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.
102
datasets available to search
ShareScore release 0.9.0
Dataset results
102 results for “tree islands”
Species Abundance Distributions (SADs) for local tree communities in 1-ha forest plots on 20 tropical islands in the Indo-Pacific region
<p>Species abundance distributions (SADs) characterise the distribution of individuals among species. This dataset was used to investigate the relative importance of disturbance regime (tropical cyclone regime) and island geography (the area and isolation of islands) on the shape of SADs.</p>
Data from: The history of tree and shrub taxa on Bol'shoy Lyakhovsky Island (New Siberian Archipelago) since the last interglacial uncovered by sedimentary ancient DNA and pollen data
<p>Ecosystem boundaries, such as the Arctic-Boreal treeline, are strongly coupled with climate and were spatially highly dynamic during past glacial-interglacial cycles. Only a few studies cover vegetation changes since the last interglacial, as most of the former landscapes are inundated and difficult to access. Using pollen analysis and sedimentary ancient DNA (<span class="html-italic">s</span>edaDNA) metabarcoding, we reveal vegetation changes on Bol'shoy Lyakhovsky Island since the last interglacial from permafrost sediments. Last interglacial samples depict high levels of floral diversity with the presence of trees (<em><span class="html-italic">Larix</span></em>,<span class="html-italic"> <em>Picea</em></span>,<span class="html-italic"> <em>Populus</em></span>) and shrubs (<em><span class="html-italic">Alnus</span></em>, <em><span class="html-italic">Betula</span></em>, <em><span class="html-italic">Ribes</span></em>, <span class="html-italic"><em>Cornus</em>, </span>Saliceae) on the currently treeless island. After the Last Glacial Maximum, <em><span class="html-italic">Larix</span> </em>re-colonised the island but disappeared along with most shrub taxa. This was probably caused by Holocene sea-level rise, which led to increased oceanic conditions on the island. Additionally, we applied two newly developed larch-specific chloroplast markers to evaluate their potential for tracking past population dynamics from environmental samples. The novel markers were successfully re-sequenced and exhibited two variants of each marker in last interglacial samples. SedaDNA can track vegetation changes as well as genetic changes across geographic space through time and can improve our understanding of past processes that shape modern patterns.</p>
Varying impacts of logging frequency on tree communities and carbon storage across evergreen and deciduous tropical forests in the Andaman Islands, India
<p>The majority of Earth's tropical forests have been selectively logged; some on repeated occasions. Selective logging is known to affect forest structure, composition and function in various ways, but how such effects vary with logging frequency and across forest types remains unclear. In the Andaman Archipelago in India, we examined adult and pole-sized trees in baseline (unlogged since 1990s), once-logged (logged between 2007 and 2014) and twice-logged (logged in early 1990s and between 2007 and 2014) evergreen and deciduous forests, and tested whether higher logging frequency was associated with lower canopy cover, tree density, tree diversity, aboveground carbon stocks and divergence in species composition, including increased relative abundances of deciduous species in these forests. While once-logged evergreen and deciduous forests were similar to their respective baselines for most attributes assessed, and twice-logged evergreen forests had 22–24% lower adult tree density and diversity, twice-logged deciduous forests had 17–50% lower canopy cover, pole density, adult species diversity and above-ground carbon stocks, and 12% higher deciduous fractions compared to the baselines. Collectively our results reveal lasting impacts of repeated selective logging, even at relative low intensity, on tree communities and carbon storage. These impacts can potentially be mitigated by reducing logging frequency and retaining unlogged patches in logged landscapes, but management must also incorporate heterogeneity in responses and recovery across different forest types. In the Andaman Islands, all forests may require more than 15–25 years between logging events, with deciduous forests potentially requiring more stringent extraction limits compared to evergreen forests.</p>
Aquatic islands in the sky: 100 years of research on water-filled tree holes
