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In the late 1990s, China’s Yangtze and Yellow River Basins suffered devastating natural disasters widely attributed to the degradation of soil and water resources. The Government of China responded with a number of major environmental programs, the most expensive and influential of which, the Grain for Green (GfG) Program, was implemented widely from 1999. Under the GfG Program—also known as the Sloping Land Conversion or Conversion of Cropland to Forest Program—the central government compensates farmers to convert cropland on steep slopes or otherwise ecologically sensitive areas to forest or grassland. Its long-term success depends on households’ ability to make sustainable changes to their household income streams and income diversification strategies. In this paper, we use a difference-in-difference estimation approach to examine the role of migration as a household-level response to the GfG Program, testing the extent to which individuals migrate following a reduction in land available for farming. Importantly, we exploit 15 years of data on migration decisions and establish that participating and non-participating households were on parallel migration paths before the program, thus refuting a key threat to causality in a difference-in-difference model. We find that participating families do, in fact, choose migration as an income diversification strategy more frequently than non-participants. The program effects varied over time but peaked post-Great Recession in 2011 when migration rates in GfG households exceeded those of non-GfG households by 5.9% points (p = 0.003) or about 26%. Our findings should encourage policymakers that families are making long-term adjustments to their livelihood strategies to avoid poverty in anticipation of the eventual withdrawal of government supports. [ABSTRACT FROM AUTHOR]

The present paper provides a scientific assessment of the inter-decadal variability of the Asian summer monsoon and its significant effect on precipitation patterns in China. The paper consists of four parts. The first part shows the observed inter-decadal weakening of the Asian summer monsoon since the end of 1970s. The second part describes the impact of the weakening Asian summer monsoon on precipitation in China, which caused the major monsoon rainbelt to shift southward from North China to South China over about 30 years, with a 60-80 oscillation dominating. The third part projects the future change of the Asian summer monsoon in the warmer climate by using IPCC AR4 climate models. It has been found that major monsoon rainfall belts in East Asia will move northward in the 2040s, with summer precipitation in North China increasing considerably and stably. Finally, in the fourth part, the implication of the adaptation to the above climate change and related water management will be discussed including the water transport engineering project from the Yangtze River to the Yellow River and North China. [ABSTRACT FROM AUTHOR]

Runoffs in the Yellow River and Yangtze River basins, China, have been changing constantly during the last half century. In this paper, data from eight river gauging stations and 529 meteorological stations, inside and adjacent to the study basins, were analyzed and compared to quantify the hydrological processes involved, and to evaluate the role of human activities in changing river discharges. The Inverse Distance Weighted (IDW) interpolation method was used to obtain climatic data coverage from station observations. According to the runoff coefficient equation, the effect of human activities and climate can be expressed by changes in runoff coefficients and changes in precipitation, respectively. Annual runoff coefficients were calculated for the period 1950-2008, according to the correlation between respective hydrological series and regional precipitation. Annual precipitation showed no obvious trend in the upper reaches of the Yellow River but a marked downward trend in the middle and downstream reaches, with declines of 8.8 and 9.8 mm/10 a, respectively. All annual runoff series for the Yellow River basin showed a significant downward trend. Runoff declined by about 7.8 mm/10 a at Sanmenxia and 10.8 mm/10 a at Lijin. The series results indicated that an abrupt change occurred in the late 1980s to early 1990s. The trend of correlations between annual runoff and precipitation decreased significantly at the Yellow River stations, with rates ranging from 0.013/10 a to 0.019/10 a. For the hydrologic series, all precipitation series showed a downward trend in the Yangtze River basin with declines ranging from about 24.7 mm/10 a at Cuntan to 18.2 mm/10 a at Datong. Annual runoff series for the upper reaches of the Yangtze River decreased significantly, at rates ranging from 9.9 to 7.2 mm/10 a. In the middle and lower reaches, the runoff series showed no significant trend, with rates of change ranging from 2.1 to 2.9 mm/10 a. Human activities had the greatest influence on changes in the hydrological series of runoff, regardless of whether the effect was negative or positive. During 1970-2008, human activities contributed to 83% of the reduction in runoff in the Yellow River basin, and to 71% of the increase in runoff in the Yangtze River basin. Moreover, the impacts of human activities across the entire basin increased over time. In the 2000s, the impact of human activities exceeded that of climate change and was responsible for 84% of the decrease and 73% of the increase in runoff in the Yellow River and Yangtze River basins, respectively. The average annual runoff from 1980 to 2008 fell by about 97%, 83%, 83%, and 91%, compared with 1951-1969, at the Yellow River stations Lanzhou, Sanmenxia, Huayuankou and Lijin, respectively. Most of the reduction in runoff was caused by human activities. Changes in precipitation also caused reductions in runoff of about 3%, 17%, 17%, and 9% at these four stations, respectively. Falling precipitation rates were the main explanation for runoff changes at the Yangtze River stations Cuntan, Yichang, Hankou, and Datong, causing reductions in runoff of 89%, 74%, 43%, and 35%, respectively. Underlying surface changes caused decreases in runoff in the Yellow River basin and increases in runoff in the Yangtze River basin. Runoff decreased in arid areas as a result of increased water usage, but increased in humid and sub-humid areas as a result of land reclamation and mass urbanization leading to decreases in evaporation and infiltration. [ABSTRACT FROM AUTHOR]

