Criteria for good biodiversity indicators for forest management in the context of product life cycle assessment
Weidema B P (2008)
Hørsholm: 2.-0 LCA consultants.
This study has been performed for a confidential client.
The objective of the study is to develop a criteria list, outlining what criteria a good biodiversity indicator for forest management should fulfil, with a special focus on the indicator requirements of product life cycle assessments, and any specific requirements related to raw material acquisition.
The developed criteria list is intended to be used for a review of indicators already proposed in previous studies, to result in an assessment of the extent to which the different proposed indicators fulfil the suggested criteria.
Human activities influence biodiversity in numerous ways by increasing the likelihood of some species or ecosystems to survive at the expense of others, most often leading to a reduction in biodiversity. This happens through:
- The release of nutrients, toxic substances or invasive species.
- The removal of soil, nutrients or biomass.
- Physical changes to the flora, fauna, surface (including changes in its albedo) or soil (including soil compaction and other changes in water infiltration and evapotranspiration).
The impacts from releases (emissions) of nutrients and toxic substances are well covered in product life cycle assessments (LCA), through impact categories such as “climate change (global warming)”, “stratospheric ozone depletion”, “human toxicity”, “eco-toxicity”, “photo-oxidant formation”, “acidification” and “nutrification”. All of these categories of impacts may eventually lead to changes in biodiversity, and attempts have been made to aggregate such impacts on biodiversity in terms of biodiversity-weighted square-meter-years (also known as PDF×m2×years, where PDF stands for Potentially Disappeared Fraction of species, a concept originating from ecotoxicity assessments).
While forest management may indeed have the potential to influence the above mentioned impact categories through regulating the releases from forestry activities, the purpose of this study is not to develop criteria for biodiversity indicators of these impacts (which also take place outside of the forests) or the impacts from releases of alien species. Rather, we shall focus solely on providing criteria for indicators of direct impacts of forests management on forest biodiversity, i.e. the issues of physical changes and removal of soil, nutrients or biomass. Nevertheless, it would be desirable that biodiversity indicators for such physical changes could eventually be related to the biodiversity indicators of the release related impact categories, so that this “compatibility” in itself could be a criterion for a good indicator, as we will discuss further in Chapter 3.
The possible criteria are discussed in three chapters. Chapter 2 describes the specific requirements of Product Life Cycle Assessment (LCA), while Chapter 3 describes the broader requirements for biodiversity indicators in general. Chapter 4 describes more general criteria that apply to indicators as such.