<p>Water-filled tree holes are unique ecosystems that may occur high up in tree crowns like aquatic islands in the sky. Insect larvae, mesofauna and other organisms colonize the waterbodies and feed on the accumulating detritus. Water-filled tree holes are not only important habitats for these species but have been used as model systems in ecology. Here we review more than 100 years of research on tree-hole inhabiting organisms and show that most studies focus on selected or even single species (most of which are mosquitoes) whereas only few studies examine groups other than insects, especially in the tropics. Using a vote counting of results and a meta-analysis of community studies, we show that the effects of tree-hole size and resources on abundance and richness were investigated most frequently. Both were found to have a positive effect, but effect sizes were modulated by site-specific environmental variables such as temperature or precipitation. We also show that parameters such as the height of the tree holes above ground, tree-hole density, predation and detritus type can be important drivers of organism abundance or richness but are less often tested. We identify several important research gaps and potential avenues for future research. Specifically, future studies should investigate the structure, functions and temporal dynamics of tree-hole food webs and their cross-system interactions, for example with terrestrial predators that act as a connection to their terrestrial surroundings in meta-ecosystems. Global observational or experimental tree-hole studies could contribute pivotal information on spatial variation of community structure and environmental drivers of community assembly. With a better understanding of these unique aquatic habitats in terrestrial ecosystems, natural and artificial tree holes can not only serve as model systems for addressing fundamental ecological questions but also as indicator systems of the impacts of environmental change on ecosystems.</p>
EST-SSR genotyping data from: Ecotype variation in the endemic tree Callicarpa subpubescens on small oceanic islands: Genetic, phenotypic, and environmental insights
<p><em>Callicarpa subpubescens</em>, endemic to the Ogasawara Islands, is suggested to have multiple ecotypes in the Hahajima Islands, specifically in the central part of the Ogasawara Islands. In this study, associations between genetic groups and spatial distribution, habitat, leaf morphology, size structure, and flowering time of each genetic group were investigated on Hahajima and the satellite Imoutojima Islands. Genetic groups were identified using EST-SSR markers, revealing four ecotypes named based on morphological features: Dwarf (D), Glabrescent (G), Tall (T), and Middle (M), with M being a result of the hybridization of G and T. Ecotype D, adapted to dry environments, is characterized by small tree size, dense thick leaves with abundant hairs, and is distributed in dry scrub. Ecotype G, adapted to understory of mesic forests, lacks leaf hairs. Ecotype T, adapted to the canopy of mesic forests, has hairy leaves and is tall in tree height. Ecotype M, adapted to the canopy of mesic scrub or edges of mesic forests, has hairy leaves but with a shorter tree height than ecotype T. Flowering peaks differed among all ecotype pairs except G and M, but the flowering times more or less overlapped among all ecotypes, suggesting that pre-mating isolation among ecotypes is not perfect. Post-mating isolation is considered absent, as there were no differences in the results, germination, and survival rates of one-year seedlings among inter- and intra-ecotype crossings. The existence of such ecotypes provides valuable insights into the ongoing speciation processes adapting to the oceanic island environments.</p>
Dataset for "Divergent selection and primary gene flow shape incipient speciation of a riparian tree on Hawaii Island"
<p>HawaiiPopulation_Raw.bcf.gz</p> <p>- Unfiltered SNP + INDEL VCF file for Hawaii Island Metrosideros</p> <p> </p> <p>HawaiiPopulation_FILTERED_SNP.bcf.gz</p> <p>- Filtered SNP VCF for Hawaii Island Metrosideros</p> <p> </p> <p>Population_WithOutgroup_Raw.vcf.gz</p> <p>- Unfiltered SNP + INDEL VCF file used in analysis that grouped G<sub>H1</sub>, G<sub>H2</sub>, N subpopulation with the outgroup samples.</p> <p> </p> <p>Population_WithOutgroup_FILTERED_SNP.vcf.gz</p> <p>- Filtered SNP VCF file used in analysis that grouped G<sub>H1</sub>, G<sub>H2</sub>, N subpopulation with the outgroup samples.</p> <p> </p> <p>Population_WithOutgroup.geno.gz</p> <p>- Genotype file generated from the genomic_general from S. Martin and used as input for Dxy and Fst window analysis</p> <p> </p> <p>Popgene_stat*</p> <p>- 5, 10, and 50 kbp windows of calculating pi, Dxy, Fst, Omega, Hscan, and H12 statistics </p> <p> </p> <p>GPHOCS_INPUT.txt</p> <p>- Input data file for GPhoCS analysis</p> <p> </p> <p>GPHOCS_control_*</p> <p>- GPhoCS control file</p> <p> </p> <p>DADI_INPUT*</p> <p>- Input 2D-SFS file for dadi analysis</p>
Figure 2. A in Defoliation of the Invasive Tree Falcataria moluccana on Hawaii Island by the Native Koa Looper Moth (Geometridae: Scotorythra paludicola), and Evaluation of Five Fabaceous Trees as Larval Hostplants
Figure 2. A defoliated Falcataria moluccana
Hourly maximum bending strains for 108 trees on Barro Colorado Island, Panama
<p>Hourly maximum bending strain time-series data for 108 trees on Barro Colorado Island. Measured at 1.3 m above ground level. Data available from March - June 2022. These hourly summaries were created from raw strain data using the R scripts provided.</p>
Aquatic islands in the sky: 100 years of research on water-filled tree holes
Open the record for dataset details and reuse information.
