The potential for an old-growth forest to store carbon in the topsoil:A case study at Sasso Fratino,Italy

There is considerable interest devoted to oldgrowth forests and their capacity to store carbon(C)in biomass and soil.Inventories of C stocks in old-growth forests are carried out worldwide,although there is a lack of information on their actual potential for C sequestration.To further understand this,soil organic carbon(SOC)was measured in one of Italy's best-preserved old-growth forests,the Sasso Fratino Integral Nature Reserve.This reserve is on the World Heritage List along with other ancient beech forests of Europe,and it is virtually untouched due to the steepness of the terrain,even before legal constraints were imposed.Although the sandstone-derived soils are often shallow,they are rich in organic matter.However,no quantification had been carried out.By systematically sampling the topsoil across the forest,we accurately determined the average amount of SOC(62.0±16.9 Mg ha^(–1))and nitrogen(4.0±1.2 Mg ha^(–1))in the top 20 cm.Using the CENTURY model,future dynamics of SOC stocks were predicted to 2050 according to two climate scenarios,A1F1 and B2,the first of high concern and the second more optimistic.The model projected an increase of 0.2 and 0.3 Mg ha^(–1)a^(–1)by 2030 under the A1F1 and B2 scenarios,respectively,suggesting that the topsoil in old-growth forests does not reach equilibrium but continues accumulating SOC.However,from 2030 to 2050,a decline in SOC accumulation is predicted,indicating SOC net loss at high altitudes under the worst-case scenario.This study confirms that soils in oldgrowth forests play a significant role in carbon sequestration.It also suggests that climate change may affect the potential of these forests to store SOC not only in the long term but also in the coming years.

Great Changes Unseen for a Century in American Politics and the 2020 US Presidential Election

American politics is currently undergoing great changes unseen in a century,which has been predominately manifested in the following hree aspects:first,the rampant COVID-19 pandemic has caused the US tosuffer its worst economic recession since the Great Depression in 1929;second,social division and political polarization are besetting the US as evidenced in its wide partisan divide between the supporters of its two major parties on a range of critical issues;and third,the US is caught in anational identity crisis,while China's rise is believed to intensify such a crisis.These three factors are bound to exert great impacts on the 2020 presidential election of the United States:the COVID-19 pandemic will have certain influence on voter turnout and the approval rating of the two parties;in the context of the aforementioned serious social divide and highly polarized political landscape,the basic constituencies of the two parties are likely to show an extraordinary degree of party loyalty,which could result in the possibility that a few voters in a handful of key states will determine the results of the election;and as China's peaceful rise ismistaken as a serious threat to the national identity of the US.China will be one of the key topics in the coming US presidential election,hence further worsening the relations between China and the United States.

Precipitation Changes in Wet and Dry Seasons over the 20th Century Simulated by Two Versions of the FGOALS Model

Seasonal precipitation changes over the globe during the 20th century simulated by two versions of the Flexible Global Ocean-Atmosphere-Land System （FGOALS） model are assessed. The two model versions differ in terms of their AGCM component, but the remaining parts of the system are almost identical. Both models reasonably reproduce the mean-state features of the timings of the wet and dry seasons and related precipitation amounts, with pattern correlation coefficients of 0.65-0.84 with observations. Globally averaged seasonal precipitation changes are analyzed. The results show that wet sea- sons get wetter and the annual range （precipitation difference between wet and dry seasons） increases during the 20th century in the two models, with positive trends covering most parts of the globe, which is consistent with observations. However, both models show a moistening dry season, which is opposite to observations. Analysis of the globally averaged moisture budget in the historical climate simulations of the two models shows little change in the horizontal moisture advection in both the wet and dry seasons. The globally averaged seasonal precipitation changes are mainly dominated by the changes in evaporation and vertical moisture advection. Evaporation and vertical moisture advection combine to make wet seasons wetter and enhance the annual range. In the dry season, the opposite change of evaporation and vertical moisture advection leads to an insignificant change in precipitation. Vertical moisture advection is the most important term that determines the changes in precipitation, wherein the thermodynamic component is dominant and the dynamic component tends to offset the effect of the thermodynamic component.

