Patterns of beta diversity in Europe: the role of climate,land cover and distance across scales

Aim We test the prediction that beta diversity (species turnover) and the decay of community similarity with distance depend on spatial resolution (grain). We also study whether patterns of beta diversity are related to variability in climate, land cover or geographic distance and how the independent effects of these variables depend on the spatial grain of the data. Location Europe, Great Britain, Finland and Catalonia. Methods We used data on European birds, plants, butterflies, amphibians and reptiles, and data on British plants, Catalonian birds and Finnish butterflies. We fitted two or three nested grids of varying resolutions to each of these datasets. For each grid we calculated differences in climate, differences in land‐cover composition (CORINE) and beta diversity (β_sim, β_Jaccard) between all pairs of grid cells. In a separate analysis we looked specifically at pairs of adjacent grid cells (the first distance class). We then used variation partitioning to identify the magnitude of independent statistical associations (i.e. independent effects in the statistical sense) of climate, land cover and geographic distance with spatial patterns of beta diversity. Results Beta diversity between grid cells at any given distance decreased with increasing grain. Geographic distance was always the most important predictor of beta diversity for all pairwise comparisons at the extent of Europe. Climate and land cover had weaker but distinct and grain‐dependent effects. Climate was more important at relatively coarse grains, whereas land‐cover effects were stronger at finer grains. In the country‐wide analyses, climate and land cover were more important than geographic distance. Climatic and land‐cover models performed poorly and showed no systematic grain dependence for beta diversity between adjacent grid cells. Main conclusions We found that relationships between geographic distance and beta diversity, as well as the environmental correlates of beta diversity, are systematically grain dependent. The strong independent effect of distance indicates that, contrary to the current belief, a substantial fraction of species are missing from areas with a suitable environment. Moreover, the effects of geographic distance (at continental extents) and land cover (at fine grains) indicate that any species distribution modelling should take both environment and dispersal limitation into account.     

Interannual patterns of the large free-living nematode assemblages in the Mexican Exclusive Economic Zone,NW Gulf of Mexico after the Deepwater Horizon oil spill

The presence and abundance of particular nematode genera in marine sediments are bioindicators of environmental disturbance. They can even reveal the existence of specific toxicants, such as trace-metals and hydrocarbons derived from fossil fuels. We studied this important infaunal component during a three-year monitoring program in Mexico’s Exclusive Economic Zone (EEZ) in the aftermath of a major oil spill in the northern Gulf of Mexico caused by the sinking of the Deepwater Horizon platform (DWH) in April of 2010. A closer look at the nematode composition and density values throughout and after the DWH oil spill revealed considerable changes. Continental shelf and upper slope sediments sampled in the summer of 2010 included 48 genera and a density of 44.45 ind/10 cm⁻². Eight months later in the winter of 2011, there was a critical decrement in genera number (23) and density (25.22 ind/10 cm⁻²). However, in 2012, the nematode community showed signs of recovery: genus diversity was 58 with a density of 91.45 ind/10 cm⁻². Significant differences were recorded between the first and the last sampling periods, driven by a remarkable turn-over in genera composition, and by an increase in density of the genera Sabatieria, Dorylaimopsis, and Cheironchus. Similarly, significant spatial differences between the nematofauna of the inner-middle shelf and the deepest zone (>2000 m) were detected. Correlation analyses confirmed the tolerant behavior of the above genera to Ni and Co, and their proliferation when hydrocarbon compounds presumably derived from the DWH oil spill increased throughout the study. The Maturity Index (MI) estimated for each survey ranged from 2.35 to 2.6. Environmental Quality Status conditions in the summer of 2010 were good while in the winter of 2011 were poor, and moderate towards the winter of 2012. Index of Trophic Diversity (ITD) values for each survey were high: 0.70, 0.68, and 0.74, respectively. A high predominance of feeding guilds 1B and 2B was recorded throughout the study.The estimated Index of Trophic Diversity (ITD) values resulted high (Table 5). These values apparently indicated that the four feeding types were proportionally distributed in the nematode assemblage. This fact was better reflected during the winter of 2012. Nonetheless, these results are not congruent with the high predominance of feeding guilds 1B and 2B observed throughout the study.     

