A plant invader declines through its modification to habitats: A case study of a 16-year chronosequence of Spartina alterniflora invasion in a salt marsh

摘要

Many invaders can substantially modify the habitats that they invade, but the long-term effects of these changes on the invaders themselves remain uncertain. Spartina alterniflora, an aggressive invasive plant of coastal wetlands, can reduce the tidal inundation time and accumulate standing litter by sediment trapping and by high production. A 16-year chronosequence of S. alterniflora invasion in Dongtan marsh in Yangtze River estuary, China revealed that S. alterniflora had a 5-year enhancement followed by a longer decline. Steady decreases in the tidal inundation time and increases in the standing litter per unit living mass were observed. A controlled experiment showed that the growth of S. alterniflora was significantly limited by the decrease in the inundation time and by the standing litter. These results indicate that the changes in habitats caused by invaders can limit the invaders over time because the accumulation of habitat changes creates certain habitat properties that exceed the optimal range for invaders. These findings highlight the importance of the impacts of invasion on the long-term dynamics of invasive populations.