9.3.1 What are ecosystem services?
The term ‘ecosystem services’ is commonly used to describe the ways in which processes in ecological systems (ecosystems) contribute to human social and economic wellbeing. Other terms have been used, such as ‘environmental services’ and ‘nature’s benefits’. The many complex interrelationships among and between species and the nonliving environment in ecosystems make it possible for people to derive benefits from natural environments, such as provision of soil in which crops can grow, control of pests and a range of cultural benefits.
One important effect of applying the concept of ecosystem services has been the identification and classification of those services in ways that allow policy-makers, land managers and communities to cross-check their plans against the full range of possible ecological implications.102
As discussed in Chapter 3: Human needs, most classifications of ecosystem services include components such as:103
- provisioning services, which provide goods essential for human wellbeing, including food, clean water, building materials, fibre and medicines
- regulating services, which regulate the environments in which people live, including regulation of air quality; regulation of climate and weather; mitigation of floods and other extreme events; stabilisation of soils, waterways and landscapes; and control of pests and diseases
- cultural services, which lead to cultural, spiritual and emotional fulfilment, and mental and physical health, including educational and recreational opportunities; sense of place and cultural connection; and spiritual experiences
- supporting services, which support other services, including soil formation, nitrogen cycling and pollination (some recent classifications regard these as intermediate processes that are not direct services in their own right).
Green infrastructure at Cotter RiverPhoto: ACT Government
Increasingly, it has been found that the benefits from these services can be assessed in economic terms that allow them to be considered alongside more obvious financial benefits in decision-making. Often, just knowing what services are provided by the environment allows people from different backgrounds to be involved in productive conversations about their relationships with the natural world and how their decisions might affect their own wellbeing in previously unrecognised ways.103
The framework shown in Figure 9.13 was developed to describe how factors influencing the environment (drivers of change) affect ecosystems and ecosystem services, and how ecosystem services then influence human wellbeing.
Source: Hassan et al104
Figure 9.13 A simplified version of the conceptual framework relating drivers of change, ecosystem services and human wellbeing
Table 9.29 shows a list of ecosystem services and how they relate to the theme chapters of this report: Chapter 4: Air; Chapter 5: Land; Chapter 6: Water, Chapter 7: Biodiversity and Chapter 8: Heritage.
Table 9.29 Ecosystem services and their relation to State of the Environment Report themes
Services (underpinned by biodiversity and a range of ecosystem processes) | Air | Land | Water | Biodiversity | Heritage | |
---|---|---|---|---|---|---|
Provision of: |
food |
✓ |
✓ |
✓ |
✓ |
|
water for consumption |
✓ |
✓ |
✓ |
✓ |
||
building and fibre |
✓ |
✓ |
✓ |
|||
fuel |
✓ |
✓ |
||||
genetic resources |
✓ |
✓ |
✓ |
|||
biochemicals, medicines and pharmaceuticals |
✓ |
✓ |
✓ |
|||
ornamental resources |
✓ |
✓ |
✓ |
|||
transport infrastructure |
✓ |
✓ |
✓ |
|||
Regulation of: |
air quality |
✓ |
✓ |
✓ |
✓ |
|
habitable climate |
✓ |
✓ |
✓ |
✓ |
||
water quality |
✓ |
✓ |
✓ |
✓ |
||
arable land |
✓ |
✓ |
✓ |
|||
buffering against extremes |
✓ |
✓ |
✓ |
|||
pollination, pests and diseases |
✓ |
✓ |
✓ |
|||
productive soils |
✓ |
✓ |
✓ |
|||
noise abatement |
✓ |
✓ |
✓ |
|||
Support for human culture and social values by provision of: |
iconic species |
✓ |
✓ |
✓ |
✓ |
✓ |
diverse environmental characteristics of cultural significance |
✓ |
✓ |
✓ |
✓ |
✓ |
|
support for spiritual and religious beliefs |
✓ |
✓ |
✓ |
✓ |
✓ |
|
systems from which humans can increase their knowledge |
✓ |
✓ |
✓ |
✓ |
✓ |
|
inspiration |
✓ |
✓ |
✓ |
✓ |
✓ |
|
aesthetically satisfying experiences |
✓ |
✓ |
✓ |
✓ |
✓ |
|
mediation of social interactions |
✓ |
✓ |
✓ |
✓ |
✓ |
|
sense of place |
✓ |
✓ |
✓ |
✓ |
✓ |
|
iconic landscapes |
✓ |
✓ |
✓ |
✓ |
✓ |
|
recreational opportunities |
✓ |
✓ |
✓ |
✓ |
✓ |
|
therapeutic landscapes |
✓ |
✓ |
✓ |
✓ |
✓ |
Note: Checkmarks indicate that the processes considered under a theme heading are involved in supporting and delivering a service.