Varying impacts of logging frequency on tree communities and carbon storage across evergreen and deciduous tropical forests in the Andaman Islands, India
Open the record for dataset details and reuse information.
EST-SSR genotyping data from: Ecotype variation in the endemic tree Callicarpa subpubescens on small oceanic islands: Genetic, phenotypic, and environmental insights
Open the record for dataset details and reuse information.
Data from: The history of tree and shrub taxa on Bol'shoy Lyakhovsky Island (New Siberian Archipelago) since the last interglacial uncovered by sedimentary ancient DNA and pollen data
Open the record for dataset details and reuse information.
Species Abundance Distributions (SADs) for local tree communities in 1-ha forest plots on 20 tropical islands in the Indo-Pacific region
Open the record for dataset details and reuse information.
1992-93 Parramore Island, VA Permanent Plot Baseline Data : Tree Data
Open the record for dataset details and reuse information.
Persisting in a glaciated landscape: Pleistocene microrefugia evidenced by the tree wētā Hemideina maori in central South Island, New Zealand
<p><span><span><b>Aim:</b> Repeated cycles of Pleistocene glaciation have influenced phylogeographic structure of taxa on New Zealand's South Island. Many taxa became restricted to refugia at either end of the island during glaciation, resulting in an area of low endemicity in central South Island. This area of low endemism is typified by the so-called beech (or biotic) gap, where the absence of <i>Nothofagus </i>forest (and many other plant and invertebrate taxa) has been attributed to repeated glaciation. Some taxa, however, appear to have persisted <i>in situ</i> in localized refugia within the biotic gap. We test these alternative hypotheses in a large flightless alpine wētā (grasshopper).</span></span></p> <p><span><span><b>Location:</b> Southern Alps, South Island, New Zealand</span></span></p> <p><b>Taxon:</b> <i>Hemideina maori</i> <span>Pictet & Saussure, 1891 </span>(Orthoptera: Anostostomatidae)</p> <p><span><span><b>Methods:</b> We used phylogeographic analysis of mitochondrial cytochrome<i> c </i>oxidase I (<i>cox1</i>) and twenty-five nuclear DNA (nuDNA) markers to test for Pleistocene glacial microrefugia within the current montane South Island range of <i>Hemideina maori.</i></span></span></p> <p><span><span><b>Results:</b> We identified eight deeply differentiated mtDNA lineages with limited sharing of haplotypes among populations. Genetic differentiation assessed using nuDNA revealed a similar pattern, with three groups broadly corresponding to the deepest mtDNA splits. The central South Island region exhibits substantial endemic mtDNA diversity and a distinctive nuclear lineage.</span></span></p> <p><span><span><b>Main conclusions: </b>These results indicate that <i>H. maori </i>likely<i> </i>persisted in microrefugia<i> </i>within the biotic gap during glaciation. These deep lineages are estimated to have started diverging prior to the initiation of glaciation, up to 3 Ma. These results add to a growing number of Southern Hemisphere examples of deep phyleogeographic differentiation in glaciated regions compared to Europe and North America, probably reflecting less intense glaciation. We suggest that other Southern Alps species showing northern and southern clades alone, are more montane than alpine, and were reliant on warmer habitat to the north and south during glacial eras. Thus, there are species-specific responses to climatic processes, influenced by distinctive habitat requirements and physiological traits.</span></span></p>
RAD-seq reveals patterns of diversification, hybridization, and the accumulation of reproductive isolation in a clade of partially sympatric, tropical island trees
<p>A common pattern observed in temperate tree clades is that species are often morphologically distinct and partially interfertile but maintain species cohesion despite ongoing hybridization where ranges overlap. Although closely related species commonly occur in sympatry in tropical ecosystems, little is known about patterns of hybridization within a clade over time, and the implications of this hybridization for the maintenance of species boundaries. In this study, we focused on a clade of sympatric trees in the genus <i>Diospyros</i> in the Mascarene islands and investigated whether species are genetically distinct, whether they hybridize, and how patterns of hybridization are related to the time since divergence among species. We sampled multiple populations from each of 12 Mascarene <i>Diospyros</i> species, generated genome-wide SNP data using 2bRADseq, and conducted population genomic and phylogenomic analyses. We found that Mascarene <i>Diospyros</i> species diverged millions of years ago and are largely genetically distinct from one another. Although hybridization was observed between closely related species belonging to the same subclade, more distantly related species showed little evidence of interspecific hybridization. Phylogenomic analyses also suggested that introgression occurred during the evolutionary history of the clade. This suggests that, as diversification progressed, interspecific hybridization also occurred among species, but became infrequent as lineages diverged from one another and evolved reproductive barriers. Species now co-exist in partial sympatry, and experience limited hybridization between close relatives. Additional research is needed to better understand the role introgression may have played in adaptation and diversification of Mascarene <i>Diospyros,</i> and its relevance for conservation.</p>
