Effects of Consumptive Water Use on Biodiversity in Wetlands of International Importance

Abstract

Wetlands are complex ecosystems that harbor a large diversity of species. Wetlands are among the most threatened ecosystems on our planet, due to human influences such as conversion and drainage. We assessed impacts from water consumption on the species richness of waterbirds, nonresidential birds, water-dependent mammals, reptiles and amphibians in wetlands, considering a larger number of taxa than previous life cycle impact assessment methods. Effect factors (EF) were derived for 1184 wetlands of international importance. EFs quantify the number of global species-equivalents lost per m2 of wetland area loss. Vulnerability and range size of species were included to reflect conservation values. Further, we derived spatially explicit characterization factors (CFs) that distinguish between surface water and groundwater consumption. All relevant watershed areas that are contributing to feeding the respective wetlands were determined for CF applications. In an example of rose production, we compared damages of water consumption in Kenya and The Netherlands. In both cases, the impact was largest for waterbirds. The total impact from water consumption in Kenya was 67 times larger than in The Netherlands, due to larger species richness and species’ vulnerability in Kenya, as well as more arid conditions and larger amounts of water consumed.

The WULCA consensus characterization model for water scarcity footprints: assessing impacts of water consumption based on available water remaining (AWARE)

“…Environmental flow requirements were calculated with the monthly natural flow values from WaterGAP, which models the flow without consideration of any human intervention or land use change (i.e., natural vegetation cover). Water requirements of terrestrial and groundwater-dependent ecosystems were not included since the link between blue water consumption (i.e., water abstracted from water bodies, for which AWARE is used) and water deprivation of terrestrial ecosystems is unclear at this time, except for specific cases such as groundwater table lowering or wetlands (van Zelm et al 2011;Verones et al 2013). Similarly, green water, or the soil moisture from precipitation, was excluded with a recommendation that it be addressed by a separate indicator assessing green water consumption, linked with land use (Boulay et al 2015a).…”

Why Include Impacts on Biodiversity from Land Use in LCIA and How to Select Useful Indicators?

“…We find it interesting that an increasing number of papers try to combine a pressure indicator, whether it is based on species counts [92,125] or structures [84,90], with a geographic weighting factor. It is also interesting that Michelsen et al [21] find a clear correlation in the results based on the proposal from de Baan et al [92] and Coelho and Michelsen [90] on a case study on forestry plantations.…”

“…Other proposals include Garcia-Quijano et al [75], who suggest a number of indicators, including pressure, structural and species indicators, without any further discussion of the relative importance, and Kløverpris et al [82,83], who identify in which biome the impact occurs, but without trying to quantify this impact in terms of biodiversity. Two exceptions to this are Hanafiah et al [124] and Verones et al [125], who both calculate characterization factors based on species loss caused by water use.…”

“…This is suggested by Coelho and Michelsen [90] to be overcome by actually combining the two methods using the generic values from Brentrup et al [71] on intactness and the geographic valuation from Michelsen [84]. de Baan et al [92] and Verones et al [125] use changes in species diversity to assess impact, but also, they include a geographic weighting factor for calculating characterization factors, making the methods similar in structure as the method proposed by Coelho and Michelsen [90].…”

“…Some proposals focus on rarity (e.g., [72,84,95,125]) and give an increasing weight to more rare species and/or structures, but if characterization factors are to change, this means that these have to be continuously updated or calculated for each case. The latter is done by Coelho and Michelsen [90], who calculated values for ecosystem vulnerability based on present levels of native vegetation in the areas in focus.…”