Arthropod prey type drives decomposition rates and microbial community processes

Area of Science:

• Ecology
• Microbiology
• Biogeochemistry

Background:

• Microbial communities drive ecosystem nutrient cycling through decomposition.
• Arthropod detritus is an understudied nutrient source compared to leaf litter.
• Carnivorous pitcher plants offer model systems for studying decomposition dynamics.

Purpose of the Study:

• To investigate how different arthropod prey types influence microbial decomposition and community function in *Sarracenia purpurea* pitcher plants.
• To determine if prey characteristics, such as exoskeleton content, affect decomposition rates and microbial activity.
• To link prey type to microbial community composition and hydrolytic enzyme activity.

Main Methods:

• Sterile mesh bags containing different sterile arthropod prey (ants, beetles, flies) were incubated in pitcher plants for 7 weeks.
• Decomposition rates were measured by mass loss of prey.
• Microbial community composition was analyzed using 16S rRNA gene metabarcoding.
• Microbial function was assessed via hydrolytic enzyme activity (protease) and carbon substrate use.
• Pitcher fluid pH was measured.

Main Results:

• Prey with higher exoskeleton content (ants, beetles) exhibited lower mass loss compared to flies.
• Fly prey, with lower exoskeleton content, showed the highest protease activity.
• Ant prey resulted in the lowest pitcher fluid pH.
• Higher bacterial amplicon sequence variant (ASV) richness in ant and beetle treatments correlated with lower mass loss.

Conclusions:

• Arthropod detritus composition significantly influences the rate of decomposition and microbial community function in pitcher plants.
• Prey type affects microbial enzyme activity, community structure, and pitcher fluid chemistry.
• Understanding these substrate-driven microbial responses is crucial for comprehending nutrient cycling in detrital-based ecosystems.