民勤西沙窝生态气候变化特征

(1 )分析得到勤试验站 1 3个观测指标中的 1 45个统计项中的前 6个主成分最大载荷因子的多年变化特征是 :年日照时数 70～ 80年代持续下降 ;年平均气温 6 0～ 80年代下降 ,90年代以后显著增高 ;1 0月份平均风速 70年代中期至 80年代中期下降 ,之后增大 ;年大风日数呈波浪式上升 ;年最大风速有增无减 ;8月降水量相对稳定。当地的气候环境在 80年代中期以前朝良性方向发展 ,80年代中期以来进一步恶化。( 2 )年沙尘暴日数的多年变化特征与年日照时数有较大的相似性 ;年平均最高气温、年平均地温和 7月份极端最高气温与年平均气温的多年分布有较大相似性 ;年大风日数和 1 0月平均风速多年分布有较大相似性。 ( 3)从 6 0年代到 80年代中期气候逐步改善 ,与当地 6 0、70年代大面积营造防风固沙林密切相关 ;80年代中期以来气候环境迅速恶化 ,与 80年代以来大面积开荒超采地下水 ,大面积人工固沙林衰败死亡有着不可分割的联系。

黔东南州生态气候条件对准两优527超级稻产量的影响

以贵州省黔东南州16个气象观测站2005—2007年的气温、降水量、日照时数以及海拔高度、播种期作为主要生态气候因子，分析其对准两优527超级交杂水稻产量的影响。结果表明：准两优527最适宜在海拔480—750m的地区栽培，尤其是海拔620m上下地带容易获得高产；最适宜播种期为3月28日-4月7日，播种期每推迟10d，产量减少48．2～376．3kg／667m^2；最适宜积温条件为3200—3800℃·d，积温每增加100℃·d，产量减少8．32～140．43kg／667m^2；最适宜降水量条件为460～800mm，降水量每增加或减少100mm，产量减少7．41～338．36kg／667m^2；最适宜光照条件为620～730h，光照少于500h或多于900h，产量降低明显。

A comprehensive review of carbon sequestration of seagrass in China from 2013

Seagrass is not only known for its ecological role,but also for its high capacity on the carbon sequestration.Although the area of seagrass meadows was less than 0.2%of the world’s oceans,the yearly organic carbon burial of seagrass reached 10%of that in the ocean.Anthropogenic activities in the past two decades and the climate change have led to a significant decrease of seagrass meadow.Since seagrass is widely distributed along the coastline of China,it is necessary to put more efforts on the seagrass conservation and restoration,which will consequently be a suitable nature based solution for mitigating the climate change.This paper provides a comprehensive review on the following five aspects:1)the seagrass distribution in China;2)the role that seagrass plays in the climate mitigation;3)carbon sequestration of seagrass in China;4)loss of seagrass habitats and 5)the restoration of seagrass habitat in China since 2013.Current research gap and prospective research direction were also pointed out in this study.

Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998

A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains.

Countermeasures for Qinghai-Tibet Plateau to Cope with Climate Change and Ecological Environment Safety

The monitoring,prediction and assessment of status about climate changes and ecological environment at home and abroad were discussed in this study,and the scientific significance and countermeasures for Qinghai-Tibet Plateau to cope with these problems were also put forward.

Assessment of Climate for Agricultural Suitability and Optimal Allocation of Agricultural Production in the Guanzhong Region, Shaanxi Province

Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method. Three coefficients, in- cluding the resource coefficient （Cr）, the efficiency coefficient （Ce）, and the utility co- efficient （K）, were used in the models, which were calculated based on temperature, moisture, and sunshine duration data of Guanzhong region, Shaanxi Province. The results indicated that resource coefficient was higher in west of the region than that in east, and higher in south （especially in the Central Shaanxi Plain） than that in the Weibei plateau. The value of Cr changed from 6.5 to 9.2 from north to plain area. Spatial change of efficiency coefficient was obvious, lower in the northeast than in the central plain, and the value of Ce changed from 2.3 to 6.5 from the northeast to the central plain. As for utility coefficient, it was lower in northeastern part of the Weibei plateau and in southern mountain areas than that in the central plain, showing significant latitudinal zonality. Furthermore, the value of K increased from 0.35 to 0.78 from northeast to the central plain, and decreased from 0.78 to 0.53 from the central plain to southern mountain areas. These indicated that climate resource in the central plain region was more abundant and potential, compared with other regions. GuanZhong region was classified into three larger agricultural zones and three small independent zones, according to agro-ecological assessment. Light, heat and water resources should be made use of in an efficient way in spatial allo- cation of agricultural production. For example, water facilities should also be im- proved in Weibei plateau region where highly-qualified fruit should be enhanced and fruit processing industrial chain should be shaped. Large-scale production area of wheat should be increased in central irrigation region and more vegetable bases should be developed around large and medium-scale cities. Thanks for outstanding water conservation function, the three-dimensional agriculture including medicine and other sideline production should be developed in Qinling Mountains and the special- ized commercial agriculture should be accelerated in independent small zones, ac- cording to local conditions. In the research, different crop varieties were developed in corresponding regions as per current eco-climatic conditions.

