Theses and Dissertations

Copyright Statement

All rights reserved. This publication is intended for use solely by faculty, students, and staff of Nova Southeastern University. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Defense Date

1986

Document Type

Thesis - NSU Access Only

Degree Name

M.S. Ocean Science

Department

Oceanographic Center

Abstract

As we have become more aware of the value of vegetation in the stabilization of coastal sand dunes, there has been an increasing desire to protect valuable native species in coastal habitats. In Florida, introduced exotic species have tended to crowd and eventually replace native vegetation, resulting in the establishment of monocultures.

The Australian pine (Casuarina eguisetifolia) introduced to south Florida in 1898 by Fairchild, has become a weed species on beaches, supressing the native grasses associated with dune formation by its exudation of allelopathic substances. A Casuarina eradication project in Jupiter Island (Martin County), Florida was conducted in an attempt to slow beach erosion by allowing reestablishment of native dune forming grasses.

Empirical data was obtained from this area to determine:

1. the effects of the loss of a dominant tree species,

2. the changing of the floristics of the area demonstrating subsequent growth of native vegetation,

3. the species reactions to different degrees of soil's salinity and pH.

Throughout the study area (Casuarina stand), the elimination of Casuarina resulted in an immediate growth of four species (Ipomoea pes-caprae –railroad vine, Paspalum vaginatum -salt joint grass, Panicum amarulum -panic grass, Uniola paniculata -sea oats ). I. pes-caprae is an opportunistic species representing an early stage of succession while P. vaginatum, P. amarulum, and U. paniculata are members of the climax community. Diversity indices declined after Casuarina eradication due to the initial rapid growth of I. pes-caprae, however significant linear or exponential growth of the native grasses was observed.

It was found that the growth rates vary significantly with season. Away from the immediate shore line, maximum growth for all species occurred from mid to late summer. Highest growth rates for the majority of species occurred on a nearby natural dune (control) site, except for two species (I. pes-caprae and P. vaginatum) which were found to be most abundant throughout the (Casuarina stand) disturbed site.

Files over 10MB may be slow to open. For best results, right-click and select "Save as..."

To access this thesis/dissertation you must have a valid nova.edu OR mynsu.nova.edu email address and create an account for NSUWorks.

Free My Thesis

If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the Free My Thesis button.

Share

COinS