Related Experiment Video
Updated: May 10, 2026
07:26
Visualizing Methane-Cycling Microbial Dynamics in Coastal Wetlands
Published on: January 31, 2025
A microbial link between elevated CO2 and methane emissions that is plant species-specific
1Department of Horticulture, Cornell University, 134A Plant Sciences Building, Ithaca, NY, 14853, USA, jtk57@cornell.edu.
Microbial Ecology
|June 21, 2013
Summary
Elevated atmospheric carbon dioxide (CO2) increased methane emissions from woolgrass but not reed canary grass. Microbial communities shifted under CO2-responsive plants, despite no changes in methanogen or methanotroph populations.
Area of Science:
- Environmental Science
- Microbiology
- Plant Science
Background:
- Rising atmospheric carbon dioxide (CO2) impacts plant physiology, but its effects on root dynamics and soil microbial mediation of greenhouse gas emissions in wetlands are poorly understood.
- Wetland plant species, including invasive Phalaris arundinacea (reed canary grass) and native Scirpus cyperinus (woolgrass), play crucial roles in soil microbial processes.
Purpose of the Study:
- To investigate how elevated atmospheric CO2 affects methane emissions and soil microbial communities in two co-occurring wetland plant species.
- To test the hypothesis that elevated CO2 increases archaeal methanogen and bacterial methanotroph populations via stimulated plant biomass.
Main Methods:
- Controlled greenhouse experiment exposing S. cyperinus and P. arundinacea to ambient (380 ppm) and elevated (700 ppm) CO2 levels.
- Measurement of methane emissions from plant shoots.
- Analysis of soil microbial community composition using phospholipid fatty acid (PLFA) profiling.
- Stable isotope (δ13C) tracing to assess plant carbon contribution to microbial lipids.
Main Results:
- Methane emissions from S. cyperinus shoots increased 1.5-fold under elevated CO2, while P. arundinacea showed no change.
- Elevated CO2 shifted the PLFA-based microbial community composition under S. cyperinus, but not under P. arundinacea.
- No significant impact of elevated CO2 on methanogen or methanotroph abundance was detected, contrary to the initial hypothesis.
- Plant-derived carbon contributed more to microbial PLFA in S. cyperinus than in P. arundinacea.
Conclusions:
- The CO2-methane link in S. cyperinus can occur independently of changes in methanogen and methanotroph abundance.
- Elevated CO2 induces shifts in bacterial and fungal community profiles within the rhizosphere of CO2-responsive wetland plants.
- Plant-specific responses to elevated CO2 influence soil microbial communities and greenhouse gas dynamics in wetlands.
Related Concept Videos
01:27Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
01:26Microbes and Methanogenesis
Methanogenesis is a critical microbial process in anaerobic ecosystems responsible for the biological production of methane, a potent greenhouse gas and valuable biofuel. This metabolic pathway is primarily facilitated by methanogenic archaea, which thrive in anoxic environments such as wetlands, sediments, and animal gastrointestinal tracts. The absence of oxygen in these habitats prevents aerobic respiration, thereby favoring alternative biochemical pathways for organic matter degradation.In...
01:25Microbial Interactions: Mutualism
Mutualism is a symbiotic interaction in which all participating organisms benefit. These relationships can be obligate or facultative and are fundamental to ecosystem functions across diverse biological systems.Plant–Fungi MutualismOne well-known example is the association between plant roots and mycorrhizal fungi, such as Rhizophagus species. The fungal hyphae penetrate the root hairs and the epidermis, forming an extensive hyphal network that establishes a symbiotic association. Through this...
01:09Microbe-Plant Interactions
Microbe-plant interactions represent a dynamic spectrum of associations shaped by intricate chemical signaling. These interactions can be neutral, beneficial, or detrimental, and profoundly influence plant physiology, growth, and ecosystem function. The plant microbiome, comprising bacteria, fungi, archaea, protists, and viruses, plays a pivotal role in mediating these effects through surface colonization, internal colonization, or systemic symbiosis.Mutualistic associations, particularly with...
01:28Carbon-dioxide Fixation
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
01:27C4 Pathway and CAM
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
C4 Pathway
The C4 pathway is used by plants such as...