Graduation Date
Summer 2018
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources: option Environmental Science and Management
Committee Chair Name
Alison O'Dowd
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Erik Jules
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
David Gwenzi
Third Committee Member Affiliation
HSU Faculty or Staff
Subject Categories
Environmental Science and Management
Abstract
The removal of invasive species as part of the restoration process can allow natives organisms to rebound. An ecosystem that incurs damages from invasive species is coastal sand dunes, which are dynamic systems. Some coastal sand dunes on the west coast of the United States have been invaded by Ammophila arenaria. The invasive grass, A. arenaria, is thought to alter and stabilize foredune morphology and reduce populations of native species. The objectives of my research are to examine the effects that manual and mechanical A. arenaria removal techniques have on coastal sand dune morphology and vegetative cover over time. The California State Parks Redwood District manages three coastal sand dune ecosystems where A. arenaria removal efforts have been conducted: Little River State Beach, Gold Bluffs Beach in Prairie Creek Redwoods State Park, and Tolowa Dunes State Park. I surveyed the vegetative cover at each of the three locations in each treatment method, manual and mechanical, and in untreated control plots during the summer and early fall of 2017. In order to measure dune morphology at restored and unrestored sites, I used an Unmanned Aerial Vehicle (UAV) that was flown over the mechanical removal and control areas. I then created a Digital Elevation Model (DEM) from photos taken during the UAV flights using Structure from Motion software. Overall, both mechanical and manual treatments lowered A. arenaria cover. Mechanical removal lowered the foredune elevation compared to control areas and changed the dune morphology in treatment areas into hummocks at Little River. Although mechanical removal was effective at lowering A. arenaria cover, it also lowered native plant diversity compared to manual removal, but was higher than control diversity. With endemic species of concern on coastal sand dunes, manual removal of A. arenaria will afford greater native plant diversity and cover compared to mechanical removal.
Citation Style
CSE
Recommended Citation
Silva Crossman, Monique R., "Effects of manual and mechanical Ammophila arenaria removal techniques on coastal dune plant communities and dune morphology" (2018). Cal Poly Humboldt theses and projects. 195.
https://digitalcommons.humboldt.edu/etd/195
Included in
Geographic Information Sciences Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Comments
Original degree title: Master of Science degree with a major in Natural Resources, option Environmental & Natural Resource Sciences