Integrated Weed Management Strategies In Dorrigo National Park, New South Wales, Australia

Write an essay on the given topic: Weed Management.

Introduction to Integrated Weed Management

Integrated weed management can be described as the integrative approach of managing weeds through the usage of a combination of policies directed towards solving a particular weed issue. The weed management techniques together form a toolbox which contains several tools and such tools are used for the purpose of weed management in a specific farm or a place. The toolbox thus consists of the prevention of the spread of the weed and it spread, biological practices, cultural practices, mechanical practices and the usage of the chemical (herbicide) (Deytieux et al., 2012). Integrated Pest Management involves a wide range of the ways and it has associated complexities, even though not all the tactics are complex. Some of the examples that are not complex are the hand-pulling techniques, changing tillage practices, cover cropping, rotating cropping, rotating herbicides, alternating the herbicide tank mixes, timely scouting and equipment cleaning. It is important to note that the herbicide technique is not always the best technique because the weeds are becoming herbicide resistant. Thus, the best method is to manage the spread of the weed and preventing the same from becoming invasive (Young, 2012). This project deals with the weed management strategies employed in Dorrigo National Park in New South Wales (Australia). The study will emphasize on the different strategies of weed management employed by the Authorities of Dorrigo National Park and the information will be gained through interviewing of the responsible person. The discussion will also include critiquing the various strategies along with the proper identification of the strengths and weakness of the strategies employed and suggesting the areas of possible improvement. The main aim is to use the theoretical knowledge about the integrated pest management to assess and design the weed management strategies in a real situation.

Integrated pest management involves a lot of complex processes like mechanical prevention, chemical prevention, cultural prevention and biological prevention demands a well-coordinated action between the responsible staff and officials when it comes to the management of weeds in a National park. Thus, to find the tactics and the various strategies that are employed in Dorrigo National Park, interviews will be conducted with:

• The green army members that were in charge of managing weed and along also the responsibility of ecological restoration.
• The locals were interviewed as they were employed for the mechanical removal of weeds.
• The contractors that were involved with the removal and management of weeds
• Organizations like Landcare that are associated with the Dorrigo National Park in the management of weed.
• The Staffs employed by the Dorrigo National Park in the management of weeds inside the National Park.

Acquiring information is the vital part in the considering the weed management is executed by a wide array of people, organization and staffs. Thus, to streamline the process, a uniformity is maintained within the conduct of the interview. The interviews were conducted in person and also on the telephone in order to reach to the maximum number of people. 

The interview questions that were asked of the selected people, organization and staffs are as follows:

• What are the different methods employed in the weed management?
• The different types of chemicals (herbicides) used in the weed management.
• The sites where the weeds are found to be most concentrated?
• The various problems experienced during the application of the weed management strategy.

Dorrigo National Park is geographically located in the New South Wales, Australia. Dorrigo National park is a part of Gondwana Rainforests of Australia which was inscribed in the year 1986 in the World Heritage Site and is also added into the Australian National Heritage Site in the year 2007. The National Park takes less than an hour drive to reach from Coffs Harbour and the national park is located on a plateau called the Dorrigo Plateau. The site has breathtaking views and the region has a wide variety of the sub-tropical vegetation. The place is best suited for a day trip, school excursion, excellent birdwatching possibilities, scenic barbecue areas and waterfall walks. The Park has a wide variety of the birds and animals like the red-necked pandemelons along with the spectacular regent bowerbird and vibrantly coloured fruit dove. The National Park also wields a Canopy Café and a Dorrigo Rainforest Centre. It is important to note that the region provides ample opportunity for the visitation to the parks and the reserves along with the sustainable recreation. The local economy is significantly benefitted by the contributions of the visitors (NSW National Parks, 2018).

Weed Management Strategies Employed at Dorrigo National Park

The weed control techniques: The Dorrigo National Park uses an integrated weed control technique in the management of the weed. The various techniques that are employed are the usage of biocontrol agents, bush regeneration, splatter gun, foliar spray. As it is a known fact that a single method cannot be applicable to a wide variety of the plants, thus techniques are used depending on the type of the weed. Certain special techniques are used in order to target the certain weed species. Biocontrol agents are used because the normal spraying technique was not able to affect the overall weed population like the lantana and mistflower. In the rainforest region especially the splatter gun technique is used and this is used so as to prevent the killing of the rainforest seedlings from the herbicides that are present under the lantana. The foliar spray technique is not used in the rainforest because that might kill the rainforest seedlings, setting the restoration program back in years. In the sensitive areas like around the waterways, the bush regeneration techniques are used so as to prevent the possibility of herbicide contaminating the waterway. 