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This paper studies the relationship between net primary productivity (NPP) and annual average air temperature (GT) at 0cm above ground in permafrost regions by using revised Chikugo NPP model, cubic spline interpolating functions, and nonlinear regression methods. The source regions of the Yangtze and Yellow Rivers were selected as the research areas. Results illustrate that: (1) There is significant non-linear relationship between NPP and GT in various typical years; (2) The maximum value of NPP is 6.17, 5.87, 7.73, and 5.41 DM·t·hm·a respectively, and the corresponding GT is 7.1, 10.0, 21.2, and 8.9°C respectively in 1980, 1990, 2000 and 2007; (3) In 1980, the sensitivity of NPP to GT is higher than in 1990, 2000 and 2007. This tendency shows that the NPP presents change from fluctuation to an adaptation process over time; (4) During 1980∼2007, the accumulated NPP was reduced to 8.05, and the corresponding carrying capacity of theoretical livestock reduced by 11%; (5) The shape of the demonstration region of ecological compensation system, livelihood support system, and science appraisal system in the source regions of Yangtze and Yellow Rivers are an important research for increasing the adaptation capacity and balancing protection and development. [ABSTRACT FROM AUTHOR]

In 2002, China launched the South-to-North Water Transfer Project after completing a 50-year feasibility study. By 2050, the three-route (i.e., East, Middle, and West) project will be capable of transferring 44.8 billion m3/year of water from the water rich Yangtze River to the arid north to alleviate water shortage and help secure a balanced social and economic development across the nation. However, diversion of such a large quantity of water could profoundly change the riverine environment of the upper Yellow River and the lower reach of the Han River, a tributary of the Yangtze River and the water supplying area of the project’s Middle Route, because of changes in the annual discharge. Secondary salinization seems inevitable in the water receiving areas of the North China Plain, and decrease in the discharge of the Yangtze River will result in seawater intrusion into the Yangtze Delta. This paper describes the project and discusses its environmental implications. Additionally, a long-term monitoring strategy under the umbrella of the Chinese Ecological Research Network is proposed for environmental monitoring. [ABSTRACT FROM AUTHOR]

Abstract: This paper discusses the spatial and temporal change of different frozen soil types from 1980s to 2000s, and the impacts of frozen soil change on rangeland productivity and sustainable livelihood in the source regions of Yangtze and Yellow Rivers employed numerical model and GIS technology. Authors use the analytical framework of adaptation of animal husbandry according to national, regional, community and household scales, and release three key instruments of cryospheric change adaptation, including adaptive capacity of the policies, adaptive capacity of the people, and adaptive capacity of the grassland ecosystem. Analysis result shows that there is clearly a need, to develop institutional processes that support policy analysis to draw on existing information, that facilitate multidisciplinary research on topics of policy relevance, and that link the accumulation of credible cryosphere scientific evidence with policy making. Finally, Authors suggest that further support to mainstream climatic and cryospheric change concerns in adaptation policies and strategies of animal husbandry must include a focus on: (1) Formulating ecological compensation policy and mechanism for grassland ecosystem maintenance; (2) Strengthening vocational training, long-term essential-qualities-oriented education to improve indigenous people''s professional skills and abilities; (3) Strengthening development of livestock replacement industries to broaden employment channels of indigenous people; (4) Strengthening the consciousness of ecosystem maintenance, improvement the social civilization level for indigenous people; (5) Continuous implementation the Ecological Protection and Restoration Program in the Three-River Source Region in national scale. [Copyright &y& Elsevier]

