Gladstone megaherbivore exclusion data 2017

Gladstone megaherbivore exclusion study carried out at South Trees seagrass meadow from August to November 2017.

Abstract [Related Publication]: Grazing by all members of an herbivore community can act to structure the ecosystems they feed on. The outcome of this grazing pressure on the plant community also depends on the interaction between different herbivore groups that are present. We carried out a three-month multi-level field exclusion experiment to understand how different groups of herbivores act both individually and interactively to structure a subtropical seagrass meadow in the Great Barrier Reef. Megaherbivore grazing had the largest impact on this seagrass meadow, significantly reducing aboveground biomass and shoot height, whereas there was no measurable impact of meso- or macroherbivores on seagrass metrics or epiphyte biomass. Megaherbivores here grazed broadly across the meadow instead of targeting grazing in one area. The principal seagrass-herbivore dynamic in this meadow is that megaherbivores are the main group modifying meadow structure, and other grazer groups that are present in lower numbers do not individually or interactively structure the meadow. We demonstrate that herbivory by large grazers can significantly modify seagrass meadow characteristics. This has important implications when designing and interpreting the results of monitoring programs that seek to conserve seagrass meadows, the ecosystem services that they provide and the herbivores that rely on them. Collectively, our results and those of similar previous studies emphasize there is unlikely to be one seagrass and herbivory paradigm. Instead, for individual meadows, their unique species interactions and differences in biotic and abiotic drivers of seagrass change are likely to have a strong influence on the dominant seagrass-herbivore dynamic.

The dataset consists of a workbook (saved in both MS Excel and Open Document formats) containing 6 spreadsheets. The first worksheet is a ReadMe file and lists the remaining worksheets and treatments as follows:

Worksheets:

Aboveground biomass: Aboveground biomass assessments from photos at the start and end of the study

Shoot height: Shoot height measurements at the start and end of the experiment

Epiphytes: Epiphyte weight per core and standardised to dry weight of seagrass in the sample

SG species composition: Shoot counts from the start of the experiment (Zc  Zostera capricorni, Hu Halodule uninervis, Ho Halophila ovalis)

Mesoherbivores: Numbers of mesoherbivores in cores at the end of the experiment

Treatments:

Con         Control

Pla         Plaster block

Car         Carbaryl block

FF         Macroherbivore frame

Fis         Macroherbivore cage

FisCar Macroherbivore cage plus carbaryl block

Meg         Megaherbivore cage

MegCar Megaherbivore cage plus carbaryl block

The full methodology is available in the publication shown in the Related Publications link below.

    Data Record Details
    Data record related to this publication Gladstone megaherbivore exclusion data 2017
    Data Publication title Gladstone megaherbivore exclusion data 2017
  • Description

    Gladstone megaherbivore exclusion study carried out at South Trees seagrass meadow from August to November 2017.

    Abstract [Related Publication]: Grazing by all members of an herbivore community can act to structure the ecosystems they feed on. The outcome of this grazing pressure on the plant community also depends on the interaction between different herbivore groups that are present. We carried out a three-month multi-level field exclusion experiment to understand how different groups of herbivores act both individually and interactively to structure a subtropical seagrass meadow in the Great Barrier Reef. Megaherbivore grazing had the largest impact on this seagrass meadow, significantly reducing aboveground biomass and shoot height, whereas there was no measurable impact of meso- or macroherbivores on seagrass metrics or epiphyte biomass. Megaherbivores here grazed broadly across the meadow instead of targeting grazing in one area. The principal seagrass-herbivore dynamic in this meadow is that megaherbivores are the main group modifying meadow structure, and other grazer groups that are present in lower numbers do not individually or interactively structure the meadow. We demonstrate that herbivory by large grazers can significantly modify seagrass meadow characteristics. This has important implications when designing and interpreting the results of monitoring programs that seek to conserve seagrass meadows, the ecosystem services that they provide and the herbivores that rely on them. Collectively, our results and those of similar previous studies emphasize there is unlikely to be one seagrass and herbivory paradigm. Instead, for individual meadows, their unique species interactions and differences in biotic and abiotic drivers of seagrass change are likely to have a strong influence on the dominant seagrass-herbivore dynamic.

    The dataset consists of a workbook (saved in both MS Excel and Open Document formats) containing 6 spreadsheets. The first worksheet is a ReadMe file and lists the remaining worksheets and treatments as follows:

    Worksheets:

    Aboveground biomass: Aboveground biomass assessments from photos at the start and end of the study

    Shoot height: Shoot height measurements at the start and end of the experiment

    Epiphytes: Epiphyte weight per core and standardised to dry weight of seagrass in the sample

    SG species composition: Shoot counts from the start of the experiment (Zc  Zostera capricorni, Hu Halodule uninervis, Ho Halophila ovalis)

    Mesoherbivores: Numbers of mesoherbivores in cores at the end of the experiment

    Treatments:

    Con         Control

    Pla         Plaster block

    Car         Carbaryl block

    FF         Macroherbivore frame

    Fis         Macroherbivore cage

    FisCar Macroherbivore cage plus carbaryl block

    Meg         Megaherbivore cage

    MegCar Megaherbivore cage plus carbaryl block

    The full methodology is available in the publication shown in the Related Publications link below.

  • Other Descriptors
    • Descriptor
    • Descriptor type
  • Data type dataset
  • Keywords
    • seagrass
    • herbivores
    • Great Barrier Reef
  • Funding source
  • Research grant(s)/Scheme name(s)
    • -
  • Research themes
    Tropical Ecosystems, Conservation and Climate Change
    FoR Codes (*)
    SEO Codes
    Specify spatial or temporal setting of the data
    Temporal (time) coverage
  • Start Date 2017/08/13
  • End Date 2017/11/17
  • Time Period
    Spatial (location) coverage
  • Locations
    • South Trees Wharf, Gladstone, Queensland, Australia
    Data Locations

    Type Location Notes
    Attachment Final Glad data for upload.xlsx MS Excel (.xlsx) format
    Attachment Final Glad data for upload.ods Open Document (.ods) format
    The Data Manager is: Abigail Scott
    College or Centre
    Access conditions Open: free access under license
  • Alternative access conditions
  • Data record size 31kb
  • Related publications
      Name Scott, A.L., York, P.H. & Rasheed, M.A. (2020) Herbivory Has a Major Influence on Structure and Condition of a Great Barrier Reef Subtropical Seagrass Meadow. Estuaries and Coasts.
    • URL https://doi.org/10.1007/s12237-020-00868-0
    • Notes
  • Related websites
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  • Related metadata (including standards, codebooks, vocabularies, thesauri, ontologies)
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    • Notes
    Citation Scott, Abigail (2020): Gladstone megaherbivore exclusion data 2017. James Cook University. https://doi.org/10.25903/x0qp-pm46