Heavy grazing reduces soil bacterial diversity by increasing soil pH in a semi-arid steppe.

Background: In a context of long-term highly intensive grazing in grassland ecosystems, a better understanding of how quickly belowground biodiversity responds to grazing is required, especially for soil microbial diversity. Methods: In this study, we conducted a grazing experiment which included the CK (no grazing with a fenced enclosure undisturbed by livestock), light and heavy grazing treatments in a desert steppe in Inner Mongolia, China. Microbial diversity and soil chemical properties (i.e., pH value, organic carbon, inorganic nitrogen (IN, NH4+-N and NO3--N), total carbon, nitrogen, phosphorus, and available phosphorus content) both in rhizosphere and non-rhizosphere soils were analyzed to explore the responses of microbial diversity to grazing intensity and the underlying mechanisms. Results: The results showed that heavy grazing only deceased bacterial diversity in the non-rhizosphere soil, but had no any significant effects on fungal diversity regardless of rhizosphere or non-rhizosphere soils. Bacterial diversity in the rhizosphere soil was higher than that of non-rhizosphere soil only in the heavy grazing treatment. Also, heavy grazing significantly increased soil pH value but deceased NH4+-N and available phosphorus in the non-rhizosphere soil. Spearman correlation analysis showed that soil pH value was significantly negatively correlated with the bacterial diversity in the non-rhizosphere soil. Combined, our results suggest that heavy grazing decreased soil bacterial diversity in the non-rhizosphere soil by increasing soil pH value, which may be due to the accumulation of dung and urine from livestock. Our results highlight that soil pH value may be the main factor driving soil microbial diversity in grazing ecosystems, and these results can provide scientific basis for grassland management and ecological restoration in arid and semi-arid area.

Effect of Emotion, Expectation, and Privacy on Purchase Intention in WeChat Health Product Consumption: The Mediating Role of Trust.

With the aging of the population and the upgrading of the consumption structure of national health demand in China, it has become a new trend for the public to actively seek health products and services on social networks. Based on the theory of reasoned behavior and the theory of expectancy confirmation, this study aims to analyze the cognitive factors and their effects on WeChat users' purchase intention in the process of health product consumption. Considering that safety is a key feature of health products that distinguishes them from other consumer products, the "satisfaction" concept in the expectancy confirmation model is replaced by "trust" in this study. Two hundred and two (202) valid samples were collected by a questionnaire survey to analyze their intentions to buy health products on WeChat. Theoretical models and corresponding research hypotheses were verified by structural equation modeling. The research results show that emotional price and emotional experience are positively correlated with trust and purchase intention. There is an obvious negative correlation between privacy invasion and trust. Expectation confirmation is positively associated with trust. Moreover, the intermediary test shows that trust has completely mediated between emotional price and purchase intention, and trust also has a full intermediary effect on expectation confirmation and purchase intention.