Responses of Functional and Taxonomic Phytoplankton Diversity to Environmental Gradients in Subtropical and Tropical Reservoirs

Abstract

Understanding the influence of environmental conditions on biodiversity is a major task in ecology. We investigated how phytoplankton taxonomic (TD) and functional (FD) diversities vary with environmental factors in eight subtropical and tropical reservoirs. We hypothesized that i) environmental variables affect phytoplankton TD and FD; ii) FD provides better relationships to environmental changes than TD, and; iii) indices based on biomass are better related to the environment than those based on identities. The relationships between phytoplankton diversities and environmental drivers were assessed through generalized linear models. Our hypotheses were partly confirmed. TD and FD were, in fact, dependent on the environment, with higher values occurring in warmer, clearer, and more enriched systems, under lower zooplankton grazing pressure; but FD based on identities was not predicted better from environmental conditions than TD based on identities. As expected, indices based on biomass are better related to the environment than their counterpart based on identities.

Role of Rare Species on Phytoplankton Size–Abundance Relationships and Size Structure across Different Biogeographical Areas

“…Several studies have investigated the patterns and mechanisms of phytoplankton diversity using different indices [77,78] and in terms of functional diversity compared to taxonomic diversity. Differences in functionality have been distinguished from morphological traits [79,80]; the majority of the studies on phytoplankton functional diversity have been based on the presence or absence of identities in terms of species richness [81,82], and very few have been conducted on functional groups defined by body size and the basis of abundance-or biovolumebased functional diversity [83][84][85]. The South-Western Pacific Ocean and Indo-Pacific Ocean regions exhibited the highest similarity in terms of phytoplankton taxa composition and abundance, while the South-Western Atlantic Ocean region was the most dissimilar compared to the others.…”

Relationship between phytoplankton community structure and environmental factors in Yinchuan City water

“…The results indicated that planktonic plant diversity was largely positively correlated with dissolved oxygen, water temperature, and total nitrogen. Studies have shown that temperature is a primary ecological driver of planktonic plant diversity, with increasing temperatures affecting plant growth and reproduction, thereby promoting increased biological diversity by occupying different ecological niches [28]. The dissolved oxygen content in water affects the distribution and abundance of planktonic organisms, thereby influencing the overall community's taxonomic diversity.…”