Optimising Land Use for Multiple Ecosystem Services Objectives: A Case Study in the WaitakiCatchment, New Zealand

Abstract: In New Zealand there has been rapid land-use change over the last 170 years, from all natural ecosystems to a mix of natural ecosystems (alpine ecosystems, indigenous forests, and tussock grasslands) and managed ecosystems (primarily pastoral farming and forestry). Tools are required to assess the balance between natural and managed ecosystems, and to ensure the sustainability of human development and equity in resource use. We use the ecosystem services approach to help resource managers achieve that balance. In this paper we combine several critical ecosystem services (provision of food and fibre, provision of clean water, regulation of water-flow, provision of natural habitat) into a framework for land-use optimisation, LUMASS. We developed spatial explicit models of these services based on process-based models upscaled to national level using look-up tables. Quantification depends on land use, climate, and soil, and can be used to analyse trade-offs and the optimal configuration of the landscape that would maximise the benefits for humans. The Waitaki catchment is subject to such trade-offs with the conversion of natural areas (mainly tussoc