Empirical analysis of the influence mechanism of vegetation and environment on negative air ion in warm temperate forest ecosystems.

Air pollution presents a significant threat to public health in megacities globally. Negative air ions (NAI), often referred to as "air vitamins," are recognized for their effectiveness in alleviating the harmful effects of air pollution. Forest ecosystems serve as natural generators of NAI, with both vegetation and environmental conditions playing critical roles in the formation and persistence of NAI.

The source of volatile organic compounds pollution and its effect on ozone in high-altitude areas.

Volatile organic compounds (VOCs) are crucial precursors in the formation of ozone (O). The sources of pollution are complex and significantly impact O generation. Long-term exposure to high-concentration O environments causes serious damage to organisms.

[Responses of soil microbial community structure to litter inputs.].

Litter decomposition is one of the most important ecosystem processes, which plays a critical role in regu-lating nutrient cycling and energy flow in terrestrial ecosystems. The influence of litter inputs on soil microbial community is helpful for understanding the relationship between soil microbial diversity and terrestrial ecosystem function. We conducted a meta-analysis to examine how litter inputs affect soil microbial activity (fungi, bacteria, actinomycetes) and microbial biomass carbon, nitrogen in China.

[Soil enzyme activities and their stoichiometry at different altitudes in Helan Mountains, Northwest China].

Understanding altitudinal variation characteristics and driving mechanism of soil enzyme activities and their stoichiometry is of great significance for studying nutrient cycling in fragile mountain forest ecosystems. In this study, we collected soil samples from different altitudes (1380-2438 m) in Helan Mountains to analyze the altitudinal changes in soil physicochemical properties, soil enzyme activities and their stoichiometry and its influencing factors. The results showed that the activities of β-glucosidase (βG) and β-N-acetylglucosaminidase (NAG) and the enzyme activities ratios of soil C/N and soil C/P firstly increased and then decreased with increasing altitude, which all peaked at 2139 m.

[Changes of the concentrations and stoichiometry of carbon, nitrogen and phosphorus in soil aggregates along different altitudes of Helan Mountains, Northwest China.].

Exploring the distribution patterns of soil nutrients in aggregates of forests along different altitudes in arid and semi-arid areas can provide a theoretical basis for understanding nutrient cycling in vulnerable mountain ecosystems. In this study, we analyzed the distribution and stability of aggregates in the 0-20 cm soil layer along different altitudes (1380-2438 m) of Helan Mountains and measured the storage and stoichiometric characteristics of organic carbon, total nitrogen, and total phosphorus in soil aggregates. Results showed that the main soil aggregates of Helan Mountains changed from micro-aggregates (0.