Abstract: This paper characterizes the distribution of phosphorus fractions and matrix-bound phosphine (MBP) in coastal surface sediments of the Southwest Yellow Sea from 2006 to 2007. Total phosphorus (TP), inorganic phosphorus (IP) and organic phosphorus (OP) concentrations (mgkg−1) range from 278±3 to 768±15, 160±1 to 653±27, and 3.42±0.05 to 267±22, respectively. MBP is a small portion of TP with values of 0.69±0.06 to 179±29ngkg−1. Phosphorus fractions and MBP are influenced strongly by riverine input and hydrodynamic conditions. High TP and MBP are found in the old Yellow River mouth and the Yangtze River mouth. OP and MBP are strongly negatively correlated to mean particle size. Significant positive correlations are found between MBP and IP and OM, suggesting that MBP production may be the microbially intermediated transformation of IP. [Copyright &y& Elsevier]

Understanding climate change impacts on hydrological regime and assessing future water supplies are essential to effective water resources management and planning, which is particularly true for the Tibetan Plateau (TP), one of the most vulnerable areas to climate change. In this study, future climate change in the TP was projected for 2041–2060 by a high‐resolution regional climate model, RegCM4, under 3 representative concentration pathways (RCPs): 2.6, 4.5, and 8.5. Response of all key hydrological elements, that is, evapotranspiration, surface run‐off, baseflow, and snowmelt, to future climate in 2 typical catchments, the source regions of Yellow and Yangtze rivers, was further investigated by the variable infiltration capacity microscale hydrological model incorporated with a 2‐layer energy balance snow model and a frozen soil/permafrost algorithm at a 0.25° ×0.25° spatial scale. The results reveal that (a) spatial patterns of precipitation and temperature from RegCM4 agree fairly well with the data from China Meteorological Forcing Dataset, indicating that RegCM4 well reproduces historical climatic information and thus is reliable to support future projection; (b) precipitation increase by 0–70% and temperature rise by 1–4 °C would occur in the TP under 3 RCPs. A clear south‐eastern–north‐western spatial increasing gradient in precipitation would be seen. Besides, under RCP8.5, the peak increase in temperature would approach to 4 °C in spring and autumn in the east of the TP; (c) evapotranspiration would increase by 10–60% in 2 source regions due to the temperature rise, surface run‐off and baseflow in higher elevation region would experience larger increase dominantly due to the precipitation increase, and streamflow would display general increases by more than 3% and 5% in the source regions of Yellow and Yangtze rivers, respectively; (d) snowmelt contributes 11.1% and 16.2% to total run‐off in the source regions of Yellow and Yangtze rivers, respectively, during the baseline period. In the source region of Yangtze River, snowmelt run‐off would become more important with increase of 17.5% and 18.3%, respectively, under RCP2.6 and RCP4.5 but decrease of 15.0% under RCP8.5. [ABSTRACT FROM AUTHOR]

The influence of hydrodynamics on the chemical composition of sediments is based on the uneven distribution of element abundances in different size fractions. In this study, 72 size-fractional sediments from the Huanghe (Yellow River) and Changjiang (Yangtze River) riverbeds were measured with XRD, SEM, ICP-AES and ICP-MS. The analysis results show that the mineral and chemical characteristics change with grain size in the Huanghe and Changjiang sediments. According to the principal components analysis, three independent geochemical factors were found. The first factor elements, Zr, Hf, Th, U, Y, La and TiO2 are influenced by the existence of heavy minerals. The second factor elements, Al2O3, alkalis, alkaline earth (excluding Ca and Sr) and most of the transitional metals are dominated by clay minerals. The third factor group includes Ca and Sr, which were controlled by calcium-bearing mineral contents and chemical weathering intensities. The various grain size distributions greatly affect the mineralogical and chemical compositions of bulk sediments. Compared to other size fractions, the 5-6PHI size fractions of the Huanghe and Changjiang sediments have special mineralogical and chemical compositions, and intermediate volume percentages. Weight or volume percentage of each size fraction may be more suitable than mean grain-size of the bulk sediment to elucidate the grain size effects. Chemical Index of Alteration (CIA) values increase steeply with decreasing grain size, while Weathering Index of Parker (WIP) values are relatively stable. Because of the big influence of the abundance of clay minerals on CIA values, it is questionable to use CIA as a proxy of weathering intensity. Considering the clay mineral effects, stability in values and heterogeneous material properties, WIP has the potential to indicate the chemical weathering intensity of sediments. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sediment settling velocity ( w) patterns are well established at the Huanghe and Changjiang river mouths, but no w results have been reported for the Yellow Sea and the East China Sea (YSECS) shelves due to the labor-intensive and time-consuming aspect of traditional w measurement approaches (e.g., settling column method). This disadvantage can be overcome by the acoustic Doppler velocimeter (ADV). In this study, ten ADV-based field campaigns were conducted over various seasons of the years 2011 and 2013 at six YSECS sites, five on the East China Sea shelf (28 to 87 m depth) and one on the Yellow Sea shelf (74 m depth). The results demonstrate that ADV backscatter was a reliable proxy of suspended sediment concentration over a measurement range of 1 to 1,000 mg/L. The ADV-estimated w was highest (1.43-1.88 mm/s) in summer in the southern East China Sea, and lowest (0.07 mm/s) in spring in the northern Yellow Sea. This can plausibly be explained by the hydrodynamic environment and bottom sediment type at the campaign sites. More importantly, the data reveal evidence of marked seasonal variations of w in the middle sector of the East China Sea, as well as intra-tidal variations at all campaign sites. However, these variations of w are not directly regulated by current velocity or suspended sediment concentration. This aspect represents a major challenge in future research in this shelf region and, for that matter, in similar settings worldwide. Evidently, expanding on the well-resolved continuous time series provided by the ADV approach is a key step in this direction. [ABSTRACT FROM AUTHOR]

