Plant Functional Group Diversity as a Mechanism for Invasion Resistance

A commonly cited mechanism for invasion resistance is more complete resource use by diverse plant assemblages with maximum niche complementarity. We investigated the invasion resistance of several plant functional groups against the nonindigenous forb Spotted knapweed (Centaurea maculosa). The study consisted of a factorial combination of seven functional group removals (groups singularly or in combination) and two C. maculosa treatments (addition vs. no addition) applied in a randomized complete block design replicated four times at each of two sites