Increased energy maize production reduces farmland bird diversity

Abstract

Producing energy crops as an alternative to fossil fuels in order to reduce CO 2 emissions will lead to large-scale changes in agricultural landscapes. Here, we quantify the potential impact of an increase in maize fields on the diversity of farmland birds by means of high resolution (25 9 25 m) land-use scenarios. We generated scenarios in which the area of maize production in Germany increases from presently 2.6 to 2.9, 3.6 and 4.3 million ha, corresponding to the energy crop production targets of the German Renewable Energy Act for the years 2020, 2035 and 2050. To test the mitigating potential of conservation measures, each scenario was generated in a standard version and a landscape protection version, with the latter excluding valuable farmland areas from being converted into maize fields. Nine species of farmland birds belonging to the governmental indicator scheme for sustainable land-use in Germany were modelled for the six nation-wide scenarios. The models predicted that only the Northern Lapwing and the Little Owl might profit from extended maize production. Despite this, the total number of breeding pairs of the indicator species was predicted to decline by about 0.4 million breeding pairs in the most intensive scenario. Protection of valuable farmland did not mitigate these negative effects in the models. Our findings suggest that increased production of energy crops conflicts with conservation of biological diversity.

To integrate or to segregate food crop and energy crop cultivation at the landscape scale? Perspectives on biodiversity conservation in agriculture in Europe

“…[14,15]). A number of spatially explicit modelling studies have also emerged to evaluate the biodiversity responses from energy crop production at regional, national and pan-national scales, maize in particular [16][17][18][19], some of which considered land-use change scenarios involving energy crop cultivation on marginal land of high nature value [20,21]. In addition, many field-scale or empirical studies with a focus on a particular energy crop have been conducted to compare biodiversity impacts with those of row crops or grasslands [22][23][24].…”

RELCA: a REgional Life Cycle inventory for Assessing bioenergy systems within a region

“…This has resulted in a scattering of decentralised bioenergy plants across the landscape, mainly due to their dependency on spatially diffuse biomass resources. Such configurations of biomass and bioenergy technologies in the landscape make the influence of bioenergy production obvious to the eye (e.g., maize and biogas plant dominated landscapes [4]) and thus open to scrutiny for a broad list of potential environmental burdens 1 , to soil, to water, and land use [5][6][7][8]. In general, life cycle assessment (LCA) is the most popular assessment approach used for investigating the environmental burdens associated with bioenergy production [9][10][11].…”

“…With many burdens of bioenergy production strongly influenced by the regional variability (e.g., management, climate, soil) of biomass production [5,6,23,24,[26][27][28], O'Keeffe et al [19] identified the need to begin determining what is happening "within" a regional context for a bioenergy producing region. They also identified that life cycle thinking framed in a regionally contextualised manner is at a nascent stage, particularly with regard to implementing a suitable or appropriate life cycle impact assessment phase 4 . For this reason it was suggested, as a first step, to begin exploring regionally contextualised life cycle thinking with the development of life cycle inventory assessments.…”

“…3 The definition of a region was that used by Loiseau et al (2012) [12] which is, "a region is a spatial scale below a nation, usually including two or more communities with naturally or arbitrary determined boundaries, and which covers from tens to thousands of kilometres". 4 For more information on aspects of the life cycle impact assessment phase for the different regional contexts, please refer to [19]. 5 Data can be transferred between the different modelling tools through the use of text files either as, delineated (.txt) or comma separated values (.csv), which can be used as input/output files.…”

Bioenergy: Challenge or support for the conservation of biodiversity?

“…The following two articles focus on the response of farmland birds to an expansion of maize cultivation for biogas at the landscape scale (Everaars et al ., and Sauerbrei et al ., ). Both studies apply spatially explicit modeling approaches, either using a generated model landscape (Everaars et al ., ) or a map of recent land use in Germany (Sauerbrei et al ., ) as the reference for different scenarios of increased maize cultivation. They arrive at the congruent finding that expanded maize cultivation and related homogenizing of landscape structures reduces breeding bird density.…”