characterized by 3 main climate classes and 1o subtypes. The east-west gradient of the climatic regimes in Siehuan is represented by the main climate classes, warm temperate climates （C）, snow climates （D） and polar climates （E）, at which the most abundant class is C. The most abundant subtype is snow climate with dry winter and cool summer （Dwe）. Shifts in K/Sppen climate classes reflect the observed trend of increasing temperature. Finally, the elevation showed an obvious impact on the distribution and the change of climate classes in Siehuan Province. The shift of areas covered by KSppen climate classes increases with elevation.
基金supported by National Basic Research Program of China[grant number:2012CB955802],Climate Change and Global Economic Problems in Climate ProtectionNational Natural Science Foundation of China[grant number:71471177],Economic Complexity-Oriented Modeling of Behavior and Computational Experiment with ApplicationsCASS-ESRC Partnership Project of China-UK Governments[grant number:ES/N00762X/1],Behavioural Compatibilitybetween Individual Choice and Collective Action with Applications
文摘In the setting of dealing with climate change, this article designs a matching mechanism for global public goods provision with the aggregative game approach. Given endowment and the technology of each country, we propose the conditions under which the matching mechanism is able to guarantee full participation and Pareto efficient provision, respectively, in the cases with certain and uncertain preference information. These conditions cannot only be adopted in international negotiation and cooperation, but also refines the theory of matching game. In comparative static analyses, we discover that: First, changes of initial stock of climate goods produce a wealth effect and the crowd-out effect is less than 1. Second, climate tax policies affect the supply and welfare of each country only when they produce wealth effects, and if tax revenue is transferred into climate goods with more advanced technology, they will produce positive wealth effects. Third, modifying matching plans dynamically and appropriately can urge countries to improve technology, and especially given a Pareto optimal mechanism, adjusting the matching plan to keep marginal rates of transformation unchanged as technology changes is still able to ensure full participation and efficient supply of climate goods.
文摘This article analyzes the perceptions of Puerto Rican citizens of global climate change (GCC) before and after an extreme weather event, specifically Hurricane Maria (HM). The purpose of the current article is to evaluate Puerto Ricans’ perceptions of the impact of extreme meteorological phenomena and of GCC before and after HM. This tropical cyclone entered the island as a category IV hurricane on September 17, 2017, causing enormous destruction, loss of life, and economic damage. In this study, two data samples were collected before and after HM struck Puerto Rico (PR) (the second sample was collected approximately six months after the hurricane). Surveyed citizens with general knowledge of GCC increased from 43% to 62%, which the researchers consider a small increase, considering the severe destruction caused by HM. This study also found that Puerto Ricans trust non-profit institutions and the scientific community more than state authorities. Furthermore, 85% of citizens believe that public policies on GCC should be directed by the state (federal, state, and municipal governments);this did not change after HM. In addition, this study found that the poor response of the federal and state governments to the destruction caused by HM increased citizens’ trust in the scientific community.
基金funded by the National Natural Science Foundation of China(52008086).
