Yellingbo Conservation Reserve - Case Study Example

Name Course Tutor Date Introduction The economy of majority of the regions in Australia depends massively on the primary production. Soil, constant rainfall, as well as temperature enhance robust agricultural production through the ideal conditions which are greatly determined by the tree cover. Both native as well as plantation forests in the production forestry have great benefits with their annual turnovers being great hence indicating their significance in the Australian economy (Australian Bureau of Statistics 2006). It also has a great variety of wildlife including the endangered species of animals, plants and birds. Therefore due to the need to conserve these species and their habitats, various conservation sites have been formed, among which is a highly significant reserve, a reserve with the responsibility of protecting the habitat of the critically endangered helmeted honeyeater, the Yellingbo Conservation Reserve. Yellingbo Conservation Reserve Yellingbo conservation reserve is a reserve which is located at Melbourne (50 kilometres east), in the state of Victoria, Australia. It is located at the Upper Yarra Valley next to Yellingbo and Macclesfield towns (MELWAY 305 G11, 1217 Macclesfield Rd Yellingbo), with an area measuring approximately 9600 hectares and 4.6 kilometres squared. History of origin This reserve was developed after a great community concerns on the dwindling Helmeted Honeyeater population. Some areas which also included Woori Yallock’s water frontage, Cockatoo as well as sheep station creeks got reserved, in accordance with the Land Act 1958(Vic.) as public purpose sites (sites for wildlife conservation). The State Government also purchased several contiguous areas which were mainly for wildlife propagation or preserving habitats of the wild life. The Land Conservation Council then later proposed most of the land as Yellingbo Nature Conservation Reserve. The management of the reserve, together with the adjoining land along the Cockatoo creek, is carried out by Parks Victoria. It has approximately 285 species of native plants among which includes the ash trees, sheoak, acacia species, river redgums, wurundjeri scar trees, woolly tea-tree ,eucalyptus and mountain swamp gums. Protection of the Mountain Swamp Gum forest has also become paramount especially since it has abundance of sedge, which has national significance. This reserve plays a major role in conserving the colonies of the last wild helmeted honeyeater, a critically endangered bird, it also conserves the habitats of wildlife along Cockatoo, Sheep Station Creeks, Woori Yallock, Macclesfield and part of McCrae Creek. Significance of the reserve The reserve has significant features of being the site for conservation of Helmeted honeyeater (Lichenostomus melanops cassidix) as well as leadbeater’s possum (Gymnobelideusleadbeateri), which have national significance. Apart from this, it also contains eleven communities of vegetation including the swamp community of Eucalyptus camphora,which is rich in sedges and has national significance, it has a great diversity of both native flora and fauna with many threatened species, provides bird watching opportunities, nature observation,as well as giving schools and the community opportunitie for education on habitat rehabiliation,conservation of ecosystem as well as endangered species. Conservation challenges. The browsing damage from wildlife results in worldwide problems, ranging from low commercial venture productivity, for instance agriculture and forestry (Gill, 370), to causes survival threats to the vulnerable species of plants in the natural systems (Go´ mez-Aparicio et al., 201). Mammalian herbivores have therefore been a great devastation in the plantation forestry. This has greatly impacted on the reserve since they browse on the young trees which may lead to consequences ranging from changes in tree form, decrease in growth rate, extinction of various plant species and seedling death, to erosions, inadequate rains and a prolonged drought. Control methods The browsing problem was formerly contained through decreasing the population of herbivores by using lethal means mostly by shooting them or poisoning them. However, of recent, increasing pressure has emerged from the political side as well as the social side for the use of lethal controls to be decreased. This has led to several research activities carried out to provide alternatives to the lethal controls since lethal controls have been known to affect endangered species. This has therefore resulted in a number of techniques with varying applicability and effectiveness. A table showing the research priorities for strategies of short-duration control (less than two years but more than one year). Priority: E = essential, H = high, M = medium, L = low, N = not recommended, blank = not applicable Topic (summarised from Tables 1–5, 7–10) Constraint Category 1: Use of all techniques, including lethal techniques with limited species specificity, are acceptable Category 2: Use of non-lethal techniques and strictly species specific lethal techniques are acceptable Category 3: Use of non-lethal techniques only Chemical repellents 1a. Benefits of products L H E 1b. Impact of site factors L H H 1c. Integration L H E 1d. Public acceptance L L L 1e. Cost-effectiveness L M H Acoustic repellents or deterrents 2a. Stimuli L M H Physical barriers (fences and tree guards) 3a. Best-practice guidelines N M H 3b. Public acceptance N L L 3c. Permeability of fences L H E 3d. Decision support system N M H 3e. Cost-effectiveness L H E Fertility control 4a. Immunocontraception 4b. Chemosterilants 4c. Delivery systems 4d. Population modelling 4e. Public acceptance Non- lethal Controls Identification of non-lethal controls that are very effective has therefore been a major concern in the conservation management decisions and therefore these controls have been tested to determine their viability. Several chemical formulations have undergone intensive tests to prove their capability of repelling and deterring herbivores from foraging (Shafer & Bowles, 123). New products that can offer best results are still being developed. These chemical repellents have effects depending on the active ingredients that are present (Mason, 327; Nolte & Wagner, 95). Some non- lethal Controls Among the chemical repellents that are registered and have been used successfully are the D-ter, Multicrop Scat and Sen-tree. Sen-tree browsing deterrent, however, has been used at Yellingbo Conservation Reserve to deter browsers from interfering with the tree seedlings. Sen-tree browsing deterrent This is an adhesive compound which is egg-based and which is sprinkled on the foliage together with grit. This combination of odour with grit deters the browsers from damaging plants by producing bad odour, apart from making plants unpalatable. It contains egg solids, acrylic polymer adhesive and silicon carbide grit or carborundum grit. The carborundum grit replicates silica which is naturally found in plants. It is also non-toxic but very hard therefore destroying the teeth of the animals, especially when it is highly concentrated (Delbridge & Lutze, 365). Sen-tree browsing deterrent was developed by the Victorian Department of Primary Industries. Sen-tree, which was trialled before as WR-1, had great success in deterring swamp wallabies from destroying seedlings of eucalypt and pine (Marks et al. 156; Johnston et al .308 ). Some feeding trials were done with captive animals for indicating effectiveness of WR-1 in dettering pademelons from browsing on the E.globulus seedlings.In plantations,WR-1 succesfully deterred Pademelons, possums, hares (Lepus capensis), and wallabies from causing browsing damage on the seedlings of E. globulus and E. nitens. It was realized that the seedlings which had WR-I treatement grew very fast compared to the untreated ones as long as the apical buds had not been tampered with or removed by the browsing animals. Sen-tree browsing deterrent application Sen-tree browsing deterrent is used for preventing the browsing of tree seedlings by Black wallabies (Wallabia bicolor), rabbits, red-necked wallabies (Macropus rufogriseus), Tasmanian pademelons (Thylogale billardierii), Bennet’s wallabies (Macropus rufogriseus rufogriseus). The egg solids and the acrylic polymer adhesive are stirred in 7.5 litres of water and then sprayed on the foliage. After this is done then the silicon carbide grit is sprinkled on the foliage using a container with tiny holes. The treatment of seedlings may be done in bulks within the nurseries. A tree seedling with Sen-tree browsing detterent treatment Effectiveness Sen-tree is most effective where the browsing pressure is low, up to moderate level. It is also very effective where browsing suppression required is for a shorter period, when it is in combination with some techniques as well as where fences and other permanent structures are prohibited. Where there is no alternative food to the browsers then it will have very little effect (Miller et al. 200). Effect of Sen-tree browsing deterrent on seedlings planted in Yellingbo Conservation Reserve. Prevention from browsing The marsupial herbivores do cause a lot of damages to young plants and especially seedlings which are in the forestry operations. These damages result in the changes in the tree form, reducing growth rate as well as causing the death of the seedlings. In yellingbo Conservation Reserve has used the sen-tree browsing deterrent on the seedlings to deter browsing by these herbivores. This chemical has characteristics of bad odour as well as unpalatability. Photo illustrating some preparations for planting The sen-tree therefore has been most effective in preventing consumption of the tree seedlings like the eucalyptus nitens by herbivores like possums and pademelons. For instance there were signs of eucalyptus and other tree seedlings being browsed on by the herbivores, but when the chemical was applied to the seedlings, browsing by herbivores was contained. This chemical is very effective on the seedlings in that the seedlings that were not treated previously were all browsed on by the herbivores, while within 24 hours after the application, the seedlings were not browsed on. Although this chemical may require re-application in order to be able to protect the seedlings continuously, since without re-application the seedlings may return to the same condition of vulnerability and be browsed on by the herbivores. The treated tree seedlings that were browsed on by the herbivores were less than 5% compared to the untreated tree seedlings that were browsed on, about 75% (Fitzgerald, Hugh et al.305). Photo of a treated and protected tree seedling Increased survival rate This deterrent has been proven to increase the survival rate of some tree seedlings by up to 52% and survival ratio of the diverse species as 5:7.this is significant compared to the survival rate of the untreated tree seedlings, which is 12% with 3:7 survival rates. However, in cases of treated and untreated seedlings in fenced plots, the survival rate was found to be 95%.Some trees that would only survive by sen-tree application included Cyperus gunnii and Goodenia ovata. The seedling species that would survive with or without sen-tree deterrent and which would have better survival with the sen-tree application include Carex appressa, Poa ensiformis and Coprosoma quadrifida.There was an indication that the survival success of the tree seedlings had increased by about five hundred days. Some tree seedlings illustrating this included the Poa ensiformis seedlings, which were not browsed on by the herbivores and which had a strong growth. Only very few seedlings were browsed on by the herbivores. Several Carex appressa seedlings were not browsed on, strong growth was also visible on the seedlings while the number that never survived was very few. The Coprosma quadrifida seedlings had been browsed on slightly and majority were able to do well. This was also the case with the Cyperus gunnii. The tree that was heavily browsed on was Ozothamnus ferrugineus while Goodenia ovate had been browsed on up to the base, while there was no perceived re-growth in some seedlings even though the stalk was still alive. However, Leptospermum continentale seedlings were an exception, with the survival rate of the untreated seedlings being 12%, they got little or no protection from this chemical hence they were browsed on. These seedlings have survival rate of up to 95 % in fenced plots (Oswalt, 133). A Photo illustrating treated seedlings under protection Reduced browsing severity The Sen-tree had great effects in reducing the browsing severity of the tree seedlings by the browsers. This is because in the initial phase few animals browsed on the seedlings but due to the unpalatability of the tree seedlings, the animals became discouraged from continuous consumption of the seedlings. Majority of the seedlings that were treated with Sen-tree browsing deterrent had greatly continued growing with very minimal disturbance from the herbivores like the wallabies and the pademelons. This was clearly evident having compared the previous untreated ones and the rate at which the herbivores were browsing on them. The untreated seedlings were browsed on as immediately as they were exposed to the browsers. They were greatly interfered with and hence it was evident that their survival was at stake. On the other hand there were some signs of little interference by the browsers on the treated tree seedlings with very few having been browsed on, this could have been due to the fact that the herbivores tried to feign some resistance to the bad odour and ended up consuming some seedlings, however this couldn’t go on for so long since the chemical compound was a great put-off for the herbivores. This therefore signifies that Sen-tree was very influential in preventing severe browsing damage to seedlings that were treated with it (Johnson, 7) Photo of an area which has been browsed on Browsing delay The browsing delay has had great effects in giving the seedlings ample and secure environment ant time to be established without the requirements of other control methods. Sen-tree browsing deterrent was very significant in delaying and reducing browsing of the tree seedlings. During the browsing delay the seedlings gained height hence increased their survival chances. Every tree seedling that was treated by the Sen-tree browsing deterrent had a great success in their growth right from the time of application since the shoots were intact and was not interfered with by the browsers. The tree shape Herbivores have great impacts on the plants that they browse on, especially seedlings that are still growing. This is because they damage different parts of the seedling hence may partially or completely alter the growth pattern of the seedlings, hence making them have a different growth pattern from the original pattern. Some of the cases have also been witnessed in the reserve where the structures of the seedlings were also interfered with and majority of them developed different structure from the expected ones. However after the application of Sen-tree browsing deterrent on the tree seedlings, there was evidence of proper tree growth being maintained, which signified that the herbivores played a major role in altering the structure of the seedlings. However in comparison with the untreated tree seedlings, this was not the case since they were not treated hence were damaged by the herbivores while their structures and