A burrowing ecosystem engineer positively affects its microbial prey under stressful conditions

Area of Science:

• Ecology
• Microbiology
• Behavioral Ecology

Background:

• Ecosystem engineers are organisms that modify habitats, influencing other species.
• The net effect of an ecosystem engineer depends on direct interactions and environmental context.
• Predator-prey dynamics can be complex, influenced by habitat modification.

Purpose of the Study:

• To investigate the trophic and engineering impacts of the nematode Caenorhabditis remanei on its prey, Escherichia coli.
• To determine how environmental stress influences the interaction between C. remanei and E. coli.
• To test the hypothesis that nematodes positively impact prey by creating protective burrows under stress.

Main Methods:

• A laboratory system was used to isolate the effects of the nematode Caenorhabditis remanei on Escherichia coli.
• Environmental stress levels were manipulated to observe changes in species interactions.
• Colony plate counts were used to quantify E. coli populations.

Main Results:

• The net impact of C. remanei on E. coli shifted from neutral to positive under stressful conditions.
• Nematode burrowing behavior created physical habitat that protected E. coli.
• Larger E. coli populations survived due to predator-induced engineering.

Conclusions:

• Predator ecosystem engineering can have a positive impact on prey populations, even in simple two-species systems.
• Environmental stress can alter the outcome of predator-prey interactions, favoring prey through engineering.
• The physical modifications made by ecosystem engineers are crucial for understanding species interactions and community dynamics.