Pesticide application is essential for stabilizing agricultural production. However, the effects of increasing pesticide diversity on soil microbial functions remain unclear, particularly under varying nitrogen (N) fertilizer management practices. In this study, we investigated the stochasticity of soil microbes and multitrophic networks through amplicon sequencing, assessed soil community functions related to carbon (C), N, phosphorus (P), and sulfur (S) cycling, and characterized the dominant bacterial life history strategies via metagenomics along a gradient of increasing pesticide diversity under two N addition levels. Our findings show that higher pesticide diversity enriches the abundance of bacterial specialists and opportunists capable of degrading or resisting pesticides, reducing the proportion of bacterial generalists in the absence of N addition. These shifts can complicate multitrophic microbial networks. Under increased pesticide diversity, selective pressure may drive bacteria to streamline their average genome size to conserve energy while enhancing C, N, P, and S metabolic capacities, thus accelerating soil nutrient loss. In comparison, N addition was found to reduce bacterial niche differentiation at higher pesticide diversity, mitigating the impacts of network complexity and functional traits associated with pesticide diversity, ultimately alleviating soil nutrient loss. Our results reveal the contrasting impacts of pesticide diversity on microbial functions under different N input scenarios and emphasize that strategic N fertilizer management can mitigate the ecological effects of pesticide use in agricultural systems.
The conservation of species diversity and improvement of forest structure are essential roles of the Natural Reserve Policy and the Natural Forest Protection Program (NFPP) in China. However, the long-term effects of NFPP are still not well-defined, and a natural reserve (Liangshui) and surrounding region were surveyed as a proxy of NFPP for approaching the protection effects. Our results showed that long-term conservation significantly altered the dominant species in the herb layer (80% of species), followed by shrub (58%) and tree layers (50%); there was a 1.6-8.0-fold increase in abundance in Corylus shrubs, Acer trees and Carex grass, but a 1.3–10.0-fold abundance decrease in larch trees, Athyrium herbs and Lonicera shrubs. In contrast, tree species diversity and distribution evenness increased by 31% and 23.4% in the reserve, respectively. Forest protection in the reserve also led to the forest structural alteration with the observation of larger-sized trees and shorter herbs, but relatively sparse forests (smaller tree density). Structural equation modeling manifested that the reserve directly altered forest structure, at a coefficient of 0.854, nearly two-fold higher than its impact on diversity (0.459) and dominant species (−0.445). The most affected parameters were plant size (trees and herbs) and tree density related to forest structure, tree diversity, herb richness and evenness for diversity traits, and Oxalidaceae and Rosaceae for dominant species. This study provides basic data that can be used to evaluate the impact of the nature reserve in NE China, and these findings can be used to guide the implementation of NFPP in the long-term in the future.
11 June 2025 in Proceedings Of The Royal Society B-Biological Sciences
Artificial light at night (ALAN) can influence plant growth, defence, interactions with herbivores and invasion by exotic plants. However, studies assessing the interactive effects of ALAN, nutrient enrichment and herbivory on invasive and native plant species remain limited. We conducted a greenhouse experiment to investigate the interactive effects of ALAN (no-ALAN versus ALAN), nutrient enrichment (low versus high) and herbivory by a generalist Spodoptera litura (without versus with) on the growth, root allocation and defence of six congeneric pairs of invasive and native plant species. Nutrient enrichment increased total biomass more in native plants than in invasive plants. ALAN enhanced total biomass in both groups of plants without herbivory, but increased native plant biomass and decreased that of invasive plants under herbivory. ALAN reduced root mass fraction, especially under low-nutrient conditions without herbivory. Native plants exhibited greater tolerance to herbivory and higher net photosynthetic rates under ALAN compared to invasive species. Moreover, S. litura larvae grew faster on invasive plants but slower on native plants under ALAN. These findings suggest that ALAN may weaken the competitive advantage of invasive species by enhancing the defence mechanisms and physiological performance of native plants, potentially shifting competitive dynamics in favour of native flora.
Understanding the determinants of the availability and spatial fairness of street greenery is crucial for improving urban green spaces and addressing green justice concerns. While previous studies have mainly examined factors influencing street greenery from an aerial perspective, there has been limited investigation into determinants at eye level, which more closely aligns with people’s actual encounters with green spaces. To address this, the Green View Index (GVI) and Gini coefficient were used to assess the availability and spatial fairness of street greenery from a pedestrian’s perspective, using Baidu Street View (BSV) images across 49 subdistricts in Changchun City, China. A dataset of 33,786 BSV images from 1877 sites was compiled. Additionally, 21 explanatory factors were collected and divided into three groups: socioeconomic, biogeographic, and landscape patterns. The Boosted Regression Tree (BRT) method was employed to assess the relative influence and marginal effects of these factors on street greenery’s availability and spatial fairness. The results showed that street greenery’s availability and spatial fairness are predominantly influenced by landscape patterns. Specifically, the percentage of landscape and edge density emerged as the most significant factors, exhibiting a threshold effect on the availability and fairness of street greenery. Increasing the proportion and complexity of urban green spaces can efficiently enhance the availability and spatial fairness of street greenery. These findings lay a new foundation for urban green infrastructure management.