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1,868 results for “Spatial Data”
Data from: Reproduction under light pollution: maladaptive response to spatial variation in artificial light in a glow-worm
<p>The amount of artificial light at night is growing worldwide, impacting the behaviour of nocturnal organisms. Yet, we know little about the consequences of these behavioural responses for individual fitness and population viability. We investigated if females of the common glow-worm <i>Lampyris noctiluca</i> – which glow in the night to attract males – mitigate negative effects of artificial light on mate attraction by adjusting the timing and location of glowing to spatial variation in light conditions. We found females do not move away from light when exposed to a gradient of artificial light, but delay or even refrain from glowing. Further, we demonstrate that this response is maladaptive, as our field study showed that staying still when exposed to artificial light from a simulated streetlight decreases mate attraction success, while moving only a short distance from the light source can markedly improve mate attraction. These results indicate that glow-worms are unable to respond to spatial variation in artificial light, which may be a factor in their global decline. Consequently, our results support the hypothesis that animals often lack adaptive behavioural responses to anthropogenic environmental changes and underlines the importance of considering behavioural responses when investigating effects of human activities on wildlife.</p>
Data from: Genetic structure at three spatial scales is consistent with limited philopatry in Ricord's Rock Iguanas (Cyclura ricordii)
Cyclura ricordii is an endemic iguana from Hispaniola Island and is threatened on the IUCN Red List. The main threats are predation by introduced mammals, habitat destruction, and hunting pressure. The present study focused on two nesting sites from Pedernales Province in the Dominican Republic. The hypothesis that natal philopatry influences dispersal and nest site selection was tested. Monitoring and sampling took place in 2012 and 2013. Polymorphic markers were used to evaluate whether natal philopatry limits dispersal at multiple spatial scales. Ripley's K revealed that nests were significantly clustered at multiple scales, when both nesting sites were considered and within each nesting site. This suggests a patchy, non-random distribution of nests within nest sites. Hierarchical AMOVA revealed that nest site aggregations did not explain a significant portion of genetic variation within nesting sites. However, a small but positive correlation between geographic and genetic distance was detected using a Mantel's test. Hence, the relationship between geographic distance and genetic distance among hatchlings within nest sites, while detectable, was not strong enough to have a marked effect on fine scale genetic structure. Spatial and genetic data combined determined that the nesting sites included nesting females from multiple locations, and the hypothesis of 'natal philopatry', was not supported because females nesting in the same cluster were no more closely related to each other than to other females from the same nesting site. These findings imply that nesting aggregations are more likely associated with cryptic habitat variables contributing to optimal nesting conditions.
Data from: Multiple scales of spatial heterogeneity control soil respiration responses to precipitation across a dryland rainfall gradient
<p><i>Aims –</i> Soil respiration (R<sub>s</sub>) is a major pathway for releasing fixed carbon back to the atmosphere. However, controls over R<sub>s</sub> are poorly understood in arid and hyper-arid systems where microbial activity is frequently constrained by moisture. We addressed key uncertainties in R<sub>s</sub>: 1) How do short-term rainfall pulses affect R<sub>s</sub> at sites that differ in long-term precipitation inputs?, 2) how do R<sub>s</sub> responses to short and long-term rainfall differ across soil surfaces?, and 3) how are R<sub>s</sub> responses affected by local-scale attributes?</p> <p><i>Methods – </i>We measured R<sub>s</sub> responses to rainfall pulses over a 48 h period. Working across a climate gradient, we compared R<sub>s </sub>responses on two contrasting soil surfaces which both had two vegetation/soil morphology patch types that differed in organic matter inputs and accumulation.</p> <p><i>Results – </i>Rates of R<sub>s </sub>were low, but highly responsive to rainfall pulses. Stimulation of R<sub>s </sub>by rainfall was generally greater in areas with higher annual rainfall. However, patterns for R<sub>s </sub>responses to rainfall differed greatly on the two soil surfaces and among patch types.</p> <p><i>Conclusions – </i>The strong role of patch type and soil surface in controlling R<sub>s</sub> points to the need to carefully consider small-scale spatial and temporal variation when interpreting dryland biogeochemical fluxes.</p>
Data from: Specialization and niche overlap across spatial scales: revealing ecological factors shaping species richness and coexistence in Australian songbirds
1. Ecological specialization enables the partitioning of resources and thus can facilitate the coexistence of species and promote higher species richness. Specialization and niche partitioning are expected to exert a decisive influence on local spatial scales, while species richness at regional scales should be shaped mostly by historical factors and abiotic conditions. Moreover, specialization is expected to be particularly important in communities that are exceptionally species rich for their environmental conditions. Concurrently, niche overlap in these communities should be minimized to enable species coexistence. 2. We tested these hypotheses by studying specialization-richness relationship and niche overlap in assemblages of 298 species of songbirds (Passeriformes) across Australia. We used local (2-6 ha) to regional (bioregions) spatial scales, and detailed data on habitat, diet, and foraging behaviour (method, substrate, and stratum). 3. We expected the richness-specialization relationship to be particularly strong i) on local spatial scales and ii) in communities exceptionally species rich for given environmental conditions (approximated by moisture and vegetation complexity). We also expected iii) low niche overlap in assemblages with specialized species. 4. Only the third prediction was partly supported. First, while the specialization and species richness were often positively related, the strength and the direction of the relationship changed between traits and across spatial scales. The strength of the specialization-richness relationship was consistently positive only in foraging stratum, and it increased towards smaller spatial scales only in case of habitat and diet. Simultaneously, species in local communities demonstrated high overlap in habitat and diet. Second, we did not find particularly strong specialization-richness relationships in exceptionally species rich communities. Third, we found the expected negative relationship between specialization and overlap in foraging stratum and substrate (in local communities), suggesting that species partition ecological space locally in terms of where they find food. 5. Our expectations were only weakly supported. Specialization on foraging stratum was probably important in facilitating species co-existence. Conversely, although species were often specialized on habitat and diet, high overlap in these traits did not preclude their local coexistence. Overall, specialization and overlap in foraging traits were more important for species coexistence than habitat or diet.
Data from: The influence of habitat and adults on the spatial distribution of juvenile corals
Population distributions are affected by a variety of spatial processes, including dispersal, intraspecific dynamics, and habitat selection. Within reef-building coral communities, these processes are especially important during the earliest life stages when reproduction provides mobility among sessile organisms and populations experience the greatest mortality bottlenecks both before and immediately after settlement. Here, we used large-area imaging to create photomosaics that allowed us to identify and map the location of 4,681 juvenile (1-5 cm diameter) and 25,902 adult (>5 cm diameter) coral colonies from eight 100m2 plots across the forereef of Palmyra Atoll. Using metrics of density, percent cover, and the relative location of each colony within each plot, we examined abundance and spatial relationships between juvenile and adult coral taxa. Within coral taxa, juvenile density was generally positively related to the numerical density and percent cover of adults. Nearest neighbor analyses showed aggregation of juveniles near adults of the same taxon for two of the focal taxa (Pocillopora and Fungiids), while all other taxa showed random spatial patterning relative to adults. Three taxa had clustered distributions of juveniles overall. Additionally, we found that on a colony level, juveniles for five of nine focal taxa (accounting for >98% of all identified juveniles) associated with a specific habitat type, with four of those five taxa favoring unconsolidated (e.g., rubble) over consolidated substrata. The general lack of clustering in juvenile corals contrasts with consistent clustering patterns seen in adult corals, suggesting that adult spatial patterns are largely driven by processes occurring after maturity such as partial colony mortality, including fission and fragmentation. The association of many taxa with unconsolidated habitat also suggests that corals may play an important role in colonizing natural rubble patches that could contribute to reef stabilization over time.
Data from: Temporal variation in spatial genetic structure during population outbreaks: distinguishing among different potential drivers of spatial synchrony
Spatial synchrony is a common characteristic of spatio-temporal population dynamics across many taxa. While it is known that both dispersal and spatially autocorrelated environmental variation (i.e., the Moran effect) can synchronize populations, the relative contributions of each, and how they interact, is generally unknown. Distinguishing these mechanisms and their effects on synchrony can help us to better understand spatial population dynamics, design conservation and management strategies, and predict climate change impacts. Population genetic data can be used to tease apart these two processes as the spatio-temporal genetic patterns they create are expected to be different. A challenge, however, is that genetic data are often collected at a single point in time, which may introduce context-specific bias. Spatio-temporal sampling strategies can be used to reduce bias and to improve our characterization of the drivers of spatial synchrony. Using spatio-temporal analyses of genotypic data, our objective was to identify the relative support for these two mechanisms to the spatial synchrony in population dynamics of the irruptive forest insect pest, the spruce budworm (Choristoneura fumiferana), in Quebec (Canada). AMOVA, cluster analysis, isolation by distance and sPCA were used to characterize spatio-temporal genomic variation using 1370 SBW larvae sampled over four years (2012-2015) and genotyped at 3,562 SNP loci. We found evidence of overall weak spatial genetic structure that decreased from 2012 to 2015 and a genetic diversity homogenization among the sites. We also found genetic evidence of a long-distance dispersal event over > 140 km. These results indicate that dispersal is the key mechanism involved in driving population synchrony of the outbreak. Early intervention management strategies that aim to control source populations have the potential to be effective through limiting dispersal. However, the timing of such interventions relative to outbreak progression is likely to influence their probability of success.
Data from: Spatial scaling of beta diversity in the shallow marine fossil record
Beta diversity quantifies the spatial structuring of ecological communities and is a fundamental partition of biodiversity, central to understanding many macroecological phenomena in modern biology and paleobiology. Despite its common application in ecology, studies of beta diversity in the fossil record are limited, particularly at regional spatial scales that are important for understanding macroevolutionary processes. The spatial scaling of beta diversity in the fossil record is poorly understood, but has significant implications due to temporal variation in the spatial distribution of fossil collections and the large spatio-temporal scales typically employed. Here we test the spatial scaling of several common measures of beta diversity using the Cenozoic shallow marine molluscan fossil record of New Zealand, and derive a spatially standardized time series of beta diversity. To measure spatial scaling we use and compare grid cell occupancy based on an equal-area grid and summed minimum spanning tree length, both based on reconstructed paleocoordinates of fossil collections. We find that beta diversity is spatially dependent at local to regional scales, regardless of the metric or spatial scaling utilised, and that spatial standardization significantly changes apparent temporal trends of beta diversity and, therefore, inferences about processes driving diversity change.
Data from: Larval assemblages over the abyssal plain in the Pacific are highly diverse and spatially patchy
Abyssal plains are among the most biodiverse yet least explored marine ecosystems on our planet, and they are increasingly threatened by human impacts, including future deep seafloor mining. Recovery of abyssal populations from the impacts of polymetallic nodule mining will be partially determined by the availability and dispersal of pelagic larvae leading to benthic recolonization of disturbed areas of the seafloor. Here we use a tree-of-life (TOL) metabarcoding approach to investigate the species richness, diversity, and spatial variability of the larval assemblage at mesoscales across the abyssal seafloor in two mining-claim areas in the eastern Clarion Clipperton Fracture Zone (CCZ; abyssal Pacific). Our approach revealed a previously unknown taxonomic richness within the meroplankton assemblage, detecting larvae from 12 phyla, 23 Classes, 46 Orders, and 65 Families, including a number of taxa not previously reported at abyssal depths or within the Pacific Ocean. A novel suite of parasitic copepods and worms were sampled, from families that are known to associate with other benthic invertebrates or demersal fishes as hosts. Larval assemblages were patchily distributed at the mesoscale, with little similarity in OTUs detected among deployments even within the same 30 x 30 km study area. Our results provide baseline observations on larval diversity prior to polymetallic nodule mining in this region, and emphasize our overwhelming lack of knowledge regarding larvae of the benthic boundary layer in abyssal plain ecosystems.
Freshwater zooplankton metapopulations and metacommunities respond differently to environmental and spatial variation data files
<p>We used this data to examine how crustacean zooplankton and rotifer species’ metapopulation genetic structure and metacommunities respond to environmental and spatial variation both within and across four regions of boreal Canada (see Martin et al. in press, Freshwater zooplankton metapopulations and metacommunities respond differently to environmental and spatial variation, Ecology).</p> <p>Whole community zooplankton samples were collected from 113 lakes from four environmentally, geologically, and geographically distinct regions of Québec, Canada. Each lake was sampled once, and the bulk zooplankton samples were sequenced using metabarcoding targeting the cytochrome c oxidase subunit I (COI) mitochondrial gene region. Sequences were clustered to species based on 3% OTUs and within species-variation was captured based on ASVs. Read abundances were then normalized using rarefaction to the lowest library to accommodate differences in sequencing depth across sites. In addition 16 environmental variables plus two spatial variables were used to capture abiotic variation between lakes. The data files include the ASV sequences, OTU and taxonomic assignment, and site variables.</p>
Data from: Spatial and temporal homogenization of freshwater macrofaunal communities in ditches
1. There is a widespread concern that we are witnessing an on-going homogenization of ecological communities. However, in contrast to human impacts on spatial patterns in biodiversity, human impacts on the temporal aspects of β-diversity have received little attention. Moreover, the interplay between spatial and temporal β-diversity is poorly understood. To address this knowledge gap, we assessed dissimilarity within freshwater macrofaunal communities of drainage ditches to determine spatiotemporal β-diversity as well as homogenization in relation to different types of land use. 2. We considered four distinct changes in community composition: spatial turnover, temporal turnover, spatial variation over time and temporal variation in space, as well as the combined effects of space and time on β-diversity. As a metric of dissimilarity, we calculated the taxonomic Hellinger distance between samples from different locations and time points and correlated these with distance in space and in time, as well as with three spatial variables, including land use type, and two temporal variables. We studied the effect of interactions between spatial and temporal variables on dissimilarity by applying a permutational analysis of variance. 3. Our results illustrate the importance of changes in community composition in time with respect to temporal turnover, spatial variation over time and temporal variation in space. While we did not find spatial turnover in community composition, both month and year had a considerable effect. Within a year, β-diversity decreased over the months, yet these assembly patterns differed between years. This suggests major effects of seasonal and year-to-year dynamics on β-diversity. Land use was also observed to be a main driver: ditches in nature conservation areas had higher β-diversity and temporal heterogeneity was lowest in ditches adjacent to the most intensive agricultural land use category, indicating agricultural practices can homogenizes biodiversity in both space and time. 4. By analyzing the spatial and temporal β-diversity patterns in freshwater macrofaunal communities in concert, we have shown that β-diversity is a sensitive and highly informative metric of both spatial and temporal changes in community composition.
Data from: Aragonite bias exhibits systematic spatial variation in the late Cretaceous Western Interior Seaway, North America
Preferential dissolution of the biogenic carbonate polymorph aragonite promotes preservational bias in shelly marine faunas. Whilst field studies have documented the impact of preferential aragonite dissolution on fossil molluscan diversity, its impact on regional and global biodiversity metrics is debated. Epicontinental seas are especially prone to conditions which both promote and inhibit preferential dissolution, which may result in spatially extensive zones with variable preservation. Here we present a multi-faceted evaluation of aragonite dissolution within the late Cretaceous Western Interior Seaway of North America. Occurrence data of molluscs from two time intervals (Cenomanian-Turonian boundary, early Campanian) are plotted on new high-resolution paleogeographies to assess aragonite preservation within the seaway. Fossil occurrences, diversity estimates and sampling probabilities for calcitic and aragonitic fauna were compared in zones defined by depth and distance from the seaway margins. Apparent range sizes, which could be influenced by differential preservation potential of aragonite between separate localities, were also compared. Our results are consistent with exacerbated aragonite dissolution within specific depth zones for both time slices, with aragonitic bivalves additionally showing a statistically significant decrease in range size compared to calcitic fauna within carbonate-dominated Cenomanian-Turonian strata. However, we are unable to conclusively show that aragonite dissolution impacted diversity estimates. Therefore, whilst aragonite dissolution is likely to have affected the preservation of fauna in specific localities, time averaging and instantaneous preservation events preserve regional biodiversity. Our results suggest that the spatial expression of taphonomic biases should be an important consideration for paleontologists working on paleobiogeographic problems.
Data from: Helianthus maximiliani and species fine-scale spatial pattern affect diversity interactions in reconstructed tallgrass prairies
1. Biodiversity and Ecosystem Function analyses aim to explain how individual species and their interactions affect ecosystem function. With this study we asked in what ways do species interact, are these interactions affected by species planting pattern, and are initial (planted) proportions or previous year (realized) proportions a better reference point for characterizing grassland diversity effects? 2. We addressed these questions with experimental communities compiled from a pool of 16 tallgrass prairie species. We planted all species in monocultures and mixtures that varied in their species richness, evenness, and spatial pattern. We recorded species-specific biomass production over three growing seasons and fitted Diversity-Interactions (DI) models to annual plot biomass yields. 3. In the establishment season, all species interacted equally to form the diversity effect. In years 2 and 3, each species contributed a unique additive coefficient to its interaction with every other species to form the diversity effect. These interactions were affected by H. maximiliani and the species planting pattern. Models based on species planted proportions better-fit annual plot yields than models based on species previous contributions to plot biomass. 4. Outcomes suggest that efforts to plant tallgrass prairies to maximize diversity effects should focus on the specific species present and in what arrangement they are planted. Furthermore, for particularly diverse grasslands, the effort of collecting annual species biomass data may not be necessary when quantifying diversity effects with Diversity-Interactions models.
Data from: Spatial structure maintains diversity of pyocin inhibition in household Pseudomonas aeruginosa
<p><span><span><span><span><span><span><span><span><span><span><span>Nearly all bacteria produce narrow-spectrum antibiotics called bacteriocins. Studies have shown that bacteriocins can mediate microbial interactions, but the mechanisms underlying patterns of inhibition are less well understood. We assembled a spatially structured collection of isolates of <i>Pseudomonas aeruginosa</i> from bathroom and kitchen sink drains in nine households. Growth inhibition of these <i>P. aeruginosa </i>by bacteriocins, known as pyocins in this species, was measured using pairwise inhibition assays. Carbon source usage of these isolates was measured and genetic distance was estimated using multilocus sequencing. We found that as the distance between sites of isolation increased, there was a significantly higher probability of inhibition, and that pyocin inhibition and susceptibility vary greatly among isolates collected from different houses. We also detected support for other mechanisms influencing diversity: inhibition outcomes were influenced by the type of drain from which isolates were collected, and while we found no indication that carbon source utilization influences inhibition, inhibition was favored at an intermediate genetic distance. Overall, these results suggest that the combined effects of dispersal limitation among sites and competitive exclusion within them maintain diversity in pyocin inhibition and susceptibility phenotypes, and that additional processes such as local adaptation and effects of phylogenetic distance could further contribute to spatial variability.</span></span></span></span></span></span></span></span></span></span></span></p>
Data from: Spatial segregation and habitat partitioning of bobcat and Canada lynx
<p>Harvest records suggest that the abundance of bobcats (<i>Lynx rufus</i>) has increased and the leading edge of their distribution has spread northward, while the trailing edge of the Canada lynx (<i>Lynx canadensis</i>) range has contracted in Ontario, Canada. There has been a debate about whether these closely related felids might compete in areas of sympatry, but there is little research on sympatric populations of bobcat and lynx. Both species are found on the north shore of Lake Huron in Ontario, Canada, which provided an opportunity to investigate their spatial patterns and habitat use. We surveyed snowmobile routes for snow tracks over 3 winters and estimated probability of occupancy for the two felid species while accounting for detectability. Bobcat and lynx tracks were never found on the same survey route. Bobcat occupancy increased with habitat heterogeneity whereas lynx occupancy increased with homogeneity. Our results fit with the common assumption of the generalist and specialist natures of bobcat and lynx, respectively. Our findings suggest that bobcats invaded former lynx territory after these areas became vacant. The story of the bobcat and the lynx is one of the loss of a unique, boreal specialist due to anthropogenic change, and eventual replacement by an adaptable generalist.</p>
Data for "TrueEBSD: correcting spatial distortions in electron backscatter diffraction maps"
<p>Data for "TrueEBSD: correcting spatial distortions in electron backscatter diffraction maps" published in Ultramicroscopy.</p> <p>Journal DOI: <a href="https://doi.org/10.1016/j.ultramic.2020.113130">https://doi.org/10.1016/j.ultramic.2020.113130</a>;<br> Preprint DOI: <a href="https://arxiv.org/abs/1909.00347">https://arxiv.org/abs/1909.00347</a>.</p> <p>The zipped folder contains:</p> <ol> <li>Readme (text file)</li> <li>'Ti-64' data subfolder: data for one of the maps in the Ti-64 map stitching example</li> <li>'ZrH' data subfolder: data for the hydride-containing Zircaloy-4 example</li> <li>'CP-Zr' data subfolder: data for the in-situ deformed Zr example</li> <li> 'MATLAB scripts' subfolder: TrueEBSD source code.</li> </ol> <p> </p> <p>Each data subfolder contains:</p> <ul> <li>Input image files</li> <li>EBSD orientation files in Bruker CTF format</li> <li>'Outputs' subfolder containing output figures as image files.</li> </ul> <p>The 'MATLAB scripts' subfolder contains TrueEBSD source code:</p> <ul> <li>The primary user interface is 'input_deck.m'. Most user settings can be changed here. <ul> <li>The input deck entries here have been pre-filled for the Ti-64 dataset.</li> </ul> </li> <li>To use TrueEBSD, run 'input_deck.m' in MATLAB.</li> <li>The method is outlined in 'main.m', which calls functions in 'MATLAB scripts\code\'.</li> </ul>
R code, spatial and tabular data to fully reproduce STEPS simulations of population change for common brushtail possum, grassland melomys and northern brown bandicoot in northern Australia
<ol> <li> <p>The development of effective fire management for biodiversity conservation is a global challenge. The highly dynamic nature of fire, the difficulty in replicating 'real-world' fire experiments, and the need to understand population changes at large spatiotemporal scales make computer simulations particularly useful for identifying optimal fire management regimes for biodiversity conservation. </p> </li> <li> <p>We aimed to develop a flexible modelling approach with which to investigate how the spatiotemporal application of fire (i.e. management scenarios) influences savanna biodiversity. We used existing data from a landscape-scale fire experiment to develop population simulations for the common brushtail possum (<i>Trichosurus vulpecula</i>), grassland melomys (<i>Melomys burtoni</i>) and northern brown bandicoot (<i>Isoodon macrourus</i>) across the Kapalga area of Kakadu National Park in northern Australia. We simulated how populations were expected to change between 1995 and 2015 in response to the fire patterns observed at Kapalga over this period, and under a hypothetical management scenario of extensive prescribed burning.</p> </li> <li> <p>Our models predicted a substantial decline in all three species in response to the observed fire regime at Kapalga, suggesting that the fire patterns observed at Kapalga, with the associated mechanisms and interactions with other ecological processes, were not conducive with the persistence of native mammal populations. </p> </li> <li> <p>Our prescribed burning scenario had little effect on the predicted population trajectory of the common brushtail possum and grassland melomys, but markedly improved the population trajectory of the northern brown bandicoot. These inconsistencies highlight the need for a nuanced approach to fire management across northern Australian savannas, that is tailored to local conditions and management objectives. </p> </li> <li> <p>Synthesis and applications. The modelling approach outlined here, provides a basis for identifying fire patterns that are beneficial for conserving biodiversity, thereby increasing our capacity to establish clear targets for prescribed fire management. Importantly, this approach is flexible and can be easily adapted to other taxa and fire-prone ecosystems.</p> </li> </ol>
Data from: Spatial dynamics of alpine treelines under global warming: what explains the mismatch between tree densification and elevational upward shifts at the treeline ecotone?
<p><b>Aim</b></p> <p>Most studies focusing on the alpine treeline responses to climate warming have used either the tree densification within the ecotone or its elevational upshift as indicators. However, it is acknowledged that the relation between densification and upshift is spatially heterogeneous, making inferences and comparability among studies tricky. The lack of consistent empirical evidence on this potential mismatch and its drivers leads us to focus on this issue in this study. The aim was twofold: (i) to quantify the mismatch between the two processes at a regional scale, and (ii) to identify its site-specific determinants.</p> <p><b>Location</b></p> <p>French eastern Pyrenees</p> <p><b>Time period</b></p> <p>1953-2015</p> <p><b>Major taxa studied </b></p> <p><i>Pinus</i><i> uncinata </i>(Ramond ex DC)</p> <p><b>Methods</b></p> <p>An object-oriented supervised classification procedure was performed on historical (1953) and current (2015) air-photos. Based on the resulting rasters, densification of the treeline ecotone and upward shift of the treeline were estimated at the two dates in 191 sites, then standardized, before finally being compared. Three site clusters were derived (no mismatch, densification prevalence, upshift prevalence). After having characterized their spatial patterns through join count statistics, a multinomial logistic regression model was computed to identify the correlates of these clusters among a list of site variables.</p> <p><b>Results</b></p> <p>No spatial pattern among the categories of responses emerges at a local scale, but buffers with no mismatch tend to aggregate at a larger scale. Changes in minimum air temperatures, site elevation, mean slope, slope morphometry and lithology appear as significant drivers of the observed mismatch, implying that the relation between densification and elevational upshift is context-specific.</p> <p><b>Main conclusions</b></p> <p><a name="_Hlk17817327">Our findings suggest that both </a><a name="_Hlk17816517">densification and upshift </a>should be considered in quantitative analyses of treeline spatial dynamics, since these two ecological processes are not controlled by the same drivers.</p>
Data from: Environmental and spatial effects on coastal stream fishes in the Atlantic rainforest
<p>Contemporary and historical factors influence assemblage structure. The environmental and spatial influences acting on fish organization of rainforest coastal streams in the Atlantic rainforest of Brazil were examined. Fish (and functional traits such as morphology, diet, velocity preference, body size), environmental variables (pH, water conductivity, dissolved oxygen, temperature, stream width, flow, depth, substrate) and altitude were measured from 59 stream reaches. Asymmetric eigenvector maps were used to model the spatial structure considering direction of fish movements. Elevation played an important role – fish abundance, biomass, and richness all decrease with increasing elevation. Fish communities are influenced by both environmental and spatial factors, but downstream movements were shown to be more important in explaining the observed spatial variation than were bidirectional and upstream movements. Spatial factors, as well as environmental variables influenced by the spatial structure, explained most of the variation in fish assemblages. The strong spatial structuring is probably attributable to asymmetric dispersal limitation along the altitudinal profile: dispersal is likely to be more limiting moving upstream than downstream. These fish assemblages reflect scale-dependent processes: at the stream reach-scale, fish respond to local environmental filters (habitat structure, water chemistry, and food supply), which are in turn influenced by a larger scale, namely the altitudinal gradient expected in steep coastal mountains. Thus, environmental drivers are not independent of spatial factors, and the effects of local factors can be confounded across the altitudinal gradient. These results may have implications for conservation, because downstream reaches are often neglected in management and conservation plans.</p>
Data from: Bacterial epibiont communities of panmictic Antarctic krill are spatially structured
<p>Antarctic krill (<i>Euphausia superba</i>) are amongst the most abundant animals on Earth, with a circumpolar distribution in the Southern Ocean. Genetic and genomic studies have failed to detect any population structure for the species, suggesting a single panmictic population. However, the hyper-abundance of krill slows the rate of genetic differentiation, masking potential underlying structure. Here we use high-throughput sequencing of bacterial 16S rRNA genes to show that krill bacterial epibiont communities exhibit spatial structuring, driven mainly by distance rather than environmental factors, especially for strongly krill-associated bacteria. Estimating the ecological processes driving bacterial community turnover indicated this was driven by bacterial dispersal limitation increasing with geographic distance. Furthermore, divergent epibiont communities generated from a single krill swarm split between aquarium tanks under near identical conditions suggests physical isolation in itself can cause krill-associated bacterial communities to diverge. Our findings show that Antarctic krill-associated bacterial communities are geographically structured, in direct contrast with the lack of structure observed for krill genetic and genomic data.</p>
Data from: Evidence for spatial clines and mixed geographic modes of speciation for North American cherry-infesting Rhagoletis (Diptera:Tephritidae) flies
An important criterion for understanding speciation is the geographic context of population divergence. Three major modes of allopatric, parapatric, and sympatric speciation define the extent of spatial overlap and gene flow between diverging populations. However, mixed modes of speciation are also possible, whereby populations experience periods of allopatry, parapatry, and/or sympatry at different times as they diverge. Here, we report clinal patterns of variation for 21 nuclear-encoded microsatellites and a wing spot phenotype for cherry-infesting <i>Rhagoletis</i> (Diptera: Tephritidae) across North America consistent with these flies having initially diverged in parapatry followed by a period of allopatric differentiation in the early Holocene. However, mitochondrial DNA (mtDNA) displays a different pattern; cherry flies at the ends of the clines in the eastern USA and Pacific Northwest share identical haplotypes, while centrally located populations in the southwestern USA and Mexico possess a different haplotype. We hypothesize that the mitochondrial difference could be due to lineage sorting but more likely reflects a selective sweep of a favorable mtDNA variant or the spread of an endosymbiont. The estimated divergence time for mtDNA suggests possible past allopatry, secondary contact, and subsequent isolation between USA and Mexican fly populations initiated before the Wisconsin glaciation. Thus, the current genetics of cherry flies may involve different mixed modes of divergence occurring in different portions of the fly's range. We discuss the need for additional DNA sequencing and quantification of prezygotic and postzygotic reproductive isolation to verify the multiple mixed mode hypothesis for cherry flies, and draw parallels from other systems to assess the generality that speciation may commonly involve complex biogeographies of varying combinations of allopatric, parapatric, and sympatric divergence.
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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.