Ecosystems provide many benefits to human society, including food, water, timber, climate control, soil formation, tourism, and recreation. Collectively these can be termed “services” and a value can be placed on them (Bryan 2014). Humans have always been dependent on services provided by ecosystems but, until recently, the main concern has been with services which provide tangible products – particularly those which can be sold for profit, such as food and timber. However, there is increasing awareness of the value of those services which, until now, could not be traded – such as clean air and water, erosion control and climate control (Close et al 2010).
Failure to understand the importance of these services has contributed to problems like climate change, soil erosion, and salinity, and a growing awareness of those problems has driven research to identify ecosystem services and quantify their value. Although such services are an important part of what can be considered as our natural capital, they have previously been considered “externalities” in economic terms and little or no account has been taken of them by businesses and governments (Close et al 2010). Rees (1998) describes the economy as a parasite on nature and a sub-system of the ecosphere.
It is clear that ignoring the intrinsic value of ecosystem services, and failing to ensure that the ecosystem continues to function properly, is not sustainable in the long term. As the economy sucks the ecosystem dry, the services that we rely on will cease to exist and serious crises will ensue.
The global population is increasing and consumption is rising with it, but the amount of land available to support that increased population and its demands remains the same. In fact, the amount of land available to natural ecosystems is decreasing, as urban areas expand. This means there is pressure to get more production from less land (Bryan 2014), but this production cannot be at the expense of the ecosystem services needed for our survival and to make our lives worth living.
As current land uses cease to be economically viable – because of irrigation costs, for example – it is important to consider the potential for enhancing ecosystem services when deciding on new uses for that land. In order to achieve such an aim, those services must be clearly identified and some form of value must be placed on them, local communities and stakeholders must be consulted and included in the planning process, and investment priorities need to be evaluated (Abel et al 2003, Close et al 2010). Changes in land use are not likely to sacrifice much production because only the least productive land will be changed, leaving the most productive land as it is (Bryan 2014).
Valuing ecosystem services is important as it allows properly informed choices to be made between competing land uses. However valuation is not a simple matter and such valuations should not merely focus on monetary value. Financial benefits arising from ecosystem services are only a part of their intrinsic value, alongside their ecological and social values (Dendoncker 2013).
Replacements for some ecosystem services (e.g., fertiliser and pesticide) have been valued for a long time, while others (e.g., carbon sequestration) have recently begun to have values placed on them. However, many other services, such as environmental flows and cultural services, have yet to be valued or included in markets (Close et al 2010).
Modelling Sustainable Land Use
Planning for future land use change is a complicated process, involving a range of tasks and requiring a deep understanding of the possibilities and the potential outcomes. A number of models have been developed over the last half century to aid this process (Arsanjani 2012).
The Landscape Futures Analysis Tool (LFAT) is one such model, developed by the University of Adelaide and the CSIRO. Its aim is to assist stakeholders to envision different land use scenarios and how they fit with considerations such as climate change and future trends in carbon prices and commodity prices. This web based tool uses different combinations of climate, commodity prices, production costs, and carbon prices to produce 256 land use scenarios. These scenarios can be used to answer planning questions related to biodiversity, weed management, carbon sequestration, and agricultural production. The outputs of this tool are maps showing the outcomes of potential land use scenarios, which can help natural resource managers and land use planners to make decisions about future land use (Meyer et al 2013).
The Land Use Trade-Offs model (LUTO) aggregates the outputs from a range of other models to generate biophysical and economic scenarios showing the impacts and trade-offs of land use, profits (yields and prices, etc), and policies. Because of the complexity of the potential outputs, the scenarios must be limited in number. These are globally agreed emissions trajectories, capacity constraints (e.g., biofuel processing capacity, or the number of trees which can be planted in a year), and global scenarios (e.g., prices of carbon, crops, livestock, etc). LUTO combines environmental, biophysical, and economic layers to produce a picture of the likely outcomes of potential land use changes (Bryan 2014).
Bryan et al (2014) used a simplified version of the LUTO model to calculate economic returns from agriculture, carbon plantings, and environmental plantings for each year until 2050. They quantified ecosystem services providing increased biodiversity and carbon sequestration resulting from potential land use changes. Modelling these for a range of global outlooks showed a carbon market would produce substantial carbon sequestration, but little biodiversity, whereas a biodiversity market would increase biodiversity but provide little carbon sequestration. Understanding this trade-off can help plan land use for a sustainable future.
Abel, N, Cork, S, Gorddard, R, Langridge, J, Langston, A, Plant, R, Proctor, W, Ryan, P, Shelton, D, Walker, B, and Yialeloglou, M 2003, Natural Values: Exploring options for enhancing ecosystem services in the Goulburn Broken Catchment, CSIRO, Canberra, ACT.
Arsanjani, JJ 2012, Dynamic land use/cover change modelling: Geosimulation and multiagent-based modelling, doctoral thesis accepted by University of Vienna, Austria, Springer, Berlin, Germany.
Bryan, BA 2014, Modelling potential futures for land use and ecosystem services, seminar presented at the University of Adelaide, 6th August 2014.
Bryan, BA, Nolan, M, Harwood, TD, Connor, JD, Navarro-Garcia, J, King, D, Summers, DM, Newth, D, Cai, Y, Grigg, N, Harman, I, Crossman, ND, Grundy, MJ, Finnigan, JJ, Ferrier, S, Williams, KJ, Wilson, KA, Law, EA, and Hatfield-Dodds, S 2014, ‘Supply of carbon sequestration and biodiversity services from Australia’s agricultural land under global change’, Global Environmental Change, 28, 166-181.
Close, A, Zammit, C, Boshier, J, Gainer, K, and Mednis, A 2010, Ecosystem Services: Key Concepts and Applications, Occasional Paper No 1, Department of the Environment, Water, Heritage, and the Arts, Canberra, ACT.
Dendoncker, N, Keune, H, Jacobs, S, and Gómez-Baggethun, E 2013, ‘Inclusive Ecosystem Services Valuation’, in S Jacobs, N Dendoncker, and H Keune (eds), Ecosystem Services, Elsevier, Boston, USA.
Meyer, W, Bryan, B, Lyle, G, McLean, J, Moon, T, Siebentritt, M, Summers, D, Wells, S 2013, Adapted Future Landscapes – From Aspiration to Implementation, National Climate Change Adaptation Research Facility, Southport, Qld.
Rees, WE 1998, ‘How should a parasite value its host?’, Ecological Economics, 25, 1, 49-52.