02 Jun 2022

Biodiversity Impact Assessment of future biomass provision for biofuel production – Phase 1

This study aims to determine environmental impacts on biodiversity due to biomass production for bioenergy use. For this purpose the Biodiversity Impact Assessment (B.I.A.) method presented by Lindner et al. is applied to assess the impact of Miscanthus cultivation in Bulgaria and Germany. In addition, a methodological comparison to the impact assessment method by Chaudhary & Brooks (called the Potentially Disappeared Fraction of species (PDF) method here) is drawn. Assumptions on the biomass cultivation are based on a preceding study by Imperial College London Consultants, which provides an estimation of biomass availability in line with the EU Renewable Energy Directive II (RED II) referring to unused, abandoned and degraded land in the EU.

The Fraunhofer study finds that the impact on biodiversity mainly depends on the state of the land before the cultivation of Miscanthus. However, regionally specific biodiversity value (addressed by ecoregion factors) and crop yields also affect the specific biodiversity value per biomass produced. Starting from this, a priority for areas (NUTS (Nomenclature des unités territoriales statistiques) region and land status types) to be used for the cultivation of Miscanthus can be derived. In a preceding study on biomass availability of Imperial College London and Concawe, up to 14.4 Mio. t/a of Miscanthus production was calculated, depending on the scenario. The cultivation of Miscanthus on initially degraded land can have a positive impact on the biodiversity value of the land.

On initially unused and abandoned land, however, damage to biodiversity is very likely. Assuming the use of low biodiversity impact areas first, a certain amount of Miscanthus can be produced on abandoned and unused land, with biodiversity damage and benefit cancelling each other out. This point of net zero biodiversity damage is calculated under varying assumptions. Under the assumption that appears most probable, this point is at 6.9 Mio. t/a of Miscanthus production. If the use of the full biomass production capacity in the preceding study on biomass availability according to RED II is assumed, the biodiversity damage from Miscanthus cultivation on unused and abandoned land exceeds the benefits from cultivation on degraded land. Methodological challenges are identified regarding the assignment of hemeroby levels the land status types. For this reason, a sensitivity analysis is included in which different hemeroby levels are assigned to the initial state before Miscanthus cultivation. The results are very sensitive to this assignment.

Depending on the assumed initial hemeroby level, either no benefits from Miscanthus cultivation at all, or significantly higher benefits are calculated. Thus, either no Miscanthus production would be possible without biodiversity damage, or the production of all 14.4 Mio. t/a linked to IC high scenario would be beneficial to biodiversity, depending on the assumed initial hemeroby level. The characterization factors readily available for the PDF method do not allow differentiation between the different initial land use types. All areas are regarded as either natural habitat or regenerating secondary vegetation, with no biodiversity loss in the initial state. Miscanthus cultivation on each area results therefore in potentially lost species with the difference in damage per functional unit mainly due to yield differences between the areas. The PDF results show the lowest impact on land that was initially unused and the highest on land that was initially degraded; contrary to the B.I.A. results.

However, a sensitivity analysis showed that, if different land use was assumed for the existing state of land and the characterization factors of other land use types – that are defined in the PDF methodology - are applied, the results are similar to the ones of the B.I.A. method. Further studies on different feedstock types in different ecoregions and biomass types are recommended to estimate the potential biomass production for biofuels in Europe without decreasing biodiversity quality under different management parameters. This could lead to different conclusions in terms of the amount of biomass that can be produced with net zero impact to biodiversity, the prioritization of areas for cultivation, and the applicability of product specific biodiversity assessment methods to different cultivation methods for further biomass types according to RED II.

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