Winter Habitat Selection by Canada Lynx in Maine: Prey Abundance or Accessibility?

Abstract: We related winter habitat selection by Canada lynx (Lynx canadensis), relative abundance of snowshoe hares (Lepus americanus), and understory stem densities to evaluate whether lynx select stands with the greatest snowshoe hare densities or the greatest prey accessibility. Lynx (3 F, 3 M) selected tall (4.4-7.3 m) regenerating clear-cuts (11-26 yr postharvest) and established partially harvested stands (11-21 yr postharvest) and selected against short (3.4-4.3 m) regenerating clear-cuts, recent partially harvested stands (1-10 yr), mature second-growth stands (>40 yr), and roads and their edges (30 m on either side of roads). Lynx selected stands that provided intermediate to high hare density and intermediate cover for hares (i.e., prey access) but exhibited lower relative preference for stand types with highest hare densities where coniferous saplings exceeded 14,000 stems/ha.     

Ecology and biological control application of multicoloured Asian ladybird, Harmonia axyridis: A review

The ecology of and biological control by multicoloured Asian ladybird beetle, Harmonia axyridis (Pallas) are reviewed. Our emphasis is on assembling and interpreting information on general characteristics, invasion and establishment, sexual activity, foraging and predation, development, survival and reproduction, predator-predator interactions, natural enemies, biocontrol, non-target effects and status of H. axyridis as a pest of fruits. Colonization of H. axyridis for aphid biocontrol in the USA have been successful in terms of its establishment, but its abundance is turning out to be a nuisance to humans. Its harmful non-target impact on beneficial organisms, humans and native species is becoming a debatable issue. The question on its present position, whether it is a biocontrol agent or pest, is a critical issue and discussed. Inferences from the empirical data are made and new avenues for future research are suggested.     

Model-assisted formate dehydrogenase-O (fdoH) gene knockout for enhanced succinate production in Escherichia coli from glucose and glycerol carbon sources

Succinic acid is an important platform chemical that has broad applications and is been listed as one of the top twelve bio-based chemicals produced from biomass by the US Department of Energy. The metabolic role of Escherichia coli formate dehydrogenase-O (fdoH) under anaerobic conditions in relation to succinic acid production remained largely unspecified. Herein we report, what are to our knowledge, the first metabolic fdoH gene knockout that have enhanced succinate production using glucose and glycerol substrates in E. coli. Using the most recent E. coli reconstruction iJO1366, we engineered its host metabolism to enhance the anaerobic succinate production by deleting the fdoH gene, which blocked H⁺ conduction across the mutant cell membrane for the enhanced succinate production. The engineered mutant strain BMS4 showed succinate production of 2.05 g l^?1 (41.2-fold in 7 days) from glycerol and .39 g l^?1 (6.2-fold in 1 day) from glucose. This work revealed that a single deletion of the fdoH gene is sufficient to increase succinate production in E. coli from both glucose and glycerol substrates.     

Building up biogeography: Pattern to process

Linking pattern to process across spatial and temporal scales has been a key goal of the field of biogeography. In January 2017, the 8th biennial conference of the International Biogeography Society sponsored a symposium on Building up biogeography—process to pattern that aimed to review progress towards this goal. Here we present a summary of the symposium, in which we identified promising areas of current research and suggested future research directions. We focus on (1) emerging types of data such as behavioural observations and ancient DNA, (2) how to better incorporate historical data (such as fossils) to move beyond what we term “footprint measures” of past dynamics and (3) the role that novel modelling approaches (e.g. maximum entropy theory of ecology and approximate Bayesian computation) and conceptual frameworks can play in the unification of disciplines. We suggest that the gaps separating pattern and process are shrinking, and that we can better bridge these aspects by considering the dimensions of space and time simultaneously.