Changes of Air–sea Coupling in the North Atlantic over the 20th Century

Changes of air–sea coupling in the North Atlantic Ocean over the 20 th century are investigated using reanalysis data,climate model simulations, and observational data. It is found that the ocean-to-atmosphere feedback over the North Atlantic is significantly intensified in the second half of the 20 th century. This coupled feedback is characterized by the association between the summer North Atlantic Horseshoe（NAH） SST anomalies and the following winter North Atlantic Oscillation（NAO）. The intensification is likely associated with the enhancement of the North Atlantic storm tracks as well as the NAH SST anomalies. Our study also reveals that most IPCC AR4 climate models fail to capture the observed NAO/NAH coupled feedback.

New Trends in International Energy Security in the Context of Profound Changes Unseen in a Century

Major changes such as the pandemic, games among great powers, and the Ukraine crisis alongside scientific and technological progress, economic transformation, social change, and cultural development have led to new features and trends in the international energy field. Historic fluctuations in international energy prices and adjustments in energy relations have taken place in the past two years. The energy system has fallen into disorder and discomfort;volatility in the energy market has triggered a strong domino effect, and major countries have taken unprecedented measures to address it. These changes have pushed international energy politics to a new development track. In a certain period of time in the future, the political and security aspects of energy will once again come to the fore. The long-term nature and complexity of the energy transition have become more obvious. In international energy politics, turbulence and uncertainty will be the new normal. A new binary opposition may emerge in the international energy landscape as well, with constant changes taking place in the connotation and extension of energy security. Academic and strategic circles should think deeply about how to dialectically discuss the relation between energy transition and the major changes of a scale unseen in a century, energy transition and energy security, and geopolitics and energy politics, among others, and consider the integration of development and security and the realization of common energy security as important principles for operating and developing energy strategies and promoting global energy governance.

The COVID-19 Pandemic and Changes Unseen in a Century

The COVID-19 pandemic can be compared to a world war that makes the existing international order unsustainable.The pandemic is interacting with global changes unseen in a century and exerting major impacts on international politics,world economy,major-country relations,the geostrategic landscape,global governance,and development models.In the next three to five years,the international landscape will be a chaotic situation,highlighting not poles but competing states and transformation,thus making it more difficult for major countries to cooperate while medium-sized and small states have to huddle for warmth and seek a way out within their respective regions.Although further observation is required during the ongoing pandemic and worldwide economic recession,some major trends in the world have emerged.A restart to China's international relations is called for.

On the Vowel Changes of English Language in History

The Vowel changes of English are more dramatic and complicated in every period of English development. Especially theGreat Vowel Shift from Middle English to Modern English influenced the whole English phonetic system. This paper examines thevowel changes in each period of English development and aims at concluding the rules of the language change and development.

Research on the construction path of the megacity from the perspective of Nudge Theory:Empirical evidence of the“Park City”construction in Chengdu Tianfu New Area

The transformation of Chengdu Tianfu New Area,a state-level new district,from the first site of constructing the“Park City”to the representative of the“Park City”,contains a unique path of“Chinese Style Governance”.To expand the diverse paths of constructing megacities,the current research references the nudge theory of behavioral science,adopts the extended case method,and takes Chengdu Tianfu New Area as a typical case to summarize the“nudge”path of“Party City”construction.The study found that the government achieves the lock-in effect by the priming mechanism and uses the nudge strategy of improving environment and guiding public opinion,thereby helping the people make free choices.It realizes the framework effect by the salience mechanism and uses the strategies of highlighting key information and optimizing information delivery methods,which directly affects the behavior of the public.It achieves the commitment effect by the comparison mechanism,including the horizontal comparison and vertical comparison strategies,and gradually realizes the policy goals.It realizes the social norm effect by the imitation mechanism and uses the strategies of creating peer pressure and playing celebrity effect,which in turn influence people’s choices.With the help of the“nudging”mechanism,the construction of the park city has realized the interactive cycle of“government output-citizen feedback”and achieved the goal of“making great change through small actions”.As a new behavioral intervention tool,“nudging”provides an alternative explanation for the construction of the park city in Tianfu New Area and opens up new ideas for the construction of megacities.This study concludes that the construction of megacities can achieve the goal of“common return”through different ways and provides practical inspiration for future urban construction.

