Does afforestation increase bird nest predation risk in surrounding farmland?

FOREST ECOLOGY AND MANAGEMENT

卷:260

Article

Reino, Luis^1,2,3  Porto, Miguel⁴  Morgado, Rui^3,5  Carvalho, Filipe⁶  Mira, Antonio⁶  Beja, Pedro¹ 

[1] Univ Porto, CIBIO Ctr Invest Biodiversidade & Recursos Genet, P-4485661 Vairao, Portugal

[2] Univ Tecn Lisboa, Ctr Estudos Florestais, Inst Super Agron, P-1349017 Lisbon, Portugal

[3] Ordenamento & Gestao Recursos Nat SA, ERENA, P-1900392 Lisbon, Portugal

[4] Univ Lisbon, Ctr Biol Ambiental, Dept Biol Vegetal, Fac Ciencias Lisboa, P-1749016 Lisbon, Portugal

[5] Univ Tecn Lisboa, Ctr Ecol Aplicada Prof Baeta Neves, Inst Super Agron, P-1349017 Tapada Da Ajuda, Portugal

[6] Univ Evora Nucleo Mitra, Unidade Biol Conservacao, Grp Ecossistemas & Paisagens Mediterranicas, Inst Ciencias Agr Mediterranicas, P-7002554 Evora, Portugal

关键词: Conservation;    Edge effects;    Forest plantations;    Grassland birds;    Habitat fragmentation;    Mediterranean farmland;   

DOI  :  10.1016/j.foreco.2010.07.032

来源: Elsevier

【 摘 要 】

Afforestation of agricultural land is increasingly used to deliver environmental benefits, but their effects on biodiversity remain poorly understood. This paper tests the hypothesis that afforestation changes predation processes in surrounding farmland, examining how the characteristics and landscape context of forest plantations affect predator (birds and mammalian carnivores) and key prey (rabbits and hares) abundances, and bird nest predation rates in Iberian cereal-steppes. Lagomorphs and predators were surveyed in fallow fields around 50 forest plantations, where predation rates were estimated using artificial nests set at 0, 100, 200 and 300 m from the forest edge. Recent plantations structurally similar to sparse (oak) or dense (pine) shrublands were associated with the highest hare and rabbit abundances, respectively, whereas both species avoided landscapes with high eucalyptus cover. In contrast, mature eucalyptus plantations showed strong positive effects on typical nest predators such as corvids and carnivores. Open farmland fragmentation favoured the abundance of lagomorphs and carnivores. Despite these effects and the high predation rate on artificial nests (49%), there was neither evidence for increased predation near plantation edges nor higher predation in fields with more lagomorphs and predators. However, predation tended to increase with cover by young oak plantations and overall forest plantation cover, to decrease with eucalyptus cover at both the local and landscape scales, and to peak in landscapes with intermediate edge densities. These results suggest that afforestation may have strong effects on bird nest predation rates by changing landscape composition and configuration, rather than by inducing local increases in predator and prey populations. Nevertheless, increased abundances of generalist predators associated with forest plantations may still be considered of conservation concern, thus supporting the recommendation for strongly restricting afforestation in areas important for open grassland birds. Where this is unavoidable, monitoring should be undertaken to provide early signals for bird population declines associated with predator increases, eventually triggering conservation action such as predator exclusion or removal. (C) 2010 Elsevier B.V. All rights reserved.

【 授权许可】

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