Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake

Area of Science:

• Environmental Science
• Ecology
• Climate Change Research

Background:

• Floating macrophytes, such as water hyacinth (Eichhornia crassipes), are invasive species in tropical aquatic ecosystems.
• These plants can influence gas exchange between water bodies and the atmosphere.
• Greenhouse gas (GHG) emissions from these systems are often underrepresented in global datasets.

Purpose of the Study:

• To investigate carbon (C) turnover and GHG emissions in a South Indian water-harvesting lake.
• To analyze the effect of floating macrophytes, specifically water hyacinths, on these emissions.
• To assess the role of invasive macrophytes in regional carbon budgets.

Main Methods:

• Field measurements of carbon dioxide (CO2) and methane (CH4) emissions using gas chambers.
• Measurement of water C mineralization rates.
• Analysis of physicochemical variables in open water and within water hyacinth stands.

Main Results:

• CO2 and CH4 emissions were reduced by 57% in areas covered by water hyacinths compared to open water.
• No significant difference was observed in C mineralization rates between vegetated and open water areas.
• Floating macrophytes significantly alter GHG emission profiles in aquatic systems.

Conclusions:

• Invasive water hyacinths and other floating macrophytes can substantially modify GHG emissions from aquatic environments.
• The impact of these plants on emissions is crucial for understanding regional carbon budgets.
• Further research is needed to fully incorporate these dynamics into global climate models.