The tradeoff between land use and natural capital

27 June 2019
Richard Aspinall and Michele Staiano

Our recently study of land use change in Scotland explored the sequence of changes in agricultural land use and the dynamics of change in provisioning services from agriculture in Scotland between 1940 and 2016. Among the changes associated with modernisation of land use in Scotland, our analysis identified some ways in which funds of capitals and flows of inputs and output ecosystem goods are linked to land management practices and policies.

Our analysis is summarised for each year from 1940 to 2016 in Figure 1, using a series of benchmarks computed from flows and funds.  Figure 1-a records the total financial inputs and outputs and total income from farming (at 2010 prices) and Figure 1-b the total energy inputs and outputs as well as the yearly balance (output-input). Results for inputs and outputs for both finance and energy follow the same general pattern of change over time, although the energy and economic efficiencies, measured as the ratio of outputs to inputs or simply as the excess of outputs over inputs, show two different patterns (Figure 1-a and b). The economic efficiency of Scotland’s farming system, taken as a whole, was greater, in real terms, before 1973, than since.  This period of greater efficiency coincides with the period of deficiency payments from 1947 until 1973, guaranteeing prices.  The energy efficiency, however, shows a different pattern, with increased efficiency following modernisation of agriculture and greater intensification after Britain joined the Common Market.

Figure 1: Our analysis is summarised for each year from 1940 to 2016, using a series of benchmarks computed from flows and funds

Figure 1-c shows two flow-flow ratios: food production efficiency of agriculture, as conversion of finance to energy (GJ energy output/£000 input) and the economic return on resource use by farming (£000 output value/TJ energy input). These two graphs combine the energy and economic output-input ratios, showing the complex change in efficiencies that have occurred between 1940 and 2016.  The graphs emphasise the changes summaries in the Nexus Times article (this issue) ‘Land use change connected with the evolution of farming systems – modernisation in practice’, placing these periods within a sequence of changes that have:

  • increased flows of provisioning goods through increased production,
  • increased the energy and resource use efficiency of farming, and
  • seen a decline in the economic efficiency and value (in real terms) of provisioning goods.

Figure 1-d shows the expenditure on fertiliser and lime inputs to Scotland’s farming from 1950 to 2016, highlighting a decrease in cost over time.  Figure 1-e however, shows the quantity of fertiliser used in Scotland each year, and particularly, the increase in nitrogen fertiliser used, albeit with a tendency to decrease since the early 1990s. 

This history of land use change, shows that although the energy efficiency and flow of goods per unit hectare and per unit labour have increased as farming has modernised, the inputs necessary to maintain those flows of ecosystem goods are also increasing, as their relative economic costs decrease.  Increases in use of fertiliser suggest that the natural capital fund is not being maintained without a large, and increasing, input.  Our analysis of the complexity of the coupled agricultural land system also shows that land management rather than biodiversity is a necessary subject for evaluation of provisioning services from agriculture, and that loss of natural capital under current management practices is unsustainable, given the large inputs of fertilisers that are required annually.

Reference:

Aspinall, R. J. and Staiano, M. (forthcoming) Ecosystem services as the products of land system dynamics: lessons from a longitudinal study of coupled human-environment systems.  Landscape Ecology