Management of invasive grasses has received little attention in
comparison to research undertaken on exotic weeds. There is a
general lack of understanding of appropriate control options,
particularly ones that are economical for application over large
areas of “low value land” and in areas of “high
conservation value”.
Grader grass ( Themeda quadrivalvis ) has the
potential to change biodiversity, reduce conservation values and
reduce grazing animal production of large areas of the tropical
savannas. Grader Grass is identified by Queensland Parks and
Wildlife Service (North Region) as a critical conservation issue
threatening biodiversity in the National Parks. It has also been
identified in the Etheridge Shire Pest Management Plan as a species
of significant effect and significant threat both economically and
environmentally and by the Mitchell River Watershed Management
Group as a significant weed species. It is a declared weed in
Charters Towers City Council and a high priority pest in the
Dalrymple Shire where it is actively controlled on roadsides
throughout the shire.
This project aims to understand some basic ecological aspects of
grader grass in response to management and natural conditions so
that management recommendations can be made based on science rather
than anecdotal evidence. This project would provide both economic
and environmental benefits through the development of management
recommendations so that land managers can reduce the economic and
environmental impacts of this weedy grass.
Project update
This project is examining four characteristics of grader grass:
seed longevity, effect of fire, digestibility and protein content,
seed dormancy and germination requirements.
August 2006 Fresh seed collected and prepared for burial.
September 2006 Study sites established at Undara National Park
and Lynwater Station.
September/October 2006 Baseline pasture composition determined
at the study sites.
Soil fertility and soil seed bank sampling was done at Lynwater
Station during this period and sites for seed burial and natural
seed bank decline were established at Lynwater Station. Lots of 50
sound grader grader grass seeds with their awns removed were buried
in November 2006 at three depths (surface, 2 cm and 5cm deep) at
Lynwater Station in vegetated and non vegetated plots. At the same
time baseline seed viability was established.
Key References
Keir, A and Vogler, W. 2006. A review of the current knowledge
of the weedy species Themeda quadrivalvis (grader
grass). Tropical Grasslands 40: 193-201.