Responses of Vegetation and Primary Production in North-South Transect of Eastern China to Global Change Under Land Use Constraint

A regional model of vegetation dynamics was revised to include land use as a constraint to vegetation dynamics and primary production processes. The model was applied to a forest transect in eastern China (NSTEC, North-South transect of eastern China) to investigate the responses of the transect to possible future climatic change. The simulation result indicated that land use has profound effects on vegetation transition and primary production. In particular, land use reduced competition among vegetation classes and tended to result in less evergreen broadleaf forests but more shrubs and grasses in the transect area. The simulation runs with land use constraint also gave much more realistic estimation about net primary productivity as well as responses of the productivity to future climatic change along the transect. The simulations for future climate scenarios projected by general circulation models (GCM) with doubled atmospheric CO2 concentration predicted that deciduous broadleaf forests would increase, but conifer forests, shrubs and grasses would decrease. The overall effects of doubling CO2 and climatic changes on NSTEC were to produce an increased net primary productivity (NPP) at equilibrium for all seven GCM scenarios. The predicted range of NPP variation in the north is much larger than that in the south.

Obsevation for Epidermal Ultrastructure of Nostoc sphaeroides Kutzing under Scanning Electron Microscope

[Objective]The experiment aimed to explore a new way for observing surface structure of Nostoc sphaeroides Kutzing. [Method] The scanning electron microscope was used to observe the epidermal ultrastructure of wild and cultured Nostoc sphaeroides Kutzing. [ Result] The epidermis of wild and cultured Nostoc sphaeroides Kutzing showed mixture structure of fibril colloid which was reticular arranged. The difference between wild and cultured Nostoc sphaeroides Kutzing was that the outer epidermis of cultured Nostoc sphaeroides Kutzing had trichome distribution but the wild Nostoc sphaeroides Kutzing did not has such distribution. The obsevation results of under smaller than 10 μm by scanning electron microscope was touched thick and showed many folds and distortions. [ Conclusion] The scanning electron microscope was an effective way to study development of Nostoc sphaeroides Kutzing colony and it was worth popularizing.

Carbon Turnover in a Crop Rotation Under Free Air CO_2 Enrichment (FACE)

Mostly based on assumptions derived from controlled-environment studies, predicted future atmospheric CO2 concentrations [CO2] are expected to have considerable impacts on carbon （C） turnover in agro-ecosystems. In order to allow the in situ examination of C-transformations in the plant-soil system of arable crop rotations under future [002], a free air carbon dioxide enrichment （FACE） experiment （550 μmol mol^-1 CO2） was started at Braunschweig, Germany in 1999. The crop rotation under investigation comprised winter barley, a cover crop （ryegrass）, sugar beets and winter wheat. Assessments of CO2 effects included the determination of above- and belowground biomass production, measurements of canopy CO2- and H2O- fluxes, soil microbial biomass and in situ soil respiration. The results obtained during the 1st crop rotation cycle （3 years） showed that for the selected crops elevated [CO2] entailed significant positive effects （P 〈 0.05） on aboveground （6%-14% stimulation） and belowground biomass production （up to 90% stimulation）, while canopy evapotranspiration was reduced. This resulted in increased soil water content. Also, depending on crop type and season, high CO2 stimulated in situ soil respiration （up to 30%）, while soil microbial biomass did not show significant respouses to elevated [CO2] during the first rotation cycle.

