PARENT SESSION
Oral Session #29: Invasions: Predicting and understanding invasibility. Presiding: K. Kearns.
Tuesday, August 7, 2001. 1:00 PM to 4:45 PM. Madison Ballroom C.
The role of resource availability in plant community invasibility.
Dukes, Jeffrey1, Hooper, David2, Verville, Julia1, 1 2
ABSTRACT- The invasibility of many plant communities is limited by resource availability, which may be affected by community composition. We examined whether resource availability explains relationships between invasibility and the composition of serpentine grassland communities. We also explored whether functional traits of invaders determine which resources limit invasion and how the invader impacts resource availability. We introduced "invaders" from two functional groups (early-season and late-season annuals) into communities that differ in functional composition (which functional groups are present) and diversity (how many functional groups are present). Functional composition affected the success of early-season annual invaders, but functional diversity did not. In contrast, functional diversity strongly affected the success of late-season annual invaders. Resource (nitrogen, phosphorus, water, light) availability helped to explain the relationship between community composition and invasibility.
KEY WORDS: biological invasions, serpentine grassland, resource availability, invasibility