文摘This study assesses the commonly adopted adaptation planning strategies of infrastructures in Northwest Florida(USA)based on economic analysis under different objective years.Specifically,the economic analysis considers both direct and indirect impacts of sea level rise by deploying the interdependence of infrastructures.We demonstrate the difference and significance of considering indirect economic impacts in the process of cost-benefit analysis under sea level rise.Based on the results,we recommend that the most effective strategy is partial protection of land use plus inundated transportation network upgrade,even though the total shoreline protection can make more benefits.Furthermore,we compare the performance of objective planning year from two criteria:total benefits and cost-effectiveness.The result indicates that the year 2080 could be the most economical if it is set as the objective year for the long-term infrastructure planning.The result also highlights that the economic analysis of infrastructure should be conducted over time since the total costs are distributed over many years.It is not to say that the farther the year is,the more effectiveness the strategy would be,although the total benefits would be greater.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2012CB417205 and 2013CB430202)National Natural Science Foundation of China(41130960)+1 种基金China Meteorological Administration Special Public Welfare Research Fund(GYHY201406001)National Science and Technology Support Program of China(2009BAC51B02)
文摘This paper presents a concise summary of the studies on interdecadal variability of the East Asian winter monsoon （EAWM） from three main perspectives. （1） The EAWM has been significantly affected by global climate change. Winter temperature in China has experienced three stages of variations from the beginning of the 1950s： a cold period （from the beginning of the 1950s to the early or mid 1980s）, a warm period （from the early or mid 1980s to the early 2000s）, and a hiatus period in recent 10 years （starting from 1998）. The strength of the EAWM has also varied in three stages： a stronger winter monsoon period （1950 to 1986/87）, a weaker period （1986/87 to 2004/05）, and a strengthening period （from 2005）. （2） Corresponding to the interdecadal variations of the EAWM, the East Asian atmospheric circulation, winter temperature of China, and the occurrence of cold waves over China have all exhibited coherent interdecadal variability. The upper-level zonal circulation was stronger, the mid-tropospheric trough over East Asia was deeper with stronger downdrafts behind the trough, and the Siberian high was stronger during the cold period than during the warm period. （3） The interdecadal variations of the EAWM seem closely related to major modes of variability in the atmospheric circulation and the Pacific sea surface temperature. When the Northern Hemisphere annular mode/Arctic Oscillation and the Pacific decadal oscillation were in negative （positive） phase, the EAWM was stronger （weaker）, leading to colder （warmer） temperatures in China. In addition, the negative （positive） phase of the Atlantic multi decadal oscillation coincided with relatively cold （warm） temperatures and stronger （weaker） EAWMs. It is thus inferred that the interdecadal variations in the ocean may be one of the most important natural factors influencing long-term variability in the EAWM, although global warming may have also played a significant role in weakening the EAWM.
文摘China harbors a rich variety of forest types and forest-associated biodiversity, linked to both historical and contemporary environmental factors. However, being a country with a large population and rapid economic development, its diverse forest is facing unprecedent challenges. The Chinese Forest Biodiversity Network （CForBio） was initiated 12 years ago to study the mainte- nance of biodiversity in China＇s forest ecosystems. In this review, we first summarize research progress in CForBio, and then give suggestions for future research. In the past 12 years, the research based on CForBio mainly focused on local ecological factors, such as environment filtering, biotic interactions and small-scale dispersal limitation. We suggest that future studies in CForBio should （1） continue research on trees, but expand more on insects, birds, mammals, microbes and other organism groups; （2） investigate the effects of widespread defaunation on forest biodiversity, structure and functioning; （3） evaluate the diverse effects of climate change on forest composition,structure and functioning; （4） include new technologies, such as remote sensing, to better monitor and study forest biodiversity change and maintenance.
文摘Inland lakes are the major surface water resource in the arid regions of Central Asia. Therefore, the surface area changes in inland lakes have been a sensitive indicator of climate changes and human activ- ities, and have often been the focus of ecological and environmental research. This study aimed to monitor the changes in surface area of nine major lakes over a 32-year period. The water body was extracted from MSS images from the mid-1970s, TM images from the early 1990s, ETM ＋ images in the late 1990s, and TM images in 2007. The results indicated that the total surface area of these nine lakes had decreased over time to 50.38% of the area, from 91402.06km^2 in 1975 to 46049.23 km^2 in 2007. As the surface area of lakes in the western part of Central Asia was larger than that in the eastern part, the shrinking trend of lake area was more significant in the west than in the east. There was a varied reduction of closed lakes in flat regions. The most substantial decrease was in the surface area of closed lakes in flat regions. Most significantly, the area of the Aral Sea was reduced by 75.7% from its original area in 1975. The area of alpine lakes remained relatively stable; the change in surface area was less than 0.7% during the period 1975-2007. The area change in opened lakes with outlets was notably different from the other two types. The area of Zaysan had increased sharply by 5.85%, and that of Bosten had decreased by 9.1%. Sasykkol had hardly any changes in this period. Due to global climate wanning, vapor transfer to the south via westerly winds had been blocked, resulting in a decrease of much-needed precipitation in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan between 1970 and 2000. The decrease in precipitation and the increase in water consumption for agricultural irrigation resulted in the decrease of fiver runoff. Consequently, thearea of inland lakes in Central Asia shrank over the past 32 years.
