A SERDP funded research effort led by Dr. Jeffrey Foster at the University of New Hampshire, recently published its research results in Science. The goal of this effort was to determine the effects of plant disperser traits, competition, predation, and landscape features on native and non-native plant dispersal and recruitment. The project team determined how environmental variables affect networks of non-native seed dispersers, the movement of non-native dispersers, the availability of fruits, seed dispersal impacts on plant communities, and the effect of changing environmental conditions on the networks of non-native seed dispersers and plant communities. To accomplish these determinations, the research integrated field-based data collection, field experiments, and ecological modeling to describe and quantify seed dispersal in novel Hawaiian communities.
It is well known that the Hawaiian Islands continue to face pressure from invasive species, a pressure that results in a high-risk for native species extinction. In order to manage and preserve Hawaiian terrestrial ecosystems, it is necessary to identify and characterize non-native invasive species that are dispersers of desired plant species, determine their role in ecosystem function, and improve non-native plant management plans. This project examined multiple seed dispersal networks comprised of interacting native and non-native plant and vertebrate species across several trophic levels and the ecological contexts required to develop predictive models for assessing recovery and maintenance of key ecological processes.
The findings discussed in the Science article suggest that shared evolutionary history is not a necessary process for the emergence of complex network structure. The research also provided an indication that interaction patterns may be highly conserved, regardless of species identity. Finally, the team determined that restoration of native ecosystems may be more challenging than previously thought due to the fact that introduced species can quickly become well integrated into novel networks.
Dr. Foster’s final report will be available on the website at the end of the summer.