Forecasting the effects of land use scenarios on farmland birds reveal a potential mitigation of climate change impacts.

Karine Princé,Morgane Barbet-Massin,Frédéric Jiguet,Romain Lorrillière,François Léger

doi:10.1371/journal.pone.0117850

Abstract

Climate and land use changes are key drivers of current biodiversity trends, but interactions between these drivers are poorly modeled, even though they could amplify or mitigate negative impacts of climate change. Here, we attempt to predict the impacts of different agricultural change scenarios on common breeding birds within farmland included in the potential future climatic suitable areas for these species. We used the Special Report on Emissions Scenarios (SRES) to integrate likely changes in species climatic suitability, based on species distribution models, and changes in area of farmland, based on the IMAGE model, inside future climatic suitable areas. We also developed six farmland cover scenarios, based on expert opinion, which cover a wide spectrum of potential changes in livestock farming and cropping patterns by 2050. We ran generalized linear mixed models to calibrate the effects of farmland cover and climate change on bird specific abundance within 386 small agricultural regions. We used model outputs to predict potential changes in bird populations on the basis of predicted changes in regional farmland cover, in area of farmland and in species climatic suitability. We then examined the species sensitivity according to their habitat requirements. A scenario based on extensification of agricultural systems (i.e., low-intensity agriculture) showed the greatest potential to reduce reverse current declines in breeding birds. To meet ecological requirements of a larger number of species, agricultural policies accounting for regional disparities and landscape structure appear more efficient than global policies uniformly implemented at national scale. Interestingly, we also found evidence that farmland cover changes can mitigate the negative effect of climate change. Here, we confirm that there is a potential for countering negative effects of climate change by adaptive management of landscape. We argue that such studies will help inform sustainable agricultural policies for the future.

Highlights

The modification and management of landscapes to produce food or other agricultural commodities for human consumption represents one of the most severe and widespread threats to global biodiversity [1]
We evaluated the response of bird populations to the different farmland cover scenarios combined with changes in proportion of farmland habitats and climatic suitability
Our results show that the climatic scenario is expected to lead to more negative effects on bird abundances than under the land-use scenarios considered

Summary

Introduction

The modification and management of landscapes to produce food or other agricultural commodities for human consumption represents one of the most severe and widespread threats to global biodiversity [1]. The increasing demand for food production, the introduction and expansion of bio-energy crops, modernization of agriculture techniques, abandonment of grazing areas and crop specialization and intensification, are main factors affecting farmland cover These land cover changes are characterized by several significant processes such as the transformation of agricultural landscapes into new combinations of crops and semi-natural elements or the management of these crops to increase their productivity [4, 13, 14]. The debate is still open between ‘land sharing’, that aims to integrate goals for food production and biodiversity protection on the same land, and ‘land sparing’, that aims to separate intensive farming from protected ecosystems at the larger scale [e.g. 15, 16] In this context, authorities need tools for decision support, to propose public policies to reconcile agricultural production and biodiversity [17]

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