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1.
Monitoring the dynamics of vegetation growth and its response to climate change is important to understand the mechanisms underlying ecosystem behaviors. This study investigated the relationship between vegetation growth and climate change during the growing seasons on the Loess Plateau in China by analyzing the normalized difference vegetation index (NDVI) derived from the Land Long Term Data Record dataset from 1982 to 2011. Results showed that growing-season NDVI had increased at an annual rate of 0.0028, particularly in the semi-arid and semi-humid regions. By contrast, the NDVI first increased from 1982 to 1994 (0.0013 year?1, P < 0.05) and then decreased from 1994 to 2011 (0.0016 year?1, P < 0.05) in the arid region. Temperature had a positive effect on NDVI in most periods within and across seasons in the semi-humid region but had no significant effect in the arid region. Precipitation had a positive effect on NDVI in the arid region in summer and in the semi-arid region in autumn. Summer precipitation was important for autumn vegetation growth in the arid region, whereas summer temperature increased autumn vegetation growth in the semi-arid and semi-humid regions. Further analyses supported the lag-time effects of climate change on vegetation growth on the Loess Plateau. Precipitation shifts had 15- to 18-month time lag effects on vegetation growth in the three climate regions. Vegetation NDVI had a 17-month lag response to temperature in the semi-arid region. Human activities should not be neglected in analyzing the relationship between vegetation growth and climate change on the Loess Plateau.  相似文献   

2.
The impacts of climate change on crop yield have increasingly been of concern. In this study, we investigated the impacts of trends in sunshine duration (S) and maximum temperature (T max) on rice yields in Jiangsu Province at both the provincial and county level during the period from 1980 to 2008. The results showed that although S and T max both were positively correlated with rice yields, the combined impacts of the decreasing trend of S (0.37 h/decade) and the increasing trend of T max (0.34 °C/decade) in August caused a reduction of 0.16 t ha?1 in rice yields (approximately 1.8 %) in Jiangsu Province, and the trend of S had played a dominant role in the yield losses. Further analyses suggest that the increasing concentration of aerosols from rapid economic development in Jiangsu Province has caused a significant solar dimming at least since 1960, making mitigations and adaptation measurements on regional haze impact imperative. Our study provides a prototype for detecting negative feedback on agricultural production caused by intensified anthropogenic activities that aim only to create rapid economic development.  相似文献   

3.
Air (vapor and particle phase) samples were collected every 12 days at five sites near the North American Great Lakes from 1 January 2005 to 31 December 2013 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of 35 polybrominated diphenyl ethers (PBDEs) and eight other halogenated flame retardants were measured in each of the ~ 1,300 samples. The levels of almost all of these flame retardants, except for pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), and Dechlorane Plus (DP), were significantly higher in Chicago, Cleveland, and Sturgeon Point. The concentrations of PBEB and HBB were relatively high at Eagle Harbor and Sturgeon Point, respectively, and the concentrations of DP were relatively high at Cleveland and Sturgeon Point, the two sites closest to this compound's production site. The data were analyzed using a multiple linear regression model to determine significant temporal trends in these atmospheric concentrations. The concentrations of PBDEs were decreasing at the urban sites, Chicago and Cleveland, but were generally unchanging at the remote sites, Sleeping Bear Dunes and Eagle Harbor. The concentrations of PBEB were decreasing at almost all sites except for Eagle Harbor, where the highest PBEB levels were observed. HBB concentrations were decreasing at all sites except for Sturgeon Point, where HBB levels were the highest. DP concentrations were increasing with doubling times of 3–9 years at all sites except those closest to its source (Cleveland and Sturgeon Point). The levels of 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) were unchanging at the urban sites, Chicago and Cleveland, but decreasing at the suburban and remote sites, Sturgeon Point and Eagle Harbor. The atmospheric concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP) were increasing at almost every site with doubling times of 3–6 years.  相似文献   

4.
This paper aims at identifying the link between significant rainfall decreases (1950–2000) in the Mediterranean basin and the atmospheric circulation at the 500 hPa level. The months and seasons of the subregions with significant rainfall decrease during this period have been identified previously (Norrant and Douguédroit, Theor Appl Climatol 83(1–4):89–106, 2006): October in the Mediterranean Iberia, March in the Atlantic Iberia, January and winter in Greece, and winter in the Near East. Canonical Correlation Analyses based on the monthly and daily data records from 62 rainfall stations and 138 grid points at the 500 hPa level over a Euro-Atlantic window were first calculated to define the TeleConnection Patterns explaining significant regional rainfall decreases. Then, 500 hPa level weather types (ZWTs) of the rainy days with important or little rainfall associated with each Teleconnection Pattern were identified in each subregion. Rainfall-causing disturbances from the Atlantic reach Iberia directly; some of them are regenerated if they reach the Mediterranean. Other disturbances are generated locally near Greece and the Near East (Meteorological Office in Weather in the Mediterranean I: general meteorology, Her Majesty’s Stationery Office, London, 1962). The relationship between significant rainfall decreases and the corresponding 500 hPa level appears to be a nonlinear phenomenon. In all of the studied subregions, a break during the 1970s separates two subperiods differing significantly from each other. Rainfall decrease is due to the higher frequency of important rainfall ZWTs over low rainfall ZWTs, during the first period, which the opposite is true during the second period. Such an inversion could be partially linked with the prevailing North Atlantic Oscillation-positive phase during the last quarter of the twentieth century.  相似文献   