HISTORICAL DESERTIFICATION PROCESS IN HEXI CORRIDOR,CHINA

Over the last 2000 years, approximately 38 ancient cities were abandoned through desertification in Hexi Corridor, Northwest China. Among them, 21.05% were abandoned during the Northern and Southern Dynasties, 21.05% during the end of the Tang Dynasty and the Five Dynasties, and 57.9% during the Ming and Qing dynasties. At the same time, main lakes were shrinking rapidly from the 5th Century to the 6th Century and the end of the Qing Dynasty. The climate in these periods was relatively arid and cold with frequent dusts. The phase of these changes indicated that there were three periods of desertification enlargement in the northern China. They were Northern and Southern Dynasties, the end of Tang Dynasty and Five Dynasties, the Ming and Qing dynasties. The macro-process of desertification in the study area was controlled mainly by the climatic changes. But from the facts that the population density in the middle of Qing Dynasty had exceeded the critical index of population pressure in arid area and the usage rate of water resources had exceeded 40% in Hexi Corridor, this paper also suggests that human activities have played an important role in desertification processes of the study area mainly during the recent 300 years.

Driving force and changing trends of vegetation phenology in the Loess Plateau of China from 2000 to 2010

Changes in vegetation phenology are key indicators of the response of ecosystems to climate change.Therefore,knowledge of growing seasons is essential to predict ecosystem changes,especially for regions with a fragile ecosystem such as the Loess Plateau.In this study,based on the normalized difference vegetation index(NDVI) data,we estimated and analyzed the vegetation phenology in the Loess Plateau from 2000 to 2010 for the beginning,length,and end of the growing season,measuring changes in trends and their relationship to climatic factors.The results show that for 54.84% of the vegetation,the trend was an advancement of the beginning of the growing season(BGS),while for 67.64% the trend was a delay in the end of the growing season(EGS).The length of the growing season(LGS) was extended for 66.28% of the vegetation in the plateau.While the temperature is important for the vegetation to begin the growing season in this region,warmer climate may lead to drought and can become a limiting factor for vegetation growth.We found that increasedprecipitation benefits the advancement of the BGS in this area.Areas with a delayed EGS indicated that the appropriate temperature and rainfall in autumn or winter enhanced photosynthesis and extended the growth process.A positive correlation with precipitation was found for 76.53% of the areas with an extended LGS,indicating that precipitation is one of the key factors in changes in the vegetation phenology in this water-limited region.Precipitation plays an important role in determining the phenological activities of the vegetation in arid and semiarid areas,such as the Loess Plateau.The extended growing season will significantly influence both the vegetation productivity and the carbon fixation capacity in this region.

Impacts of Climate Change on Forest Ecosystems in Northeast China

This paper reviews the studies and research on climate change impacts on the forest ecosystems in Northeast China. The results show that in the context of global and regional warming, the growing season of coniferous forests has been increasing at an average rate of 3.9 d per decade. Regional warming favors the growth of temperate broad-leaved forests and has a detrimental effect on the growth of boreal coniferous forests. Over the past hundred years, the forest edge of the cool temperate zone in the southern Daxing＇anling region has retreated 140 km northward. From 1896 to 1986, the northern boundary of broad-leaved forests in Heilongjiang province has extended northwestward about 290 km. Future climatic changes （until 2060） may lead to the northern deciduous needle forests moving out of China＇s territory altogether. The occurrence cycles of pests and diseases have shortened; their distribution ranges have expanded. The life cycle of tent caterpillars （Malacosoma neustria testacea Motschulsky） has shortened from 14-15 years in the past to 8-10 years now. The pine caterpillar （Dendrolimus tabulaeformis Tsai et Liu）, which has spread within western Liaoning province and the nearby areas, can now be found in the north and west. Lightning fires in the Daxing＇anling region have significantly increased since 1987, and August has become the month when lightning fires occur most frequently. Overall, the net primary productivity （NPP） of forest in Northeast China has increased. The NPP in 1981 was around 0.27 Pg C, and increased to approximately 0.40 Pg C in 2002. With the current climate, the broad-leaved Korean pine forest ecosystem acts as a carbon sink, with a carbon sink capacity of 2.7 Mg C hm-2. Although the carbon sink capacity of the forest ecosystems in Northeast China has been weakened since 2003, the total carbon absorption will still increase. The forest ecosystems in Northeast China are likely to remain a significant carbon sink, and will play a positive role in the mitigation of climate change.

