Connecting species’ geographical distributions to environmental variables: range maps versus observed points of occurrence

Connecting the geographical occurrence of a species with underlying environmental variables is fundamental for many analyses of life history evolution and for modeling species distributions for both basic and practical ends. However, raw distributional information comes principally in two forms: points of occurrence (specific geographical coordinates where a species has been observed), and expert-prepared range maps. Each form has potential short-comings: range maps tend to overestimate the true occurrence of a species, whereas occurrence points (because of their frequent non-random spatial distribution) tend to underestimate it. Whereas previous comparisons of the two forms have focused on how they may differ when estimating species richness, less attention has been paid to the extent to which the two forms actually differ in their representation of a species’ environmental associations. We assess such differences using the globally distributed avian order Galliformes (294 species). For each species we overlaid range maps obtained from IUCN and point-of-occurrence data obtained from GBIF on global maps of four climate variables and elevation. Over all species, the median difference in distribution centroids was 234 km, and median values of all five environmental variables were highly correlated, although there were a few species outliers for each variable. We also acquired species’ elevational distribution mid-points (mid-point between minimum and maximum elevational extent) from the literature; median elevations from point occurrences and ranges were consistently lower (median −420 m) than mid-points. We concluded that in most cases occurrence points were likely to produce better estimates of underlying environmental variables than range maps, although differences were often slight. We also concluded that elevational range mid-points were biased high, and that elevation distributions based on either points or range maps provided better estimates

Effects of Longitudinal Bending Stiffness of forefoot rocker profile shoes on ankle kinematics and kinetics

INTRODUCTION: Rocker profile shoes with a proximally placed apex are currently one of the most prescribed shoe modifications for treatment and prevention of lower leg deficits. Three geometrical rocker design parameters apex position (AP), apex angle (AA) and rocker radius (RR) influence both plantar pressure redistribution and kinetic and kinematic alterations of the lower leg. In addition, longitudinal bending stiffness (LBS) of the outsole influences these parameters as well. This study aims to investigate the effects of the LBS in combination with different forefoot radii of rocker shoes on kinematics and kinetics of the lower limb. METHODS: 10 participants walked in standard shoes and six experimental shoe conditions with high and low LBS and three different forefoot rocker radii with the same (proximal) AP and AA. Lower extremity kinematics and kinetics were collected while walking on an instrumented treadmill at preferred walking speed and analysed with a repeated measures ANOVA and Statistical Parametric Mapping (SPM) (α = .05; post hoc α = .05/6). RESULTS: SPM analyses revealed no significant differences for LBS and interaction LBS*RR for most research variables in terminal stance (ankle angle, ankle moment, ankle power, foot-to-horizontal angle, shank-to-vertical angle, external ankle moment, ground reaction force angle). A significant LBS effect was found for anterior-posterior position of the centre of pressure during pre-swing and peak ankle dorsiflexion angle. No relevant significant differences were found in spatio-temporal parameters and total work at the ankle between low and high LBS. CONCLUSION: This study showed that longitudinal bending stiffness does not affect the biomechanical working mechanism of rocker profile shoes as long as toe plantarflexion is restricted. Providing that the forefoot rocker radius supports at least a normal foot-to-horizontal angle at toe-off, there is no reason to increase sole stiffness to change ankle kinematics and kinetics

Effects of rocker radii with two longitudinal bending stiffnesses on plantar pressure distribution in the forefoot

INTRODUCTION: Outsole parameters of the shoe can be adapted to offload regions of pain or region of high pressures. Previous studies already showed reduced plantar pressures in the forefoot due to a proximally placed apex position and higher longitudinal bending stiffness (LBS). The aim of this study was to determine the effect of changes in rocker radii and high LBS on the plantar pressure profile during gait. METHOD: 10 participants walked in seven shoe conditions of which one control shoe and six rocker shoes with small, medium and large rocker radii and low and high longitudinal bending stiffness. Pedar in-shoe plantar pressure measuring system was used to quantify plantar pressures while walking on a treadmill at self-selected walking speed. Peak plantar pressure, maximum mean pressure and force-time integral were analyzed with Generalized Estimated Equation (GEE) and Tukey post hoc correction (α = .05). RESULTS: Significantly lower plantar pressures were found in the first toe, toes 2-5, distal and proximal forefoot in all rocker shoe conditions as compared to the control shoe. Plantar pressures in the first toe and toes 2-5 were significantly lower in the small radius compared to medium and large radii. For the distal forefoot both small and medium radii significantly reduced plantar pressure compared to large radii. Low LBS reduced plantar pressure at the first toe significantly compared to high LBS independent of the rocker radius. Plantar pressures in the distal forefoot and toes 2-5 were lower in high LBS compared to low LBS. CONCLUSION: Manipulation of the rocker radius and LBS can effectively reduce peak plantar pressures in the forefoot region during gait. In line with previous studies, we showed that depending on the exact target location for offloading, different combinations of rocker radius and LBS need to be adopted to maximize treatment effects