5.
Abstract

This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view, and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand. Then, the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand, but this is not the key factor for the insufficient consumption demand because of the low level of per capital income. At last, it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously.  相似文献   

6.
Spatio-temporal variations in the technetium-99 content of Fucus serratus samples from the French coast of the English Channel were studied between 1982 and 1984 using various sampling strategies. The lack of constancy in measurements from within the seaweed zone of the same station is revealed by a variation of 18% in the mean contents of samples collected from different sampling levels, a variation which reaches 41% if the extreme values of all results are taken into account. Regional variations over the Channel as a whole show an asymmetric diminution of the 99Tc content of the seaweed on the two sides of the liquid effluent discharge outlet from the reprocessing plant at La Hague and this confirms a predominant drift of Channel waters towards the North Sea. Variations with time at three stations during 1983 and 1984 have revealed that there is a time-lag between fluctuations observed in the discharges and those in F. serratus. In addition, a periodic component observed at the Roscoff and Wimereux stations, where the 99Tc content of the seaweed varies by a factor of 2–3 between winter and summer periods, could be correlated with seasonal changes both in the metabolic state of F. serratus and in the currents to the south-west of Cap de La Hague. 99Tc, which here has no radiological impact on man, would thus appear to be a radioactive label for sea waters and one which is particularly sensitive to variations in environmental conditions.  相似文献   

7.
8.
The surface of the earth has been continuously sculptured by the exogenetic processes primarily by the climatic hydrological attributes. Over the sequential phases of evolution of earth, the climatic attributes have altered. The alternative processes such as glaciation and declaciation, fluctuations of sea level and variability in rainfall pattern have changed the surface configuration through maneuvering the operations of the geographical processes. The issue of climate change has become a matter of scientific concern all over the world as the human communities are facing severe problems manifested in the form of flood, drought and submergence of low-lying coastal regions, estuaries and deltas. The present study is an attempt to understand the nature and extent of climate change (1890–2012) and related sea level rise (1970s–2010) in the deltaic Sundarban region of India since the last century and how far they are impacting the erosion–depositional processes (1925, 1926–2014). The changing trend of mean annual temperature, rainfall pattern and frequencies of tropical cyclones has been studied in detail, and spatiotemporal changes of geomorphic environment in different reaches of the study area have also been monitored with available multi-temporal geospatial data. The observation reveals that the flat sandy coastal belt and low-lying island in the extreme southern part have been severely affected by wave dash and seasonal storm surges which are mostly responsible for vigorous erosion. On the other hand, high tidal velocity is observed along the exposed concave bank in the upper–middle reaches of the Muriganga estuary and exposed outer bank in lower–middle reaches of Saptamukhi estuary. The thalweg line, which is very close to the river bank in those reaches of estuary, intensifies the hydraulic pressure along marginal parts of river bank which leads to erosion. Depositional activities are mostly observed along the sheltered inner reaches and convex river banks of the estuaries due to less effective tidal rushes, shallow channel depth, marginal flow velocity and gentle channel slope. Therefore, erosional and depositional processes cannot be explain by the relative mean sea level rise, because increasing mean sea level will affect the erosional processes uniformly in the entire estuary. In this present study area, both the erosional and depositional processes are simultaneously active depending on geographical exposure, sinuous channel pattern, channel depth and lithological compositions.  相似文献   

9.
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11.
Land use and land cover change (LUCC) has emerged as an important issue of global change with significant influences on the geochemical cycle and regional climate change. Understanding the historical changes of land use and analyzing the environmental effects of LUCC make such reconstructions important. Based on historical statistics, this article reconstructs cropland area at the municipality level (härad/kommun) in the Scandinavian Peninsula during 1875–1999. The total acreage of cropland increased 36.84 % during 1875–1930, kept stable during 1930–1950, and decreased 14.25 % during 1950–1999. The croplands of Sweden and Norway both increased before 1950 and changed in different ways during 1950–1999 when the cropland decreased by 19.79 % in Sweden but increased by 9.63 % in Norway. The counties in the south Scandinavian Peninsula owned most of the cropland, with a cropland proportion of over 20 %, and experienced relatively obvious cropland changes. Growth centers with a rate of increase of over 5 % during 1875–1910 were found in Skåne, Stockholm, the Uppsala counties in Sweden, and the area around Oslo county in Norway. The general cropland distribution showed almost no change during this period, which mainly reflects the suitability of the natural conditions for agriculture. Multi-social factors co-impacted land use activities and induced temporal and spatial variations of the cropland. These factors included food supply, world trade, wars, agriculture policies, the economic and political environment, urbanization, and national differences. Compared with the widely used global land use dataset Historical Database of the Global Environment (HYDE), this study shows different cropland change curves before 1950. This article is a case study showing that the hindcasting model of the HYDE dataset has difficulty estimating multi-determined cropland change in the Scandinavian Peninsula, and the empirical study contributes to the improvement of the accuracy of historical land use data at the regional level.  相似文献   

