FIF - Ecosystem Services in Ohiwa Catchment

This case study provides an example of the Forest Investment Framework model (FIF) which, in comparison with other methods, has been used to assess and estimate key ecosystem values within the Ohiwa catchment.    

This study serves as a proof of concept for the application of the ecosystem services approach as a framework for realising the full value of the services derived from ecosystems in a catchment.

FIF is a spatial economic model developed by Scion who carried out this case study with the aims of:

  1. providing an initial list of key ecosystem services related to existing land uses in the Ohiwa catchment,
  2. estimate their values using a desktop analysis, and
  3. compile and present data in order to facilitate discussions around the full value of ecosystem services within the catchment.

Another objective was to undertake a gap analysis in assessing ecosystem services for the catchment.

The land within the Ohiwa catchment is used in many ways and provides several ecosystem service benefits to society, as a result a better understanding of these ecosystem services in the area can help inform planning and management decisions surrounding functioning natural ecosystems and the value they hold both economically and intrinsically.

FIF+ Ohiwa context

Land use in the Ohiwa catchment

Method

The FIF model estimated the annual value per ha of providing wood and pulp from exotic planted forests in the catchment. It was also used to estimate the values of carbon sequestration and avoided erosion. Value per hectare of each ecosystem service could then be applied throughout the catchment area for each land use type resulting in the total value of ecosystem services per land use type.

This case study also provides examples of scenario analysis. Using the indicative ecosystem service values that had been calculated the study was able to estimate the impact of possible land use changes in the catchment area. The goal of such scenarios was to demonstrate the ability to show modelled changes and there outcomes economically in an effort to stimulate land management discussions.

The three scenarios within the Ohiwa Catchment were;

  1. Converting 320 ha of dry stock area to exotic forestry thus increasing the exotic forestry area by 10%
  2. Converting 32 ha of dairy to wetlands thus increasing the wetlands area by 10%
  3. Developing a technology that reduces nitrogen leaching in dairy, dry stock and horticulture farms by 25%. Under this scenario, we assumed that a new technology is developed to reduce nitrogen leaching by 25% in the three productive land uses (dry stock, dairy and horticulture). There is no land-use change involved but the technology would be adopted in pasture and horticulture areas which account for 45% of the catchment. 

Findings

This study showed the benefits and practicality of using FIF in the assessment of ecosystem services within a catchment system. Key ecosystem services in the Ōhiwa catchment with market values were identified as food (meat, milk and fruit) and fibre (wool, wood and pulp), and the tradeable carbon sequestration credits from exotic planted forests. A number of ecosystem services with non-market values were also identified. These were:

  • avoided erosion/sedimentation;
  • flood mitigation/disturbance regulation;
  • regulating nutrient (nitrogen) supply (e.g. avoided N leaching);
  • pollination; water regulation; waste treatment;
  • pest and disease regulation;
  • water supply;
  • recreation;
  • species conservation;
  • nutrient cycling; and
  • soil formation.

The study was able to highlight the value of avoided erosion which includes off-site benefits from soil stabilisation as is provided by exotic and indigenous forests in the catchment. It was noted that these off-site benefits that ecosystem services provide can often impact the general public more and to a lesser extent the landowner directly.

FIF+ erosion values output

The study gives a much fuller overall picture of the full value of the catchment within an ecosystem services framework. It provides the opportunity to explore ways to attain future goals for the catchment. The results of this desktop study, although preliminary, can be used in discussions about ecosystem services in the catchment and as a tool to support land-use planning.

Associated Models

Forest Investment Framework (FIF)

The Forest Investment Framework (FIF), previously called the Forest Investment Finder, has been developed to enable the assessment of key ecosystem services provided by planted forests in New Zealand.

References

Richard T. Yao and Sandra J. Velarde (2014): Ecosystem Services in the Ōhiwa Catchment. Scion Report S0011, Prepared for Bay of Plenty Regional Council.