Data from: Life-history dimensions indicate non-random assembly processes in tropical island tree communities
<p>Community assembly processes on islands are often non-random. The mechanisms behind non-random assembly, however, are generally difficult to disentangle. Functional diversity in combination with a null model approach that accounts for differences in species richness among islands can be used to test for non-random assembly processes, but has been applied rarely to island communities. By linking functional diversity of trees on islands with a null model approach, we bridge this gap and test for the role of stochastic vs. non-random trait-mediated assembly processes in shaping communities by studying functional diversity-area relationships. We measured 11 plant functional traits linked to species dispersal and resource acquisition strategies of 57 tree species on 40 tropical islands. We grouped traits into four life-history dimensions representing (i) dispersal ability, (ii) growth strategy, (iii) light acquisition, and (iv) nutrient acquisition. To test for non-random assembly processes, we used null models that account for differences in species richness among the islands. Our results reveal contrasting responses of the four life-history dimensions to island area. The dispersal and the growth strategy dimensions were underdispersed on smaller islands, whereas the light acquisition dimension was overdispersed. The nutrient acquisition dimension did not deviate from null expectations. With increasing island area, shifts in the strength of non-random assembly processes increased the diversity of dispersal and acquisition strategies in island communities. Our results suggest that smaller islands may be more difficult to colonize and provide more limited niche space compared to larger islands, whose tree communities are likely determined by stochastic processes and higher niche diversity. Our null model approach highlights that analysing the functional diversity of different life-history dimensions provides a powerful framework to unravel community assembly processes on islands. These complex, non-random assembly processes are masked by measures of functional diversity that do not account for differences in species richness between islands.</p>
Data from: Tropical trees in a wind-exposed island ecosystem: height-diameter allometry and size at onset of maturity
1. Tropical tree species adapted to high wind environments might be expected to differ systematically in terms of stem allometry and life-history patterns, as compared with species found in less windy forests. We quantified height-diameter (H-D) allometries and relative size at onset of maturity (RSOM) for rainforest tree and tree fern species native to Dominica, West Indies, an island that experiences some of the highest average wind speeds pantropically. 2. H-D allometries for 17 Dominican angiosperm tree species were strongly concave on a log-log scale with asymptotic heights ranging from 9-32 m among species, averaging 25 m for canopy trees. H-D allometries for species-pooled data deviated strongly from recorded patterns for other tropical forest trees: asymptotic heights for trees in Dominica were 30-116% lower than those recorded for continental rainforest trees in Australia, South America, Africa, and Southeast Asia. In a subset of canopy trees sampled in steep, sheltered valleys, heights were 12-26% larger at a given diameter, and approached those observed in other tropical regions, suggesting large phenotypic responses of H-D allometries to wind conditions. 3. RSOM (quantified as the ratio of height at onset of reproduction to asymptotic maximum height) for Dominican angiosperm species was highly variable, ranging from 0.23-0.89 (mean 0.54), similar to patterns observed in Malaysia and Panama; very low RSOM values were estimated for two tree fern species. Pooling data from Dominica with published values from other tropical forests, we observed a significant negative correlation between RSOM and wood density. 4. Synthesis: Our data suggest that wind regimes are a critical determinant of height-diameter (H-D) allometries of tropical trees at both the local and global scale. Although we found no evidence for a systematic differences in reproductive onset related to wind regime, RSOM was negatively correlated with species' wood density, suggesting that more shade-tolerant tree species show a longer period of gradually increasing reproductive allocation through ontogeny.
