Degradation-driven vegetation-soil-microbe interactions alter microbial carbon use efficiency in Moso bamboo forests.

Microbial carbon utilization efficiency (CUE) is a crucial indicator for evaluating the efficiency of soil carbon sequestration and transformation, which is applied to quantify the proportion of soil carbon extracted by microbes for anabolism (growth) and catabolism (respiration). Previous studies have shown that the degradation of Moso bamboo forests (Phyllostachys edulis) destroyed the aboveground bamboo structure, reduced vegetation carbon storage, and weakened ecosystem carbon sequestration capacity. Interestingly, soil organic carbon stocks are gradually increasing. However, the mechanism by which degradation-induced changes in soil and vegetation characteristics affect microbial CUE and drive soil carbon sequestration remains unclear. Here we selected four stands with the same origin but different degradation years (intensive management, CK; 2 years' degradation, DM1; 6 years' degradation, DM2; and 10 years' degradation, DM3) based on the local management profiles. The principle of space-for-time substitution was used to investigate the changes in microbial CUE along a degradation time and to further identify the controlling biotic and abiotic factors. Our finding showed that microbial CUE increased by 12.27 %, 31.01 %, and 55.95 %, respectively, compared with CK; whereas microbial biomass turnover time decreased from 23.99 ± 1.11 to 17.16 ± 1.20 days. Promoting microbial growth was the main pathway to enhance microbial CUE. Massive inputs of vegetative carbon replenished soil carbon substrate content, and altered microbial communities and life history strategy, which in turn promoted microbial growth and increased microbial CUE. These findings provide theoretical support for the interactions between carbon dynamics and microbial physiology in degraded bamboo forests, and reinforce the importance of vegetation and microbial properties and soil carbon substrates in predicting microbial CUE.

Death Anxiety During COVID-19 and its Related Factors among Chinese Elderly People.

This study aimed at investigating death anxiety and its related factors in Chinese elderly people during COVID-19. This study totally interviewed 264 participants from four cities in different regions of China. Death anxiety scale (DAS), NEO-Five-Factor Inventory (Neo-FFI) and Brief COPE were scored on the basis of one-on-one interviews. Quarantine experience didn't make significant difference in death anxiety among the elderly; Elderly people with high death anxiety had higher scores of neuroticism, and were more likely to use a Behavior Disengagement coping strategy; Multiple linear regression analysis showed that neuroticism, openness and COVID impact predicted 44.6% of the variance in the death anxiety among elderly people. The results support both theories of vulnerability-stress model and terror management theory (TMT). In the post-epidemic era, we suggest to pay attention to the mental health status of elderly people with personality susceptibility to handling the stress of infection badly.