The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (https://www.nhm.ac.uk/our-science/our-work/biodiversity/predicts.html)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Biodiversity of tropical forests varies at spatial and temporal scales, but at what scale and how the assemblages differ when we consider the same kind of forest and the same altitude has been poorly documented. We examined the variation in species richness and composition of three subfamilies of scarab beetles (Dynastinae, Rutelinae, and Melolonthinae) along a northwest-southeast (NW-SE) transect of premontane rain forests in Costa Rica. Sampling was carried out at six sampling sites comprising three mountain ranges. Two forest sites were selected in each mountain range at the same altitudinal strip and same life zone. We conducted eight field surveys from June 2007 to January 2008. UV light traps were used to catch the beetles. We studied beetle diversity at three spatiotemporal levels: mountain range, forest site, and monthly trap. Species composition and richness varied at the three levels studied, and this variation was not necessarily related with geographic distance. Forest site and monthly trap levels showed higher variation in similarity indices than the mountain range level did. Additive partitioning of diversity showed values of diversity higher than expected only at the spatial levels with the mountain ranges showing the highest contribution to gamma diversity. Our results show high spatiotemporal variation in scarab beetle assemblages across Costa Rican premontane rain forests and underline that the analysis of a variety of spatiotemporal scales within a single kind of forest is crucial to understand scarab beetle biodiversity patterns in forest ecosystems.

The saproxylic beetle Cetonia aurataeformis Curti (Scarabaeoidea: Cetoniidae) is a common Iberian species, whose larvae develop in tree cavities feeding on wood and litter. The aim of this paper is to analyse how the larvae of this cetonid modify the woody substrate by feeding and what the ecological implications on their microhabitat could be. Thermal analysis and infrared spectroscopy have been used to study the changes suffered by different substrates, litter and wood of Betula alba and Quercus pyrenaica, after digestion by the larvae. Results show that larvae of C. aurataeformis are able to digest polysaccharides and lignin producing a residue richer in nutrients than the original substrate and with an organic structure that contains a fraction of lignin that is easier to decompose. The main conclusion is that the action of cetonid larvae on woody substrates could facilitate their use by other saproxylic organisms in natural ecosystems.