Niche overlap and species co-occurrence patterns in carabid communities of the northern Chinese steppes

Microplastic-contamination can reshape plant community by affecting soil properties

Microplastics, as emerging contaminants, pose a serious threat to terrestrial ecosystems, yet their impact on plant communities remains largely unexplored. This study utilized the soil seed bank to establish naturally germinated plant communities and investigated the effects of polyethylene (PE) and polypropylene (PP) on community characteristics. Additionally, the study aimed to elucidate the mechanisms by which variations in soil properties influenced plant community. The results indicated that microplastics led to a significant increase in soil available potassium (AK), likely due to alterations in soil microorganism proliferation. Furthermore, microplastics caused a decrease in soil salinity, total phosphorus (TP), and ammonium nitrogen (AN). Additionally, plant community composition shifted, resulting in reduced stability and niche breadth of dominant species. Microplastics also impacted niche overlap and interspecific associations among dominant species, possibly due to the reduced accessibility of resources for dominant species. Salinity, AK, and TP were identified as major drivers of changes in niche breadth, niche overlap, and community stability, with TP exerting the strongest impact on plant community composition. These findings provide valuable insights for the restoration of plant communities in coastal saline-alkali wetland contaminated by microplastics.

Nitrogen and water addition alters species diversity and interspecific relationship in a desert grassland

Water and nitrogen (N) often affect plant species diversity and interspecific relationship among plant populations in global terrestrial ecosystems. However, the effects of water and N addition on plant diversity and interspecific relationship remain poorly understood. In the study, we designed a three-year field experiment in a desert grassland to assess the effect of increased water (natural +50 %) and N addition (10 g·N·m-2·a-1) on plant diversity and interspecific relationship. Our results showed that the alpha diversity was significantly changed under increased water (W), N addition (N), and water plus N addition (WN). The species richness was decreased significantly on year scales (10 %-27 %), whereas the Pielou index first increased and then decreased over three years and was significantly affected by the interaction between increased water and N addition. The total and pairwise beta diversity were significantly increased by N addition, the community was mainly caused by the turnover component after N addition, especially in 2019 and 2020 (16.6 % and 9 %, respectively). There were significant negative associations among overall populations and dominant populations under N addition, especially Stipa bungeana and Gypsophila davurica, Gypsophila davurica and Oxytropis acemose, Artemisia dalai-lamae, and Haplophyllum dauricum. Our findings suggested that plant community structure and composition changes may be due to competition for resources among dominant populations and the turnover component under increased water and N addition, which should be considered in ecosystem management.

Imitation or Innovation? Research on the Path Selection of Enterprise Performance Improvement from the Perspective of Organizational Ecology

This paper analyzes how imitation and innovation strategies of high-tech small and medium-sized enterprises (SMEs) impact their sustainable performances and also the whole business ecosystem with the NK-model that mimics the fitness landscape and simulates enterprises’ choice of technological strategy in response to causal ambiguity and environmental complexity. Our study yielded three findings: (1) When the imitation barriers are low, the imitation strategy of high-tech SMEs has a better effect on the performance improvement in the early stage of the operation than the innovation strategy. In the long run, high-tech SMEs exhibit innovation, which plays a greater and more lasting role in enhancing sustainable performance. On the contrary, it is always difficult for imitators to realize significant performance improvement, (2) In a simple environment, imitation strategy plays a more effective role in improving high-tech SMEs’ performance, whereas in a complex environment, innovation strategy is more conducive to discovering opportunities, and it issues from high levels of competition, and (3) more importantly, the simulation finds that the innovation of high-tech SMEs contributes more to the performance of the business ecosystem as a whole. The introduction of the NK-model simulation method in the research of technological strategies and the new scope of looking at the strategies in the business ecosystem provide new research venues for the literature.