Data from: Diversity partitioning confirms the importance of beta components in tropical rainforest Lepidoptera

Tropical beta diversity, and particularly that of herbivorous insects in rainforests, is often considered enormous, but this notion has recently been challenged. As tropical beta diversity is highly relevant to our view on biodiversity, it is important to gain more insights and resolve methodological problems that may lead to the contradictions in different studies. We used data on two ecologically distinct moth families from Southeast-Asia and analyzed separately the contribution of beta components to overall species richness at three spatial scales. Observed diversity partitions were compared under different types of null models. We found that alpha diversity was lower than expected from null models, whereas hierarchical beta components were larger than expected. Beta components played a significant role in shaping gamma diversity, and their contribution can be high (multiplicative beta >5). We found a reduction of beta components when comparing primary forests and agricultural sites (cf. “biotic homogenization”), but even in these habitats beta components were still substantial. Our analyses show that beta components do play an important role in our data on tropical herbivorous insects, and that these results are not due to lumping different habitats when sampling environmental gradients.热带地区的β多样性（beta diversity），尤其是热带雨林中的植食性昆虫类群，常被认为极具规模，但这一观点近来受到了质疑。鉴于热带β多样性与我们对生物多样性的整体认知密切相关，因此深入剖析相关机制并解决可能导致不同研究结论矛盾的方法学问题，具有重要的学术价值。 我们使用了源自东南亚的两个生态习性迥异的蛾科类群的数据集，在三个空间尺度上分别分析了β多样性组分对总物种丰富度的贡献。针对不同类型的零模型（null models），我们对比了观测得到的多样性分区结果。 研究结果显示，α多样性（alpha diversity）低于零模型的预期值，而层级式β多样性组分则高于预期水平。β多样性组分在塑造γ多样性（gamma diversity）的过程中发挥了显著作用，其贡献比例可高达（乘性β多样性>5）。 我们还发现，相较于原始森林与农业生境的对比场景，β多样性组分出现了下降（可参见"生物均质化（biotic homogenization）"），但即便在这类生境中，β多样性组分依然占据可观比例。 本研究的分析表明，β多样性组分在我们的热带植食性昆虫相关数据中确实扮演了关键角色，且该结果并非源于在采样环境梯度时合并不同生境所导致。