The herbaceous weeds that are seen in the Dorrigo National Park are pennywort, silver-leaf desmodium, nodding thistle, spear thistle, Noogoora burr, painted spurge, Formosa lily, coralberry, trad, Crofton weed, mistflower. Species like Lantana camara favours growing in the humid conditions and it invades the disturbed rainforest, forest edges and it is highly spread throughout Australia. The control technique includes the foliar sprays with herbicide and the along with the mechanical techniques are also followed. The plant’s habit of stopping the growth during the frost or the dry periods makes it more resistant to the herbicides. There are other herbaceous weeds like. The control method includes the foliar sprays with glyphosate and extra care is taken to the native plants and the faunal species like frogs are not adversely affected. Weeds like trad and mist flower plants are removed by hand and hung up so that these weeds do not regrow. It is also important to note that the areas were foliar sprays is required, in such places the native plants are removed first. A recent technique is employed which talks about the white smut fungus (Entyloma ageratinae) in places where there is a large number of mistflower plants and it is found to be showing great promise (NSW Environment & Heritage, 2018).

The woody weeds that are seen in Dorrigo National Park are polygala, umbrella tree, smooth senna, mulberry, willow wattle, coastal tea-tree, ochna, winter senna, camphor laureal, large-leaved pivet, narrow-leaved pivet. The prevention of the woody weeds is controlled either through the large-scale bush regeneration technique or through the single species focussed method if a single species infestation is seen in a large number. Majority of the woody weeds are controlled through the stem injection method and the certain cases cutting, scraping and painting with herbicide is also done. These woody weeds are also controlled by the foliar sprays or through removing physically (NSW Environment & Heritage, 2018).

Control Techniques for Herbaceous and Woody Weeds

The exotic vines that are seen in Dorrigo National Park are turkey rhubarb, climbing nightshade, Mysore thorn, passionfruits, Japanese honeysuckle, asparagus ferns, moth vine, Dutchman’s pipe, balloon vine, morning glory, Madeira vine, cat’s claw creeper. The priority of the vine weed control method involves the controlling of the vines that are under the canopy. Depending on the species, the plant's vine weeds are cut and painted or scrapped with the herbicide. For weeds like balloon vine and Madeira and the seed pods and the aerial tubers are composted and bagged. All these are followed by the foliar spraying of the seedlings of both the isolated and the hand removed plants. Areas where there are infestations of Asparagus, a physical clearing is necessary and the remaining part is cleared with the application of herbicide, also light infestations are controlled through the process of crowning (NSW Environment & Heritage, 2018).

The weed control is given the most priority in the areas where there are endangered ecological communities and the visitor facilities areas. The management strategies are focussed on the critical down to the low priority. The program of weed control is limited by the staff time, money provided to the contractors. The Natural Park seek additional funds from the external grants or in partnership with the external organizations like landcare or with the neighbours. The task of prioritising is done through the ways by which the weed is transported. This means the way through which the weeds are being transported or are being washed into the park from the adjacent private land which is infested with a particular weed. Thus, this results in weed control techniques to be a cumbersome one. But if the whole catchment is present in the park then the weed management strategies are a lot better. The weed biology is also taken into account which brings forth the issue of seed longevity during the prioritization.

The environmental weeds are detrimental for the natural environment or the natural ecosystems and this requires proper weed management strategies in order to control weed for a longer time period. The underlying concepts underlying the integrated weed management involves the wise use of herbicides wherever applicable along with the specific usage of methods like biocontrol. It is important to note that the damage posed by the agricultural weeds can be both measured and quantified by assessing the damage done to the agricultural field and the agricultural yield. However, the threat of the environmental weed is that they pose issues like biodiversity loss, functional complexity, issues related to the ecosystem stability. Thus, there arises a definite need to consider an integrated weed management strategy for the protection of the environment. The main aim of the integrated weed management is threefold:

• To effectively prevent the spread of the weeds that are already existing in a region.
• Proper management of the environment for the effective prevention of the new weeds.
• Rehabilitation of the disturbed ecosystem to the farthest extent (Harker & O'donovan, 2013).

The major strategies that are employed by the Dorrigo National Park are biocontrol agents, bush regeneration, splatter gun, foliar spray, mechanical methods. The majority of the methods are employed depending on the cost-effectiveness, and most of all taking into the concern for the environment. It is important to note that the methods like a biological agent and the chemical controls that are employed by Dorrigo National Park must undergo field trials and extensive testing in quarantine conditions so that the chemical agents and the biological agents have minimal impact on the natural ecosystem. The main rationale here is that the environment is much more complex in comparison to the agricultural ecosystem or the agricultural pastures. While it is important to note that in comparison to the agricultural land or pasture there are lot many non-target organisms that may get affected (Power, Kelly & Stout, 2013). In comparison to the dominant species, there are sub-dominant species as well along with the mature individuals, seedlings, geophytes, grasses and forbs. Thus, the natural community is much more complex and diverse which needs to be considered (Pianka, 2017).

