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.
81
datasets available to search
ShareScore release 0.9.0
Dataset results
81 results for “treeline”
Data from: Axial xylem architecture of Larix decidua exposed to CO2 enrichment and soil warming at the treeline
1. Trees continuously adjust their axial xylem structure to meet changing needs imposed by ontogenetic and environmental changes. These axial structure-function responses need to be coordinated among competing biophysical constraints to avoid failure of the xylem system. Here, we investigated if ontogeny or experimental manipulation of CO2 and soil temperature influence these structure-function responses. 2. We performed detailed xylem cell anatomical quantification along the axis of 40-year-old Larix decidua trees planted at the Swiss treeline and exposed to a combination of elevated CO2 (+200 ppm) and soil warming (+4 °C) between 2001 and 2012. We assessed how mean hydraulic tracheid diameter (Dh), the cell wall reinforcement ((t/b)2), tracheid wall thickness (CWT) and the percent area of ray parenchyma (PERPAR) – proxies for hydraulic efficiency, hydraulic safety, biomechanical support and metabolic xylem functions, respectively – co-vary along the tree axis. 3. Dh increased from the stem apex to base, strictly following a power function (R2=0.81), independent from ontogeny and experimental treatments. In contrast, axial trends of (t/b)2 and CWT were either influenced by treatment and/or ontogeny, or showed no axial trend (PERPAR). Additionally, we found that a larger Dh only at the stem apex promoted primary and secondary growth. 4. Our approach of analyzing xylem anatomical traits along the tree axis and across tree-rings provides novel insights into xylem functional architecture and allows reconstructing xylem function over time. We conclude that the maintenance of hydraulic efficiency during ontogeny is very robust, as the conduit diameter undergoes a strong apical control, and plays a fundamental role for assimilation and tree growth. Instead, the other functional traits more plastically vary with ontogeny and environmental changes.
Data from: Recent decadal drought reverts warming–triggered growth enhancement in contrasting climates in the southern Andes treeline
Aims: Rising temperature and declining summer precipitation due to the 1970s-climate shift in southern South America have reduced forest productivity at dry sites. Here, we worked with the most widespread Southern Hemisphere treeline species, Nothofagus pumilio, across contrasting climatic conditions and determined whether rising atmospheric CO2 concentrations as well as warmer and drier climatic conditions provoked by the 70s-climatic shift have been causing systematic changes in treeline growth rates and intrinsic water-use efficiency (iWUE).Location: 36–54° S, southern Andes. Time period: 1950–2010. Major taxa studied: Nothofagus pumilio. Methods: We worked at five disparate climatic treeline locations, spanning 18 degrees of latitude; at each location, we sampled trees at four different elevations, including treeline elevation. We quantified the variation of annual tree-ring width (TRW) as a function of climate, elevation, tree age, size, annual CO2 concentrations, and location, using linear mixed-effects models and interpreted TRW trends in relation to iWUE and isotope (δ13C and δ18O) signalling. Results: Across locations, the patterns of treeline growth occurring in the 1980–2010 period exhibited a clear and significant negative trend, in contrast to the previous 1950–1980 period. We found an increase of iWUE and δ18O across time and locations. Given that an increase in δ18O indicates a decrease in stomatal conductance, we assert that drought-induced stomatal closure appears to be causing the reduction in growth. Main conclusions: We show unequivocal evidence that warmer and drier summer conditions translated into a decrease of growth rates along the elevational treeline of the southern Andes, reverting previous growth improvements linked to climate warming. An improvement in iWUE at all locations is most likely explained by decreased stomatal conductance given the rising δ18O signal. An iWUE–growth decoupling may act as an ecological strategy to respond to drought.
