The TCT already has a forests policy (available on the TCT website) but we have decided that there is a need to provide more detail on what our nature conservation and, in particular, our biodiversity priorities are. We hope to address geoheritage issues later. This article outlines a draft addendum to our forest policy, which will be completed over the next few months.
One purpose is to provide further evidence to support TCT’s statements made over the last two years regarding the inadequacy of current and proposed public land reserves in addressing the conservation requirements of many biodiversity values, most of which are found on private land.
- biodiversity values need to be conserved through both off-reserve measures and reservation in formal reserves
- biodiversity values need to be managed as well as protected through reservation or other legal measures
- biodiversity values must be proteced, outside the formal reserve system, from the impacts of forestry operations and agricultural clearing, and it is essential to retain a strong and scientifically credible forest practices system.
Due, in part, to the failure of the ongoing forestry negotiations to give proper attention to biodiversity conservation, the Ecological Society of Australia held a symposium in Hobart on 12 April 2012 ‘Forgotten Conservation Priorities in Tasmania’. The papers provided at this event give a fairly comprehensive, authoritative and current overview of Tasmania’s biodiversity values and have been very useful in developing this policy. The full program for the symposium can be downloaded from: http://www.ecolsoc.org.au/regionalEvents.html. For more information about outcomes from the symposium contact Kerry Bridle: email Tas@ecolsoc.org.au.
The TCT policy will not include a neat map of Tasmania’s biodiversity priorities. It is very difficult to clearly define the distribution of many biodiversity values and priorities, even where there is accurate and complete data – biodiversity is complex and can move and change due to natural processes as well as human-induced changes.
There are also problems with data. For example, maps showing the distribution of threatened species can only use recorded data of known localities, i.e. there may be populations that have not yet been found. Locality records are also of varying levels of reliability, accuracy and age. Even the best distribution data can only be loosely indicative of habitat distribution, particularly for threatened fauna species. Even where data is sufficient, prioritising populations of species or areas of habitat can be very complicated and different scientists have different methods or criteria that will deliver different results.
Identifying biodiversity priorities also depends on the context and scale at which the prioritising is done. If the Australian Government was allocating funding to mitigate threats to nationally listed threatened species and wanted a list of priority locations and species, the list would be very different from one produced by a state-based conservation group identifying areas of high biodiversity forest for addition to the reserve system. It depends on what questions are asked, by whom, and for what reason.
Rod Knight, Fred Duncan and Peter Davies spoke at the ESA Symposium about the need for systems that can be used (and updated) to address a range of conservation questions or problems, including prioritising values and assisting landholders and regulatory bodies with land-use and management decisions.
The TCT has a long-term interest in ensuring that:
- Tasmania continues to improve its Forest Practices System;
- forestry and agricultural companies and other land managers utilise Rod Knight’s Regional Ecosystem Model for property-based management planning; and
- the Conservation of Freshwater Ecosystem Values (CFEV) system is improved and utlised more effectively, in particular in the land-use and development-assessment processes.
Although there are many limitations to the maps and the data that is used to create them, maps can still prove to be very useful. Almost all those shown at the ESA Symposium, by a range of speakers looking at different aspects of biodiversity, displayed a remarkably consistent pattern. They showed that priority areas for biodiversity were generally on private land in the eastern half of the state and Midlands, and areas of existing state forest were not very important.
We can see from Rod Knight’s map, ‘Threatened species and vegetation communities’ that most priority areas (putting aside relative threatened or endemic status) are found overwhelmingly in the eastern half of the state, in a broad area including the Midlands and central east coast and, but there are a number of significant smaller concentrations in the far north-west, Flinders Island, greater Hobart area and perhaps others.
Fred Duncan’s map, ‘Distribution of Threatened Forest Vegetation’, mirrors the broad pattern identified above, but there are myriad important and sometimes very small locations across the state.
Peter Davies’ map, ‘Freshwater Ecosystem Conservation Management Priority’, shows that the existing reserve system significantly ove- protects some values (reserve redundancy) and the conservation priorities found outside the reserve system largely overlap those for threatened species and vegetation, but with some very significant differences.
Dr Davies’ map is too complicated to publish in full with this article. It would be very hard for readers to interpret it accurately without very lengthy explanation and qualifications by the author. The map of threatened forest communities shown below is perhaps the best map to get across a simple but key point, that many biodiversity values are found outside the current and proposed public reserve estate. Threatened forest communities are less amorphous and can be, but are not always, mapped more completely and precisely. Out of a total area of 254,000 hectares of Threatened Forest Communties found in Tasmania (listed on the Nature Conservation Act):
- 5000 ha or 2 per cent of the total is within the 563,000 ha of ENGO proposed reserves
- 94,000 ha or 37 per cent of the total is within existing reserves on public land
- 17,000 ha or 6.7 per cent of the total is within existing reserves on private land (Private Nature Reserves and conservation covenants)
- 138,000 ha or 54.3 per cent of the total is within unreserved land and land not proposed for reservation
The small area of threatened forest communities in proposed reserve areas reflects the methods and priorities applied by the environmental non-government organisations (ENGO) in developing their reserve proposals. The ENGO-proposed reserves were designed without an analysis of threatened forest communities and it was just chance that any are within proposed reserves. ENGOs’ priorities centred around wilderness, World Heritage, other large tracts of forest with high naturalness and other areas needed to create more robust or neater reserve boundaries.
The TCT shares Rod Knight’s interest in ensuring that the most threatened parts of the landscape, i.e. areas suffering high-clearing bias and with small and fragmented remnants, are treated as a priority. Even where these landscapes do not retain habitat of threatened species or threatened vegetation communities, it is important not to give up on the most damaged parts of the Tasmanian landscape. We need to advocate for restoration: better connectivity and improved vegetation condition in remnants and in particular areas with high-clearing levels. These areas face irreversible species loss and ecosystem change and are perhaps the most urgent priority. They also include important parts of the productive landscapes where we grow our agricultural products; retaining healthy landscapes is essential to ensure long-term productivity.
In identifying priorities for biodiversity conservation the TCT should also acknowledge a major point made by Rod Knight, that we must ensure that these key areas are conserved within ‘functioning ecosystems’ capable of sustaining the elements of biodiversity they contain. It is not sufficient to identify biodiversity priorities and reserve them or manage them in isolation from the surrounding landscape (the ‘zoo’ approach): if the landscape is not kept in good shape then the biodiversity may disappear. This is another argument for having better systems or tools to assist land management decisions.