nontrophic

Nontrophic is an ecological term used to describe interactions and processes that do not involve feeding relationships between organisms. It contrasts with trophic interactions, which involve consumption and energy transfer, such as predation, herbivory, or decomposition. The nontrophic perspective focuses on how species influence one another through non-feeding means.

Non-trophic interactions can be direct or indirect and may have positive or negative effects on individuals or communities. They include changes in habitat structure, microclimate, or resource availability that occur without consumption, as well as chemical signaling and interference that affect growth, reproduction, or survival. Examples encompass habitat modification by ecosystem engineers (such as beavers or corals), shading or litter effects that alter soil moisture and temperature, and chemical interactions like allelopathy among plants. Facilitation and nurse-plant effects, where one species improves conditions for others without feeding, are also included.

In research, non-trophic interactions are important because they can modify or cascade through trophic networks, altering energy flow and community dynamics in ways not captured by food-web analyses alone. The concept helps explain variation in species distributions, abundances, and responses to disturbance that cannot be attributed solely to feeding relationships. Terminology varies; many authors use non-trophic interactions, while others employ nontrophic as a shorthand. Both terms describe the same broader idea: ecological effects that arise independently of consumption and energy transfer.