Category Archives: EMR 20th anniversary updates

Long-term restoration in the Box Gum Woodlands of south-eastern Australia – UPDATE of EMR feature

David Lindenmayer, Mason Crane, Daniel Florance, David Smith, and Clare Crane

Update to article published in EMR – Murray Catchment habitat restoration: Lessons from landscape level research and monitoring doi: 10.1111/emr.12051

Keywords: Revegetation, biodiversity recovery, monitoring, birds

Figure 1. Revegetated woodland near Wagga Wagga in the South West Slopes of New South Wales. (Photo courtesy of the Sustainable Farms project at The Australian National University. Australia).

Introduction

This project encompasses a major set of large-scale, long-term integrated studies quantifying the response of various groups of biota to replanted woodlands in the Box Gum Grassy Woodlands of south-eastern Australia. The work has been underway since 2002 and contrasts revegetated areas with regrowth woodlands and old growth woodlands on multiple farms nested within landscapes with varying amounts of native vegetation cover (Fig 1.). The responses of birds, arboreal marsupials, terrestrial mammal, reptiles, frogs and native plants to these different kinds of broad vegetation types (and within-site and landscape-level attributes) have been documented over the past 17 years.

Further works undertaken

Since the inception of the original project and associated monitoring, an array of additional studies have been completed (https://www.anu.edu.au/about/strategic-planning/sustainable-farms). These include investigations of the impacts on birds and reptiles of livestock grazing in plantings, the benefits for birds of understorey plantings within old growth woodlands, the impacts of a control program for the Noisy Miner (Manorina melanocephala) on other woodland bird species, and interaction effects between long-term climate, short-term weather and revegetation programs on birds (Figs 2 and 3). Further work aims to quantify the biodiversity and livestock production benefits of enhancing the ecological condition (and associated water quality) of farm dams.

Figure 2. Flame Robin and Rufous Whistler – two bird species of conservation concern that respond positively to revegetated woodland. (Photos by Robin Patrick Kavanagh.)Further results to date

Research and monitoring in the past six years have resulted in a number of key new insights of considerable importance for restoration programs. A small subset of these findings includes:

  • The conservation benefits of replanted areas for bird and reptile biodiversity are undermined by intensive livestock grazing in these revegetated areas.
  • The bird biodiversity values of old growth temperate woodlands can be enhanced by underplantings of shrubs and other non-overstorey plants, although it can take many years for such benefits to manifest. Importantly, the occurrence of hyper-aggressive species such as the Noisy Miner is diminished in woodlands where underplantings have been established.
  • Experimental efforts to reduce populations of the Noisy Miner were largely unsuccessful; sites where this species was culled twice were rapidly recolonized by the Noisy Miner.
  • Replanted woodlands provide critical refugia for woodland birds, especially during prolonged drought periods.

Collectively, these findings indicate that restored woodlands have important conservation values (especially for birds but also reptiles), with restoration being valuable to conduct not only in existing old growth woodland (through establishing underplantings) but also in previously cleared sites. The conservation value of woodlands can be particularly critical during climate extremes such as droughts. Efforts to control the Noisy Miner will likely be most effective through targeted revegetation efforts rather than direct culling of birds. Finally, there is a need to limit grazing pressure in revegetated woodlands and this can require the repair or replacement of fences around replantings, especially when such key infrastructure begins to deteriorate.

Figure 3. Noisy Miner – a reverse keystone species for which experimental culling programs have proven to be ineffective. (Photo by Pete Richman.)

Lessons learned and future directions

The ongoing work has clearly demonstrated the important new insights that are derived from long-term ecological research and monitoring. Indeed, long-term changes in patterns of occupancy of restored areas could not have been quantified without rigorous monitoring of a wide range of sites of different sizes, ages and other attributes. Key manager-researcher partnerships have been fundamental to the ongoing success of the array of projects in this restoration initiative. Indeed, some research and monitoring studies were prompted by  questions posed by natural resource managers (such as if there were vegetation cover thresholds for birds in temperate woodlands). Close working relationships with farmers have also been critical to the persistence of the various projects. Field staff in the project, who are based permanently in rural Australia, are key points of outreach and communication with farmers and other natural resource managers. Their presence has accelerated the rate of knowledge transfer and adoption of new practices (such as widening shelterbelts so that they have multiple production and conservation values).

Stakeholders and funding bodies

Ongoing work has been supported by many funding bodies and partners. These include the owners of more than 250 private properties (whom have allowed access to their land and undertaken major restoration works). Funding for the work has been provided by The National Environmental Science Program (Threatened Species Recovery Hub), the Australian Research Council, Murray Local Land Services, Riverina Local Land Services, Central Tablelands Local Land Services, the Ian Potter Foundation, the Vincent Fairfax Family Foundation, The Australian National University, and the Calvert-Jones Foundation.

Contact information

David Lindenmayer, Sustainable Farms Project, Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, david.lindenmayer@anu.edu.au

Restoration and conservation in an iconic National Park – UPDATE of EMR feature

David Lindenmayer, Chris MacGregor, Natasha Robinson, Claire Foster, and Nick Dexter

Update to article published in EMR – Booderee National Park Management: Connecting science and management – doi: 10.1111/emr.12027

Keywords: Invasive animal and plant control, reintroduction, monitoring

Introduction

Booderee National Park is an iconic, species-rich, coastal reserve that supports a range of threatened and endangered native animals and plants. Several key management actions have been implemented to promote the conservation of biodiversity in Booderee National Park. These include the control of an exotic predator (the Red Fox Vulpes vulpes), the control of highly invasive Bitou Bush (Chrysanthemoides monilifera subsp. rotundata), the management of fire, and the reintroduction of previously extinct native mammals. A key part of work at Booderee National Park has been a long-term monitoring program that commenced in late 2002 and which has aimed to quantify the effectiveness of major management interventions, including the four listed above. The monitoring program has documented the long-term trajectories of populations of birds, arboreal marsupials, terrestrial mammals, reptiles, frogs and native plants in a range of major vegetation types (from heathland and sedgeland to woodland, forest and rainforest) and in response to fire, and weed and feral predator control. Importantly, the monitoring program has provided a foundational platform from which a suite of post-graduate studies and other research programs have been completed.

