Land clearing and biodiversity
Habitat loss is the primary threat to biodiversity in Australia (Fig. 1; SoE Report, 2011). Every year Australia spends millions of dollars addressing the impacts of land clearing on biodiversity and threatened species. Yet land clearing is continuing at a relentless rate. It takes longer, and costs more, to restore vegetation than to remove it. So why are we spending all this effort restoring vegetation instead of preventing clearing in the first place? It makes little economic or environmental sense.
Fig. 1. Pressures affecting species listed as threatened nationally under the Environment Protection and Biodiversity Conservation Act 1999. Source: Evans et al. (2011).
Economic costs of land clearing
The Australian government has funded many projects to restore and improve biodiversity. In recent years, at least $360 million over 2015-2019 has been committed to the Green Army to plant trees, restore and improve native vegetation. The 20 Million Trees Programme, at a cost of $42.7 million, aims to plant 20 million trees by 2020 to re-establish green corridors and urban forests. The Australian Government is partnering with states and territories to deliver $6.6 million for threatened species projects under the Threatened Species Strategy. More than $2 billion in the next decade has been committed protect the Great Barrier Reef under the Reef 2050 Long-Term Sustainability Plan, which includes investment in better land management to improve the quality of water entering the reef from agriculture.
At the same time, native vegetation clearing continues and has increased in some areas. In Queensland, 296,000 hectares of woody vegetation was cleared in 2014-15, almost double the area cleared in 2011-12 (DSITI, 2016). This includes 108,000 hectares cleared in Great Barrier Reef catchments in 2014-15, which increases runoff entering the reef. In 2014–15, the biogeographic region with the highest woody vegetation clearing rate was the Brigalow Belt with 130 000 hectares cleared per year (DSITI, 2016). The Brigalow Belt contains a high level of biodiversity and provides habitat for a number of nationally threatened species.
To address the impacts of habitat loss on biodiversity, Commonwealth and state governments spend considerable time and money developing recovery plans for threatened species and communities. However, under Commonwealth legislation there is no requirement to implement these plans. Their implementation depends entirely on the goodwill of state governments and stakeholders, such as landholders and developers. As a consequence, many recovery plans fail (Watson et al., 2011). Even when there is goodwill, it can be difficult and expensive to halt the decline of threatened species. For example, millions of dollars have been spent in recovery actions for the orange-bellied parrot, but numbers have not increased and it remains critically endangered.
The relentless cycle
This cycle of land clearing, restoration, species recovery efforts, and more clearing sounds counterproductive. What is the problem here? Some vegetation clearing is inevitable when there is population growth and development. The problem is that continual, and escalating, growth and development is taken as a given by government. This means that we are effectively committed to a relentless cycle of clearing, revegetating and species recovery at ever increasing costs to society and the environment.
Fig. 2. Cleared areas and remnant patches of native vegetation in Australia. Source: DEWHA, 2009.
The folly of development
As funding decreases and more species become threatened, some scientists have suggested using triage to determine which threatened species to save and which to let die (Bottrill et al., 2006). However, when it comes to development, the question of which developments should be allowed has not been properly answered, with most going ahead on the assumption that impacts to the environment can mostly be avoided, minimised or offset. Developments are viewed as good by politicians in the interests of ‘progress’, jobs and economic growth.
The Australian government’s offsets policy seeks to balance the need for development with the need to manage biodiversity. It stipulates that biodiversity offsets, which compensate for environmental impacts due to clearing, must meet a number of requirements. One of these is that offsets must “deliver an overall conservation outcome that improves or maintains the viability of the aspect of the environment that is protected by national environment law and affected by the proposed action”. However, this principle of ‘no net loss’ can only be achieved under a limited set of circumstances (Gibbons and Lindenmayer, 2007).
Yet offsets are widely applied, which has led some to assert that offsets are being used as an excuse to allow development (paragraph 1.4-1.6, Australian Greens Minority Report, in Parliament of Australia, 2014). There are many examples where offsets have not been applied appropriately and the principle of no net loss has not been achieved (paragraphs 3.68-3.77, Parliament of Australia, 2014). Some developments have also been approved on the assumption that impacts can be offset, only to find that suitable offset sites cannot be secured (paragraphs 4.27-4.29, Parliament of Australia, 2014). The result of all this must surely be a net loss of biodiversity due to land clearing. As Dr Martine Maron puts it:
“It should be made much more explicit that many impacts cannot be offset, and then the choice is between development and associated biodiversity loss, or the alternative. We cannot always have our cake and eat it, and it is misleading to imply otherwise” (paragraph 3.57, Parliament of Australia, 2014).
Outlook for the future
The situation is only likely to get worse in the future. There are a limited number of sites that can be used to offset development impacts (paragraph 3.94, Parliament of Australia, 2014). As development pressure increases due to predicted population growth, it is likely under the current policies that impacts cannot be offset but developments will go ahead regardless. This effectively commits us to a path of continual habitat and biodiversity loss.
Actions to address the loss of vegetation and habitat cannot compensate for the loss of vegetation and habitat in the first place. Restoration and recovery actions are costly, uncertain to succeed, and difficult to implement. We cannot protect biodiversity unless we think more strategically, drastically reduce land clearing, challenge the assumption that all development is good, and reduce population pressures. Humans rely on a healthy environment to provide goods and services such as food, freshwater, good air quality and recreation. Sustaining, instead of denuding, the environment will have many benefits for the economy and society. When it comes to a problem, prevention is always best.
Department of Science, Information Technology and Innovation (DSITI) (2016). Land cover change in Queensland 2014-15: Statewide Landcover and Trees Study Report. State of Queensland.
Evans, M.C., Watson, J.E.M., Fuller, R.A., Venter, O., Bennett, S.C., Marsack, P.R. and Possingham, H.P. (2011). The spatial distribution of threats to species in Australia. BioScience 61(4), 281-9.
Gibbons, P. and Lindenmayer, D.B. (2007). Offsets for land clearing: No net loss or the tail wagging the dog? Ecological Management and Restoration 8(1), 26-31.
Parliament of Australia (2014). Environment and Communicates References Committee: Environmental Offsets. Parliament House, Canberra.
State of the Environment 2011 Committee. Australia State of the Environment 2011 (SoE 2011).
Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities. Canberra: DSEWPaC.
Watson, J.E.M., Bottrill, M.C., Walsh, J.C, Joseph, L.N. and Possingham, H.P. (2011). Evaluating threatened species recovery planning in Australia. Prepared on behalf of the Department of the Environment, Water, Heritage and the Arts by the Spatial Ecology Laboratory, University of Queensland, Brisbane.