The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-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.

In the state of Tabasco, South-eastern, Mexico, land-use changes such as the conversion of natural into agricultural systems, modify soil quality and the abundance of soil macrofauna, including earthworms. The aim of this study was to characterize by near-infrared spectroscopy (NIRS) the earthworms’ fingerprint in soil, in six sites including natural and agricultural ecosystems with low and high earthworm biomass and low and high earthworm diversity, in order to identify specific wavelengths that discriminate the presence/abundance of earthworm species and functional groups. The spectral region of 1860–1870 nm was significantly correlated with total earthworm density, particularly at one of the sites (Cedar polyculture; r = 0.8, p < 0.05). Earthworm biomass had a specific NIRS wavelength according to the earthworm species and feeding category: 1820 and1860–1870 nm wavelengths were significantly correlated with Polypheretima elongata (r2 = 0.7, p < 0.05; mesohumic species) biomass and 2090 nm for biomass of all Lavellodrilus species (polyhumics). Two species had a much wider spectral range: L. bonampakensis and Dichogaster saliens (an epigeic worm; 1690–2300 nm, r2 = 0.7, p < 0.05). Biomasses of Periscolex brachysistis and Diplotrema murchiei were not significantly correlated with any near infrared wavelength spectra analyzed. Combining a maximum of 4 species per wavelength, mesohumic earthworms had a wider wavelength spectrum than polyhumics. Therefore, earthworm species diversity, biomass and abundance are associated with soil quality (as measured by NIR spectra) and this relationship varies with species and ecological category. Sites with lower and higher earthworm diversity have lower and higher soil organic matter quality, respectively, as observed by the wider or narrower spectral range with which earthworm biomasses are correlated.

Enhancing the carrying capacity of cultivated areas for beneficial soil macrofauna is still an important aim in the tropics. The promotion of mearthworms to improve soil fertility is progressively mconsidered a complementary alternative to current practices. Mucuna pruriens var. utilis was applied in a maize field as fresh litter, at La Mancha, Veracruz, Mexico. Different quantities (1.5 kg m-2 and 4.5 kg m-2) of this litter legume were applied: on the soil surface, integrated into the soil, or half on the surface and half in the soil; there were three treatments with 1.5 kg m-2 and three treatments with 4.5 kg m-2, two controls were installed, a control with tillage, and another without tillage. Eight combinations were tus tested with three replicates each, distributed in a random design in a 30 x 37 m field. After one year, in mucuna plots the highest earthworm densities (99.2 ± 44.6 ind m-2) and biomasses (10.6 ± 5.6 g m-2) were found in those quadrants where Mucuna was applied on the surface with 4.5 kg m-2. This treatment also showed the highest maize production (70.3 ± 22.6 g ind m-2, P < 0.05). Nevertheless, the effect of mucuna on the cosmopolitan endogenous species Polypheretima elongata was not clear, because the highest P. elongata biomasses were found in quadrants without mucuna (16.8 ± 10.2 g m-2, P < 0.05). Control with tillage showed the lowest earthworm biomasses (3 ± 0.4 g m-2).