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Bumblebees play an important role in maintaining the balance of natural and agricultural ecosystems, and the characteristic gut microbiota of bumblebees exhibit significant mutualistic functions. China has the highest diversity of bumblebees; however, gut microbiota of Chinese bumblebees have mostly been investigated through culture‐independent studies. Here, we analyzed the gut communities of bumblebees from Sichuan, Yunnan, and Shaanxi provinces in China through 16S ribosomal RNA amplicon sequencing and bacterial isolation. It revealed that the bumblebees examined in this study harbored two gut enterotypes as previously reported: one is dominated by Gilliamella and Snodgrassella, and the other is distinguished by prevalent environmental species. The gut compositions obviously varied among different individual bees. We then isolated 325 bacterial strains and the comparative genomic analysis of Gilliamella strains revealed that galactose and pectin digestion pathways were conserved in strains from bumblebees, while genes for the utilization of arabinose, mannose, xylose, and rhamnose were mostly lost. Only two strains from the Chinese bumblebees possess the multidrug‐resistant gene emrB, which is phylogenetically closely related to that from the symbionts of soil entomopathogenic nematode. In contrast, tetracycline‐resistant genes were uniquely present in three strains from the USA. Our results illustrate the prevalence of strain‐level variations in the metabolic potentials and the distributions of antibiotic‐resistant genes in Chinese bumblebee gut bacteria. [ABSTRACT FROM AUTHOR]

The climate change on the impact of grain production potential has significant regional differences. Researchers have studied the grain production potential of various crop combinations or focused on single crop types in a typical area; however, the regional differences of the climate change on the impact of grain production potential were neglected. This paper used the Global Agro-Ecological Zone (GAEZ 3.0) model to focus on the analysis what is the climate change on the impact of grain production potential in different geographic units (Northern Shaanxi Plateau, Guanzhong Basin, Qinba Mountain) in Shaanxi Province of China. The case showed that the precipitation (Pre) what made changes of grain production potential was the most important factor in different geographic units. The increase of Pre had a positive impact on the grain production potential in Northern Shaanxi Plateau and Guanzhong Basin. However, in Qinba Mountain, due to excessive Pre in the Qinba Mountains, the decrease of Pre had a certain positive impact on the grain production potential. The precipitation was less in the Northern Shaanxi Plateau; therefore, its major factors leading to changes of crop production were precipitation and rainfall days. The increase of the mean maximum temperature (Tmx) and the mean minimum temperature (Tmn) had a positive impact of the grain production potential in the Northern Shaanxi Plateau and Guanzhong Basin. The higher temperature had a negative impact on the grain production potential. In Qinba Mountain, the increase of the temperature has a certain negative impact on the grain production potential. It has more influence of Tmx in the Guanzhong Basin and Qinba Mountain rather than that in the Northern Shaanxi Plateau. Generally speaking, the major climatic factors leading grain production potential were Pre and Tmx in Guanzhong Basin and Qinba Mountain. [ABSTRACT FROM AUTHOR]

Transitioning to a more optimal land use morphology contributes to the sustainable use of land resources. Land use transition refers to the land use morphology changes from one to another, which should be portrayed from both correlated spatial morphology and functional morphology. However, the current studies have the problem of separating the land use spatial and functional transition, which causes the degree and the mechanism of the correlation between them to be still unclear. Taking Shaanxi Province as a case study, based on the land use data and socio-economic data, this study used the sustainability evaluation model of land use spatial transition, the multifunctional coupling coordination model of land use, and the grey correlation model to quantify the correlation between the land use spatial and functional transition. The results showed that the correlation between land use spatial and functional transition was high in Shaanxi Province during 1980–2018, and the change in correlation had an interdecadal cycle, which was embodied in the correlation reached extremely high when a positive land use functional transition occurred. The correlation between land use spatial transition and the change of land use ecological function was extremely high, and the correlation with both production and living function was high. The high correlation between the land use spatial and functional transition was essentially a strong driving force, bound by the vulnerability of land ecology and strengthened by the rapidly changing demands of production and living. It can drive the land use spatial morphology transition to another that can give full play to the multifunctionality of land use. The study established a quantitative analysis framework for the correlation between land use spatial and functional transition, which provided quantitative evidence for the regional land use transition theory and contributed to formulating rational land use policies to achieve regional sustainable development. • Proposed a new theory for identifying land use spatial transitions. • Quantitatively explored the relationship between land use spatial and functional transition. • Elucidated correlation mechanism between land use spatial and functional transition [ABSTRACT FROM AUTHOR]

Abstract: Changes in indices of precipitation extremes were analyzed on the basis of daily precipitation observational data at 19 surface meteorological stations over Shaanxi Province during 1960–2011, originating from the China Meteorological Administration. Ten indices of extreme precipitation were studied. Maximum 1-day precipitation, very wet day precipitation, extremely wet day precipitation, simple daily intensity index, and consecutive dry days in the study area during 1960–2011 exhibit non-significant increasing trends. Decreasing trends are found for maximum 5-day precipitation, wet day precipitation, number of heavy precipitation days, number of very heavy precipitation days, and consecutive wet days, all statistically non-significant. For number of heavy precipitation days and consecutive wet days, stations in the study region have consistently negative trends. The variation trends for the other extreme precipitation indices have regional differences, and the change patterns of these indices are not spatially clustered. Very wet day precipitation experiences abrupt decreases in 1977 and 1985, while a significant abrupt increase change for extremely wet day precipitation is detected in 1983. There are multiple cycles in the changes for the very wet day precipitation and extremely wet day precipitation over Shaanxi Province during 1960–2011, showing variations of time and frequency. Except for consecutive dry days, the other extreme precipitation indices have high correlations with annual total precipitation. The elevation is positively correlated with consecutive dry days. There are negative correlations between the other extreme precipitation indices and elevation. [Copyright &y& Elsevier]