biotic facilitation

any interaction where the action of one species has a beneficial effect on another. This includes mutualistic interactions where both the facilitated and facilitator benefit (+/+), those which are commensal (+/0) when the effects of the facilitated on the facilitator are neutral as well as those which are antagonistic (+/?) when the facilitated negatively impact the facilitator. Note that this concept partially overlaps with that of mutualism, ecological engineering and niche construction