نتایج جستجو برای: loess deposits
تعداد نتایج: 31955 فیلتر نتایج به سال:
Arid central Asia (ACA) is one of the most arid regions in the mid-latitudes and one of the main potential dust sources for the northern hemisphere. The lack of in situ early Pleistocene loess/dust records from ACA hinders our comprehensive understanding of the spatio-temporal record of aeolian loess accumulation and long term climatic changes in Asia as a whole. Here, we report the results of ...
Analyzing spatiotemporal variation of tree cover could enhance understanding of the environment and promote a sustainable resource use of ecosystems. This study investigated the variation in tree cover in the Loess Plateau after an ecological restoration effort called the ‘Grain for Green Project’ (GGP). The results show that the proportion of tree covered area in the Loess Plateau changed from...
Daily feed intake (DFI) is an important consideration for improving feed efficiency, but measurements using electronic feeder systems contain many missing and incorrect values. Therefore, we evaluated three methods for correcting missing DFI data (quadratic, orthogonal polynomial, and locally weighted (Loess) regression equations) and assessed the effects of these missing values on the genetic ...
Selenium is a trace element in animal nutrition provided through forage. Vegetation should accumulate adequate levels to meet this livestock requirement. This study assessed southeastern Missouri soils for their selenium concentrations. Multiple sites across were sampled, from which total of twenty-six collected. Parent materials ranged coarse fine-textured alluvium and terrace deposits, colluv...
The Loess Plateau in China is internationally known for its unique geographical features and has therefore been studied by many researchers. This research exploits the regional differences in the spatial morphological characteristics of Loess shoulder lines in different landform types as an important basis for geomorphological regionalization. In this study, we used ensemble empirical mode deco...
The life cycle, within-field distribution, crop damage and impact of natural enemies of the potato tuber moth, Phthorimaea operculella (Zeller) were investigated in two potato cropping systems. The two systems differed in soil type (sandy vs. loess) which in turn affected the choice of cultivars, irrigation programme, insecticide application method (ground vs. aerial), and planting and harvest ...
The Loess Plateau of China has the highest soil erosion rate in the world where billion tons of soil is annually washed into Yellow River. In recent decades this region has experienced significant climate change and policy-driven land conversion. However, it has not yet been well investigated how these changes in climate and land use have affected soil organic carbon (SOC) storage on the Loess ...
Abstract The origin and provenance of eolian sediments such as loess can potentially reveal paleo-air circulation directions that drive temporal changes in climate. these deposits has been mostly assessed by detrital zircon U-Pb geochronology remains debated. Recent studies constraining sediment using only yields a restricted view the overall sources, because commonly records high-temperature t...
Loess grain size data used to infer transport direction or wind strength are generally derived from vigorously disaggregated samples. However, these data may not adequately represent the effective particle size distribution during loess transport, if the transported dust contained aggregates of finegrained material. Thin sections of minimally altered C and BC horizons in the late Pleistocene Pe...
Time series of remotely sensed data are an important source of information for understanding land cover dynamics. In particular, the fraction of absorbed photosynthetic active radiation (fAPAR) is a key variable in the assessment of vegetation primary production over time. However, the fAPAR series derived from polar orbit satellites are not continuous and consistent in space and time. Filterin...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید