Luke S. O'Loughlin, Greg Baines, Emma Carlson, Claire Wimpenny, Rosie Cooney
{"title":"An assessment of potential herbivory impacts of a reintroduced marsupial in a predator-free woodland sanctuary","authors":"Luke S. O'Loughlin, Greg Baines, Emma Carlson, Claire Wimpenny, Rosie Cooney","doi":"10.1111/emr.12591","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>Fenced sanctuaries that exclude feral predators are critical for threatened species conservation. However, adaptive management of these sanctuaries requires careful consideration of the potential impact herbivore populations free from predation can have on the condition of native vegetation. The Mulligans Flat Woodland Sanctuary in the Australian Capital Territory comprises Critically Endangered box-gum grassy woodland, threatened orchids, abundant macropods, and a reintroduced population of the Eastern Bettong (<i>Bettongia gaimardi</i>, hereafter “Ngaluda”). To understand how Ngaluda, along with other herbivores, may be potentially impacting vegetation across the sanctuary, we undertook an assessment of indicator plant species. We monitored 106 plots for 13 indicator species (10 species with tuberous roots that the burrowing Ngaluda would be preferentially targeting and three non-tuberous species). We found that most floristic indicators we investigated – including richness of indicator species and the abundance of lilies – were higher in the Goorooyarroo area of the sanctuary (where Ngaluda are absent and wallabies are rare) compared to the Mulligans Flat area of the sanctuary (where Ngaluda are present and wallabies are abundant), suggesting a negative impact of the overall herbivore assemblage of Mulligans Flat. However, within just Mulligans Flat, some indicators, including the abundance of a common orchid, were significantly lower in areas associated with high Ngaluda activity irrespective of other herbivore densities. We found no instance of Ngaluda presence or higher activity being associated with higher values for any floristic indicator we investigated. These results are consistent with known impacts of abundant herbivores and reintroduced digging marsupials in other predator-free sanctuaries in Australia. Our results highlight that Ngaluda herbivory may be outweighing any positive effect of their diggings on native vegetation and indicate the need for careful risk mitigation when deciding how critically endangered animals and vegetation communities are managed together in sanctuaries.</p>\n </div>","PeriodicalId":54325,"journal":{"name":"Ecological Management & Restoration","volume":"25 1","pages":"37-50"},"PeriodicalIF":1.9000,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ecological Management & Restoration","FirstCategoryId":"93","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/emr.12591","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Fenced sanctuaries that exclude feral predators are critical for threatened species conservation. However, adaptive management of these sanctuaries requires careful consideration of the potential impact herbivore populations free from predation can have on the condition of native vegetation. The Mulligans Flat Woodland Sanctuary in the Australian Capital Territory comprises Critically Endangered box-gum grassy woodland, threatened orchids, abundant macropods, and a reintroduced population of the Eastern Bettong (Bettongia gaimardi, hereafter “Ngaluda”). To understand how Ngaluda, along with other herbivores, may be potentially impacting vegetation across the sanctuary, we undertook an assessment of indicator plant species. We monitored 106 plots for 13 indicator species (10 species with tuberous roots that the burrowing Ngaluda would be preferentially targeting and three non-tuberous species). We found that most floristic indicators we investigated – including richness of indicator species and the abundance of lilies – were higher in the Goorooyarroo area of the sanctuary (where Ngaluda are absent and wallabies are rare) compared to the Mulligans Flat area of the sanctuary (where Ngaluda are present and wallabies are abundant), suggesting a negative impact of the overall herbivore assemblage of Mulligans Flat. However, within just Mulligans Flat, some indicators, including the abundance of a common orchid, were significantly lower in areas associated with high Ngaluda activity irrespective of other herbivore densities. We found no instance of Ngaluda presence or higher activity being associated with higher values for any floristic indicator we investigated. These results are consistent with known impacts of abundant herbivores and reintroduced digging marsupials in other predator-free sanctuaries in Australia. Our results highlight that Ngaluda herbivory may be outweighing any positive effect of their diggings on native vegetation and indicate the need for careful risk mitigation when deciding how critically endangered animals and vegetation communities are managed together in sanctuaries.
期刊介绍:
Ecological Management & Restoration is a peer-reviewed journal with the dual aims of (i) reporting the latest science to assist ecologically appropriate management and restoration actions and (ii) providing a forum for reporting on these actions. Guided by an editorial board made up of researchers and practitioners, EMR seeks features, topical opinion pieces, research reports, short notes and project summaries applicable to Australasian ecosystems to encourage more regionally-appropriate management. Where relevant, contributions should draw on international science and practice and highlight any relevance to the global challenge of integrating biodiversity conservation in a rapidly changing world.
Topic areas:
Improved management and restoration of plant communities, fauna and habitat; coastal, marine and riparian zones; restoration ethics and philosophy; planning; monitoring and assessment; policy and legislation; landscape pattern and design; integrated ecosystems management; socio-economic issues and solutions; techniques and methodology; threatened species; genetic issues; indigenous land management; weeds and feral animal control; landscape arts and aesthetics; education and communication; community involvement.