Long-term variability of air temperature and precipitation conditions in the Polish Carpathians

Mountain regions are sensitive to climate changes, which make them good indicators of climate change. The aim of this study is to investigate the spatial and temporal variability of air temperature and precipitation in the Polish Carpathians. This study consists of climatological analyses for the historical period 1851-2010 and future projections for 2021-2100. The results confirm that there has been significant warming of the area and that this warming has been particularly pronounced over the last few decades and will continue in the oncoming years.Climate change is most evident in the foothills;however, these are the highest summits which have experienced the most intensive increases in temperature during the recent period. Precipitation does not demonstrate any substantial trend and has high year-to-year variability. The distribution of the annual temperature contour lines modelled for selected periods provides evidence of the upward shift of vertical climate zones in the Polish Carpathians,which reach approximately 350 meters, on average,what indicates further ecological consequences as ecosystems expand or become extinct and when there are changes in the hydrological cycle.

Effect of Aspect on Climate Variation in Mountain Ranges of Shennongjia Massif, Central China

The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with contrasting aspects as mediated by changes in global climate. It may help predict trends of vegetation variations in native ecosystems in natural reserves. As measures of climate response, temperature and precipitation data from the north, east, and south-facing mountain ranges of Shennongjia Massif in the coldest and hottest months(January and July), different seasons(spring, summer, autumn, and winter) and each year were analyzed from a long-term dataset(1960 to 2003) to tested variations characteristics, temporal and spatial quantitative relationships of climates. The results showed that the average seasonal temperatures and precipitation in the north, east, and south aspects of the mountain ranges changed at different rates. The average seasonal temperatures change rate ranges in the north, east, and south-facing mountain ranges were from –0.0210℃/yr to 0.0143℃/yr, –0.0166℃/yr to 0.0311℃/yr, and –0.0290 ℃/yr to 0.0084℃/yr, respectively, and seasonal precipitation variation magnitude were from –1.4940 mm/yr to 0.6217 mm/yr, –1.6833 mm/yr to 2.6182 mm/yr, and –0.8567 mm/yr to 1.4077 mm/yr, respectively. The climates variation trend among the three mountain ranges were different in magnitude and direction, showing a complicated change of the climates in mountain ranges and some inconsistency with general trends in global climate change. The climate variations were significantly different and positively correlated cross mountain ranges, revealing that aspects significantly affected on climate variations and these variations resulted from a larger air circulation system, which were sensitive to global climate change. We conclude that location and terrain of aspect are the main factors affecting differences in climate variation among the mountain ranges with contrasting aspects.

Identifi cation of national priority areas for adaptation to climate change in China

The problem of global warming has been identif ied as the f irst in the list of the top ten environmental prob-lems in the world.As climate change will seriously affect the social and natural world that people live in,so it may lay serious repercussions on economic progress,social improvement,and sustainable development.International bodies everywhere and many of the countries' governments are responding urgently to this call.In recent years,climate change has affected different regions in China in different ways.In its national agenda,the Chinese government should address the problem of climate change and its negative impact on socio-economic development.In this endeavor the nation should introduce policies which will help its people and economy to adapt to these effects and changes.Priorityf ields of adaptation to climate change are the sensitive areas or departments which are more vulnerable to the negative influences of climate change.The negative impacts of climate change in some parts of China are considered to be very serious indeed as they affect the whole economy and community.As a result,priority should be given to these more affected regions for the limited state f inancing.This paper def ines adaptation and discusses the basic principles and programs in the identif ication of national priority areas where adaptation should be exercised.Based on the past studies,four priority areas in China are identif ied,namely,disaster prevention and mitigation,water resources,agriculture,and ecosystem.An analysis on the identifi cation procedures,and the reasons and tasks involved are given for each.

