ILCD Handbook: Framework and requirements for LCIA models and ...

ILCD Handbook: Framework and requirements for LCIA models and indicators First edition
Iwasa 2000) 16 , meaning that the population disappears from the ecosystem before it would
have if the ecosystem had not been exposed to the stress, ―due to a reduction of the growth
rate of the population. The estimated decrease in growth rate can be translated into an
extinction risk, corresponding to the reduction of the MET (Hakoyama and Iwasa 2000)
called MET risk (Tanaka and Nakanishi 2000). The MET model requires knowledge of the life
history of the considered species, in order to assess the growth rate of the population. The
population life-history data needed for estimation of the MET is the ecosystem’s carrying
capacity for the population, an intrinsic growth rate for the population and its variance.
Hakoyama and Iwasa demonstrate that estimation of values for these three needed
population life history parameters requires a time series of population fluctuation including at
least 10 data points.‖ 17
This data requirement is not generally considered realistic in an LCIA context.
Nevertheless, the MET approach has now been applied to LCIA in the Japanese LIME
methodology 17 as a basis for deriving endpoint indicators for ecotoxicity effects - the EINES
indicator (Expected Increase in Number of Extinction Species). Further study into the related
simplifications and robustness of this approach is justified.
3.2.4.2 Changes in genetic diversity
Both approaches to the assessment of biodiversity loss described above suffer from ―a
conceptual divergence from the earlier quoted Rio Convention’s definition of biodiversity‖ 17 ,
quoted as including the diversity within a species reflecting the genetic variation within the
population. Instead of using biodiversity as a basis for the endpoint modelling, use of ―genetic
diversity could be a good alternative in solving some of the problems‖ 17 related to the
divergence of concepts focusing on diversity within species, versus concepts focusing on
diversity between species. This also considers the problem with vulnerability of species after
repeated exposure to contaminants.
“With the development of new genetic techniques, it has become possible to quantify the
number of genes of some species or some loci. Genetics of ecotoxicology has become an
important field of research (van Straalen and Timmermans, 2002; Belfiore and Anderson
1998; Bickham et al. 2000). This approach is based on the principle that genetic changes in
a population are resulting from mutations, migration, genetic drift, and natural selection. The
possession of one or more alleles by individuals will confer it a better “fitness”, compared to
other individuals. The increase in reproductive effort of this individual compared to others will
change the frequency of the same allele in the population.‖ 17 This is, however, still a field of
research, and to the extent that models exist (e.g. Norberg et al., 2001) the data are not yet
available to run such models for the combinations of species and chemicals required in
applications like LCA.
3.3 Natural Resources
3.3.1 Recommendation
No recommendation is made here at the endpoint level for the Area of Protection of
‗Natural Resources‘. Recommendations for specific indicators can be based on current
practice, while these are unlikely to address all options. For example, the characterisation
models used in current LCIA practice for resources are based on quantifying the effort
16 See Hakoyama and Iwasa, 2000
17 See Itsubo et al., 2003; Itsubo and Inaba, 2003; Narita et al., 2004
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