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β多样性（beta diversity），尤其是热带雨林中的植食性昆虫β多样性，向来被认为极为丰富，但这一观点近来受到了挑战。鉴于热带β多样性与我们对生物多样性的认知密切相关，深入探究相关问题并解决可能导致不同研究结论矛盾的方法学难题具有重要意义。本研究使用了源自东南亚的两个生态习性迥异的蛾类科群数据，分别分析了三种空间尺度下β多样性组分对总物种丰富度的贡献。我们针对不同类型的零模型（null model）对观测得到的多样性分区结果进行了对比分析。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，其贡献值可处于较高水平（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组，β多样性组分有所降低（可参照“生物均质化”现象），但即便在这类生境中，β多样性组分依然可观。本研究的分析结果表明，β多样性组分在我们的热带植食性昆虫数据集当中确实发挥了重要作用，且该结论并非源于在采样环境梯度时将不同生境合并所导致的偏差。