12.
13.
Chen  Yi  Wang  Pin  Zhang  Zhao  Tao  Fulu  Wei  Xing 《Regional Environmental Change》2017,17(8):2397-2408
Regional Environmental Change - Increasing population, limited land resources, and the demand for environmental protection highlight the urgency of improving crop yield on the limited cultivated...  相似文献   

14.
This paper aims to establish whether the longitudinal framing of climate change (CC) in Greek newspapers exhibits the characteristics of a “narrative cycle,” with different themes becoming prominent at different periods in accordance with the media’s narrative considerations. In order to test this assumption, we formulate a number of hypotheses which we test with data originating from three Greek newspapers over the period 2001–2008. We find that the scientific and ecological/meteorological themes of CC are more often mentioned during the initial phase of media coverage, arguably due to media’s attempt to open the narrative and capture the public’s attention. Public protests and debate feature more prominently during the peaked phase of coverage, in accordance with the narrative need for a climax, while the later period of coverage, when some kind of resolution to the story should be offered, is characterized by the prominence of policy-making and economy-related issues.  相似文献   

15.
Russian Journal of Ecology - As found by comparing historical topographic maps and present-day satellite images, steppificated areas in the southern part of the eastern macroslope of the Southern...  相似文献   

16.
This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view, and draws the conclusion that there is an inverse relationship between income distribution gap a...  相似文献   

17.
The relationship between Scots pine (Pinus sylvestris L.) tree-ring width and temperature and precipitation was analyzed in pine forests on the Bugulma–Belebey Upland, Bashkiria. A close correlation between tree-ring width and the current spring–summer precipitation was revealed. On this basis, a reconstruction of May–June precipitation in the period from 1860 to 1994 was made.  相似文献   

18.
How the past human society responded to climatic disasters could provide better understanding on the nature of climate–human–ecosystem interactions and the knowledge of the vulnerability for the society in the context of changing climate. In this paper, the North China Plain in the Qing dynasty (1644–1911) is selected as a typical regional social-ecological system; with historical information kept in official documents, social responsive behavior and measures to flood/drought (e.g., reclamation, disaster relief, migration, revolt) are quantitatively described with proxy indicator time-series. It is found that the dominant responsive strategy altered significantly in different stages: (1) stage of cropland expansion (1644–1720); (2) stage of governmental disaster relief (1721–1780); (3) stage of increasing climate refugees (1781–1860); (4) stage of revolt and emigration (1861–1911). The multi-stage evolution of social response was impacted by various natural and social factors: (1) regional population–food balance and governmental finance were the most important limiting factors; (2) the interaction between the governmental policy and refugees’ behavior in disasters affected the social consequences to a certain extent; (3) decadal-to-multi-decadal climate change would also impact the social response measures, even directly trigger the shift of dominant responsive strategy. This study would be helpful for deeper understanding of social resilience and better responding to climate change and extreme events in the present and future.  相似文献   

19.
Regional Environmental Change - We analyse the changes to agricultural metabolism in four municipalities of Vallès County (Catalonia, Iberia) by accounting for their agroecosystem funds and...  相似文献   

20.
In order to analyze the factors influencing carbon emissions in the region of Beijing–Tianjin–Hebei and to explore the pathways to developing a low-carbon economy, this paper begins with the terminal energy consumption of three industries and residential consumption, and constructs an identical equation which is composed of population size, level of economic development, energy intensity, the proportion of energy consumption, energy structure, and the coefficient of carbon emissions. Based on the data of terminal energy consumption during 2000–2012, various factors are analyzed and their contribution is measured by Logarithmic Mean Divisia Index (LMDI). The results show that the levels of population and economy have a positive driving effect while energy intensity, energy structure, and carbon intensity have a negative driving effect; the proportion of energy consumption had a negative driving effect prior to 2006, then changed to positive. Among suggestions for a low-carbon economy are controlling population size, improving the quality of economic development, supporting research into new energy technology, accelerating regional integration and optimizing industrial structure, and enhancing environmental protection and spreading the concept of a low-carbon economy.  相似文献   

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