Ord Land and Water has been successful in gaining a $20,000 grant to map and control the weed lantana on properties just to the north of Kununurra. Lantana is a highly invasive weed and has infested many areas in Queensland and NSW.
The Weed of National Significance has been present on small agricultural- rural/residential blocks just north of Kununurra for a number of years. Some ad-hock control has been carried out in the past but with greater priorities and the weed's relatively small footprint the infestation has been largely left alone.
Recent observations indicate that the infestation is now reaching a point where it’s starting to substantially increase both its distribution and density. Currently the weed is isolated to this one area in the East Kimberley.
This project will initially map for the first time its distribution and then initiate a control program in partnership with landholders as a component of an ongoing program of control and hopefully future eradication.
In 2014 and 2015 the Ord Land and Water Management Plan is being reviewed and where required revised. The initial plan was produced in 2000 so a review was essential to take the organisation towards 2020. The five main components of the plan are -
- Irrigated Land Issues
- River Issues
- Conservation Isuues
- Town Issues
- Pastoral Land Issues
Following on from the weed identification brochure ‘Weeds - East Kimberley’s Most Wanted’ revised and reprinted by Ord Land and Water in 2011 a new brochure designed for weed identification specifically for town sites was produced in 2014. Titled ‘Weeds in Our Towns’ it lists the 12 most prevalent and potentially destructive to the environment weeds that are found around the town sites of Halls Creek, Kununurra and Wyndham and adjacent communities. Funding for the project came from the Shire of Wyndham East Kimberley.Weeds listed include –
- Bellyache bush
- Coffee senna
- Coral vine
- Hairy Merremia
- Khaki weed
- Snake weed
- Wild passion vine
Ord Land and Water has two control programs currently running on prickle bush control in the East Kimberley, both are partnership programs run jointly between Ord Land and Water and the Kimberley Rangelands Biosecurity Group.
The prickly acacia program has been running at Nulla Nulla and El Questro Station since 2010 when a reliable source of funds finally became available to continue on the work that had been started by the Department of Agriculture and Food in 2007. This is the only place in Western Australia the weed has established apart from a few isolated plants found on Gordon Downs, Nicholson Station and the Kununurra Quarantine yards, all controlled.
Since that time there has been a steady decline in plants found in the 15,000ha control area. In 2014 only 296 plants were found compared with 9,104 found in 2010.
Due to the isolated nature of the area access and control is carried by helicopter working out of either Home Valley Station or Wyndham.
There are high hopes that this weed could be virtually eradicated from the area within a decade.
The second program is controlling mesquite on Nicholson Station 200 kilometres to the east Halls Creek and has the land holders Heytesbury Beef Pty Ltd as an active partner. The infested area covers just over 16,000ha and has had a number of small control programs carried out in the past but suffered from lack of funding to maintain them.
Initial work in this program in 2012 was carried out using a bull dozer to tip out all the mature trees, combined with some chemical control on the smaller plants. In subsequent years the program went to chemical control on the subsequent germinations.
A bio control agent Evippe spp., a leaf tying moth assists with the control work by reducing the seed set on mature plants. Since 2012 the plant controlled dropped from 5,958 to 1,763 in 2014.
There is an expectation that eventually this infestation could be eradicated in years to come.
2013 and 2014 saw the rubber vine control in the East Kimberley reach a new level of commitment from partner organisations due to a cash injection from State NRM through Rangelands WA in 2012.Partner organisations for the project include –
- Department of Agriculture and Food;
- Department of Parks and Wildlife;
- Kimberley Rangelands Biosecurity Association;
- Ord Land and Water;
- and Rio Tinto.
Despite the increase in numbers of plants controlled from 2013 to 2014 it appears from survey work done on a number of hot spots there will likely to be a crash in the population in 2015. This is expected because of likely reduced germinations and the very low count of misses recorded where control was carried out previously.
In the 2007 dry season a number of banks and spillways were placed across an actively eroding gully system on Argyle Downs Station to test their effectiveness in the control of the highly erosive local red soil. It was hoped the banks would slow down or halt the passage of water allowing sediment to accumulate within the gully system rather than be washed down into Lake Argyle. Funding for the project was provided by the National Landcare Program and the National Action Plan for Salinity and Water Quality.