Source: Maynard103
Each theme chapter discusses the ecosystem services relevant to that theme. In the following sections, the key implications of each theme for ecosystem services are considered. Following these theme-specific treatments, conclusions about overall impacts on ecosystem services in the ACT are summarised in Table 9.30.
9.3.2 How is the state of the environment affecting ACT ecosystem services?
Air
Air is essential for sustaining life. Plants and soil organisms exchange gases with the air, which affects its composition and makes it suitable for human life.
Poor-quality air can affect ecosystems and the services they might provide to humans. The ACT generally has good air quality, so the ecosystem services provided to humans by air are rarely negatively affected. Conversely, the state of land, water and biodiversity all have potential impacts on the state of air.
Trees play an important role in improving air quality by removing air pollution.105 Vegetation generally binds soil to limit the amount of dust stirred up by wind. Trees in particular have been noted for their ability to absorb gaseous pollution (eg ozone, sulfur dioxide, nitrogen dioxide) and to intercept particulate pollution on their leaf surface. Reduced air temperatures from vegetation shading can reduce the chemical reactions that produce secondary air pollution (secondary air pollutants, such as ozone, form in the air when primary pollutants react or interact).28,106-109
Urban forests also contribute to a range of other functions, including sequestering carbon, regulating the local climate, reducing noise, mitigating run-off, intercepting stormwater, improving water quality, providing shading and cooling, enhancing aesthetic values and providing opportunities for recreation.105,106,110 The value of these services provided by urban forests can be substantial. One study estimated that the combined benefits of pollution mitigation, energy-use reduction and carbon sequestration by Canberra’s urban forests in 2008–2012 would be valued at US$20–67 million.106
The assessment in Chapter 4: Air shows that the ACT has good air quality. Most emissions are controlled below levels of concern. Air quality measures are within compliance ranges, apart from occasional increases in carbon monoxide from motor vehicles and particulate matter from wood smoke.
Land
Humans benefit directly from land and fertile soils when crops or forests are grown, or when the land is used for a variety of economic and social reasons. They benefit indirectly from the many other roles of land and its soil, such as buffering and moderating the movement of water through ecosystems, disposing of wastes and dead organic matter, and regulating major element cycles such as carbon, nitrogen and sulfur.111–113
In recent years, the capacity of soils to sequester carbon has become a major focus of policies and efforts aimed at reducing levels of atmospheric carbon dioxide.114,115 Carbon sequestration has the potential to indirectly benefit human wellbeing through reducing the impacts of climate change. However, there is debate around the technical and economic constraints to how effective agricultural soils are at offsetting greenhouse gas emissions, and more research is needed.116–118
Different land uses contribute to ecosystem services and human wellbeing in different ways and land management decisions often involve difficult trade-offs among ecosystem services (Figure 9.14). For instance, although converting natural ecosystems into agricultural land provides services like food and fibre production, this process typically degrades land and water resources, and leads to declines in other services like provision of clean water, pest control and regulation of river.119–121 The legacy of broadscale land-use change also creates substantial ongoing financial costs in managing things like soil erosion, salinity and weeds.122–124 Such trade-offs are inevitable, but understanding, acknowledging and factoring in the consequences of land management for the delivery of ecosystem services and the impact on human wellbeing are vital for effective decision-making.125
Source: Adapted from Foley et al126
Figure 9.14 Hypothetical comparison between land in three different states and the mix of ecosystem services provided by each
In the ACT, urban development is increasing. Soon, it is anticipated to become the second-most dominant land use after conservation reserves.127 Urban development usually involves converting open land with natural or seminatural ecosystems to built-up areas. In the process, soil is permanently covered with impermeable or semi-impermeable surfaces, which can have negative effects on the provision of ecosystem services. For instance, it can result in increased water run-off, increased localised temperatures, reduced ability for local food production, and the loss and fragmentation of flora and fauna.128
The high proportion of land under conservation tenure in the ACT means that a wide range of regulating and cultural ecosystem services are maintained at high levels. Forestry and a small amount of farmland provide provisioning services. The question of whether the balance between provisioning and other ecosystem services is appropriate for meeting society’s needs and demands is addressed through planning mechanisms that take account of those needs and demands, and the overriding goal of sustainability. Chapter 10 focuses on whether these mechanisms are functioning effectively. The growth of urban development should be monitored in terms of how it affects the production and availability of ecosystem services in the ACT.