Spatial patterns and driving forces of land use change in China during the early 21st century

Land use and land cover change as the core of coupled human-environment systems has become a potential field of land change science （LCS） in the study of global environmental change. Based on remotely sensed data of land use change with a spatial resolution of 1 km × 1 km on national scale among every 5 years, this paper designed a new dynamic regionalization according to the comprehensive characteristics of land use change including regional differentiation, physical, economic, and macro-policy factors as well. Spatial pattern of land use change and its driving forces were investigated in China in the early 21 st century. To sum up, land use change pattern of this period was characterized by rapid changes in the whole country. Over the agricultural zones, e.g., Huang-Huai-Hai Plain, the southeast coastal areas and Sichuan Basin, a great proportion of fine arable land were engrossed owing to considerable expansion of the built-up and residential areas, resulting in decrease of paddy land area in southern China. The development of oasis agriculture in Northwest China and the reclamation in Northeast China led to a slight increase in arable land area in northern China. Due to the ＂Grain for Green＂ policy, forest area was significantly increased in the middle and western developing regions, where the vegetation coverage was substantially enlarged, likewise. This paper argued the main driving forces as the implementation of the strategy on land use and regional development, such as policies of ＂Western Development＂, ＂Revitalization of Northeast＂, coupled with rapidly economic development during this period.

Progress in China's climate change study in the 20th century

Studies on the 20th century climate change in China have revealed that under the background of global warming over the past century, climate in China has also experienced significant change with mean annual temperature increased by about 0.5 oC. More reliable results for the latter part of the 20th century indicate that the largest warming occurred in Northwest China, North China and Northeast China, and the warming in winter is most significant. Although no obvious increase or decrease trends were detected for mean precipitation over China in the past half century, regional differences are very distinct. In the middle and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased. Studies suggest that climate change in China seems to be related not only with the internal factors such as ENSO, PDO, and the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change studies in China seem to be important in narrowing understanding the nature of China's climate change and its main causes, since it is significant for projection and for impact assessment of climate change in the future.

Climate Change Impacts, Local Knowledge and Coping Strategies in the Great Ruaha River Catchment Area, Tanzania

Climate change has profound implications for managing freshwater resources and species dependent on those resources. Water is an essential component of the life support system of the earth, and a basic resource for socio-economic development. The Great Ruaha River Catchment Area is a dynamic and complex ecosystem requiring inclusion climate change adaptation in the management of the freshwater and natural resources available to reduce the severity of climate change impacts. Rainfall has decreased considerably during the last 10 - 30 years, and characterised by high interannual variability, seasonal shifts and variable seasonal distribution with unpredictable onset and ending of rains and shortened growing seasons. Temperature has increased considerably during this period causing increased evapotranspiration losses and incidences of pest and diseases. The freshwater of Ruaha River and it tributaries are vulneable to changing climate, such as drought, which can negatively impact on the livelihoods of the people through de- creased crop and livestock production, and on local biodiversity. The changing climate has had negative impacts on, among other aspects, land use and water shortages for irrigation, livestock and domestic uses. This has compelled riparian communities in the catchment to devises coping strategies including practicing irrigation to provide supplementary water to crops, using drought tolerant crop varieties, rationing of irrigation water in farmlands, wetland cultivation, and diversification to non-agricultural activities. Despite the existence of many indicators used for local climate forecasting, there are limitations to local adaptation, including among others, poverty, institutional aspects and limited integration of climate adaptation in various sectors. The bulk of indigenous knowledge could be integrated into formal adaptation planning, and may be important components of environmental conservation at the local level.