Infl uences of large-scale climatic phenomena, such as the El Niño/La Niña-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), on the temporal variations of the annual water discharge at the Lijin station in the Huanghe (Yellow) River and at the Datong station in the Changjiang (Yangtze) River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis (EMDMESA) method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the interannual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers. [ABSTRACT FROM AUTHOR]

The diverse hydro-climate between northern and southern China causes serious complications related to increasing food demand, declining water availability, and increasing flood risk in Changjiang and Yellow River basins. The huge projects of Three Gorges Dam (TGD) for diminishing flood and South-to-North Water Transfer Project (SNWTP) for driving water from Changjiang to Yellow and Hai Rivers to compensate for an imbalance of environmental resources will not necessarily solve all of the problems that they were originally intended to address. A sophisticated eco-hydrological model is required to evaluate the optimum amount of transferred water associated with these projects, together with socio-economic and environmental consequences. For this purpose, the process-based National Integrated Catchment-based Eco-hydrology (NICE) model was modified to couple with complex sub-systems in irrigation, stream junction, reservoir operation, and water transfer, to develop coupled human and natural systems and evaluate cause and effect of uneven water resources. The model clarified the impact of irrigation on eco-hydrological processes and predicted hydrologic change after TGD and SNWTP to estimate whether dilemmas between water stress, crop productivity, and ecosystem degradation would diminish. The result also showed the missing role of surface water - groundwater interactions and lateral subsurface flow, usually not considered important by assuming stationarity in previous researches of continental scales. A heterogeneous pattern of Time-Integrated Normalized Difference Vegetation Index gradient in agricultural fields helped to estimate uneven crop yield and its relation to water availability. This integrated approach will have some roles not only to re-consider this complex process from the view point of hydrologic and biogeochemical cycles, but also to clarify how the substantial pressures of complicated problems can be overcome by effective trans-boundary solutions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The alpine ecosystems in permafrost regions are extremely sensitive to climate change. The headwater regions of Yangtze River and Yellow River of the Qinghai-Tibet Plateau are on the permafrost area. Aerial photos of the Source Regions of the Yangtze and Yellow River taken in 1968 and three phases of TM images acquired from 1986, 2000, and 2008 were used to analyze the spatial alterations of the land cover and corresponding effects on the environment guided by landscape ecology theory. Firstly, land cover types were divided into three classes and 11 subclasses. Analysis results revealed the trends and magnitude of the eco-environmental changes in the regions over the past four decades and showed a continuous degradation of grasslands and the extension of desertification and salinization. Secondly, five landscape pattern indices (i.e., NP, MPS, PR, SHEI, CONTAG) commonly used in landscape ecological studies were calculated, and results showed that this region had become more centralized and diversified. Finally, the factors causing the degradation of alpine grasslands were analyzed. The regional climate exhibited a tendency toward significant warming and desiccation with the air temperature increased by 0.03 °C per year and relative stable precipitation over the last 40 years. And the temperature of permafrost in 0-20 cm soil layer obviously raised by 0.2-0.3 °C in the last 40 years. The combined effects of climate warming and permafrost variation were the major drivers for the changes of landscape in alpine ecosystems. [ABSTRACT FROM AUTHOR]