Interviews Conducted for Information Gathering

Also, the chemical controls that are employed for controlling the environmental weed needs to be applied and handled the same way chemical agents are applied in the agriculture systems. The concerns of the non-target effects and the potential contamination must be taken in to consideration when the herbicides are being applied against the environmental weed. Thus, in order to apply herbicides, careful application, proper selection, and pre-testing is required in order to minimize the damage to the non-target organisms (Heap, 2014). Thus, a widespread blanket spray of the herbicides is not the proper option and not the only option for the application of herbicides. There are other techniques like the weed wipers, stem injection, cut stump can also be used and this method is target specific and minimizes any contact with the non-target organisms (Miller, Manning & Enloe, 2013). Mowing and cutting are both the labour intensive process and there are certain habitats that make cutting by hand or even by machine as an impractical solution (Milakovic, Fiedler & Karrer, 2014). This also applies to the fact that grazing is also not the proper solution considering that majority of the national parks do not allow grazing. One of the strategy that can be used is using the livestock to trample the weeds that are standing tall and thus it will the smaller weeds to grow. This occurs with weeds like Lantana camara and also some of the natural grasslands that are infested with thistles (Frid et al., 2013). Several public places that are infested with environmental weeds can be hand pulled by employing a large number of volunteers and this will reduce the impact on the surrounding non-target organisms. Another technique which is beneficial in the removal of environmental weeds but is to some extent not appropriate when other systems are also considered, is the usage of fire. It is important to note that, this strategy is not used in Dorrigo National Park. Usage of fire is a long-term strategy for the management of environmental weeds considering the fact that the fire is a vital factor when it comes to the regeneration ecology of the several native species. Fire, thus can be considered a beneficial for the native plants that compete against the weeds. In comparison to the wildfires, the prescribed fires are far more suitable when it comes to target the environmental weeds (Pearson et al., 2016). Revegetation technique can be used considering the scenario of reintroduction or introduction of plant in to a habitat where it was initially got degraded by either human force and natural force. The might be an exotic species which might not be an indigenous species and might also have a slightly altered genetic material. This method although sounds good but it lacks practicability with issues pertaining to preservation of the local gene pool. While, it is vital to consider that the conservation of local gene pool is necessary for maintaining genetic diversity and biological diversity as well (Lake, Hough?Goldstein & D'amico, 2014). Bush regeneration is one of the technique employed by Dorrigo National Park and the technique used I called Bradley method. This technique is basically beneficial to work on areas that are either lightly infested with weeds or can be highly infested with weeds. The Bradley method also minimises any disturbance to the soil and at the same time reduces the regeneration rate of the native plants and dictates the rate of weed removal. This process thus has a downside and the areas that have high density of the weed populations is a makes the weed removal a labour intensive process. Thus the revegetation technique must include the three main techniques like manipulation of the seed bank, sowing of seed and planting of seedlings (Head, 2014).

Location and Description of Dorrigo National Park

Based on the interviews conducted via phone and face to face interviews, the success of the strategies employed by the Dorrigo National Park is promising. However, considering the fact that there are issues like weeds getting resistant to the excessive usage of herbicides, and native plants are unable to compete with the invasive species as well. Thus, future strategies will include the deployment of weed control techniques that will promote safeguard of the environment. Weed seed destruction is one such technique which will be used to control the seeds of the weeds from germinating and this will prevent the retention of the seed from soil seed bank (Harrington & Powles, 2012). Eliminating the seeds from attaining maturity. Systems like bale direct, chaff carts, narrow windowrow burning and Harrington seed destructor can be used be used for controlling the weed seeds. Weed Seed predation technique can be used through the deployment of small mammals and insect species like granivorous insects. Seed predation techniques can be employed when the seed is still attached to the plant or when seeds are dispersed after attaining maturity. Also small mammals, birds and insects are the major post seed dispersal predators (Honek, Martinkova & Jarosik, 2013). Bioherbicides are the plant pathogens that can be applied to the weeds exogenously and in a repeated fashion to control the weeds (Cordeau  et al., 2016). Microwaves and radiations are the futuristic weed killing techniques, and this involves the usage of the high energy microwaves. This method has been found to be efficient considering the fact that it can kill the weeds efficiently and is highly targeted and has no effect on the non-target species (Brodie, Ryan & Lancaster, 2012). Hot air, steam or hot water are the other effective techniques of weed control and this process is used in several countries with much success (Rask et al., 2013).

Conclusion

From the above study, it can be concluded that weed management has become a vital part whether to the safeguard natural environment or an agricultural field. The study has included a national park called Dorrigo National Park where the weed management strategies are taken into account. Considering the large geographical area on to which the National park is spread, thus requires an integrated weed management strategy to curb the growth and spread of the weeds. Based upon the interviews it has been found that the various techniques that are employed by Dorrigo National Park are the usage of biocontrol agents, bush regeneration, splatter gun, foliar spray. The most common weeds that are found within the Dorrigo National Park are lantana and mistflower. The other weeds that are found within the Dorrigo National Park are woody weeds, exotic vines and herbaceous weeds. Keeping in mind the different types of the new issues arising due to the infestation of weeds like the herbicide resistance and increase in the invasive nature of the weeds. It is thus important to note that the modern techniques need to be applied in order to control the spread of the weed. Techniques like Weed seed destruction, Weed Seed predation, Bioherbicides, Microwaves and radiations, Hot air, steam or hot water can be used to manage weeds.

Reference

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