The Great Lapse: Climate Change, Water Resources and Economic Risks in the Great Lakes

The striking vastness of the world’s largest surface freshwater resource, the Laurentian Great Lakes, has generated the fallacy that they are not highly vulnerable to climate change. This fallacy has created a great lapse in our research and understanding of the effects of climate change on the Great Lakes, which are approaching critical environmental thresholds and jeopardizing ecosystem services. This article takes the novel approach of correcting the disconnect between the perception of vastness and the reality of vulnerability to climate change in the Great Lakes, and takes an additional novel step to link the water risks with the economic risks. The primary purpose is to demonstrate the interdependence of the freshwater ecosystem services affected by climate change with the economies that are highly dependent on those freshwater services in the Great Lakes region. Although many believe that environmental science or ethical arguments should be sufficient to warrant action on climate change, evidence shows that policy-makers are not compelled to generate advances unless there are strong economic components. This article highlights the leading edge of climate science for the Great Lakes, having conducted 32 in depth interviews with experts in microbiology, ecology, and limnology, among others, but it also adds substantively to previous work by providing economic evidence of water risks in the agricultural sector and energy sector, which constitute over $6 trillion in value and jobs that are specifically dependent on lakes waters. The article concludes by articulating three specific conclusions: the economic viability of the agricultural sector and the energy sector are jeopardized by loss of federal funding for climate change adaptation in the water sector;the existing policies such as between sectors such as the Farm Bill and Energy Future Bill are mal-aligned and should be aligned with the water sector;and negative environmental externalities including factors that exacerbate climate change should be incorporated into the true cost of water so we can more accurately conduct ecosystem valuation and, thus, address the true economic and environmental cost of climate change on the Great Lakes and our greatest water resources. This paper has not previously been published.

Spatio-temporal Changes and Associated Uncertainties of CENTURYmodelled SOC for Chinese Upland Soils, 1980-2010

Detailed information on the spatio-temporal changes of cropland soil organic carbon(SOC) can significantly contribute to the improvement of soil fertility and mitigate climate change. Nonetheless, information and knowledge on the national scale spatio-temporal changes and the corresponding uncertainties of SOC in Chinese upland soils remain limited. The CENTURY model was used to estimate the SOC storages and their changes in Chinese uplands from 1980 to 2010. With the Monte Carlo method, the uncertainties of CENTURY-modelled SOC dynamics associated with the spatial heterogeneous model inputs were quantified. Results revealed that the SOC storage in Chinese uplands increased from 3.03(1.59 to 4.78) Pg C in 1980 to 3.40(2.39 to 4.62) Pg C in 2010. Increment of SOC storage during this period was 370 Tg C, with an uncertainty interval of –440 to 1110 Tg C. The regional disparities of SOC changes reached a significant level, with considerable SOC accumulation in the Huang-Huai-Hai Plain of China and SOC loss in the northeastern China. The SOC lost from Meadow soils, Black soils and Chernozems was most severe, whilst SOC accumulation in Fluvo-aquic soils, Cinnamon soils and Purplish soils was most significant. In modelling large-scale SOC dynamics, the initial soil properties were major sources of uncertainty. Hence, more detailed information concerning the soil properties must be collected. The SOC stock of Chinese uplands in 2010 was still relatively low, manifesting that recommended agricultural management practices in conjunction with effectively economic and policy incentives to farmers for soil fertility improvement were indispensable for future carbon sequestration in these regions.