Simulating Net Carbon Budget of Forest Ecosystems and Its Response to Climate Change in Northeastern China Using Improved FORCCHN

As dominant biomes,forests play an important and indispensable role in adjusting the global carbon balance under climate change.Therefore,there are scientific and political implications in investigating the carbon budget of forest ecosystems and its response to climate change.Here we synthesized the most recent research progresses on the carbon cycle in terrestrial ecosystems,and applied an individual-based forest ecosystem carbon budget model for China(FORCCHN) to simulate the dynamics of the carbon fluxes of forest ecosystems in the northeastern China.The FORCCHN model was further improved and applied through adding variables and modules of precipitation(rainfall and snowfall) interception by tree crown,understory plants and litter.The results showed that the optimized FORCCHN model had a good performance in simulating the carbon budget of forest ecosystems in the northeastern China.From 1981 to 2002,the forests played a positive role in absorbing carbon dioxide.However,the capability of forest carbon sequestration had been gradually declining during the the same period.As for the average spatial distri-bution of net carbon budget,a majority of the regions were carbon sinks.Several scattered areas in the Heilongjiang Province and the Liaoning Province were identified as carbon sources.The net carbon budget was apparently more sensitive to an increase of air temperature than change of precipitation.

More than Carbon Stocks:A Case Study of Ecosystem-based Benefits of REDD+ in Indonesia

During the 15th Conference of the Parties （COP 15）, Parties agreed that reducing emissions from deforesta- tion and forest degradation and enhancing ＇removals of greenhouse gas emission by forests＇ （REDD＋） in developing countries through positive incentives under the United Nations Framework Convention on Climate Change （UNFCCC） was capable of dealing with global emissions. As REDD＋ seeks to lower emissions by stopping deforestation and for- est degradation with an international payment tier according to baseline scenarios, opportunities for ecosystem benefits such as slowing habitat fragmentation, conservation of forest biodiversity, soil conservation may be also part of this effort. The primary objective of this study is to evaluate ecosystem-based benefits of REDD＋, and to identify the rela- tionships with carbon stock changes. To achieve this goal, high resolution satellite images are combined with Normal- ized Difference Vegetation Index （NDVI） to identify historical deforestation in study area of Central Kalimantan, In- donesia. The carbon emissions for the period of 2000-2005 and 2005-2009 are 2.73 ×10^5 t CO2 and 1.47× 10^6 t CO2 respectively, showing an increasing trend in recent years. Dring 2005-2009, number of patches （NP）, patch density （PD）, mean shape index distribution （SHAPE_MN） increased 30.8%, 30.7% and 7.6%. Meanwhile, largest patch index （LPI）, mean area （AREA MN）, area-weighted mean of shape index distribution （SHAPE_AM）, neighbor distance （ENN_MN） and interspersion and juxtaposition index （IJI） decreased by 55.3%, 29.7%, 15.8%, 53.4% and 21.5% re- spectively. The area regarding as positive correlation between carbon emissions and soil erosion was approximately 8.9 x l03 ha corresponding to 96.0% of the changing forest. These results support the view that there are strong syner- gies among carbon loss, forest fragmentation and soil erosion in tropical forests. Such mechanism of REDD＋ is likely to present opportunities for multiple benefits that fall outside the scope of carbon stocks.

The Connection of Vegetation with Tourism Development and Economic Growth： A Case Study for Aruba

Vegetation is an important ecosystem on earth. It influences the earth system in many ways. Any influences on this fragile variable should be investigated, especially in a changing climate. Humans can have a positive or a negative influence on plants. This paper investigates the possible impact of tourism development and economic growth on vegetation health using cointegration and causality for Aruba. The proposed framework contributes to a better understanding on the use of remote sensing of vegetation response to tourism development and economic growth. Thereby, provide opportunities for improving the overall strategy for achieving sustainable development on a small island state. The calculations showed that there were relationships between the tourism demand and economic growth on the vegetation health on Aruba for the western part of the island. On the other hand, for the central part of the island, no relationships were found.

Climate Change Impacts on Central China and Adaptation Measures

In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within the study area, and with the harmful effects far more prevalent. Under the A1B scenario, it is reported that temperature, precipitation, days of heat waves, and extreme precipitation intensity will increase at respective rates of 0.38℃ per decade, 12.6 mm per decade, 6.4 d and 47 mm per decade in the 21st century. It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems, water resources, wetland ecosystem, forest ecosystem, human health, energy sectors and other sensitive fields in Central China. Due to the limited scientific knowledge and researches, there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results. Therefore, it is urgent and essential to increase the studies of the regional climate change adaptation, extend the research fields, and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments.

Primary Discussion of a Carbon Sink in the Oceans

As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people＇s living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula： C=A-B and G=E＋F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the calrying capacity of the oceans.