Variability of the climate in the headwater drainage basins of the Yangtze River and Yellow River during 1961-2010 was investigated by examining four typical climatic variables: daily minimum, mean, and maximum temperatures and daily precipitation. The results indicate that the temporal trends vary among the climatic variables and the time periods examined. The increase in daily minimum temperature began later than the daily mean and maximum temperatures, but the increase rate of the former was relatively greater after 1985. The abrupt increases in precipitation that occurred near 1978 were much clearer than the three temperature variables. Four dominant periodicities (3, 7, 11, and 18-20 yr) of temperature and precipitation were identified, and these variation patterns directly determined the periodic discharge variations in the two rivers. Under climate change impacts, periodic variations in temperature and precipitation at long temporal scales were intensified after the 1980s. Comparatively, climate change more severely impacts the minimum temperature and precipitation than the maximum and mean temperatures in the study area, and the variability of daily precipitation is more complex than the three temperature variables. Overall, the headwater drainage basin of the Yellow River is more susceptible to climate change compared with the other basin. After 2008, the increase rate of temperature (especially the daily mean and minimum temperatures) became greater, and precipitation showed a downward trend in the study areas. These trends are unfavorable for the safety of water resources and for eco-environmental safety in the two basins. [ABSTRACT FROM AUTHOR]

A one-year study was carried out to investigate the seasonal fluxes and source variation of organic carbon transported by two major Chinese rivers, the Yellow River and Changjiang. In 2009, the Yellow River and Changjiang transported 3.20 × 1010g and 1.58 × 1012 g DOC and 3.89 × 1011g and 1.52 × 1012 g POC, respectively. The dominant input of the terrestrial organic matter occurred during the high discharge period from June to July for the Yellow River and from June to August for Changjiang, accounting for 36-44% of the DOC and 72-86% of the POC transported by the two rivers in 2009. The Yellow River transported much higher concentrations of inorganic carbon than organic carbon, while a reverse trend was found in the Changjiang, indicating the different sources of carbon discharged by the two rivers. Using radiocarbon and stable carbon isotope measurements, we identified the different sources and seasonal variations of organic carbon transported by the Yellow River and Changjiang. The Yellow River carried old POC with radiocarbon ages ranging from 4000 to 8000 years, while POC transported by Changjiang had a relatively younger 14C age ranging from 800 to 1060 years. The 14C ages of DOC were relatively younger (305-1570 years) and showed less variation between the two rivers. The seasonal variations found in 14C ages of DOC and POC indicate that a large fraction of recent-fixed labile organic carbon was transported by the two rivers in the spring and summer months. The different sources and seasonal variations in both fluxes and sources of organic carbon transported by the Yellow River and Changjiang could have an important influence on the biogeochemical cycle and ecosystems in the estuaries and adjacent coastal waters of the East China Sea. [ABSTRACT FROM AUTHOR]

Quantitative evaluations of the impacts of climate change on water resources are primarily constrained by uncertainty in climate projections from GCMs. In this study we assess uncertainty in the impacts of climate change on river discharge in two catchments of the Yangtze and Yellow River Basins that feature contrasting climate regimes (humid and semi-arid). Specifically we quantify uncertainty associated with GCM structure from a subset of CMIP3 AR4 GCMs (HadCM3, HadGEM1, CCSM3.0, IPSL, ECHAM5, CSIRO, CGCM3.1), SRES emissions scenarios (A1B, A2, B1, B2) and prescribed increases in global mean air temperature (1 °C to 6 °C). Climate projections, applied to semi-distributed hydrological models (SWAT 2005) in both catchments, indicate trends toward warmer and wetter conditions. For prescribed warming scenarios of 1 C to 6 C, linear increases in mean annual river discharge, relative to baseline (1961-1990), for the River Xiangxi and River Huangfuchuan are +9% and 11% per +1 C respectively. Intra-annual changes include increases in flood (Q05) discharges for both rivers as well as a shift in the timing of flood discharges from summer to autumn and a rise (24 to 93%) in dry season (Q95) discharge for the River Xiangxi. Differences in projections of mean annual river discharge between SRES emission scenarios using HadCM3 are comparatively minor for the River Xiangxi (13 to 17% rise from baseline) but substantial (73 to 121%) for the River Huangfuchuan. With one minor exception of a slight (-2%) decrease in river discharge projected using HadGEM1 for the River Xiangxi, mean annual river discharge is projected to increase in both catchments under both the SRES A1B emission scenario and 2 rise in global mean air temperature using all AR4 GCMs on the CMIP3 subset. For the River Xiangxi, there is substantial uncertainty associated with GCM structure in the magnitude of the rise in flood (Q05) discharges (-1 to 41% under SRES A1B and -3 to 41% under 2 global warming) and dry season (Q95) discharges (2 to 55% under SRES A1B and 2 to 39% under 2° global warming). For the River Huangfuchuan, all GCMs project a rise in the Q05 flow but there is substantial uncertainty in the magnitude of this rise (7 to 70% under SRES A1B and 2 to 57% under 2 global warming). Differences in the projected hydrological changes are associated with GCM structure in both catchments exceed uncertainty in emission scenarios. Critically, estimated uncertainty in projections of mean annual flows is less than that calculated for extreme (Q05, Q95) flows. The common approach of reporting of climate change impacts on river in terms of mean annual flows masks the magnitude of uncertainty in flows that are of most importance to water management. [ABSTRACT FROM AUTHOR]

