Department of Zoology, University of Oxford Oxford, U.K.
Department of Zoology, University of Oxford Oxford, U.K ; Department of Agricultural Sciences, University of Helsinki Helsinki, Finland.
Ecol Evol. 2014 Apr;4(7):1049-60. doi: 10.1002/ece3.1003. Epub 2014 Mar 5.
Agricultural expansion and intensification are major threats to global biodiversity, ecological functions, and ecosystem services. The rapid expansion of oil palm in forested tropical landscapes is of particular concern given their high biodiversity. Identifying management approaches that maintain native species and associated ecological processes within oil palm plantations is therefore a priority. Riparian reserves are strips of forest retained alongside rivers in cultivated areas, primarily for their positive hydrological impact. However, they can also support a range of forest-dependent species or ecosystem services. We surveyed communities of dung beetles and measured dung removal activity in an oil palm-dominated landscape in Sabah, Malaysian Borneo. The species richness, diversity, and functional group richness of dung beetles in riparian reserves were significantly higher than in oil palm, but lower than in adjacent logged forests. The community composition of the riparian reserves was more similar to logged forest than oil palm. Despite the pronounced differences in biodiversity, we did not find significant differences in dung removal rates among land uses. We also found no evidence that riparian reserves enhance dung removal rates within surrounding oil palm. These results contrast previous studies showing positive relationships between dung beetle species richness and dung removal in tropical forests. We found weak but significant positive relationships between riparian reserve width and dung beetle diversity, and between reserve vegetation complexity and dung beetle abundance, suggesting that these features may increase the conservation value of riparian reserves. Synthesis and applications: The similarity between riparian reserves and logged forest demonstrates that retaining riparian reserves increases biodiversity within oil palm landscapes. However, the lack of correlation between dung beetle community characteristics and dung removal highlights the need for further research into spatial variation in biodiversity-ecosystem function relationships and how the results of such studies are affected by methodological choices.
农业扩张和集约化是全球生物多样性、生态功能和生态系统服务的主要威胁。鉴于其高生物多样性，油棕在热带森林景观中的快速扩张尤其令人担忧。因此，确定在油棕种植园中维持本地物种和相关生态过程的管理方法是当务之急。河岸保护区是在种植区沿河流保留的森林带，主要是因为它们对水文有积极的影响。然而，它们也可以支持一系列依赖森林的物种或生态系统服务。我们调查了沙巴（马来西亚婆罗洲）油棕占主导地位的景观中的蜣螂社区，并测量了粪便清除活动。河岸保护区中蜣螂的物种丰富度、多样性和功能群丰富度明显高于油棕，但低于相邻的伐木业森林。河岸保护区的群落组成与伐木业森林更相似，而不是油棕。尽管生物多样性存在明显差异，但我们没有发现不同土地利用方式之间粪便清除率有显著差异。我们也没有发现河岸保护区在周围油棕中增强粪便清除率的证据。这些结果与先前的研究结果形成对比，先前的研究表明，在热带森林中蜣螂物种丰富度与粪便清除之间存在正相关关系。我们发现，河岸保护区的宽度与蜣螂多样性之间存在微弱但显著的正相关关系，保护区植被复杂性与蜣螂丰度之间也存在正相关关系，这表明这些特征可能会增加河岸保护区的保护价值。综合与应用：河岸保护区与伐木业森林之间的相似性表明，保留河岸保护区可以增加油棕景观中的生物多样性。然而，蜣螂群落特征与粪便清除之间缺乏相关性突出表明，需要进一步研究生物多样性-生态系统功能关系的空间变化，以及这些研究结果如何受到方法选择的影响。
