Growing status rather than temperature was more associated with phytoplankton stoichiometry

Area of Science:

• Aquatic Ecology
• Limnology
• Phytoplankton Ecology

Background:

• Phytoplankton growth is controlled by temperature and nutrient availability.
• Global warming and eutrophication necessitate understanding phytoplankton responses to these factors.

Purpose of the Study:

• Investigate interactive effects of temperature and nutrient availability (N/P ratios) on phytoplankton stoichiometry and community assembly.
• Assess how temperature and nutrient limitation influence phytoplankton elemental composition and homeostasis.
• Predict shifts in phytoplankton communities under future climate and eutrophication scenarios.

Main Methods:

• Experimental manipulation of temperature (15°C vs 25°C) and nitrogen/phosphorus (N/P) ratios in subtropical reservoir communities.
• Analysis of phytoplankton biomass, cellular stoichiometry (elemental content), alkaline phosphatase activity, and community composition.
• Evaluation of growth phase and thermal regime effects on stoichiometric homeostasis.

Main Results:

• Temperature and nutrient interactions significantly shape phytoplankton cellular stoichiometry and growth dynamics.
• Biomass increased with warming and nutrient enrichment, particularly under phosphorus-replete conditions.
• Phytoplankton homeostasis was growth-phase dependent, with distinct responses at different temperatures; Cyanobacteria dominated warmer conditions.

Conclusions:

• Temperature indirectly affects phytoplankton stoichiometry by altering growth rates, metabolism, nutrient demand, and resource allocation.
• Warming and nutrient enrichment can shift nutrient limitation thresholds and influence homeostasis strategies.
• Findings provide crucial data for predicting phytoplankton bloom dynamics in response to climate change and eutrophication.