Ecosystem legacy of the introduced N2-fixing tree Robinia pseudoacacia in a coastal forest.

Habitat invasibility has been found to increase dramatically following the alteration of ecosystem properties by a nonnative species. Robinia pseudoacacia, black locust, is a nitrogen-fixing, clonal tree species that aggressively invades open habitats and expands outside of plantations worldwide. Robinia pseudoacacia stands in Cape Cod National Seashore were particularly susceptible to a hurricane in 1991 that caused widespread blowdown and a dramatic reduction in Robinia in some stands.

Effect of recurrent selfing on inbreeding depression and mating system evolution in an autopolyploid plant.

Genome duplication resulting in polyploidy can have significant consequences for the evolution of mating systems. Most theory predicts that self-fertilization will be selectively favored in polyploids; however, many autopolyploids are outcrossing or mixed-mating. Here, we examine the hypothesis that the evolution of selfing is restricted in autopolyploids because the genetic cost of selfing (i.

Floral morphology mediates temporal variation in the mating system of a self-compatible plant.

The mating system of self-compatible plants may fluctuate between years in response to ecological factors that cause variation in the deposition of self pollen vs. outcross pollen on stigmas. Such temporal variation may have significant ecological and evolutionary consequences, but it has rarely been studied, and the mechanisms that mediate temporal variation have almost never been investigated.