University of Tasmania
Browse

File(s) under permanent embargo

Spatial variation in reproductive effort of a southern Australian seagrass

journal contribution
posted on 2023-05-19, 01:46 authored by Smith, TM, York, PH, Macreadie, PI, Keough, MJ, Donald RossDonald Ross, Sherman, CDH
In marine environments characterised by habitat-forming plants, the relative allocation of resources into vegetative growth and flowering is an important indicator of plant condition and hence ecosystem health. In addition, the production and abundance of seeds can give clues to local resilience. Flowering density, seed bank, biomass and epiphyte levels were recorded for the temperate seagrass Zostera nigricaulis in Port Phillip Bay, south east Australia at 14 sites chosen to represent several regions with different physicochemical conditions. Strong regional differences were found within the large bay. Spathe and seed density were very low in the north of the bay (3 sites), low in the centre of the bay (2 sites) intermediate in the Outer Geelong Arm (2 sites), high in Swan Bay (2 sites) and very high in the Inner Geelong Arm (3 sites). In the south (2 sites) seed density was low and spathe density was high. These regional patterns were largely consistent for the 5 sites sampled over the three year period. Timing of flowering was consistent across sites, occurring from August until December with peak production in October, except during the third year of monitoring when overall densities were lower and peaked in November. Seagrass biomass, epiphyte load, canopy height and stem density showed few consistent spatial and temporal patterns. Variation in spathe and seed density and morphology across Port Phillip Bay reflects varying environmental conditions and suggests that northern sites may be restricted in their ability to recover from disturbance through sexual reproduction. In contrast, sites in the west and south of the bay have greater potential to recover from disturbances due to a larger seed bank and these sites could act as source populations for sites where seed production is low.

History

Publication title

Marine Environmental Research

Volume

120

Pagination

214-224

ISSN

0141-1136

Department/School

Institute for Marine and Antarctic Studies

Publisher

Elsevier Sci Ltd

Place of publication

The Boulevard, Langford Lane, Kidlington, Oxford, England, Oxon, Ox5 1Gb

Rights statement

Copyright 2016 Elsevier Ltd.

Repository Status

  • Restricted

Socio-economic Objectives

Coastal or estuarine biodiversity

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC