Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
174
datasets available to search
ShareScore release 0.9.0
Dataset results
174 results for “structural size”
Diptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Hemiptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Homoptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Hymenoptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Abundance and Body size of Insects Collected: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Insects caught in pitfall traps: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Lepidoptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Miscellaneous inscet species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Orthoptera species abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Formicidae species (ants) abundance: Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
All Insect Savanna Sweepnet Sampling 2004:Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Old Field All Arthropod Sweepnet Sampling 2004 :Trophic Structure: Insect Species Diversity, Abundance and Body Size
The goal of this study was to examine the populations of insects in prairies and savannas. Most of the prairies had developed after being abandoned from agriculture, but none of the savannas had been cultivated. The history of burning varied between sites. The main sampling for this study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman. Insects were sampled via sweep-net sampling, pitfalls and ant scent plates throughout the growing season in each of 49 grassland fields and savannas. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. In 2004, John Haarstad conducted two similar studies by identifying and enumerating all insects collected in sweepnet samples taken in old fields (prairies) as part of E014 grasshopper studies and from sweepnet samples taken in savannas.
Data from: eDNA concentration, population size structure, and mark-recapture data
<p>Organism abundance is a critical parameter in ecology, but its estimation is often challenging. Approaches utilizing eDNA to indirectly estimate abundance have recently generated substantial interest. However, preliminary correlations observed between eDNA concentration and abundance in nature are typically moderate in strength with significant unexplained variation. Here we apply a novel approach to integrate allometric scaling coefficients into models of eDNA concentration and organism abundance. We hypothesize that eDNA particle production scales non-linearly with mass, with scaling coefficients < 1. Wild populations often exhibit substantial variation in individual body size distributions; we therefore predict that the distribution of mass across individuals within a population will influence population-level eDNA production rates. To test our hypothesis, we collected standardized body size distribution and mark-recapture abundance data using whole-lake experiments involving nine populations of brook trout. We correlated eDNA concentration with three metrics of abundance: density (individuals/ha), biomass (kg/ha), and allometrically scaled mass (ASM) (∑(individual mass<sup>0.73</sup>)/ha). Density and biomass were both significantly positively correlated with eDNA concentration (adj. r<sup>2</sup> = 0.59 and 0.63, respectively), but ASM exhibited improved model fit (adj. r<sup>2</sup> = 0.78). We also demonstrate how estimates of ASM derived from eDNA samples in 'unknown' systems can be converted to biomass or density estimates with additional size structure data. Future experiments should empirically validate allometric scaling coefficients for eDNA production, particularly where substantial intraspecific size distribution variation exists. Incorporating allometric scaling may improve predictive models to the extent that eDNA concentration may become a reliable indicator of abundance in nature.</p>
Predator population size structure alters consumption of prey from epigeic and grazing food webs
<p>Numerous studies have found that predators can suppress prey densities and thereby impact important ecosystem processes such as plant productivity and decomposition. However, prey suppression by spiders can be highly variable. Unlike predators that feed on prey within a single energy channel, spiders often consume prey from asynchronous energy channels, such as grazing (live plant) and epigeic (soil surface) channels. Spiders undergo few life cycle changes and thus appear to be ideally suited to link energy channels, but ontogenetic diet shifts in spiders have received little attention. For example, spider use of different food channels may be highly specialized in different life stages and thus a species may be a multichannel omnivore only when we consider all life stages. Using stable isotopes, we investigated whether wolf spider (Pardosa littoralis, henceforth Pardosa) prey consumption is driven by changes in spider size. Small spiders obtained > 80% of their prey from the epigeic channel, whereas larger spiders used grazing and epigeic prey almost equally. Changes in prey consumption were not driven by changes in prey density, but by changes in prey use by different spider size classes. Thus, because the population size structure of Pardosa changes dramatically over the growing season, changes in spider size may have important implications for the strength of trophic cascades. Our research demonstrates that life history can be an important component of predator diet, which may in turn affect community- and ecosystem-level processes.</p>
Data from: Allometric scaling of eDNA production in stream-dwelling brook trout (Salvelinus fontinalis) inferred from population size structure
<p>Environmental DNA (eDNA) concentration exhibits a positive correlation with organism abundance in nature, but modelling this relationship could be substantially improved by incorporating the biology of eDNA production. A recent model (Yates et al. 2020) extended models of physiological allometric scaling to eDNA production, hypothesizing that brook trout eDNA production scales non-linearly with mass as a power-function with scaling coefficients < 1 in lakes. To validate this hypothesis, we re-analysed data from Wilcox et al. (2016) that examined the correlation between eDNA concentration and brook trout abundance in streams. We found that allometrically scaled mass (ASM) (e.g. ∑(individual mass<sup>0.36</sup>) best described patterns of eDNA concentration across streams (r<sup>2</sup> = 0.43). ASM<sup> </sup>exhibited substantially improved model fit relative to biomass (r<sup>2</sup> = 0.31, ∆AIC = 5.19), indicating that eDNA production did not scale linearly with biomass. However, the explanatory power of ASM was comparable to density (r<sup>2</sup> = 0.40, ∆AIC = 1.25). Additionally, the optimal scaling coefficient estimated from the data (0.36) was substantially lower than that found in Yates et al. (2020) (0.72). Discrepancies between datasets could be attributable to ecological differences between study habitats (streams vs lakes) or due to the exclusion of juveniles (i.e. individuals < 75 mm) that can be abundant in stream environments. Nevertheless, this study adds to the growing body of literature demonstrating that individual eDNA production does not scale linearly with biomass.</p>
Data from: Long-term population size of the North Atlantic humpback whale within the context of worldwide population structure
Once hunted to the brink of extinction, humpback whales (Megaptera novaeangliae) in the North Atlantic have recently been increasing in numbers. However, uncertain information on past abundance makes it difficult to assess the extent of the recovery in this species. While estimates of pre-exploitation abundance based upon catch data suggest the population might be approaching pre-whaling numbers, estimates based on mtDNA genetic diversity suggest they are still only a fraction of their past abundance levels. The difference between the two estimates could be accounted for by inaccuracies in the catch record, by uncertainties surrounding the genetic estimate, or by differences in the timescale to which the two estimates apply. Here we report an estimate of long-term population size based on nuclear gene diversity. We increase the reliability of our genetic estimate by increasing the number of loci, incorporating uncertainty in each parameter and increasing sampling across the geographic range. We report an estimate of long-term population size in the North Atlantic humpback of ~112,000 individuals (95% CI: 45,000 – 235,000). This value is 2-3 fold higher than estimates based upon catch data. This persistent difference between estimates parallels difficulties encountered by population models in explaining the historical crash of North Atlantic humpback whales. The remaining discrepancy between genetic and catch-record values, and the failure of population models, highlights a need for continued evaluation of whale population growth and shifts over time, and continued caution about changing the conservation status of this population.
Data from: Fuelwood sustainability revisited: integrating size structure and resprouting into a spatially realistic fuelshed model
Much concern has been expressed about the sustainability of fuelwood harvesting in Africa. Most models predict that demand will outstrip supply within a few decades, resulting in severe deforestation. However, despite substantial impacts of harvesting on woody vegetation structure, the 'fuelwood crisis' predicted since the 1970s has not materialized. We propose that this is at least partially because regeneration through coppicing has been poorly accounted for in most models. We developed a local fuelwood model that is demographically and spatially explicit, and that incorporates coppice dynamics. The model simulates the dynamics of multiple stem size classes (seedling, sapling, pole and adult), the harvesting decisions of villagers based on fuelwood availability and village demand across the landscape. Importantly, we specify size-dependent coppice production of cut stems, and the probability of progression of coppice shoots into larger size classes, after accounting for self-thinning of shoots. In general, our model projections for a rural South African savanna system suggest that current levels of harvesting (barring changes in human population size) are relatively sustainable. Declines in total woody biomass were predicted to be modest (˜20%), and the loss of intact stems of sapling size was predicted to be more than offset by increases in coppiced stems. Synthesis and applications. The results from our local fuelwood model clearly demonstrate that the impact of deforestation and wood removal on tree populations and wood resources is strongly influenced by the resprouting ability of trees. This highlights the importance of considering coppice dynamics when assessing the sustainability of wood harvesting. Our model is not system specific, and can be transferred to other systems, with the relevant parameters and geographic information system layers specified. Because of the transferability of this model, it can help address key international concerns about deforestation and sustainable fuelwood management.
Data from: Structural complexity and large-sized trees explain shifting species richness and carbon relationship across vegetation types
<p>1. It is prominently claimed that enhancing forest diversity would play a dual role of nature conservation and climate regulation. While the idea is intuitively appealing, studies show that species richness effects on aboveground carbon (AGC) are not always positive, but instead unpredictable especially across scales and complex terrestrial systems having large-diameter and tall-stature trees. Previous studies have further considered structural complexity and larger trees as determinants of AGC. Yet it remains unclear what drives differential diversity-AGC relationships across vegetation types.</p> <p>2. Here, we test whether structural complexity and large-sized trees play an influential role in explaining shifting diversity-AGC relationships across vegetation types, using a 22.3 ha sampled dataset of 124 inventory plots in woodlands, gallery forests, tree/shrub savannahs and mixed plantations in West Africa.</p> <p>3. Natural vegetation had greater species richness and structural complexity than mixed plantations, as expected. In addition, AGC was highest in gallery forests and mixed plantations, which is consistent with favorable environmental conditions in the former and high stocking densities and presence of fast-growing species in the latter. Significant interaction effects of species richness and vegetation on AGC revealed a vegetation-dependent species richness-AGC relationship: consistently, we found positive species richness-AGC relationship in both mixed plantations and woodlands, and nonsignificant patterns in gallery forests and tree/shrub savannah. Further, there was a vegetation-dependent mediation of structural complexity in linking species richness to AGC, with stronger positive structural complexity effects where species richness-AGC relationships were positive, and stronger positive large-sized trees' effect where species richness-AGC relationships were neutral.</p> <p>4. Our study provides strong evidence of vegetation-dependent species richness-AGC relationships, which operated through differential mediation by structural complexity of the species richness and large trees' effects. We conclude that even higher species richness in diversified ecosystems may not always relate positively with AGC, and that neutral pattern may arise possibly as a result of larger dominant individual trees imposing a slow stand dynamic flux and overruling species richness effects.</p>
Data from: Size structuring and allometric scaling relationships in coral reef fishes
Temperate marine fish communities are often size structured, with predators consuming increasingly larger prey and feeding at higher trophic levels as they grow. Gape limitation and ontogenetic diet shifts are key mechanisms by which size structuring arises in these communities. Little is known, however, about size structuring in coral reef fishes. Here, we aimed to advance understanding of size structuring in coral reef food webs by examining the evidence for these mechanisms in two groups of reef predators. Given the diversity of feeding modes amongst coral reef fishes, we also compared gape size—body size allometric relationships across functional groups to determine if they are reliable indicators of size structuring. We used gut content analysis and quantile regressions of predator size—prey size relationships to test for evidence of gape limitation and ontogenetic niche shifts in reef piscivores (n=13 species) and benthic invertivores (n=3 species). We then estimated gape size—body size allometric scaling coefficients for 21 different species from four functional groups, including herbivores/detritivores, which are not expected to be gape-limited. We found evidence of both mechanisms for size structuring in coral reef piscivores, with maximum prey size scaling positively with predator body size, and ontogenetic diet shifts including prey type and expansion of prey size. There was, however, little evidence of size structuring in benthic invertivores. Across species and functional groups, absolute and relative gape sizes were largest in piscivores as expected, but gape size—body size scaling relationships were not indicative of size structuring. Instead, relative gape sizes and mouth morphologies may be better indicators. Our results provide evidence that coral reef piscivores are size-structured, and that gape limitation and ontogenetic niche shifts are the mechanisms from which this structure arises. Although gape allometry was not indicative of size structuring, it may have implications for ecosystem function: positively allometric gape size—body size scaling relationships in herbivores/detritivores suggests that loss of large-bodied individuals of these species will have a disproportionately negative impact on reef grazing pressure.
Data from: Progressively excluding mammals of different body size affects community and trait structure of ground beetles
Mammalian grazing induces changes in vegetation properties in grasslands, which can affect a wide variety of other animals including many arthropods. However, the impacts may depend on the type and body size of these mammals. Furthermore, how mammals influence functional trait syndromes of arthropod communities is not well known. We progressively excluded large (e.g. red deer, chamois), medium (e.g. alpine marmot, mountain hare), and small (e.g. mice) mammals using size-selective fences in two vegetation types (short- and tall-grass vegetation) of subalpine grasslands. We then assessed how these exclusions affected the community composition and functional traits of ground beetles (Coleoptera, Carabidae), and which vegetation characteristic mediated the observed effects. Total carabid biomass, the activity densities of carabids with specific traits (i.e. small eyes, short wings), the richness of small-eyed species and the richness of herbivorous species were significantly higher when certain mammals were excluded compared to when all mammals had access, regardless of vegetation type. Excluding large and medium mammals increased the activity density of herbivorous carabid species, but only in short-grass vegetation. Similarly, excluding large mammals (ungulates) altered carabid species composition in the short-, but not in the tall-grass vegetation. All these responses were related to aboveground plant biomass, but not to plant Shannon diversity or vegetation structural heterogeneity. Our results indicate that changes in aboveground plant biomass are key drivers of mammalian grazers' influence on carabids, suggesting that bottom-up forces are important in subalpine grassland systems. The exclusion of ungulates provoked the strongest carabid response. Our results, however, also highlight the ecological significance of smaller herbivorous mammals. Our study furthermore shows that mammalian grazing not only altered carabid community composition, but also caused community-wide functional trait shifts, which could potentially have a wider impact on species interactions and ecosystem functioning.
ScienceDex guides
Understand access before you commit
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.