Water
The values and benefits provided by water for residents of the ACT include the supply of sufficient, high-quality water for drinking, as well as water that can be used for cultural and recreational activities. Water management systems also contribute to human wellbeing through the appropriate management of stormwater to protect human health, private property, public infrastructure and downstream ecosystems.
Healthy soils, terrestrial environments and aquatic ecosystems help to filter and purify water after it falls as rain and snow, before it flows into our rivers and streams, and before it is collected and distributed for human use. The quality of water can decline significantly when it passes though ecosystems and soils that have been degraded by poor management, or where they have been disturbed by events such as fire.129–132
The assessments in Chapter 6: Water show that overall surface water quality is in a good state and improving relative to 2007–2011. However, there has been some deterioration in the ability of ecosystems to filter and detoxify water, apparently due to land management practices that both reduce vegetation cover and result in higher levels of chemicals than the ecosystems can cope with. Consequently, some aspects of water quality (turbidity and total nitrogen) were assessed as poor.
Water’s role in supporting local biodiversity, regulating the microclimate and contributing to urban aesthetic values are other important ecosystem services to consider in the ACT.133,134 The assessments in Chapter 6 indicate that the overall ecological condition of the ACT’s waterways is poor, implying a decline in ecosystem processes that support biodiversity (although most sampling was in areas affected by development of some kind, and waterways in more remote areas appear to be in good condition).
As discussed in Section 9.4, the interrelationships between water, land, biodiversity, built infrastructure and human decision-making will determine the ability of the ACT to maintain ecosystems and human quality of life in the face of pressures and risks such as:
- climate variability (particularly droughts and floods)
- activities that affect water quantity or quality in water catchments
- population growth
- climate change.
Biodiversity
The diversity of life in natural systems, interacting with the nonliving components of the environment, underpins and produces ecosystem services. Therefore, any changes in the state of biodiversity are likely to affect a range of interconnected ecosystem services.
Provisioning services are affected mostly by the ecosystem processes that influence soil fertility, protection from extreme weather, stabilisation of riverbanks, erosion control and pest control. Therefore, the ongoing pressure from pest species is a concern, as is the poorly documented influence of land management on the state of waterways.
Regulating services are strongly influenced by vegetation cover and the associated ecological processes happening above and below ground that keep vegetation communities healthy and resilient. The high proportion of land in conservation tenure in the ACT suggests that regulating services are at high levels, but the 2003 bushfires illustrated how fire in particular can change the state of these services if it is extensive and intense, or not managed well. It appears that there is good cooperation between conservation, land, water and emergency management agencies in the ACT to manage fires and other pressures that might influence regulatory ecosystem services (see Chapter 10).
There is a strong focus on threatened and endangered species in the ACT, including those that have a declining geographic distribution, declining population size and numbers of mature individuals, or are possibly becoming extinct. These species are considered important because of their cultural significance, and because of the ethical and moral obligation to other species we accept as humans. To an extent, the state of threatened and endangered species reflects provision of cultural services and the possibility that this state is declining is of concern. Cultural services are also strongly influenced by the visual condition of landscapes, which appears to be good in the ACT since a high proportion of land is under conservation tenure.