Data from: An assessment of carbon and nutrient limitations in the formation of the southern Andes treeline
Although the principal mechanism determining tree line formation appears to be carbon (C)-sink limitations due to low temperatures, few studies have assessed the complementary role of reduced soil nutrient availability with elevation. We tested the hypothesis that nutrient (especially nitrogen, N) limitations at tree line may directly (via C-source) or indirectly (via C-sink) reduce the growth of a winter deciduous tree line species. If a shortage of soil N with elevation is involved in tree line formation, it should occur in two alternative ways: (i) through sink limitations because N is required for tissue formation, which would indirectly limit C investments (N decreases and C reserves increase with elevation), and (ii) through C limitations because this would lead directly to a reduction of photoassimilates (N and C reserves decrease with elevation). In testing our hypothesis, we analysed tree growth rates (basal area increment), twig non-structural carbohydrate (NSC) and N concentrations, leaf N, phosphorus (P), N:P ratio concentrations, and soil nutrient levels (NO3−, NH4+, Olsen–P) in four disparate climate and soil Nothofagus pumilio tree lines spanning 18 degrees of latitude in the southern Andes of Chile. We found a significant decrease in tree growth with elevation. Twig NSC concentrations pooled across locations also decreased significantly with elevation (starch constituted most of the NSC and was highly responsible for the negative trend), although this trend was mostly driven by the northernmost locations. Contrary to soil N availability, leaf N and P concentrations increased significantly with elevation. Twig N concentrations, soil P and leaf N:P ratios did not change with elevation. Synthesis. The elevational decrease in NSC concentrations supports C-source limitation in N. pumilio trees at tree line elevation. In the light of this, we assert that the current global explanation for tree line formation (C-sink-limitation driven by low temperatures) must be revisited. Given that leaf N and P concentrations increased and twig N concentrations did not change with elevation, nutrient limitation is not likely to be involved in the C-limitations and could not therefore be an explanation for tree line formation.
Data from: Ecological gradients drive insect wing loss and speciation: the role of the alpine treeline
Alpine ecosystems are frequently characterised by an abundance of wing-reduced insect species, but the drivers of this biodiversity remain poorly understood. Insect wing reduction in these environments has variously been attributed to altitude, temperature, isolation, habitat stability, or decreased habitat size. We used fine-scale ecotypic and genomic analyses, along with broad-scale distributional analyses of ecotypes, to unravel the ecological drivers of wing reduction in the wing-dimorphic stonefly Zelandoperla fenestrata complex. Altitudinal transects within populations revealed dramatic wing reduction over very fine spatial scales, tightly linked to the alpine treeline. Broad biogeographic analyses confirm that the treeline has a much stronger effect on these ecotype distributions than altitude per se. Molecular analyses revealed parallel genomic divergence between vestigial-winged (high altitude) and full-winged (low altitude) ecotypes across distinct streams. These data thus highlight the role of the alpine treeline as a key driver of rapid speciation, providing a new model for ecological diversification along exposure gradients
Data from: Global drivers of tree seedling establishment at alpine treelines in a changing climate
Alpine and Arctic treeline expansion depends on establishment of tree seedlings beyond the current treeline, which is expected to occur with climate warming. However, treelines often fail to respond to higher temperatures, and it is therefore likely that other environmental factors are important for seedling establishment. We aimed to analyse our current understanding of how temperature and a range of other environmental drivers affect tree seedling establishment at the alpine and Arctic treelines worldwide, and to assess the relative importance of temperature compared with other factors and how they interact. We collected 366 observations from 76 experimental and observational papers for a qualitative analysis of the role of a wide range of environmental factors on tree seed germination, tree seedling growth, survival and natural occurrence. For a subset of these studies, where the experimental design allowed, we conducted formal meta-analyses to reveal if there were global drivers for different seedling life traits. The analyses showed that a wide range of abiotic and biotic factors affected tree seedling establishment besides from temperature, including water, snow, nutrients, light, and surrounding vegetation. The meta-analyses showed that different seedling life stages do not respond similarly to environmental factors. For example, temperature had positive effects on growth, while tree seedling survival and germination showed mixed responses to warming. Further, warming was as often as not the strongest factor controlling tree seedling establishment, when compared to with one of five other environmental factors. Moreover, warming effects often depended on other factors such as moisture or the presence of surrounding vegetation. Our results suggests that population dynamics of trees at the alpine and Arctic treeline are responsive to environmental changes and show that there is a clear need for multi-factorial studies if we want to fully understand and predict the interplay between warming and other environmental factors and their effect on tree seedling establishment across current treelines.
