Relationship of insect biomass and richness with land use along a climate gradient

This dataset contains data from a field study conducted in 2019 and described in the paper "Relationship of insect biomass and richness with land use along a climate gradient" by Uhler et al. In this study, arthropod communities were collected by Malaisetraps along a land use and climate gradient and identified by Metabarcoding. Malaise traps are versatile passive net-traps, capable of catching a large spectrum of insect taxa and are very effective when the aim is to get a representative snapshot of the local insect community. Overall, 179 Malaise traps were set up in 2019 along a gradient of increasing land use intensity, ranging from forests, to meadows, to arable fields, and settlements. The analyzed sites were spatially distributed over 400km and covered an elevational gradient of 1000m. Generalized additive models were fitted to test for the effects of local and landscape-level land-use categories on insect biomass and species richness. We found the largest difference in biomass between semi-natural and urban environments (−42%), whereas differences in total richness (−29%) and the richness of threatened species (−56%) were largest from semi-natural to agricultural environments. These results point to urbanization and agriculture as major drivers of decline. We also found that richness and biomass increase monotonously with increasing temperature, independent of habitat. The contrasting patterns of insect biomass and richness question the use of these indicators as mutual surrogates. Our study provides support for the implementation of more comprehensive measures aimed at habitat restoration in order to halt insect declines.

本数据集包含2019年开展的野外研究数据，相关成果发表于Uhler等人的论文《沿气候梯度的昆虫生物量与丰富度和土地利用的关系》（Relationship of insect biomass and richness with land use along a climate gradient）。该研究中，研究者沿土地利用与气候梯度使用马氏网（Malaise traps）采集节肢动物群落，并通过宏条形码技术（metabarcoding）进行物种鉴定。马氏网是一种多功能被动式网捕装置，可捕获多类昆虫类群，若目标是获取当地昆虫群落的代表性采样快照，其效果十分理想。本研究于2019年沿土地利用强度递增的梯度布设了179个马氏网，采样生境涵盖森林、草地、农田与人类定居点。所有调研样点的空间分布跨度达400千米，覆盖1000米的海拔梯度。研究采用广义可加模型（Generalized Additive Models），检验局地与景观尺度的土地利用类型对昆虫生物量及物种丰富度的影响。研究结果显示，半自然生境与城市环境间的昆虫生物量差异最为显著（降幅达42%）；而物种总丰富度（降幅29%）与濒危物种丰富度（降幅56%）的最大差异则出现在半自然生境向农田生境的转变过程中。上述结果表明，城市化与农业活动是昆虫种群衰退的主要驱动因素。同时研究发现，无论生境类型如何，昆虫物种丰富度与生物量均随温度升高呈单调递增趋势。昆虫生物量与丰富度呈现出的迥异模式，对二者作为彼此替代指标的适用性提出了质疑。本研究为制定更全面的栖息地修复措施以遏制昆虫种群衰退提供了科学依据。