Chapter 7: Biodiversity reveals that the pressures on biodiversity from pest species are high. Pressures from land clearing or modification are unclear as a result of limited information in the ACT, but urban development is likely to be an increasing pressure that has major impacts on ecosystem services where it occurs. It is important that there is strategic consideration of the cumulative impacts of small modifications to habitat, because these can lead to thresholds being crossed unknowingly and unintentionally for at least some ecosystem services. Pressures from fire are likely to be moderate to high, and to increase with climate change, but there is a high level of risk planning and management aimed at containing this risk.
Heritage
The links between heritage and ecosystem services are complex. The values of natural and Aboriginal heritage places are often derived from elements of the ecological systems in which those places are situated. When this is the case, degradation in the state of land, water or biodiversity will affect heritage value. Historical heritage places often also have links with the natural environment. For example, Canberra was designed to fit into the surrounding landscape, and to take advantage of views and availability of water and recreational opportunities.
There are insufficient data available to assess specifically if and how trends in the state of land, water or biodiversity have affected heritage places in general. Concerns have been raised about the impacts of urban expansion on Aboriginal heritage sites, including the impacts of removing artefacts from their original location for their protection. Fires have temporarily had major impacts on the visual amenity of the ACT and some long-term effects on heritage structures. Decisions about how burnt areas have been managed also have impacts that were not able to be considered in this report. It was noted previously that there is a need to better consider the cumulative impacts of urban development and other land modification on biodiversity and ecosystem functions. The same applies to the cumulative impacts of land modification on heritage values.
Assessment summary
Table 9.30 summarises the assessments of the effects of the state of the environment in the ACT on ecosystem services.
Table 9.30 How the ACT state of the environment is affecting ecosystem services, by theme
Theme | Description of effect on ecosystem services | Effect |
---|---|---|
Air |
Poor-quality air can affect ecosystems and the services they might provide to humans, but the ACT generally has good air quality and so ecosystems are unlikely to be affected |
Positive |
The abundance of natural ecosystems surrounding Canberra help to absorb air pollutants and minimise the impacts of wind-blown particulate matter |
Positive |
|
Land |
The high proportion of land under conservation tenure means that a wide range of regulating and cultural ecosystem services are maintained at high levels |
Positive |
Increasing urban development may increase run-off, increase localised temperatures, reduce ability for local food production, and cause the loss and fragmentation of flora and fauna |
Potentially negative |
|
Water |
The high proportion of land under conservation tenure means that a wide range of regulating and cultural ecosystem services are maintained at high levels |
Positive |
Overall surface water quality is in a good state and improving |
Positive |
|
ACT residents have access to high-quality drinking water and overall were satisfied with the quality of drinking water |
Positive |
|
There has been some deterioration in the ability of ecosystems to filter and detoxify water, because of reduced vegetation cover and increased chemical levels |
Negative |
|
Canberra’s lakes, ponds and constructed wetlands improve biodiversity, aesthetics, heat mitigation and recreational opportunities – thereby supporting human wellbeing |
Positive |
|
The overall ecological condition of the ACT’s waterways (particularly in built areas) is poor, indicating a decline in ecosystem processes that support biodiversity; however, measurements were mostly made in disturbed areas and protected areas were healthier |
Potentially negative |
|
Biodiversity |
The high proportion of land under conservation tenure supports healthy and resilient ecosystems, and provides protection from extreme weather, stabilises riverbanks and controls erosion |
Positive |
Some threatened and endangered species in the ACT are declining, but others are increasing |
Potentially negative |
|
Pressures on biodiversity from pest species and fire are high |
Potentially negative |
|
Incremental change (eg in urban development) may lead to thresholds being crossed unknowingly for at least some ecosystem services |
Potentially negative |
|
Heritage |
The high proportion of land under conservation tenure protects natural and Aboriginal heritage |
Positive |
Degradation in the state of land, water or biodiversity, as well as pressure from urban development and fire, may affect heritage value |
Potentially negative |
|
Incremental change (eg in urban development) may lead to thresholds being crossed unknowingly for at least some ecosystem services |
Potentially negative |