Development of LCIA characterisation factors for land use impacts on biodiversity

The UNEP/SETAC life cycle initiative has recently proposed a framework for life cycle impact assessment (LCIA) of land use. Still, a lack of appropriate LCIA-methods for assessing land use impacts exist in life cycle assessment (LCA). Most existing methods are either too coarse-grained regarding the differentiation between different land use types (e.g. conventional farming versus organic farming), or they are too narrow regarding spatial coverage (e.g. only part of Europe). Therefore, the purpose of this article is to develop a method that overcomes these problems. A secondary goal is to develop a method for which it is possible to determine characterisation factors for any land use type in any region without the need for overwhelming data and data manipulation requirements. The developed method for LCIA of biodiversity focuses on species richness of vascular plants which can be determined from species–area curves. The category indicator is calculated as the multiplication of occupied area, the number of species affected per standard area (100 m2), the duration of occupation and renaturalisation from transformation, and a factor for ecosystem vulnerability. The main uncertainties of the method are related to the determination of renaturalisation times and the establishment species–area curves. The intention of the study presented in this article, i.e. to develop an applicable model with global coverage and no constraints on resolution regarding spatial and land use type differentiation, has widely been met. The limiting factor for applicability is the access to species richness surveys for the relevant regions and land use types. But still, the method shows that, with limited efforts, it is possible to calculate characterisation factors for a large range of land use types in different parts of the world.