South Endeavour Trust Strategic Gamba Grass Control 2016 Report

 Report for 03/03/2017 to 05/05/2017

We were asked by the director of the South Endeavour Trust, Mr Tim Hughes to continue to follow up with a comprehensive Gamba Grass control program at Alkoomie station, Cooktown.

• This will be our second year being involved with the South Endeavour Trust.

• We were to work through their manager, Mr Darryl Paradise.

• Travelled to Alkoomie Station to conduct follow up of a Strategic Gamba Grass control program.

• This program is a part of a systemic control program for the South Endeavour Trust.

• Gamba grass is classified as Restricted Matter Category 3 under the Biosecurity Act 2014.

• The program was conducted for by one operator and equipment for a total of twenty-nine man days over a seven-week period.  While most of the control was carried out by a single team member, we had a second operator’s help occasionally, when available.

• Liaised with the Director and the on ground manager of the South Endeavour Trust.

• South Endeavour Trust were keen to fulfil their obligations under the Biosecurity Act.

• A strategic survey and control program was designed and established.

•  Gamba Grass is classified as a high priority weeds for control on the South Endeavour Trust Pest Management Plan.

• A survey was carried out to determine the where and how the control work was to be undertaken.

• The gamba grass surveyed and is quite thick and covers huge areas, especially along gullies, river, river flats and grazing paddocks.

• The majority of gamba grass is very well established, with some of the grass being over three metres tall.

• Gamba is intertwined in amongst the blood wood and iron wood trees everywhere.

• If not controlled, late season fires have the potential to wipe these big trees and the native grass species that are there.

• This affects all native species and the natural ecosystems that are in this catchment area.

• The gamba grass has the potential to spread further along the river and gully systems.

• Vehicles, humans and stock, travelling along these areas also have the capacity to spread it out further from these areas.

• Because of the sheer size of these areas, CYWAFA_ INC developed a comprehensive Strategic Control Plan.

• As resources are limited, it was decided to concentrate on all the trafficked areas and watering points throughout Alkoomie.

•  It will also provide a buffer zone to limit the spread of seed by wind and water.

• Other pest species declared under the Biosecurity act were controlled as we went along.

• All of the pest species identified on the pest management Plan were controlled.

• Other species controlled includes Hymenachne, Sicklepod, Grader Grass, Rubber vine, Coffee Senna, Sida Win Cassia, and Hypti.

• Regular meetings were conducted to coordinate the control activities. The South Endeavour Trust Manager, Darryl Paradise liaised with us and let us know what was wanted.

• Gamba Grass had been planted as a part of pasture improvement by previous land managers, as it was run as a cattle station.

• Conducted a tool box talk and carried out a risk assessment before any control work was commenced.

• As the area was very wet and access roads washed out there was only limited access to the bigger areas on the flat at Alkoomie.

• Peripheral areas such as the Broken Dam, Old Homestead and cattle yards will have to be accessed when it dries up.

• We commenced spraying well before the gamba grass had started to flower and seed, while it was still at small growth stage

• By the time we had finished the control program we were tasked with, the remaining gamba grass had seeded and the seed was viable.

• Even though this was the case, we got rid of the mature parent plant so that it could not re grow, as it is a perennial species.

• Therefore, reducing the density of the Gamba grass regrowth was the priority.

• By controlling the some of the gamba before seeding we were able to start reducing the viable seed bank along the strategic areas we sprayed.

• While carrying out the Gamba Grass Control Program, we received the odd storm and rainfall event,  which hampered our ability to control the gamba.

• This set the program back a bit as we had to wait until it was dry enough to access some areas.

• Monitoring points were set up, using easily identifiable natural features as scale object.

• A series of gamba grass surveys were carried out on all the areas we could get to,as it was still too wet in a lot ofareas .

• Everything that was surveyed was mapped, including the spraying that was completed.

• Over thirty one point four hectares of strategic control was carried out.

• There was as far greater area surveyed to find out where the Gamba Grass actually was.

• All areas of control work were mapped using the GIS and QGIS systems.

• All data has been sent to the South Endeavour Trust.

• The data and herbicide usage sheets were also completed.

• It was advised to let the controlled gamba grass areas to naturally mulch down, rather than burn. This would provide a blanket of mulch which would suppress seedling regrowth from the seed bank. Further reducing the amount of seed in the ground.

• It would also stop the seedlings, which are very light and feathery, being spread over vast areas by the fire front.

• With less gamba regrowing from seed it would take far less resources to spot spray anything coming up.

• Cape York Weeds and Feral Animals Incorporated spent as much time as possible controlling all trafficked areas, watering points, and high conservation areas.

• A follow up control program needs to be implemented to further protect and reduce the impact of Gamba Grass in these fragile ecosystems and habitats.