Ongoing monitoring was carried most years just after the wet season, usually in May-July. The results showed a significant reduction in soil moving down the system over time, from an initial 5.74 cubic metres/ha in 2008 reducing down annually to 0.38 in 2013 (see graph).
As a result further funds were successfully sought through State NRM to carry this work further downstream on the same gully system to complete it. Two more banks were built with associated spillways in the 2013 dry season and measurements were once again taken in early 2014.
Unfortunately the new banks were still holding a significant amount of water midyear but bank subsidence had appeared to have raised the floor up at least a couple of metres, meaning none of that soil had been lost downstream. The likely cause of the subsidence was a significant downpour of around 500mm over a couple of days in February 2014 that caused a lot of regional flooding. However the older banks were accessible and measuring them indicated a slight increase of soil movement to 0.65cubic metres/ha for that wet season.
Ord Land and Water was successful in negotiating with the Department of Environment and Conservation the use of mechanised equipment to clear weeds on unallocated crown land on behalf of adjacent landholders. The land was a 50 metre section between the Ord River and rural blocks on Riverfarm Road just outside Kununurra.
In all 10 hectares were cleared with funding coming from the Australian Government’s Caring for Our Country Program. Initially the trees, mainly neem, leucaena and parkinsonia were basal bark sprayed to kill them and then a mulcher was put over the top of them to enable landholders’ access to carry out ongoing control. The mulching also provided a good ground cover to reduce the risk of any erosion occurring before a ground cover could be established between the remaining native trees.
Ord land and Water spent much of 2012 mapping the MG/DEC Conservation Reserves around Kununurra. The parks are currently managed by the Miriuwung Gajerrong people and the Department of Environment and Conservation. There are a total of six reserves –
- Ngamoowalem Conservation Park covers 70,311 hectares and is located adjacent and to the west of Kununurra. It extends 45 kilometres south-west of the town between the Victoria Highway and Parry Creek Road. The greater part of Ngamoowalem is surrounded by Ivanhoe pastoral lease and the western side adjoins Parry Lagoons Nature Reserve.
- Mijing Conservation Park covers 25,529 hectares and is located about 60 kilometres to the north of Kununurra. The area adjoins the Carlton Hill pastoral lease to the north, east and south. To the west it adjoins Ord River Nature Reserve.
- Goomig Conservation Park covers 14,165 hectares and is located about 27 kilometres north-east of Kununurra. The area is mostly surrounded by the Ivanhoe pastoral lease with unallocated Crown land to the south-west.
- Darram Conservation Park covers 896 hectares and is located adjacent to the south side of the townsite of Kununurra, bordering Lake Kununurra.
- Darrmalanka Conservation Park covers 29,121 hectares and is located about 44 kilometres north of Kununurra and extends to the Northern Territory border. The area is mostly surrounded by the Ivanhoe pastoral lease and adjoins Carlton Hill pastoral lease in the north. Point Springs Nature Reserve adjoins the southern boundary.
- Barrbem Conservation Park covers 14,328 hectares and is located 22 kilometres east of Kununurra. The area is located within the Ivanhoe pastoral lease and adjoins the Northern Territory to the east.
Most of the reserves only had low levels of weeds located on them with the exception of Darram which was heavily infested with a number of weeds. A total of 10 weed species were selected and prioritised from the 26 noted and considered to be a pest or potential pest in the six Reserves.
- Priority 1: Bellyache bush (Jatropha gossypiifolia)
- Priority 2: Neem (Azadirachta indica)
- Priority 3: Coffee bush (Leucaena leucocephala)
- Priority 4: Parkinsonia (Parkinsonia aculeata)
- Priority 5: Phalsa (Grewia asiatica)
- Priority 6: Rain tree (Albizia lebbeck)
- Priority 7: Fruit trees (Various spp)
- Priority 8: Mimosa bush (Vachellia farnesiana)
- Priority 9: Rubber bush (Calotropis procera)
- Priority 10: Stinking passion vine (Passiflora foetida)
Aerial suppression has been proven to be an effective tool around Kununurra with a privately owned aircraft used in the control operations of seven fires in 2010. A total of 62,000 litres of water was dropped with an estimated 100,000 hectares of pastoral and high value conservation land protected as a result.
Some of this work was done ninety kilometres from Kununurra utilising a station airstrip and station hands delivering water to the aircraft by tanker. FESA has identified 2011 as a year of significant risk for bushfires in the Kimberley due to the carryover of unburnt fuel loads from 2010 and the significant production of new fuel during the exceptional 2010/11 wet season.