How Managers Can Manage Change and Stability to Deliver Better Service to Customers in the 21st Century

In an ever-changing world at present, many enterprises and organizations are put under the great pressure of tremendous opportunities and challenges arising from globalization, technological innovation, intense competition and also a highly competitive market."The whole business environment becomes more competitive, dynamic, and complex in 21st century."(Olsen, West and Ching Yick Tse 2008) Hussey (2005) also has the view that the organization' external and internal environment has changed ever more turbulently in past few decades.[1] The frequency of changes has become faster and the period of stability has tended to be much shorter. Therefore change management skills become more and more important for managers.(Hussey, 2005) Dawson also has the same point of view. He says "the large-scale change really occurs and the changes were rarely so rapid and unpredictable"(Dawson, 1994). This situation may continue in to the next century (Hussey, 2005) which means that managers need to deeply understand how to manage both external and internal changes.[2] Hussey also mentions some important factors that may influence external environment changes including competition globally;customers service expectation increase, fast development of technology,[3] and changes in government regulations (Hussey, 2005).

Factors for the Major Changes in the English Language

本文阐述了引起英语变迁的历史因素-罗马人,条顿人,诺尔曼人的四次入侵;以及音变因素-e音的丢失和元音大转移。此外,印刷业的发展加速了拼写的标准化,十六、十七世纪英国文艺复兴极大地丰富了英语词汇。

Great Changes in Zhoukou City

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Ecological environment quality evaluation of the Sahel region in Africa based on remote sensing ecological index

Long-term monitoring of the ecological environment changes is helpful for the protection of the ecological environment.Based on the ecological environment of the Sahel region in Africa,we established a remote sensing ecological index(RSEI)model for this region by combining dryness,moisture,greenness,and desertification indicators.Using the Moderate-resolution Imaging Spectroradiometer(MODIS)data in Google Earth Engine(GEE)platform,this study analyzed the ecological environment quality of the Sahel region during the period of 2001-2020.We used liner regression and fluctuation analysis methods to study the trend and fluctuation of RSEI,and utilized the stepwise regression approach to analyze the contribution of each indicator to the RSEI.Further,the correlation analysis was used to analyze the correlation between RSEI and precipitation,and Hurst index was applied to evaluate the change trend of RSEI in the future.The results show that RSEI of the Sahel region exhibited spatial heterogeneity.Specifically,it exhibited a decrease in gradient from south to north of the Sahel region.Moreover,RSEI in parts of the Sahel region presented non-zonal features.Different land-cover types demonstrated different RSEI values and changing trends.We found that RSEI and precipitation were positively correlated,suggesting that precipitation is the controlling factor of RSEI.The areas where RSEI values presented an increasing trend were slightly less than the areas where RSEI values presented a decreasing trend.In the Sahel region,the areas with the ecological environment characterized by continuous deterioration and continuous improvement accounted for 44.02%and 28.29%of the total study area,respectively,and the areas in which the ecological environment was changing from improvement to deterioration and from deterioration to improvement accounted for 12.42%and 15.26%of the whole area,respectively.In the face of the current ecological environment and future change trends of RSEI in the Sahel region,the research results provide a reference for the construction of the"Green Great Wall"(GGW)ecological environment project in Africa.

Water storage changes in North America retrieved from GRACE gravity and GPS data

As global warming continues,the monitoring of changes in terrestrial water storage becomes increasingly important since it plays a critical role in understanding global change and water resource management.In North America as elsewhere in the world,changes in water resources strongly impact agriculture and animal husbandry.From a combination of Gravity Recovery and Climate Experiment（GRACE） gravity and Global Positioning System（GPS） data,it is recently found that water storage from August,2002 to March,2011 recovered after the extreme Canadian Prairies drought between 1999 and 2005.In this paper,we use GRACE monthly gravity data of Release 5 to track the water storage change from August,2002 to June,2014.In Canadian Prairies and the Great Lakes areas,the total water storage is found to have increased during the last decade by a rate of 73.8 ± 14.5 Gt/a,which is larger than that found in the previous study due to the longer time span of GRACE observations used and the reduction of the leakage error.We also find a long term decrease of water storage at a rate of-12.0 ± 4.2 Gt/a in Ungava Peninsula,possibly due to permafrost degradation and less snow accumulation during the winter in the region.In addition,the effect of total mass gain in the surveyed area,on present-day sea level,amounts to-0.18 mm/a,and thus should be taken into account in studies of global sea level change.