Title: Evaluating barriers to native seedling establishment in an invaded Hawaiian lowland wet forest
Author: Cordell, S.; Ostertag, R.; Rowe, B.; Sweinhart, L.; Vasquez-Radonic, L.; Michaud, J.; Cole, T.C.; Schulten, J.R.
Source: Biological Conservation 142(12): 2997-3004
Description: Many tropical island forest ecosystems are dominated by non-native plant species and lack native species regeneration in the understorey. Comparison of replicated control and removal plots offers an opportunity to examine not only invasive species impacts but also the restoration potential of native species. In lowland Hawaiian wet forests little is known about native species seed dynamics, recruitment requirements, or the effects of management. In a heavily invaded lowland wet forest, we examined the relationship between seed presence and seedling establishment in control and removal plots. Non-native species were competitively superior because they had higher germination percentages and dominated the seed bank; only seven out of 33,375 seedlings were native. In contrast, the seed rain contained native seed, but native seedling recruitment was almost exclusively limited to removal plots, suggesting that optimum establishment conditions are not met in the presence of a dense mid-storey of non-native species. Non-native species dominance was altered and biomass significantly decreased over time resulting in a reduced weeding effort (12.38–0.77 g day−1). We suggest that with opening of the canopy through non-native species removal and subsequent weeding, it may be possible to reduce the seed bank enough to skew the regeneration potential towards native species. Our results suggest that germination success and lack of a seed bank are the main bottlenecks for native species. We conclude that without invasive species control, future regeneration of Hawaiian lowland wet forests is likely to be almost entirely non-native.
Keywords: Germination, Melastoma, Metrosideros, Non-native species, Seed bank, Seed rain
View or Print this Publication (606 KB)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
Cordell, S.; Ostertag, R.; Rowe, B.; Sweinhart, L.; Vasquez-Radonic, L.; Michaud, J.; Cole, T.C.; Schulten, J.R. 2009. Evaluating barriers to native seedling establishment in an invaded Hawaiian lowland wet forest. Biological Conservation 142(12): 2997-3004
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility