Accurate analysis of spatiotemporal variations in algal biomass and their underlying causes is crucial for controlling algal blooms and enhancing aquatic ecological quality. The present study, spanning 2011 to 2020, was conducted across 10 sites in Lake Dianchi, where peak algal biomass levels occur from May to September, with higher concentrations in the lake’s northern zones compared to other areas. Employing Spearman’s correlation analysis, generalized additive models (GAMs), and random forest (RF) techniques, the relationships between algal biomass and water quality indicators were investigated. Spearman’s correlation analysis revealed a positive relationship between chlorophyll a (Chla) and total phosphorus (TP) across various spatial scales. RF analysis identified TP as the most influential factor on a lake-wide scale; while in localized RF models, organic pollution-related indicators (COD, COD_Mn, and BOD₅) and TP consistently emerged as the primary predictors of Chla at most sites. GAM results indicated spatially variable and nonlinear responses of algal biomass to predictors, reinforcing TP’s significance lake-wide and at many localized scales. This comprehensive analytical approach provides valuable insights into the role of water quality factors and nonlinear dynamics, thereby advancing our understanding of the relationships between algal biomass and environmental conditions. These findings are pivotal for the development of scientifically informed strategies for lake management and conservation.

The biomanipulation technique has been developed and implemented for decades, yielding favorable results in various lakes both domestically and globally. This technology uses fish to reduce algae biomass, giving a natural and environmentally friendly solution to improve water quality. The effectiveness of biomanipulation technology in large-scale artificial water canals, on the other hand, has been unclear. To address this, from 15 December 2019 to 30 April 2020, an in situ experimental study on the biomanipulation of periphytic algae was conducted in the Lushan section of the main canal of the Middle Route of the South-to-North Water Diversion Project (MSNWDP). The study aimed to verify the control effect of fish on periphytic algae. Various combinations of Megalobrama terminalis and Xenocypris davidi were fixed on the canal with a triangular cylindrical cage, and their feeding effects on periphytic algae were observed. The results showed that the density of periphytic algae at the bottom of the cages was substantially lower than before the experiment, with a 68.75% average reduction. We graded the food-filling results based on the amount of digestive tract content, which was represented using Arabic numerals ranging from 0 to 5. The study discovered that M. terminalis had the best adaptability to the environment, with full intestines primarily composed of periphytic algae and a food-filling degree between grades 4 and 5. X. davidi, on the other hand, had a food-filling degree of 0. Furthermore, the weight of each M. terminalis increased significantly following the experiment, whereas the weight of each X. davidi decreased to varying degrees. Additionally, the study highlights the importance of selecting the appropriate fish species for biomanipulation, as different species may have varying levels of effectiveness in controlling periphytic algae. Overall, this study provides valuable insights into the potential of biomanipulation technology in large-scale artificial water canals and other water conservancy projects.

World J Tradit Chin Med, Official publication of World Journal of Traditional Chinese Medicine Press

PDF file 218K, Figure S5. (A) 72 proteins significantly differed between cells treated with KX-01 and control cells in RMUG-S cells. (B) 60 proteins significantly differed between cells treated with KX-01 and control cells in RMUG-L cells. (C) Western blot results showing cyclin B1 and CDC2 expression in RMUG-S and RMUG-L cells treated with 100nM or 200nM KX-01 for 24 hours. Bars represent means with standard errors. *p<0.05 compared with the control group. (D, E) Lamin B1 immunofluorescence staining (green) in RMUG-S and RMUG-L cells treated with 100 nM KX-01 for 24 hours and incubated with anti-lamin B1 antibody. Nuclei (blue) were stained with DAPI

PDF file 190K, Figure S6. (A, B) Glu-tubulin immunofluorescence staining (green) in RMUG-S and RMUG-L cells treated with 100 nM KX-01 for 24 hours and incubated with anti-glu-tubulin antibody followed by Alexa Fluor 488-conjugated anti-rabbit antibody. Nuclei (blue) were stained with DAPI. Left: tubulin stain only; Middle: DAPI nuclear stain; Right: tubulin and DAPI nuclear stain

Colonial volvocine algae (CVA), which range from four-celled to complex multicellular forms, are vital for understanding life evolution. This study aims to quantify the impacts of human land-use intensity on CVA communities across the Yangtze River Basin and explore how anthropogenic changes drive CVA ecological niche dynamics and assembly processes. Findings reveal that increased land-use intensity reduces forest cover, expands construction land, and elevates water nutrients, thereby worsening water quality. This environmental shift provides elevated nutrient resources for CVA, expanding their ecological niche width ( P < 0.01) and reducing competition (interspecific niche overlap network simplified), particularly benefiting larger-bodied colonial volvocine algae, such as Volvox carteri . However, morphological similarity among CVA species, such as Eudorina elegans and Colemanosphaera charkowiensis , results in niche overlap and intensified competition. Notably, CVA complexity does not substantially correlate with distribution patterns, indicating that factors other than basic morphological characteristics play a role in determining their ecological success. On the other hand, CVA community assembly in the Yangtze River Basin, analogous to eukaryote and prokaryote, was initially dominated by stochastic processes at low land-use intensities (β-NTI mostly ranges between −2 and 2). Increased intensity enhances environmental filtering, leading to community homogenization (β-diversity decreased from 0.9119 ± 0.2236 under low HAILS to 0.8974 ± 0.2332 under high HAILS, P < 0.001), which diminishes biodiversity, alters ecological processes, and reduces ecological stability, ultimately affecting ecosystem integrity and sustainability. This study highlights that land-use intensification-induced environmental changes restructure CVA community dynamics, niche relationships, and assembly processes. These findings provide critical insights for sustainable land management and freshwater biodiversity conservation. IMPORTANCE: This study underscores the importance of colonial volvocine algae as a model for understanding how human land-use intensification reshapes freshwater biodiversity, ecological niches, and community assembly, offering key insights for sustainable ecosystem management.