Distribution Pattern of SN in Qinghai-Tibet Plateau and Its Relationship with Environmental Factors

Abstract

Studying the distribution pattern and driving mechanism of Soil Nitrogen (SN) in the agricultural areas of the Qinghai-Tibet Plateau is of certain significance for the rational use of N fertilizer, improving the quality of land use and protecting the environment. The SN content of cultivated soil in Qinghai-Tibet Plateau agricultural areas was analyzed by combining geographical and meteorological factors. It was found that the average Soil Total N (STN) in farmland was 2.4690 g/kg, which was the first class standard (>2.0 g/kg) of nutrient classification standard in the second national soil census. Horizontally, the areas with low N are mainly concentrated in the southwest of the Qinghai-Tibet Plateau and the high in the southeast and eastern regions of the Tibetan Plateau. From the vertical distribution pattern of 2000 m to 5000 m, it gradually decreases with the increase of altitude. The climatic factors affecting the STN are daily average temperature ≥ 10°C accumulated temperature > annual evaporation > daily average temperature ≥ 0°C accumulated temperature. The climatic factors that affect the Soil Available N (SAN) are daily average temperature ≥ 10°C accumulated temperature > daily average temperature ≥ 0°C accumulated temperature > annual evaporation> annual sunshine hours> monthly average maximum temperature > annual precipitation amount.

Prediction of Suitable Habitat of Alien Invasive Plant Ambrosia trifida in Northeast China under Various Climatic Scenarios

“…At the beginning of the study, field investigation of Ambrosia trifida distribution points also confirmed this conclusion, Ambrosia trifida is mostly distributed in cultivated land, both sides of roads, both sides of rivers, and so on, which is consistent with the field survey results of Ma Qianqian et al on Ambrosia trifida [30]. At the same time, Huang Qiaoqiao et al [31] also pointed out that human activities have a significant role in promoting the spread and distribution of alien invasive plants, whether on a large-scale or a small-scale, its impact is also higher than the natural environmental factors [32]. In addition to the human factors, the temperature and humidity factors in this study also have an important impact on the distribution and diffusion of Ambrosia trifida.…”