© 2014 John Wiley & Sons Ltd
Edited By: Steve Long
Impact Factor: 4.714
ISI Journal Citation Reports © Ranking: 2012: 2/78 (Agronomy); 8/81 (Energy & Fuels)
Online ISSN: 1757-1707
Associated Title(s): Global Change Biology
Changes in crop composition for bioenergy production affect farmland biodiversity
With an increased need for bioenergy to reduce carbon dioxide emissions, many options generate energy from biomass are being considered. Biogas, which can be used to generate electricity and heat, is produced from anaerobic digestion of biomass. Maize is considered to have the highest biogas yield potential compared to other field crops and may therefore experience an increase in agricultural biomass production. An increase in production of maize will likely lead to changes in the composition and spatial configuration of crops which could have a negative impact on farmland biodiversity.
Gevers and coauthors used a model to assess the indirect effects of future land-use changes on biodiversity. The model included three landscape types with differing proportions of land types (e.g. arable land, forest and grassland). Land-use change was simulated by altering the amount of maize produced and its spatial configuration within the landscape (clustered vs. dispersed). The type of crop that was displaced by maize was also considered. One “crop” type that was included is known to have environmental benefits, “set-aside” land. This is land that is “set-aside” from, or not used for, agricultural production and provides diverse habitat for wildlife in the farmed landscape, while reducing the need for pesticides and fertilizers (Institute for European Environmental Policy, 2008). To assess the impact of land-use changes on community composition, a wide variety of species were considered: skylark, grey partridge, European brown hare, field vole, linyphiid spider, and carabid beetle.
The authors found that the six species evaluated in this study responded differently to the increase in maize cultivation because every species has specific habitat requirements and sensitivities to land management such as tilling and pesticide use. The use of set-aside land to grow maize had the largest impact on the skylark, partridge and hare. A 50% loss of set-aside land had almost the same negative effect as the loss of 100% of set-aside land.
The replacement of cereal crops by maize led to an increase in spider and beetle populations, likely due to less use of insecticides in maize fields than in cereals. Voles were not affected because they do not use cropland as habitat.
The authors conclude that the negative effects of biogas-related land-use change on animal populations can be avoided if crops, rather than set-aside land, are replaced for the cultivation of biomass for energy purposes.
Institute for European Environmental Policy, 2008. Institute for European Environmental Policy, The Environmental Benefits of Set-aside in the EU. A Summary of Evidence, Institute for European Environmental Policy, UK (2008).
Gevers, J., Høye, T. T., Topping, C. J., Glemnitz, M. and Schröder, B. (2011), Biodiversity and the mitigation of climate change through bioenergy: impacts of increased maize cultivation on farmland wildlife. GCB Bioenergy, 3: 472–482. doi: 10.1111/j.1757-1707.2011.01104.x
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