Farmlands with smaller crop fields have higher within-field biodiversity
Farmlands with smaller crop fields have higher within-field biodiversity
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DOI：
10.1016/j.agee.2014.11.018
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发表时间：
2015-02-01
影响因子：
6.6
通讯作者：
Tischendorf, Lutz
中科院分区：
文献类型：
--
作者：
Fahrig, Lenore;Girard, Judith;Tischendorf, Lutz
景观管理的简单规则似乎难以捉摸，因为不同的物种和物种组与不同的土地覆盖类型有关；景观结构的变化增加了一个组的多样性，可能会减少另一个组的多样性。另一方面，如果确实存在简单的景观-生物多样性关系，尽管存在这种复杂性，它们将对保护管理有很大的实际好处。考虑到这些因素，我们测试了景观异质性和农田(农业景观中的种植区)生物多样性之间的一致关系，以期制定简单的景观管理规则，以增加农田内的生物多样性。我们衡量农田异质性的指标是作物多样性和平均农田面积，其中作物多样性的增加和/或平均农田面积的减少代表景观异质性的增加。我们在931公里x1公里的农田中采集了鸟类、植物、蝴蝶、食蚁兽、蜜蜂、步行动物和蜘蛛的丰度以及阿尔法、伽马和贝塔多样性。选取景观组成和异质性三个梯度：景观在作物中所占比例、农田平均作物面积和农田香农作物类型多样性。我们发现，平均作物田面积对作物田生物多样性指标的总体影响最大，而且这种影响始终是负的。根据我们的结果，我们建议，如果农作物田的生物多样性保护是优先事项，则应考虑旨在减少农田规模的政策和指导方针。(C)2014爱思唯尔B.V.保留所有权利。
Simple rules for landscape management seem elusive because different species and species groups are associated with different land cover types; a change in landscape structure that increases diversity of one group may reduce diversity of another. On the other hand, if simple landscape-biodiversity relationships do exist despite this complexity, they would have great practical benefit to conservation management. With these considerations in mind, we tested for consistent relationships between landscape heterogeneity and biodiversity in farmland (the cropped areas in agricultural landscapes), with a view to developing simple rules for landscape management that could increase biodiversity within farmland. Our measures of farmland heterogeneity were crop diversity and mean crop field size, where increases in crop diversity and/or decreases in mean field size represent increasing landscape heterogeneity. We sampled the abundance, and alpha, gamma and beta diversity of birds, plants, butterflies, syrphids, bees, carabids and spiders, in crop fields within each of 93 1 km x 1 km agricultural landscapes. The landscapes were selected to represent three gradients in landscape composition and heterogeneity: proportion of the landscape in crop, mean crop field size and Shannon crop type diversity of the farmland. We found that mean crop field size had the strongest overall effect on biodiversity measures in crop fields, and this effect was consistently negative. Based on our results we suggest that, if biodiversity conservation in crop fields is a priority, policies and guidelines aimed at reducing crop field sizes should be considered. (C) 2014 Elsevier B.V. All rights reserved.