The dispersal, establishment and management of Ammophila arenaria seed in coastal foredunes
- Author
- McLachlan K
- Year
- 2014
- Journal / Source
- Master of Applied Science
- Publisher / Organisation
- University of Otago
- Summary
- This thesis examines the seed ecology of the coastal dune grass, Ammophila arenaria (L.) Link (marram grass) in a densely vegetated foredune (Type-1, after Hesp, 2002) in southern New Zealand. A. arenaria is widely recognised as a threat to the biological and landform diversity of temperate dune systems around the world, yet the characteristics of seed production, seed dispersal, and seed storage on A. arenaria dominated foredunes is not fully understood. An understanding of these processes will assist greatly in the future management and eradication of this highly invasive species. Through a series of empirical field-based investigations at Mason Bay, Stewart Island and Oreti Beach, Southland, this thesis examines: (i) the relationship between seed production and the foredune landscape; (ii) the primary and secondary dispersal of A. arenaria seed and the influence of the vegetation canopy on dispersal in the foredune; (iii) the effect of the foredune vegetation canopy on A. arenaria seed germination and seedling survival; and (iv) the relative density of the A. arenaria seed bank in relation to spatial seed distribution and burial depths within the foredune and deflation zone. The implications of these findings in relation to the eradication of A. arenaria at Mason Bay, Stewart Island are discussed.