Environmental factors indirectly reduce phytoplankton community stability via functional diversity

Abstract

The biodiversity-stability relationship is a fundamental subject of ecological research. Considerable evidence demonstrates that biodiversity can either increase or decrease stability. Most relevant research mainly focuses on grassland and forest ecosystems. The biodiversity-stability relationship in aquatic ecosystems and the underlying mechanisms remain poorly understood. To fill the gap, we conducted a year-long study on the phytoplankton of reservoir ecosystems in the Xiangxi Bay of Three Gorges Reservoir (TGR) to test the following hypotheses: (H1) phytoplankton species richness and functional diversity directly reduce phytoplankton community stability in reservoir ecosystems; (H2) nutrient enrichment and water temperature increasing directly reduce phytoplankton community stability; and (H3) nutrients and water temperature indirectly reduce phytoplankton community stability via biodiversity. The structural equation model (SEM) found that functional diversity (community-weighted means of traits and functional divergence) had significant negative correlations with phytoplankton community stability (p < 0.05), while the species diversity had no significant correlation with phytoplankton community stability (p > 0.05). This finding partially supported the hypothesis H1, which suggested that the functional diversity had a closer tie with stability than the species diversity. SEM did not find any direct effect of environmental factors on phytoplankton community stability, which rejected our hypothesis H2. Instead, SEM found that water temperature and phosphate decreased phytoplankton community stability by increasing the first principal component of the community-weighted means of traits (CWM_PC1), which supported hypothesis H3. Further analysis showed that the increased water temperature and phosphate concentration can promote “r-strategists” species (larger CWM_PC1), which are less resistant to environmental disturbances, therefore decreasing the phytoplankton community stability. Our study highlights the importance of functional diversity in maintaining the relationship between biodiversity and stability in the phytoplankton community, which may provide a mechanistic understanding of the biodiversity-stability relationships in aquatic ecosystems.

How is copepod functional diversity shaped by 2015-2016 El Niño and seasonal water masses in a coastal ecosystem of Southwest Atlantic?

“…Maintaining balance and compensating for the impacts caused by disturbances, such as El Niño events, are of utmost importance for a marine protected area like Arvoredo MPA. The ability of planktonic populations to exhibit compensatory Copepod diversity in the Southwest Atlantic Menezes et al responses contributes to the resilience and stability of the ecosystem in the face of environmental changes (Zhang et al, 2022). By compensating for shifts in copepod species composition and functional diversity, these mechanisms help to maintain essential ecological functions and processes within the ecosystem.…”

Study on the Effect and Enhancement of Near-Natural Integrated Plant Positioning Configuration in the Hilly Gully Region, China

“…This approach provided a more intuitive representation of the stability of vegetation communities. By eliminating subjective human influence, this approach more accurately represented the stability of vegetation communities, aligning with the principles of ecological development [49].…”

Aggregation of monitoring datasets for functional diversity estimation

“…The declining diversity in the Marsdiep basin is likely explained by the dominance of Phaeocystis globosa spring and summer blooms (Cadeé and Hegeman, 2002;Niu et al, 2015). The inter-annual variability among stations also suggests a blooming limitation by nutrients or light, which triggered the prevalence of fast-growing nutrient opportunist, C-strategist or R-strategist phytoplankton species such as Micromonas pusila, Thalassiosira sp., Chaetoceros sp., particularly in the second half of last decade (Smayda and Reynolds, 2001;Reynolds, 2006;Zhang et al, 2022).…”