Coastal sand dunes protect people’s communities by buffering storm surges. In an age of increasing frequency and intensity of storms, these buffering dunes need to be restored often. Current practices of planting Ammophila breviligulata to stabilize dunes would be enhanced by adding the North American woody vine, Parthenocissus quinquefolia. This fast growing vine provides food for wildlife, increasing the habitat value of restored dunes. We ask: How is the growth of P. quinquefolia affected by the simulated dune stressors of salt water spray and sand burial? We then ask: Do coastal-sourced plants perform better than those sourced from inland populations in response to dune stressors? To answer these questions, we sampled seeds from three environment types: coastal sand dunes, coastal maritime forests, and inland forests. We then exposed them to either foliar salt spray or gradual sand burial in a greenhouse. To test the response of plants to foliar salt spray, plants from provenance were sprayed daily for 24 days and the number of non-necrotic (living) leaves were counted to compare leaf loss ratios over time. To test the response of plants to sand burial, we gradually buried vines in 11cm of beach sand over six weeks and compared their change in growth to plants that remained unburied.
Results/Conclusions
When exposed to foliar salt spray, the leaves of plants grown from inland seeds were significantly more damaged than leaves of plants grown from coastal seeds. When tested with gradual sand burial, all plants that received sand treatment grew larger than plants that received no sand burial. When grouped by seed source, there was no difference in the plant growth of those that received no sand burial. However, there were significant differences in growth correlated with seed source among plants that were buried in sand. Plants from coastal dunes grew longer stems than plants from inland forests, but showed no difference when compared to maritime forest plants. When comparing leaf growth, plants from dunes grew less than plants from maritime forests. While plants from maritime forests had more leaf growth than plants from dunes, they did not have significantly more leaf growth or stem growth than inland plants. These results show that some critical aspects of plant performance in response to dune stressors are related to seed provenance. Coastal land managers should prioritize the selection of coastal ecotypes of P. quinquefolia over inland sources to improve restoration success and habitat value.