shapes were greatly transformed as opposed to the expectations. This might have been due to the interference with the shoot of the seedlings, which is an indication that the Sen-tree deterrent has a great role in maintaining proper growth of the seedlings. Photo illustrating a normally growing treated tree seedling. Browsing recovery For the seedlings which were earlier browsed on by the herbivore, this chemical was influential in increasing their recovery ability. The seedlings which were still alive even after browsing had continuous growth. The height as well as cover of the vegetations which surrounded the seedlings had also great effect of improving their recovery from early browsing. Some trees that were previously browsed on and which were still alive tended to pick on with their growth even after some browsing damage were done on them. The Sen-tree gave them protection hence allowing for successful sprouting of the shoot and hence continuous growth since there was no further interference from the herbivores, having been contained by Sen-tree deterrent. Seedling height/inhibiting growth Sen-tree browsing deterrent also played some role in inhibiting the growth of the seedlings. In some cases it was found that some seedlings couldn’t grow faster until a given period, while others grew faster when the chemical was applied. This implied that it had some effects on the growth of the tree seedlings. This could also be extended to cater for the fact that by discouraging the predators who might have been attracted to the treated tree seedling due to their visible height, it played an integral part in maintenance of the growth pattern. Graphs showing the height of the seedlings within and after several weeks Conclusion Browsing has been one of the greatest challenges that has faced parks, reserves and other wildlife protection sites. However, there have been various techniques formed to counteract the browsing problems caused by the browsing animals among which include shooting, physical barriers like fences, tree guards, fertility control, farm and forestry crop and site practices, trapping, snaring, alternative toxins, chemical repellents ,commercial harvesting and bounty use, predator urines, predator sounds, predator blood, extracts from irritating plants, development of resistant plants as well as acoustic repellents or deterrents. Among all these methods, the deterrents are preferred by majority and therefore are widely used, Sen-tree is among the most recommended ones as it is registered and deters browsing effectively thereby providing much protection for tree seedlings as is evident in the case of Yellingbo Conservation Reserve .Application of Sen tree browsing deterrent therefore has had a great effect on the tree seedlings. . Works cited Mason, J.R .Mammal repellents: options and considerations for development. In: Baker RO, Crabb AC eds Proceedings of the 18th Vertebrate pest Conference. University of California, Davis. 1998.Pp. 325–29. Nolte Dale & Kimberly Wagner. “Comparing the efficacy of delivery systems and active ingredients of deer repellents”. In: Salmon TP, Crabb AC eds Proceedings of the 19th Vertebrate pest Conference. University of California, Davis , 2000. Pp. 93–100. Marks C.A. “Techniques for the mitigation of plantation seedling damage by the European rabbit (Oryctolagus cuniculus) and swamp wallaby (Wallabiabicolor).” Proceedings of the 10th Australian Vertebrate Pest Control Conference, Hobart,Tasmania. 1995 Pp. 155–160. Delbridge, J., Lutze, M. “An evaluation of the effectiveness of WR-1 repellent for browsing control in HEMS forest”. Forests Service, Department of Natural Resources and Environment, Victoria. Report 1998.nr 365. Gill, Robin. 1992. A review of damage by mammals in north temperate forests: 3. Impact on trees and forests. Forestry 65, 363–388 M Johnston MJ, Marks CA, Moore SJ, Fisher PM, Hague N 1998. WR-1 and AD-3 browsing repellents:a journey from problem to product. Proceedings of the 11th Australian Vertebrate Pest Conference, Bunbury, Western Australia. Pp. 305–311. Johnston P, Fletcher M 1998. Do fungi influence leaf palatability to browsing possums? He Korero Paihama – Possum Research News 10: 8–9. Australian Bureau of Statistics 2006. hhtp://www.abs.gov.au/AUSSTATS/abs Miller, Alison et al, 2006a. Characteristics of tree seedlings and neighbouring vegetation have an additive influence on browsing by generalist herbivores. Forest Ecology and Management 228: 197–205. Fitzgerald, Hugh P et al. (2008) Effectiveness of repellents for reducing damage to eucalypt seedlings by browsing mammals. Australian Forestry, 71 (4). pp. 303-310. ISSN 0004- 915 Go´ mez-Aparicio, Lorenzo,et al,2005. The regeneration status of the endangeredAcer opalus subsp. granatense throughout its geographical distribution in the Iberian Peninsula. Biological Conservation 121, 195–206. Oswalt, Christopher,et al., 2006. Impacts of deer herbivory and visual grading on the early performance of high-quality oak planting stock in Tennessee, USA. Forest Ecology and Management 229, 128–135. Johnston P, Fletcher M 1998. Do fungi influence leaf palatability to browsing possums? 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