With this in mind OLW and other groups are seeking to work through the Minister for Emergency Services more closely with the relevant agencies to improve the communities capacity to deal with the expected series of wild fires that usually occur from August on until the start of the wet season.
Currently State Agencies personnel and volunteers are unable to work on the ground in conjunction with aircraft in the Kimberley due to safety and training factors.
Further work also needs to be done on identifying where aircraft fit within local suppression programs alongside the existing methods of ground control. OLW is hopeful a way can be found through the red tape to improve fire suppression in the area.
Ord Land and Water has taken a lead role in the control of prickly acacia at Nulla-Nulla just north of Home Valley Station in the East Kimberley. Using Federal Government funding through the Caring for Our Country initiative OLW was able to kill over 90% of the mature trees in a 5,120 hectare area in November 2010.
Prickly acacia is a weed of national significance and the Nulla-Nulla site is the only infestation known to be in WA. It is a significant threat to the Kimberley environment as it is capable of quickly displacing native pastureland with a barrier of thorny trees impacting on stock production and reducing wildlife habitat.
The Nulla-Nulla site is situated in such an isolated area that the trees were not found until 2004, approximately 25 years after they were thought to have come to the area. The only reliable access to the area is by helicopter as the road in has succumbed to numerous wet seasons and is no longer able to take traffic.
OLW has secured enough funding to carry out control work until the 2012 wet season. By that time it is expected that much of the threat will be abated requiring only minimal funds to completely eradicate the pest.
Crossing Falls and Packsaddle communities now have weed management plans developed by the residents to protect both private land and the neighbouring environment. Implementation of the plans is been taken up by residents on their properties and OLW on adjoining ground.
Both communities were able to make big inroads into populations of the high and medium priority weeds over this dry season, particularly in Crossing Falls. Packsaddle has some weeds such as mission grass and coral vine that will be best tackled early in the new year before the plants has a chance to seed.
The plans were pulled together with the initial mapping of properties and surrounding bushland. Two workshops for each community followed on from the mapping and priority areas and weeds were identified. From this information a control program was worked out. Priority weeds at both communities included all the declared weeds such as chinee apple and sicklepod senna as well as environmental weeds such as neem and coral vine.
Crucial to the project were two contractors used by OLW. Sarah Strutt did much of mapping and worked up the plans while Charlie Buckley carried out the control work. Having the local knowledge and an understanding of the threat the weeds posed he helped significantly with the project results.
On October 2nd 2009 in front of a small group of participants the waterweed salvinia was declared ‘eradicated’ from the Lake Kununurra Ramsar site in the north of Western Australia.
The informal ceremony closed the book on a nine year eradication program that involved the efforts of two community groups as well as Local and State Government organisations. It also went a long way to securing the future of a significant ecological and public recreational asset in Australia’s north.
The weed was first found by a local resident in May of 2000. Following the discovery various attempts were made to eradicate the weed including the installation of a boom to limit its spread.
In December 2004 an assessment concluded that the eradication process was not working and there was a risk that the weed may spread during the expected flood events of the 2004/05 wet season so two groynes were built to assist with the control program. This was fortuitous as the week after their completion 162mm of rain fell in an afternoon effectively flooding the area.
With no plants found during 2005 it was hoped the plant may have finally been killed. However it was located again on site in early 2006 prompting more funding to be sort and secures through a partnership between the community group Ord Land and Water and the Shire of Wyndham East Kimberley.
An area on site was in filled with soil and another groyne was constructed to hold two more booms. Most of the control work either consisted of spraying the plant or pulling it out by hand. The last piece of salvinia was removed in October of 2007 but monitoring continued on a regular basis. Finally the plant was declared eradicated two years later.
Wins such as this against any of the Weeds of National Significance are a rare occurrence, especially one situated in such a difficult location but the success if this program demonstrates that given the resources communities can deal effectively with these situations and come out on top.
Ord Land and Water was one of the winners of the Western Australia Weeds Committee Invasive Plants Award at the recent State Landcare Awards night in Bridgetown. The award recognises the group’s achievements in the control of neem trees around Kununurra and its ongoing weed project on Lake Kununurra.
