Th e metacommunity framework is a powerful platform for evaluating patterns of species distribution in geographic or environmental space. Idealized patterns (checkerboard, Clementsian, evenly spaced, Gleasonian and nested distributions) give the framework shape. Each pattern represents an area in a multidimensional continuum of metacommunity structures; however, the current approach to analysis of spatial structure of metacommunities is incomplete. To address this, we describe additional non-random structures and illustrate how they may be discerned via objective criteria. First, we distinguish three distinct forms of species loss in nested structures, which should improve identifi cation of structuring mechanisms for nested patterns. Second, we defi ne six quasi-structures that are consistent with the conceptual underpinnings of Clementsian, Gleasonian, evenly spaced and nested distributions. Finally, we demonstrate how combinations of structures at smaller spatial extents may aggregate to form Clementsian structure at larger extents. Th ese refi nements should facilitate the identifi cation of best-fi t patterns, associated structuring mechanisms, and informative scales of analysis and interpretation. Th is conceptual and analytical framework may be applied to network properties within communities (i.e. structure of interspecifi c interactions) and has broad application in ecology and biogeography.

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – http://www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.

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.

Habitat fragmentation and conversion are among the human activities that pose the greatest threat to species persistence and conservation of biodiversity. This is particularly true in the Neotropics, where bats represent important components of biodiversity from taxonomic and functional perspectives, and provide critical ecosystem services (e.g., seed dispersal and pollination). We assessed the degree to which conversion of lowland Amazonian rain forest to agriculture, and its subsequent abandonment and secondary succession, affect the abundances of populations of phyllostomid bats in the vicinity of Iquitos, Perú. During 90,720 net‐m‐h of sampling, we captured 3789 bats of five families; of these 3764 were phyllostomids representing 44 species, 23 genera, and three feeding guilds. We focus on the 24 most abundant species of phyllostomids. In terms of abundance, frugivores dominated assemblages in all habitat types and seasons. Eight species consistently responded to habitat conversion, two species consistently responded to season, two species responded consistently to both habitat and season, and five species responded to habitat conversion in a season‐specific manner. Frugivores and nectarivores were abundant in areas that had been converted to agriculture, which suggests that these bats are resilient to extant levels of disturbance and may be important in promoting secondary succession. However, this result may be scale‐ or context‐dependent. If habitat conversion continues and dramatically reduces the areal extent and increases fragmentation of mature forest, then a complex metacommunity dynamic may characterize the region and source populations of bats may become threatened or extirpated locally.

Techniques to evaluate elements of metacommunity structure (EMS; coherence, species turnover and range boundary clumping) have been available for several years. Such approaches are capable of determining which idealized pattern of species distribution best describes distributions in a metacommunity. Nonetheless, this approach rarely is employed and such aspects of metacommunity structure remain poorly understood. We expanded an extant method to better investigate metacommunity structure for systems that respond to multiple environmental gradients. We used data obtained from 26 sites throughout Paraguay as a model system to demonstrate application of this methodology. Using presence-absence data for bats, we evaluated coherence, species turnover and boundary clumping to distinguish among six idealized patterns of species distribution. Analyses were conducted for all bats as well as for each of three feeding ensembles (aerial insectivores, frugivores and molossid insectivores). For each group of bats, analyses were conducted separately for primary and secondary axes of ordination as defined by reciprocal averaging. The Paraguayan bat metacommunity evinced Clementsian distributions for primary and secondary ordination axes. Patterns of species distribution for aerial insectivores were dependent on ordination axis, showing Gleasonian distributions when ordinated according to the primary axis and Clementsian distributions when ordinated according to the secondary axis. Distribution patterns for frugivores and molossid insectivores were best described as random. Analysis of metacommunities using multiple ordination axes can provide a more complete picture of environmental variables that mold patterns of species distribution. Moreover, analysis of EMS along defined gradients (e.g., latitude, elevation and depth) or based on alternative ordination techniques may complement insights based on reciprocal averaging because the fundamental questions addressed in analyses are contingent on the ordination technique that is employed.