Adiabatically changing the phase-space density of a trapped Bose gas

We show that the degeneracy parameter of a trapped Bose gas can be changed adiabatically in a reversible way, both in the Boltzmann regime and in the degenerate Bose regime. We have performed measurements on spin-polarized atomic hydrogen in the Boltzmann regime demonstrating reversible changes of the degeneracy parameter (phase-space density) by more than a factor of two. This result is in perfect agreement with theory. By extending our theoretical analysis to the quantum degenerate regime we predict that, starting close enough to the Bose-Einstein phase transition, one can cross the transition by an adiabatic change of the trap shape.Comment: 4 pages, 3 figures, Latex, submitted to PR

Trophic interactions will expand geographically but be less intense as oceans warm

Interactions among species are likely to change geographically due to climate-driven species range shifts and in intensity due to physiological responses to increasing temperatures. Marine ectotherms experience temperatures closer to their upper thermal limits due to the paucity of temporary thermal refugia compared to those available to terrestrial organisms. Thermal limits of marine ectotherms also vary among species and trophic levels, making their trophic interactions more prone to changes as oceans warm. We assessed how temperature affects reef fish trophic interactions in the Western Atlantic and modeled projections of changes in fish occurrence, biomass, and feeding intensity across latitudes due to climate change. Under ocean warming, tropical reefs will experience diminished trophic interactions, particularly herbivory and invertivory, potentially reinforcing algal dominance in this region. Tropicalization events are more likely to occur in the northern hemisphere, where feeding by tropical herbivores is predicted to expand from the northern Caribbean to extratropical reefs. Conversely, feeding by omnivores is predicted to decrease in this area with minor increases in the Caribbean and southern Brazil. Feeding by invertivores declines across all latitudes in future predictions, jeopardizing a critical trophic link. Most changes are predicted to occur by 2050 and can significantly affect ecosystem functioning, causing dominance shifts and the rise of novel ecosystems.Postprint6,86

Spatially explicit species distribution models: A missed opportunity in conservation planning?

Aim: Systematic conservation planning is vital for allocating protected areas given the spatial distribution of conservation features, such as species. Due to incomplete species inventories, species distribution models (SDMs) are often used for predicting species habitat suitability and species probability of occurrence. Currently, SDMs mostly ignore spatial dependencies in species and predictor data. Here, we provide a comparative evaluation of how accounting for spatial dependencies, that is, autocorrelation, affects the delineation of optimized protected areas. Location: Southeast Australia, Southeast U.S. Continental Shelf, Danube River Basin. Methods: We employ Bayesian spatially explicit and non-spatial SDMs for terrestrial, marine and freshwater species, using realm-specific planning unit shapes (grid, hexagon and subcatchment, respectively). We then apply the software gurobi to optimize conservation plans based on species targets derived from spatial and non-spatial SDMs (10% 50% each to analyse sensitivity), and compare the delineation of the plans. Results: Across realms and irrespective of the planning unit shape, spatially explicit SDMs (a) produce on average more accurate predictions in terms of AUC, TSS, sensitivity and specificity, along with a higher species detection probability. All spatial optimizations meet the species conservation targets. Spatial conservation plans that use predictions from spatially explicit SDMs (b) are spatially substantially different compared to those that use non-spatial SDM predictions, but (c) encompass a similar amount of planning units. The overlap in the selection of planning units is smallest for conservation plans based on the lowest targets and vice versa. Main conclusions: Species distribution models are core tools in conservation planning. Not surprisingly, accounting for the spatial characteristics in SDMs has drastic impacts on the delineation of optimized conservation plans. We therefore encourage practitioners to consider spatial dependencies in conservation features to improve the spatial representation of future protected areas. © 2019 The Authors. Diversity and Distributions Published by John Wiley and Sons LtdThis study was funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 642317. SDL has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No. 748625, and SCJ from the German Federal Ministry of Education and Research (BMBF) for the “GLANCE” project (Global Change Effects in River Ecosystems; 01 LN1320A). We wish to thank Gwen Iacona and two anonymous referees for their constructive comments on an earlier version of the manuscript

Disparate dispersal limitation in Geomalacus slugs unveiled by the shape and slope of the genetic–spatial distance relationship

