Xiaolong Du

As one of the most well-preserved areas in the vertical band spectrum of vegetation in central China and even in the northern hemisphere at the same latitude, the vegetation in Shennongjia Forest District is vital to global ecological balance. In order to fully understand the vegetation change in the study area, remotely sensed data since 1990, combined with the Sen-MK test, Geo detector, and LandTrendr algorithm, were used to analyze the vegetation distribution characteristics and change trends. The results showed that: (1) the overall NDVI in the study area displayed an upward trend. (2) Vegetation disturbance occurred frequently before 2000 and decreased significantly after 2000. The most severely disturbed year was 1991 when the disturbed area amounted to 4.0851 km², accounting for 16.76% of the total disturbed area. The analysis of the topographic environment reveals that most of the vegetation disturbances occur in areas with slopes of 15–25° and elevations of 1500–2000 m, which indicates that these areas have frequent human activity. (3) The explanatory power of different influences on vegetation changes varied, with altitude having the most significant effect and the superposition of two influences increasing the effect on vegetation change. Over the past 30 years, vegetation in the Shennongjia Forest District has shown a general trend of recovery, with natural forest protection initiatives playing a critical role in mitigating disturbance. This comprehensive study of vegetation changes in Shennongjia offers a valuable research paradigm for forest conservation and sustainable development in temperate forests at similar latitudes, providing significant insights into the protection and management of similar ecosystems.

The variation in egg and clutch mass in sympatric species at high altitudes is poorly understood, and the potential causes of variation are rarely investigated. This study aimed to describe the interspecific variation in avian egg and clutch mass among 22 sympatric bird species at an altitude of 3430 m. Our objective was to reduce potential confounding effects of biotic/abiotic factors and investigated hypotheses concerning allometry, clutch size, parental care, nest predation, and lifespan as possible correlates and explanations for the observed variation. Our findings indicated that both egg and clutch mass evolve with body mass across species. We found that egg mass variation was not explained by clutch size when controlling for allometric effects, which contrasts the “egg mass vs. clutch size trade-off” hypothesis. Additionally, we found that clutch mass was positively associated with parental care (reflected by development period) but negatively associated with predation rate. By substituting egg mass and clutch size into the models, we found that clutch size was significantly correlated with parental care, predation rate, and lifespan, while egg mass was only significantly associated with development period. Overall, these findings support life-history theories suggesting that reduced clutch size or mass is associated with a higher risk of predation, reduced parental care, but longer adult lifespan. Interestingly, our results indicate that clutch size has a greater influence on these factors compared to egg mass. This could be attributed to the fact that smaller clutch sizes result in a more notable decrease in energetic allocation, as they require a reduced effort in terms of offspring production, incubation, and feeding, as opposed to solely reducing egg size. These findings contribute to the growing evidence that life-history and ecological traits correlate with egg and clutch mass variation in sympatric species. However, further research is needed to explore the potential evolutionary causes underlying these patterns.

To reduce the indiscriminate use of pesticides and extend the postharvest shelf life of peach fruit (Prunus persica, cv. Baihua) from southeast China, mainly the microbial antagonism of indigenous yeasts was studied and applied in the construction of composite film. In this study, 14 yeast strains of 9 genera were screened out from the surface of peaches by isolation, purification, cultivation, and identification. Through an experimental analysis of the in vitro inhibition zone and the in vivo colonizing capacity, 1 × 10⁸ CFU mL⁻¹ of Candida oleophila sp-ELPY12B and Cryptococcus laurentii sp-ELPY15A proved most efficient against the major pathogens and were chosen as candidate fungicides. In combination with Na-alginate film (0.4% glycerin as the plasticizer and 0.1% Tween-80 as the emulsifier), the preservative effects of these composite-treated groups also showed the best antifungal effects, which significantly delayed the postharvest preservation period by about 6–7 d under an ambient temperature of 25 ± 3 °C and a relative humidity of 50–70%.

To reduce the indiscriminate use of pesticides and extend the postharvest shelf life of peach fruit (cv. Baihua) from southeast China, microbial antagonism of indigenous yeasts was mainly studied and applied in construction of composite film. After isolation, purification, cultivation and identification, a total of 14 yeast strains from 9 genera were screened out from the surface of peaches. By experimental analysis of in vitro inhibition zone and in vivo colonizing capacity, Candida oleophila sp-ELPY12B and Cryptococcus laurentii sp-ELPY15A, which have conservative structure of D1/D2 domain sequences and were considered as new species by phylogenetic analysis, were finally chosen as fungicides against the major pathogens. In combination of Na-alginate film (0.4 % glycerin as plasticizer and 0.1 % Tween-80 as emulsifier), the preservative effects of composite-treated groups (1 × 108 CFU mL−1 of Candida oleophila sp-ELPY12B and Cryptococcus laurentii sp-ELPY15A) showed best antifungal effects, which significantly delayed the postharvest preservation period about 6 - 7 d under ambient temperature of 25 ± 3°C and relative humidity of 50 - 70%.