Changing characteristics of ecosystem and water storage under the background of warming and humidification in the Qilian Mountains, China.

The Qilian Mountains provide an ecological security barrier, and the region is an important river runoff area in China. Water resources play an essential role in the natural environment of Northwest China. This study used daily temperature and precipitation data from meteorological stations in the Qilian Mountains from 2003 to 2019, Gravity Recovery and Climate Experiment, and Moderate Resolution Imaging Spectroradiometer satellite data. Additionally, we used the Gravity Recovery and Climate Experiment satellite's monthly gravity field model data. Furthermore, we analyzed the characteristics of climate warming and humidification in the eastern, central, and western sections of the Qilian Mountains based on spatial precipitation interpolation and linear trend analysis. Finally, we examined the relationship between water storage changes and precipitation and its impact on vegetation ecology. The results revealed a significant warming and humidification trend in the western Qilian Mountains. The temperature increased significantly, and the increased precipitation rate in summer reached 1.5-3.1 mm/10a. Water storage in the Qilian Mountains displayed an increasing trend, with an increase of approximately 14.3 × 108 m3 over the 17 years study period, averaging an increase of 8.4 mm/year. The spatial distribution of water storage in the Qilian Mountains increased from north to south and east to west. There were noticeable seasonal differences, with the largest surplus occurring in the western Qilian Mountains (71.2 mm in summer). The fractional vegetation coverage in 95.2 % of the western Qilian Mountains and net primary productivity in 90.4 % of the area displayed an increasing trend, and vegetation ecology improved significantly. This study aims to investigate the characteristics of ecosystem and water storage changes in the Qilian Mountain area under the background of climate warming and humidification. The results obtained from this study provided an assessment of the vulnerability of alpine ecosystems and helped in making spatially explicit decisions for the rational utilization of water resources.

Fatty acid composition of the methylotrophic yeast Komagataella phaffii grown under low- and high-methanol conditions.

In this study, we analysed the intracellular fatty acid profiles of Komagataella phaffii during methylotrophic growth. K. phaffii grown on methanol had significantly lower total fatty acid contents in the cells compared with glucose-grown cells. C18 and C16 fatty acids were the predominant fatty acids in K. phaffii, although the contents of odd-chain fatty acids such as C17 fatty acids were also relatively high. Moreover, the intracellular fatty acid composition of K. phaffii changed in response to not only carbon sources but also methanol concentrations: C17 fatty acids and C18:2 content increased significantly as methanol concentration increased, whereas C18:1 and C18:3 contents were significantly lower in methanol-grown cells. The intracellular content of unidentified compounds (Cn H2n O4 ), on the other hand, was significantly greater in cells grown on methanol. As the intracellular contents of these Cn H2n O4 compounds were significantly higher in a gene-disrupted strain for glutathione peroxidase (gpx1Δ) than in the wild-type strain, we presume that the Cn H2n O4 compounds are fatty acid peroxides. These results indicate that K. phaffii can coordinate intracellular fatty acid composition during methylotrophic growth in order to adapt to high-methanol conditions and that certain fatty acid species such as C17:0, C17:1, C17:2 and C18:2 may be related to the physiological functions by which K. phaffii adapts to high-methanol conditions.

[Influence of light and temperature factors on biomass accumulation of winter wheat in field].

To explore the influence of light and temperature factors on the biomass accumulation of winter wheat at its development stages and in different organs, this paper analyzed the variation patterns of the biomass accumulation and the influence of TEP (thermal effectiveness photosynthetically active radiation) on the accumulation at each development stage, based on the observation data from the Xifen Agrometeorological Experiment Station in Gansu Province, including winter wheat phenophase and yield factors in 1981-2008, biomass at three-leaf, over-wintering, jointing, heading, milky maturity, and maturity stages in 1995-2008, and meteorological data in 1995-2008. The biomass accumulation of winter wheat in its whole growth period presented "S" curve, with the maximum value at heading-milky maturity stage. Since 1981, the TEP at heading-milky maturity stage increased with a rate of 3. 314 MJ x m(-2) x a(-1), and the TEP at other stages varied as parable curves. The TEP at turning green-jointing and milky maturity-maturity stages had a higher value in the 1990s and a lower value in the 1980s and early 21st century, while that at jointing-heading stage had a lower value in the 1990s but a higher value in the 1980s and early 21st century. There was a significant correlation between the TEP at each development stage and the actual yield. The LAI (leaf area index) at each development stage also had a significant correlation with the utilization rate of TEP at corresponding stage. When the LAI at jointing and heading stages was increased by 1, the utilization rate of TEP was correspondingly increased by 0.049 and 0.259 g x MJ(-1), respectively.

[Responses of winter wheat growth to winter warming in Gansu Province].

Based on the observation data of the air temperature at Tianshui and Xifeng in 1951-2005 and of the phenology of winter wheat at Tianshui and Xifeng in 1981-2003, the tendency of winter warming in past 50 years and the responses of winter wheat growth to climate warming in Gansu Province were analyzed. The results showed that the growth and development of winter wheat were seriously influenced by winter warming. In recent 20 years or more, the overwintering mortality of winter wheat dropped to <2% , overwintering days reduced by 7-8 days, whole growth period shorted by 8-10 days, and jointing-flowering period extended by 7 days, which would benefit the production of winter wheat and the utilization of climatic resource. However, the higher winter temperature and lesser precipitation also made the grain yield instable and the plant diseases and insect pests more frequent, resulting in more uncertain factors in winter wheat safe production.