Data from: Evidence of widespread topoclimatic limitation for lower treelines of the Intermountain West, U.S.A.
Many forests in dry mountain regions are characterized by a lower elevational treeline. Understanding the controls on the position of lower treeline is important for predicting future forest distributional shifts in response to global environmental change. Lower treelines currently at their climate limit are expected to be more sensitive to changing climate, whereas lower treelines constrained by non-climatic factors are less likely to respond directly to climate change but may be sensitive to other global change agents. In this study, we used existing vegetation classifications to map lower treelines for our 1.7 million km2 study region in the Intermountain West, USA. We modeled topoclimatic drivers of lower treeline position for each of three dominant forest types to identify topoclimatically-limited treelines. We then used spatial data of edaphic properties, recent fire, and land use to identify lower treelines potentially constrained above their ecophysiological limits by non-climatic processes. We found that the lower treeline ecotone of pinyon-juniper woodlands is largely limited by topoclimate and is likely to be sensitive to increasing temperatures and associated droughts, though these effects may be heterogeneously distributed across the landscape. In contrast, dry mixed conifer lower treelines in the northern portion of the study area rarely reached their modeled topoclimatic limit, suggesting that non-climatic processes, including fire and land use, constrain lower treeline above its ecophysiological limits in this forest type. Our results suggest that much of the lower treeline in the Intermountain West is currently climate-limited and will thus be sensitive to ongoing climate changes. Lower treelines in other arid or semi-arid mountainous regions around the globe may also be strongly sensitive to climate, though treeline response to climate change will be mediated at the local scale by soil properties, biotic interactions, and natural or anthropogenic disturbances. Our regional study of lower treeline provides a framework for identifying the drivers of lower treeline formation and allows for more robust projections of future treeline dynamics, which are needed to anticipate shifting global distributions of the forest biome.
Data from: Insect wing loss is tightly linked to the treeline: evidence from a diverse stonefly assemblage
The secondary loss of flight in previously winged insect lineages has long fascinated biologists. Habitat stability and isolation are thought to play important roles in driving wing reduction (Roff 1990, 1994), with exposure to high winds suggested to accelerate this process (Darwin 1859), although the role exposure plays in insect wing loss has never been empirically demonstrated. Here we assess fine-scale distributional records from a diverse regional stonefly assemblage, to demonstrate a widespread association between wing loss and the treeline in New Zealand. The observed pattern suggests that exposure plays a crucial role driving wing loss in alpine insects.
Data from: Impact of environmental conditions on wood anatomical traits of green alder (Alnus alnobetula) at the alpine treeline
<p><strong>The data file</strong> (<em>Alnus alnobetula</em>_Wood anatomy.xlsx) contains all raw data, which have been used to create Figures 3-7 in the article.</p> <p> </p> <p><strong>Data are documented in the following article</strong>:</p> <p>Gruber A, G Wieser, M Fink, W Oberhuber (2024) Impact of environmental conditions on wood anatomical traits of green alder (<em>Alnus alnobetula</em>) at the alpine treeline.<strong> Forests, 15, 24; doi:10.3390/f15010024 <br></strong></p> <p> </p> <p><strong>Summary</strong></p> <p>Due to land use change, green alder (<em>Alnus alnobetula</em>), formerly restricted to moist slopes, is now expanding to drier south-facing sites at the alpine treeline. To evaluate wood anatomical adaptations, we analyzed vessel characteristics (mean vessel area, MVA; vessel density, VD; and theoretic conductive area, TCA) and axial parenchyma abundance, as well as their distribution in the annual ring at a moist north-facing and a dry south-facing site at the alpine treeline (2150 m asl) on Mt. Patscherkofel (Central European Alps, Austria). Results revealed that lower soil water availability and enhanced evaporative demand did not affect MVA, while VD and TCA were significantly reduced at the dry south-facing site. This suggests that in <em>A. alnobetula</em>, vessel size is a static trait whereas vessel number responds plastic. Harsh environmental conditions at the distributional limit of <em>A. alnobetula</em> led to a near semi-ring-porous distribution of vessels and an accumulation of parenchyma in the late growing season. We conclude that in a warmer and drier climate, physiological stress may set limits to the distribution of <em>A. alnobetula</em> at drought-prone sites at the alpine treeline.</p>
Mapping forest in the Swiss Alps treeline ecotone with explainable deep learning: label data
<p>Label data used in the paper "Nguyen T.-A., Kellenberger B., Tuia D. (2022), <em>Mapping forest in the Swiss Alps treeline ecotone with explainable deep learning</em>" (<a href="https://doi.org/10.1016/j.rse.2022.113217">https://doi.org/10.1016/j.rse.2022.113217</a>).</p> <p>Code available at <a href="https://github.com/thienanhng/ExplainableForestMapping">github.com/thienanhng/ExplainableForestMapping</a>.</p>
Estimated climate treeline in Carpathians
Open the record for dataset details and reuse information.
