LiDAR-derived canopy structure supports the more-individuals hypothesis for arthropod diversity in temperate forests

Despite considerable progress in the ability to measure the complex 3-D structure of forests with the improvement of remote-sensing techniques, our mechanistic understanding of how biodiversity is linked to canopy structure is still limited. Here we tested whether the increase in arthropod abundance and richness in beech forest canopies with increasing canopy complexity supports the more-individuals hypothesis or the habitat-heterogeneity hypothesis. We used fogging to collect arthropod samples from 80 standardized plots from canopies of single- to multi-layered mature montane European beech stands. Tree height and an independent measure of vertical heterogeneity — the vertical distribution ratio — on each arthropod sampling plot were derived from high-resolution full-waveform airborne laser scanning data. Mixed-model path analysis based on almost 20,000 specimens of 762 species from 11 orders provided support for the more-individuals hypothesis, with higher arthropod abundance but not ...