Interactions between lakes and the atmosphere at high altitudes are still poorly understood due to difficulty in accessibility of direct measurements. This is particularly true for the Qinghai‐Tibet Plateau (QTP), where approximately 50% of the lakes in China are located. Continuous direct measurements of the water flux and surface energy budget were made over the largest high‐altitude saline lake in China, Qinghai Lake on the northeastern QTP, using the eddy covariance method from 11 May 2013 to 10 May 2015. Results indicated that annual evaporation of Qinghai Lake was 832.5 mm for 2013/2014 and 823.6 mm for 2014/2015, respectively. The surface energy budget and evaporation showed a strong seasonal pattern, with peaks in the latent and sensible heat flux observed in autumn and early winter. There was a 2–3 month delay between the maximum net radiation and maximum latent and sensible heat fluxes. Intraseasonal and seasonal variations in latent and sensible heat flux were strongly affected by different air masses. Westerly cold and dry air masses increased evaporation while southeast moist air mass suppressed evaporation, suggesting that the lakes might serve as an “air conditioner” to modify the temporal heat and water flux in the QTP.
The complex interactions between shrub traits, soil structure, and soil water dynamics are not well understood yet. This study investigated rainfall partition by C. microphylla L., spatial soil water pattern, soil hydraulic conductivity, and soil macropores to ascertain preferential water flow to deep soil layer by shrub. Results indicated that high variability in throughfall existed within individual shrub stand: average coefficient of variation was 0.36 ± 0.13 for shrub and 0.15 ± 0.13 for interspace grass. Throughfall was less at the center of the shrub patch (30–60% of rainfall) than the outward positions at the edges of the canopy (70–90% of rainfall). Soil water responded differently to rainfall, soil depth, and vegetation type and showed high variability within shrub patches and on the slope. Greater and deeper infiltration was observed beneath C. microphylla L. canopy than interspaces grass after rainfall with large amount and high intensity, suggesting that macropore flow dominated in shrub patches. X‐ray CT showed that macroporosity was over six times greater in soil under C. microphylla L. than interspace grass. Soil hydraulic conductivity for shrub at saturation and the pressure heads of −30, −60, and −150 mm were 3, 2, 2.5, and 2 times than those of grass, respectively. Shrub patches had a significant lower bulk density and higher porosity than grass patches at the top 0‐ to 30‐cm depth. Soil hydraulic conductivity was significantly correlated to organic matter content, total N, bulk density, and porosity. This study suggests that rainfall partition by shrub's canopy and subsurface soil macropores induced by root architecture results in preferential water flow into deep soil layer, which might favor competitive advantages for water by shrubs under arid conditions.
The authors recruited 401 suicide attempters from general hospitals and 409 matched non-attempters to evaluate the psychometric properties of the Beck Hopelessness Scale (BHS) in rural China. All participants completed the BHS, Center for Epidemiologic Studies Depression Scale (CES-D), and Trait Anxiety Inventory (TAI). Suicide attempters had higher BHS scores than non-attempters. Cronbach's alpha coefficients were satisfactory and BHS scores significantly correlated to CES-D and TAI scores. Confirmatory factor analysis supported a four-factor model for suicide attempters and a five-factor model for non-attempters. The BHS is satisfactory in assessing hopelessness among suicide attempters in rural China.
Desertification is a form of land degradation principally in semi-arid and arid areas influenced by climatic and human factors. As a country plagued by extensive sandy desertification and frequent sandstorms and dust storms, China has been trying to find ways to achieve the sustainable management of desertified lands. This paper reviewed the impact of climate change and anthropogenic activities on desertified areas, and the effort, outcome, and lessons learned from desertification control in China. Although drying and warming trends and growing population pressures exist in those areas, the expanding trend of desertified land achieved an overall reversal. In the past six decades, many efforts, including government policies, forestry, and desertification control programs, combined with eco-industrialization development, have been integrated to control the desertification in northern China. Positive human intervention including afforestation, and the rehabilitation of mobile sandy land, and water conservation have facilitated the return of arid and semi-arid ecosystems to a more balanced state. China’s practices in desertification control could provide valuable knowledge for sustainable desertified land management on a global scale.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.