Further works undertaken

A key part of the researcher-manager partnership has been to analyse the long-term trajectories of populations of mammals, birds and reptiles in Booderee National Park. The monitoring data indicate that many species of mammals are declining, with some having become recently locally extinct (e.g. Greater Glider Petauroides volans) or close to extinction in the reserve (e.g. Common Ringtail Possum Pseudocheirus peregrinus) . This is despite populations of these species persisting in nearby reserves.  Robust interrogation of the multi-taxa monitoring data has been unable to identify reasons for these declines. Interestingly, the declines observed for mammals have not been observed to date in other vertebrate groups, including birds, reptiles and amphibians. An experimentally-based reintroduction program for the Greater Glider aims to not only re-establish populations of the species in Booderee National Park, but also to identify the reasons for the original decline. That program will be in addition to reintroduction programs already underway for other mammal species, the Long-nosed Potoroo (Potorous tridactylus), the Southern Brown Bandicoot (Isoodon obesulus) and Eastern Quoll (Dasyurus vivverinus) that used to inhabit Booderee National Park but which went extinct many decades earlier.

Additional research being undertaken in Booderee National Park has included: (1) studies of the effectiveness of control efforts for Bitou Bush and associated recovery of native vegetation and native fauna, (2) the interactive effects of fire and browsing on native plants and an array of animal groups, and (3) studies of leaf litter and other fuel dynamics in relation to previous fire history and macropod browsing.

Figure 1. Key area of Booderee National Park showing an area of coastal forest before and after Bitou Bush treatment.

Further results to date

Research and monitoring in the past six years have resulted in many new insights including some of considerable value for informing restoration programs. A small subset of these findings is outlined below.

  • Conventional approaches to the control of invasive Bitou Bush entail spraying ultra-low volume herbicide (Fig. 1), followed by burning of the “cured” dead material, and then respraying of the seedlings that germinate after fire. This spray-burn-spray protocol is both the most ecologically effective and the most cost-effective way of controlling Bitou Bush and, at the same time, facilitates the recovery of native vegetation. More recent analysis has revealed spray frequency as the most important determinant of long-term control. There are mixed effects of control methods on native species; plant species abundance was positively related to Bitou Bush control, while native bird abundance (except for Eastern Bristlebird Dasyornis brachypterus, Fig 2.) and mammal abundance were weakly negatively associated with Bitou control.
  • There can be strong interactions between the occurrence of fire and browsing by macropods on native plants as well as particular groups of animals such as spiders.
  • Reintroduction programs for the Southern Brown Bandicoot and Eastern Quoll have been relatively successful, although the latter species suffers high rates of mortality, particularly as a result of fox predation and collisions with motor vehicles. Nevertheless, populations of both species have survived over multiple years and reproduced successfully.

Figure 2. The Eastern Bristlebird, a species for which Booderee National Park is a stronghold. Notably, the species responds positively to management interventions to control Bitou Bush. (Photo Graeme Chapman)

Lessons learned and future directions

The work at Booderee National Park is a truly collaborative partnership between reserve managers, a university and the local Indigenous community.  A key part of the enduring, long-term success of the project has been that a full-time employee of The Australian National University has been stationed permanently in the Parks Australia office in the Jervis Bay Territory. That person (CM) works on an almost daily basis within Booderee National Park and this provides an ideal way to facilitate communication of new research and monitoring results to managers. It also enables emerging management concerns to be included as part of adaptive monitoring practices.

One of the key lessons learned from the long-term work has been the extent of ecological “surprises” – that is, highly unexpected results, including those which continue to remain unexplained. An example is the rapid loss of the Greater Glider and the major decline in populations of the Common Ringtail Possum. One of the clear benefits of this integrated monitoring-management team has been the rapid response to emerging threats. For example in response to high rates of mortality of reintroduced Eastern Quolls, control of the Red Fox was intensified within the park and greater cross-tenure control efforts with neighbouring private and public land managers have commenced. Regular evaluation of monitoring data and management actions has also enabled careful examination of the kinds of risks that can compromise reintroduction programs. These and other learnings will inform other, future reintroduction and translocation programs that are planned for Booderee National Park such as that for the Greater Glider.

Stakeholders and funding bodies

Ongoing work has been supported by many funding bodies and partners. These include the Wreck Bay Aboriginal Community who are the Traditional Owners of Booderee National Park as well as Parks Australia who co-manage the park with the Wreck Bay Aboriginal Community. Other key funders include the Department of Defence, the Thomas Foundation, The National Environmental Science Program (Threatened Species Recovery Hub), the Australian Research Council, the Margaret Middleton Foundation, and the Norman Wettenhall Foundation. Partnerships with Rewilding Australia, Taronga Conservation Society, WWF Australia, NSW Forestry Corporation and various wildlife sanctuaries have been instrumental to reintroduction programs.

Contact information

David Lindenmayer, Chris MacGregor, Natasha Robinson and Claire Foster are with the National Environmental Science Program (Threatened Species Recovery Hub), Fenner School of Environment and Society, The Australian National University (Canberra, ACT, 2601, david.lindenmayer@anu.edu.au). Nick Dexter is with Parks Australia, Jervis Bay Territory, Australia, 2540.