Data from: Genetic diversity and population divergences of an indigenous tree (Coffea mauritiana) in Reunion Island: role of climatic and geographical factors
Oceanic islands are commonly considered as natural laboratories for studies on evolution and speciation. The evolutionary specificities of islands associated with species biology provide unique scenarios to study the role of geography and climate in driving population divergence. However, few studies have addressed this subject in small oceanic islands with heterogeneous climates. Being widely distributed in Reunion Island forest, Coffea mauritiana represents an interesting model case for investigating patterns of within-island differentiation at small spatial scale. In this study, we examined the genetic diversity and population divergences of C. mauritiana using SNP markers obtained from 323 individuals across 34 locations in Reunion Island. Using redundancy analysis, we further evaluated the contribution of geographic and climatic factors to shaping genetic divergence among populations. Genetic diversity analyses revealed that accessions clustered according to the source population, with further grouping in regional clusters. Genetic relationships among the regional clusters underlined a recent process of expansion in the form of step-by-step colonization on both sides of the island. Divergence among source populations was mostly driven by the joint effect of geographic distance and climatic heterogeneity. The pattern of isolation-by-geography was in accordance with the dispersal characteristics of the species, while isolation-by-environment was mostly explained by the heterogeneous rainfall patterns, probably associated with an asynchronous flowering among populations. These findings advance our knowledge on the patterns of genetic diversity and factors of population differentiation of species native to Reunion Island, and will also usefully guide forest management for conservation.
Data from: Genetic analysis of an ephemeral intraspecific hybrid zone in the hypervariable tree, Metrosideros polymorpha, on Hawai'i Island
Intraspecific hybrid zones involving long-lived woody species are rare and can provide insights into the genetic basis of early-diverging traits in speciation. Within the landscape-dominant Hawaiian tree, Metrosideros polymorpha, are morphologically distinct successional varieties, incana and glaberrima, that dominate new and old lava flows, respectively, below 1200 me on volcanically active Hawai'i Island, with var. glaberrima also extending to higher elevations and bogs. Here, we use morphological measurements on 86 adult trees to document the presence of an incana-glaberrima hybrid zone on the 1855 Mauna Loa lava flow on east Hawai'i Island and parent-offspring analysis of 1311 greenhouse seedlings from 71 crosses involving 72 adults to estimate heritabilities and genetic correlations among vegetative traits. Both the variation in adult leaf pubescence at the site and the consistency between adult and offspring phenotypes suggest the presence of two hybrid classes, F1s and var. incana backcrosses, as would be expected on a relatively young lava flow. Nine nuclear microsatellite loci failed to distinguish parental and hybrid genotypes. All four leaf traits examined showed an additive genetic basis with moderate to strong heritabilities, and genetic correlations were stronger for the more range-restricted var. incana. The differences between varieties in trait values, heritabilities and genetic correlations, coupled with high genetic variation within but low genetic variation between varieties, are consistent with a multi-million-year history of alternating periods of disruptive selection in contrasting environments and admixture in ephemeral hybrid zones. Finally, the contrasting genetic architectures suggest different evolutionary trajectories of leaf traits in these forms.
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.