The group was also a finalist two more categories, Landcare Professional Award and the Community Group Award.Coordinator Dick Pasfield traveled to Bridgetown to accept the Award and a cheque for $1,000 on behalf of the group. In his acceptance he acknowledged the work done by his Project Officer Blu who has been the backbone of the neem project since it started in 2006.
The award was shared with the Esperance Weed Action Group’s Coral Turley demonstrating weed control is a priority right across the state and country groups are leading the way in participation.
As well as controlling weeds Ord Land and Water’s current projects include erosion control, fire management and litter reduction.
The East Kimberley Fire Forum was held by Ord Land and Water and Landcare Australia in late March, three sessions (indigenous, community and land-mangers) were held over two days. All sessions had good participation and some good issues and actions came out of them. One of the main points of interest was the response of the State Minister for Police and Emergency Services to the Environmental Protection Authority’s (EPA) Review into Fire Management in the Kimberley and other Rangeland Regions. Although the minister did not attend the forum a letter was received from the minister, in which he recommended that the Minister for Environment be contacted. The minister for Environment has to date not responded to questions relating to how the State Government intends on addressing the recommendations in the review.
The EPA Review into Fire Management in the Kimberley and other Rangeland Regions was initiated in response to ongoing concern over the intensity and scale of late dry season fires that have been causing large amounts of the Kimberley to be burnt every year. From this report came key recommendations which are currently sitting with the Minister for Environment.
The general feedback from the East Kimberley Fire Forums’ three sessions supported these recommendations.
Common messages from the three fire forum sessions were:
- Fire regimes have changed and are having negative impacts;
- Cool early burning does limit the extent of hot late season fires;
- Inter-property & inter-agency cooperation is improving control of wildfire;
- The opportunity in the future for fire management to provide financial outcomes.
Future aspirations for fire management in the East Kimberley are:
- Cooperative burning programs across tenures;
- Increased engagement of pastoral industry;
- Additional funding to; encourage ‘cells’ of cooperating land owners, implement aerial fire suppression & support local volunteer fire brigades;
- Local Shires supporting and accepting fire management plans;
- Increased support for indigenous ranger groups to do fire management planning, obtain equipment, training & implement fire management;
- Provide pastoralists with a simple guide on how to achieve fire permits for late season fires for woody weed control;
- Reduce volunteer probation time to one or at least by one month;
- Recognition from State bodies and support for fire management to protect values beyond their State responsibilities;
- Be able to communicate as a group to funding bodies;
- Education program for the broader community to promote the idea that irresponsible burning is wrong and to promote an understanding of good & bad fires;
- Produce posters to educate the broader community about the link between fire and wildlife.
As an extension to the erosion workshops OLW has been running across the Ord catchment a couple of demonstration sites were installed during 2007. The first site is situated on red loamy soil typical of pastoral land south and west of Lake Argyle, whilst the second site is situated on sandier soils just a few kilometres north of Kununurra.The pastoral site consists of a number of banks placed across an actively eroding gully system. The banks serve as a silt trap and reduce erosion by slowing the flow of water off the hills. Of the eleven banks installed nine held up over the wet season successfully retaining silt within them whilst the gullies started to fill with trash. Follow up work will begin in July 2008 to repair the broken banks and install more if required. The second site had a number of check banks installed across a badly eroded firebreak that was responsible for diverting the course of several small creeks that ran through several private properties. All these banks held over the wet season and some of the erosion scars are starting to infill.
With just over 9,000 ha of neems destroyed work has started on evaluating the success rate of the initial work and how much re-infestation could be expected.
Three sites have been gone over between once and twice more they are –
- Weaber Plain Monitoring Site: 29hectatres.
- Lake Kununurra monitoring site: 140 hectares.
- Cave Springs monitoring site: 160 hectares.
The Weaber Plain site showed a 38% reduction in plants after two periods of control but the there was an unexpected reinfestation of seedlings from a tree unsighted in an adjoining property.
The Lake Kununurra site showed a 34% reduction in plants after one control period. Work is currently underway on the second control period. There are expectations that this percentage of control will increase significantly
The Cave Springs site showed a 95% reduction in plants after two periods of control.
Both the Weaber Plain and Lake Kununurra sites were classed as very heavy to medium density infestations (over 1,000 trees/ha) while the Cave Springs site was classed as a medium to light infestation.
See project report