Plants living in close proximity commonly make demands on the same resources. Those that benefit from their neighbors are also likely to compete with them. Intercropping systems, such as mixtures of clovers and sycamore seedlings, rely on beneficial competition between plants. Evidence for beneficial interactions among plants, however, is relatively scarce but has increased notably within the last two decades. This article summarizes various ways in which plants may benefit others growing nearby.

Plants affect the microclimate around them enabling others to gain growth footholds. Soil modification by one species allows other species to thrive. Numerous studies have found that diverse plant communities form 'plant defense guilds' that lower herbivore loads among themselves. Plants living close together may aid each other in dispersing seeds and attracting pollinators. The article also considers the theoretical implications of beneficence in vegetation, especially as it may interact with competition in affecting community structure.

A.F. Hunter and L.W Aarssen, BioScience, 1/88, Vol. 38, #1; pp. 34-40