Practice question

Interference competition involves direct actions that reduce another individual's access to resources or habitat. Aggression, territorial exclusion, overgrowth, and allelopathic chemicals are examples; exploitative competition is indirect because competitors interact only through depletion of a shared resource. Ecological interaction labels describe causal pathways rather than merely similar outcomes. Two organisms can decline together because they consume the same limiting resource, physically exclude one another, or are connected through a common predator. Experiments distinguish these cases by manipulating resources, access, or enemy abundance. Correct classification matters because coexistence mechanisms also differ: resource partitioning reduces exploitation, spatial separation may reduce interference, and enemy specialization can weaken apparent competition. In this context, the keyed term, Directly among individuals, identifies the relevant mechanism or quantitative relationship and links the observed pattern to its underlying ecological cause. The distinction is testable by measuring changes in organisms, resources, or process rates through time rather than relying on the label alone.