Long‐term dispersal ability is a key species’ trait constraining species ranges and thus large‐scale biodiversity patterns. Here we infer the long‐term dispersal abilities of three Geomalacus (Gastropoda, Pulmonata) species from their range‐wide genetic–spatial distance relationships. This approach follows recent advances in statistical modelling of the analogous pattern at the community level: the distance decay in assemblage similarity. While linear relationships are expected for species with high long‐term dispersal abilities, asymptotic relationships are expected for those with more restricted mobility. We evaluated three functional forms (linear, negative exponential and power‐law) for the relationship between genetic distance (computed from mitochondrial cox1 sequences, n = 701) and spatial distance. Range fragmentation at present time and at the Last Glacial Maximum was also estimated based on the projection of climatic niches. The power‐law function best fit the relationship between genetic and spatial distances, suggesting strong dispersal limitation and long‐term population isolation in all three species. However, the differences in slope and explained variance pointed to disparities in dispersal ability among these weak dispersers. Phylogeographic patterns of Geomalacus species are thus largely driven by the same major process (i.e. dispersal limitation), operating at different strengths. This strong dispersal limitation results in geographic clustering of genetic diversity that makes these species highly vulnerable to genetic erosion due to climate changThe authors were supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) through grant CGL2016‐76637‐P and fellowship IJCI‐2014‐20881 to CG‐RS

The correlation between posterior tibial slope and dynamic anterior tibial translation and dynamic range of tibial rotation

PURPOSE: The amount of passive anterior tibial translation (ATT) is known to be correlated to the amount of posterior tibial slope (PTS) in both anterior cruciate ligament-deficient and reconstructed knees. Slope-altering osteotomies are advised when graft failure after anterior cruciate ligament (ACL) reconstruction occurs in the presence of high PTS. This recommendation is based on studies neglecting the influence of muscle activation. On the other hand, if dynamic range of tibial rotation (rTR) is related to the amount of PTS, a “simple” anterior closing-wedge osteotomy might not be sufficient to control for tibial rotation. The purpose of this study was to evaluate the correlation between the amount of PTS and dynamic ATT and tibial rotation during high demanding activities, both before and after ACL reconstruction. We hypothesized that both ATT and rTR are strongly correlated to the amount of PTS. METHODS: Ten subjects were studied both within three months after ACL injury and one year after ACL reconstruction. Dynamic ATT and dynamic rTR were measured using a motion-capture system during level walking, during a single-leg hop for distance and during a side jump. Both medial and lateral PTS were measured on MRI. A difference between medial and lateral PTS was calculated and referred to as Δ PTS. Spearman’s correlation coefficients were calculated for the correlation between medial PTS, lateral PTS and Δ PTS and ATT and between medial PTS, lateral PTS and Δ PTS and rTR. RESULTS: Little (if any) to weak correlations were found between medial, lateral and Δ PTS and dynamic ATT both before and after ACL reconstruction. On the other hand, a moderate-to-strong correlation was found between medial PTS, lateral PTS and Δ PTS and dynamic rTR one year after ACL reconstruction. CONCLUSION: During high-demand tasks, dynamic ATT is not correlated to PTS. A compensation mechanism may be responsible for the difference between passive and dynamic ATT in terms of the correlation to PTS. A moderate-to-strong correlation between amount of PTS and rTR indicates that such a compensation mechanism may fall short in correcting for rTR. These findings warrant prudence in the use of a pure anterior closing wedge osteotomy in ACL reconstruction. TRIAL REGISTRATION: Netherlands Trial Register, Trial 7686. Registered 16 April 2016—Retrospectively registered. LEVEL OF EVIDENCE: Level 2, prospective cohort stud

Range-wide variation in local adaptation and phenotypic plasticity of fitness-related traits in Fagus sylvatica and their implications under climate change

Aim To better understand and more realistically predict future species distribution ranges, it is critical to account for local adaptation and phenotypic plasticity in populations' responses to climate. This is challenging because local adaptation and phenotypic plasticity are trait-dependent and traits covary along climatic gradients, with differential consequences for fitness. Our aim is to quantify local adaptation and phenotypic plasticity of vertical and radial growth, leaf flushing and survival across the range of Fagus sylvatica and to estimate the contribution of each trait to explaining the species' occurrence. Location Europe. Time period 1995-2014; 2070. Major taxa studied Fagus sylvatica L. Methods We used vertical and radial growth, flushing phenology and mortality of F. sylvatica L. recorded in the BeechCOSTe52 database (>150,000 trees). Firstly, we performed linear mixed-effect models that related trait variation and covariation to local adaptation (related to the planted populations' climatic origin) and phenotypic plasticity (accounting for the climate of the plantation), and we made spatial predictions under current and representative concentration pathway (RCP 8.5) climates. Secondly, we combined spatial trait predictions in a linear model to explain the occurrence of the species. Results The contribution of plasticity to intraspecific trait variation is always higher than that of local adaptation, suggesting that the species is less sensitive to climate change than expected; different traits constrain beech's distribution in different parts of its range: the northernmost edge is mainly delimited by flushing phenology (mostly driven by photoperiod and temperature), the southern edge by mortality (mainly driven by intolerance to drought), and the eastern edge is characterized by decreasing radial growth (mainly shaped by precipitation-related variables in our model); considering trait covariation improved single-trait predictions. Main conclusions Population responses to climate across large geographical gradients are dependent on trait x environment interactions, indicating that each trait responds differently depending on the local environment.Peer reviewe