What has changed since 2011?

• The effects of the millennium drought in southern Australian (2000–10, although in some areas it began as early as 1997 and ended as late as 2012) have continued to relax, and many areas are starting to recover; 2010–11 was Australia’s wettest 2-year period on record.
• Dry conditions developed in Queensland again in 2013, and, by 2015, some 86.1 per cent of the state was drought declared—the highest proportion in the state’s history.
• Australia’s conservation estate has increased, with significant additions to the National Reserve System, largely through the addition of new Indigenous Protected Areas.
• The use of land and vegetation for carbon sequestration, carbon emissions avoidance and emissions reductions has expanded.
• Although 2014–15 was a period of significant downturn, mining is still a major industry in many regions, particularly Western Australia, Queensland and New South Wales.
• Soil acidification and erosion continue to be significant problems in Australia’s agricultural areas, although the impacts of soil salinity have slowed.

State and trends

Land use

The impacts of human land use are spread unevenly across the country. Vegetation clearing is concentrated in the long-settled agricultural and coastal zones, where more than 50 per cent of native vegetation has typically been cleared.

The general pattern of land use is well established across Australia (Table OVW1). Estimates of the areas affected are imprecise in some cases, but give a general indication of the scale of different land-use activities across Australia.

In terms of extent, the dominant land use in Australia is livestock grazing of native vegetation (45 per cent). Grazing of modified pastures accounts for another 9 per cent and dryland cropping about 3.6 per cent (note that there is no consistent assessment of grazing land condition with national applicability). Nature conservation and other forms of protection, together with land not formally protected but subject to minimal use, account for 36 per cent of Australia’s land area.

The distribution of these land uses reflects the history and pattern of European settlement; the availability of soil, water and climate to support primary industries; the distribution of other natural resources; and the transport networks that link them.

Indigenous land

Indigenous people, their land, and their cultural and natural resource management activities make core contributions to managing Australia’s environment (see Box OVW2). Indigenous lands contain significant levels of biodiversity, and long-term investment in Indigenous land management programs has delivered environmental, cultural and economic benefits (Altman et al. 2007, SVA Consulting 2014, van Bueren et al. 2015).

Recent increases in Australia’s terrestrial protected area network have been driven primarily by an increase in the number of Indigenous Protected Areas (Figure OVW5). At the end of 2014, there were 67 Indigenous Protected Areas across approximately 55 million hectares, covering about 40 per cent of terrestrial protected areas. This includes an increase since 2008 of 42 Indigenous Protected Areas and 20.6 million hectares. However, not all Indigenous Protected Areas have the same protected status.

Protected areas

The National Reserve System seeks to reserve comprehensive, adequate and representative areas of land within the country’s 89 bioregions. Priority is given to increasing the protected areas that are under-represented in bioregions (i.e. less than 10 per cent protected). The National Reserve System is a mosaic of multijurisdictional, multitenure areas under government, Indigenous or private management (Figure OVW6).

Australia has made significant progress in increasing the extent of the National Reserve System since 2011. At the end of 2014, the National Reserve System covered 137.5 million hectares, or 17.9 per cent of Australia’s land area (DoEE 2014), compared with 13.4 per cent in 2011 (DoEE 2010). It is estimated that, by 2016, the total terrestrial protected area will have increased to at least 19.2 per cent of Australia’s land area.

However, despite this growth, only minor progress has been made since 2011 in meeting representation targets for ecosystems and threatened species. In part, this is because most growth has been in desert bioregions, so that representation improvements have been highly localised. Nearly 30 per cent of terrestrial endangered communities have more than 50 per cent of their extent represented in the National Reserve System. However, 30 per cent of endangered communities and 50 per cent of critically endangered communities have less than 5 per cent of their extent represented.

Conservation covenants have grown rapidly on private lands in Australia, and contribute to the terrestrial component of the National Reserve System. These protected areas have restrictions on use attached to the title of freehold lands, and special conditions on leasehold lands, to enable their management as private protected areas. These covenants are essential for meeting the challenge of expanding the National Reserve System to meet national goals (Craigie et al. 2015), but they do not exempt private land from mineral exploration and extraction, and do not have the same level of management oversight and monitoring as the National Reserve System (Fitzsimons & Carr 2014).

Agriculture and forestry

The sophistication of Australia’s agricultural land management continues to increase, with ongoing reductions in the intensity of agricultural chemical use in the cotton industry, largely because of the adoption of genetically modified cotton (Acworth et al. 2008), more careful use of fertilisers in sensitive environments (e.g. catchments of the Great Barrier Reef), and more flexible approaches to grazing management to reduce erosion and increase productivity. However, pesticide loads continue to be a cause for concern. Horticultural production, quality and profitability are threatened by introduced and native pests, diseases and weeds.