Severe soil erosion in the upper reaches of the Yangtze River and the middle reaches of the Yellow River is a serious environmental problem in western China. In order to control this soil erosion, the national government implemented the Grain for Green Program (GGP) in Sichuan Province (in the upper reaches of the Yangtze River) and Shaanxi Province (in the middle reaches of the Yellow River) in 1999. To evaluate the effects of the GGP on soil erosion, the present study investigated the relationships between annual precipitation and three parameters, annual runoff, sediment concentration, and sediment discharge, for these rivers. As the area covered by the GGP increased, sediment concentration and sediment discharge both decreased, and the correlation with the GGP area was much stronger than the correlation with annual precipitation. Therefore, China's GGP appears to be controlling soil erosion in the upper reaches of the Yangtze River and the middle reaches of the Yellow River. [ABSTRACT FROM AUTHOR]

In the source regions of the Yangtze and Yellow Rivers of China, glaciers, frozen ground, the hydrological system, and alpine vegetation have changed over the past decades years. Climatic causes of these variations have been analyzed using mean monthly air temperature and monthly precipitation between 1956 and 2000, and monthly evaporation from φ20 evaporation pans between 1961 and 1996. In the source region of the Yangtze River, lower temperature and plentiful precipitation during the 1960s and continuing into the early 1980s triggered a glacier advance that culminated in the early 1990s, while a robust temperature increase and precipitation decrease since 1986 has forced glaciers to retreat rapidly since 1995. Permafrost degradation is another consequence of the climatic warming. The variations in the hydrological system and alpine vegetation are controlled mainly by the climate during the warm season. Warmer and drier summer climate is the major cause of a degradation of the vegetation, desiccation of the high-cold marshland, a decrease in the areas and numbers of lakes and rivers in the middle and north source regions of the Yangtze and Yellow Rivers, and a reduction in surface runoff in the source region of the Yangtze River for the last 20 years. The causes of eco-environmental change in Dari area, near the outlet from the source area of the Yellow River, are different from those elsewhere in the study area. A noticeable reduction in runoff in the source region of the Yellow River and degradation of alpine vegetation in Dari area are closely related to the permafrost degradation resulting from climate warming. [ABSTRACT FROM AUTHOR]

The bronze gudgeon ( Coreius heterodon) and the congeneric species largemouth bronze gudgeon ( Coreius guichenoti), two endemic fish species in China, are important economic fishes in local areas. The bronze gudgeon is distributed in Yangtze River and Huanghe River basin, whereas the largemouth bronze gudgeon is distributed only in the middle and upper reaches of Yangtze River. Here, we sequenced the complete mitochondrial genomes of the two species and compared the evolutionary rate differences between the two species. The complete mitochondrial genomes of C. heterodon and C. guichenoti are 16,611 and 16,612 bp, respectively. Both of the complete mitogenome sequences contain 13 protein-coding genes, 2 rRNA subunits, 22 tRNAs and 1 non-coding control region, which are typical vertebrate mitogenomes. The relative rate test shows that the mitochondrial genome of C. heterodon evolves nearly threefold faster than that of C. guichenoti, which is mostly caused by the higher substitution rates in rRNAs and especially in tRNAs in C. heterodon. [ABSTRACT FROM AUTHOR]