Subjects: Geosciences >> Geography submitted time 2024-04-29 Cooperative journals: 《干旱区研究》
Abstract： Five typical vegetation types (i.e., coniferous forests, meadow grasslands, alpine shrubs, alpine meadows, and sparse vegetations of limestone flat) along a vertical belt of the Qilian Mountains were selected to explore the spatial elevational patterns of soil carbon, nitrogen, and phosphorus and their stoichiometric ratios. Results showed that: (1) The contents of total carbon (C), nitrogen (N), and phosphorus (P) at the 0~40 cm depth were 15.33~83.46, 1.63~7.76, and 0.37~0.74 mg·kg-1, respectively. Soil C and N decreased gradually with increasing altitudes, following the order coniferous forests > meadow steppes > alpine shrubs > alpine meadows > sparse vegetations of limestone flat. Soil P in alpine scrubs was significantly higher than that in alpine meadows, but the other three vegetations showed no significant difference. (2) The contents of NH+ 4-N, NO- 3-N and available phosphorus at the 0~40 cm depth were 11.01~14.73, 2.78~12.46, and 4.35~13.57 mg·kg-1, respectively. Ammonium was the main inorganic nitrogen form in all vegetation types. The nitrite content decreased gradually with increasing altitude. The content of soil available phosphorus was higher in sparse vegetations of limestone flats. (3) The ratios of soil C:N, C:P, and N:P at the 0~40 cm depth were 9.52~10.11, 29.89~320.24, and 3.18~29.63, respectively. Soil C:N decreased with elevation. Soil C:P and N:P were significantly lower in the soil of sparse vegetations of the limestone flat than in other vegetations, indicating that carbon and nitrogen were the limiting nutrients in the limestone flat. By contrast, the limestone flat was in a phosphorus-rich state. Elevational variations in soil C, N, and P contents and their stoichiometric ratios reflect the joint control of multiple environmental factors, thereby affecting the biochemical processes of soil C, N, and P.
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Desert plants have developed highly evolved water preservation and transportation systems for collecting and storing water through air under chronic water scarcity, the accessory structures such as trichomes on the leaf surface have important biological significance in ollection, storage and transportation of the condensed water. Based on the current research progress, this review briefly summarizes the biological and ecological effects of condensate on desert plants, and expounds the theories related to leaf surface wettability and water collection capacity. Based on this, the important role of special structure of desert plants’leaf surface (trichome) in the formation, transport and absorption of condensate is mainly discussed. The research methods of surface retention and absorption of condensate water were summarized, which may provide guidance for further study on trichome function and is helpful to understand the mechanism of condensate collection by desert plants driven by its structural characteristics in arid areas of China.
Subjects: Geosciences >> Geography submitted time 2023-03-15 Cooperative journals: 《干旱区地理》
Abstract： Under the background of the postindustrial and post-epidemic eras, the amount of energy consumed by households in urban areas continuously increases. Thus, households have become the main contributor to carbon emissions and large amounts of energy consumed. Accordingly, a study on household energy consumption plays a vital role in the construction of ecological civilization in China. Plateau cities are important custodians of ecological security, and Xining City is a representative of plateau cities. Therefore, we selected it as the research object of this study. We aimed to explore the characteristics and influencing factors of household energy consumption and to visualize the process of household energy consumption under different income conditions. We utilized 2021 survey data, mainly using household energy estimates and ordinary least squares regression models and constructing household energy flows. We found that: (1) The annual per capita energy consumption of urban households in Xining City is 461.57 kgce·a- 1 . (2) Regarding energy use, the per capita heating energy consumption of urban households in Xining City is 307.52 kgce·a-1 , which is the main cause of the high energy consumption (66.62%), followed by the per capita energy consumption of kitchen equipment (74.56 kgce·a- 1 ). Conversely, large household appliances are relatively few, and washing machines especially consume the lowest energy. (3) The total year- end household income is the core factor that affects the annual per capita energy consumption of households in Xining City, China. (4) The annual per capita energy consumption of high-income households is large, and the type of energy consumed varies. Additionally, as household income levels increase, the amount of energy consumed in heating households decreases. Finally, to effectively promote energy transition, we suggest the residents should enhance their awareness of renewable energy, and governments should increase the supply of clean energy for residents by constructing rooftop photovoltaics and laying natural gas pipelines. What is more, governments should also increase the energy- saving publicity for middle- and highincome groups to enhance residents’awareness of independent energy conservation and must customize energy policies for local conditions.
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：利用新疆地区2016年夏季（6—8月）近2000个区域自动站小时降水数据，以最新一代GPM(Global Precipi⁃tation Measurement Mission，全球降水测量计划)IMERG(Integrated Multi-satellite Retrievals for GPM)卫星降水产品为初始场，运用概率密度匹配与最优插值两步融合校正方法（probability density function-optimal interpolation, PDFOI），开展干旱区多源降水融合试验。首先，通过将实况观测与卫星反演降水进行概率密度函数（PDF）匹配，从而实现对IMERG降水的偏差订正；然后以偏差订正后的IMERG降水为初估场，实况降水为观测场，通过最优插值（OI）将偏差订正后的IMERG降水量估计值与雨量计实况相结合，最终得到经过两步校正后的新疆地区小时雨量数据。交叉验证结果表明，与雨量计实况和原始卫星降水数据相比，PDF-OI两步校正方法构建的融合降水不仅大大消除了系统误差，而且显著提高了数据精度。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-10 Cooperative journals: 《干旱区研究》
Abstract：标准化降水蒸散指数(SPEI)通过标准化潜在蒸散与降水的差值，表征一个地区干湿状况偏离常年的程度，是分析干旱演变趋势的新的理想指标，目前已经广泛应用于干旱评估、水资源管理等领域。利用SPEI和1961—2015年新疆天山山区8个代表站点的月降水量及月平均气温资料，对天山山区55 a以来气温和降水的变化特征、不同时间尺度的干旱变化特征、草地生长季干旱特征及变化趋势进行了分析，结果表明：近55 a，天山山区气温呈现显著的上升趋势；降水量总体呈略微上升的趋势，但年际变化较大，变化趋势不显著；天山山区月、季、半年尺度以及年尺度的干旱事件分别为42个、25个、16个和7个；天山山区草地生长季发生轻度、中度和重度干旱的频率分别为37.5%、7.1%和1.8%；近55 a，天山山区草地生长季降水量有所增加，但由于气温升高带来的蒸散作用加强，气候仍呈变干的趋势。近55 a来，天山山区草地生长季气候存在变干的倾向，且年际间的干旱程度变化剧烈，对草地的年际间生长状况差异存在较大的影响。
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