Agricultural practices also aim to protect the soil and prevent sediment movement. Significant investment by the Australian Government, and state and industry groups has led to a better understanding of the source and causes of nutrient and sediment increases in waterways. Modelling suggests that engagement with natural resource management bodies, industry and farmers could potentially achieve significant (10–30 per cent) decreases in loads.

The area of public native forest managed for wood production has continued to decline since 2011, to around 7.5 million hectares, and there was a corresponding increase in the extent of public native forest in conservation reserves (ABARES 2015b).

Carbon sequestration

Use of land and vegetation for carbon sequestration, carbon emissions avoidance and emissions reductions has become a mainstream interest for industries and governments (see, for example, Box OVW3); this use has recently expanded. Biosequestration may have an impact on future rural land use and management.

Mining

The recent downturn in the mining industry has put some proposed developments on hold and stopped other activities.

There has been a significant expansion of coalmining and the coal-seam gas industry in areas across Queensland and New South Wales. Expansion of these developments in areas known as ‘prime agricultural land’ has caused conflict because of competition for land. Enhanced regulatory oversight at state and national levels has been introduced to address concerns about competition for, and potential contamination of, water resources. Other possible adverse impacts on the environment and human health exist through, for example, hydraulic fracturing (fracking), habitat fragmentation, disruption of ecological processes and fugitive gas emissions. The EPBC Act was amended in 2013 to include a new water trigger, which allows the impact of large coalmining developments and coal-seam gas on water resources to be assessed at a national level. Some state and territory governments have introduced moratoriums that restrict growth of the coal-seam gas industry.

Most of the announced coal-seam gas reserves are already committed to the liquid natural gas industry from 2015–16. This will likely see demand for further development of unconventional (coal, shale and tight) gas resources to meet domestic and international demand. A consequence is that exploration for shale gas and tight gas has increased; in particular, shale gas is likely to be plentiful and has the potential to be an important additional energy source (Cook et al. 2013). Shale gas, like coal-seam gas, has possible adverse effects on the environment and human health, with state regulatory regimes having a major role in risk mitigation.

Soils

Salinity, soil carbon stocks, acidification and erosion affect soil condition and productivity in Australia.

Increases in dryland salinity appear to have been slowed by the millennium drought, although the return to wetter conditions is likely to increase the spread of salinity.

The management of soil carbon is central to maintaining soil health and ensuring global food security, as well as providing an important sink for atmospheric carbon. Australia has a lower baseline soil organic carbon stock than other parts of the world, and few regions have increasing soil carbon stores. The time since vegetation clearing is a key factor determining current trends. For example, large parts of Queensland are on a declining trend, because widespread clearing for agriculture was still occurring in the 1990s. Similarly, regions with intensifying systems of land use (e.g. northern Tasmania) and most regions with a projected drying climate have declining trends. The savanna landscapes of northern Australia have significant potential for increasing soil carbon stores, but this requires changes in grazing pressures and fire regimes.

Soil acidification is another challenge facing agriculture. Soil acidification restricts options for land management, because it limits the choice of crops and vegetation to acid-tolerant species and varieties. Soil acidity affects approximately 50 million hectares (or 50 per cent) of Australia’s agricultural land, and about 23 million hectares of subsoil layers, mostly in Western Australia and New South Wales (NLWRA 2001). Soil acidification is of greatest concern in situations where:

• the soil already has a low pH (i.e. is already acidic)
• agricultural practices increase soil acidity (e.g. use of high-ammonium nitrogen fertilisers, large rates of product removal)
• the soil has a low capacity to buffer the increase in acidity (e.g. infertile, light-textured soils).

It is relatively straightforward to reverse short-term surface soil acidification through the application of lime. However, it is much harder to reverse the problem if the acidification has advanced deeper into the soil profile, because incorporating lime at depth is prohibitively expensive. Although rates of lime application appear to be increasing, they still fall far short of what is needed to arrest the problem in some jurisdictions.

Current rates of soil erosion by water across large areas of Australia exceed soil formation rates, although progress has been made in reducing soil erosion through soil conservation measures.

A new generation of fine-grained soil mapping is being conducted that will inform national mapping and monitoring of carbon, biodiversity, agricultural impact and ecosystem functions in general. It is the result of national collaborative research, funded through the Terrestrial Ecosystem Research Network, involving CSIRO; the University of Sydney; Geoscience Australia; and national, state and territory government agencies.