Rocha-Santos Larissa, Benchimol Maíra, Mayfield Margaret M, Faria Deborah, Pessoa Michaele S, Talora Daniela C, Mariano-Neto Eduardo, Cazetta Eliana
Graduate Program in Ecology and Biodiversity Conservation, Applied Ecology and Conservation Lab, State University of Santa Cruz, Ilhéus, Bahia, Brazil.
School of Biological Sciences, The University of Queensland, St Lucia Campus, Queensland, Australia.
PLoS One. 2017 Apr 12;12(4):e0175545. doi: 10.1371/journal.pone.0175545. eCollection 2017.
As tropical rainforests are cleared, forest remnants are increasingly isolated within agricultural landscapes. Understanding how forest loss impacts on species diversity can, therefore, contribute to identifying the minimum amount of habitat required for biodiversity maintenance in human-modified landscapes. Here, we evaluate how the amount of forest cover, at the landscape scale, affects patterns of species richness, abundance, key functional traits and common taxonomic families of adult trees in twenty Brazilian Atlantic rainforest landscapes. We found that as forest cover decreases, both tree community richness and abundance decline, without exhibiting a threshold. At the family-level, species richness and abundance of the Myrtaceae and Sapotaceae were also negatively impacted by the percent forest remaining at the landscape scale. For functional traits, we found a reduction in shade-tolerant, animal-dispersed and small-seeded species following a decrease in the amount of forest retained in landscapes. These results suggest that the amount of forest in a landscape is driving non-random losses in phylogenetic and functional tree diversity in Brazil's remaining Atlantic rainforests. Our study highlights potential restraints on the conservation value of Atlantic rainforest remnants in deforested landscapes in the future.
随着热带雨林被砍伐，森林残余部分在农业景观中越来越孤立。因此，了解森林丧失如何影响物种多样性，有助于确定人类改造景观中维持生物多样性所需的最小栖息地面积。在这里，我们评估了景观尺度上的森林覆盖量如何影响巴西二十个大西洋雨林景观中成年树木的物种丰富度、丰度、关键功能性状和常见分类科的格局。我们发现，随着森林覆盖面积减少，树木群落的丰富度和丰度都会下降，且没有表现出阈值。在科的水平上，桃金娘科和山榄科的物种丰富度和丰度也受到景观尺度上剩余森林百分比的负面影响。对于功能性状，我们发现随着景观中保留的森林量减少，耐荫、动物传播和小种子物种的数量也会减少。这些结果表明，景观中的森林量正在推动巴西剩余大西洋雨林中系统发育和功能树木多样性的非随机丧失。我们的研究突出了未来森林砍伐景观中大西洋雨林残余部分保护价值的潜在限制。