Data from: Living, dead, and absent trees - How do moth outbreaks shape small-scale patterns of soil organic matter stocks and dynamics at the Subarctic mountain birch treeline?
<p>Mountain birch forests (<i>B. pubescens</i> Ehrh. ssp. <i>czerepanovii</i>) at the subarctic treeline not only benefit from global warming, but are also increasingly affected by caterpillar outbreaks from foliage-feeding geometrid moths. Both of these factors have unknown consequences on soil organic carbon (SOC) stocks and biogeochemical cycles. We measured SOC stocks down to the bedrock under living trees and under two stages of dead trees (12 and 55 years since moth outbreak) and treeless tundra in northern Finland. We also measured in-situ soil respiration, potential SOC decomposability, biological (enzyme activities, microbial biomass), and chemical (N, mineral N, pH) soil properties. SOC stocks were significantly higher under living trees (4.1±2.1 kg m²) than in the treeless tundra (2.4±0.6 kg m²), and remained at an elevated level even 12 (3.7±1.7 kg m²) and 55 years (4.9±3.0 kg m²) after tree death. Effects of tree status on SOC stocks decreased with increasing distance from the tree and with increasing depth, i.e. a significant effect of tree status was found in the organic layer, but not in mineral soil. Soil under living trees was characterized by higher mineral N contents, microbial biomass, microbial activity, and soil respiration compared with the treeless tundra; soils under dead trees were intermediate between these two. The results suggest accelerated organic matter turnover under living trees but a positive net effect on SOC stocks. Slowed organic matter turnover and continuous supply of deadwood may explain why SOC stocks remained elevated under dead trees, despite the heavy decrease in aboveground C stocks. We conclude that the increased occurrence of moth damage with climate change would have minor effects on SOC stocks, but ultimately decrease ecosystem C stocks (49% within 55 years in this area), if the mountain birch forests will not be able to recover from the outbreaks.</p>
Asymmetric effects of daytime and nighttime warming on alpine treeline recruitment
<p><span>Trees at their upper range limits are highly sensitive to climate change, and thus alpine treelines worldwide have changed their recruitment patterns in response to climate warming. However, previous studies focused only on daily mean temperature, neglecting the asymmetric influences of daytime and nighttime warming on recruitments in alpine treelines. Here, based on the compiled dataset of tree recruitment series from 172 alpine treelines across the Northern Hemisphere, we quantified and compared the different effects of daytime and nighttime warming on treeline recruitment using four indices of temperature sensitivity, and assessed the responses of treeline recruitment to warming-induced drought stress. Our analyses demonstrated that even in different environmental regions, both daytime and nighttime warming could significantly promote treeline recruitment, however, treeline recruitment was much more sensitive to nighttime warming than to daytime warming, which could be attributable to the presence of drought stress. The increasing drought stress primarily driven by daytime warming rather than by nighttime warming would likely constrain the responses of treeline recruitment to daytime warming. Our findings provided compelling evidence that nighttime warming rather than daytime warming could play a primary role in promoting the recruitment in alpine treelines, which was related to the daytime warming-induced drought stress. Thus, daytime and nighttime warming should be considered separately </span><span>to improve future projections of global change impacts across alpine ecosystems.</span></p>
A global data set of realized treelines sampled from Google Earth aerial images
<div> <span>We </span><span>sampled</span><span> Google Earth aerial images</span><span> to get a representative and globally distributed dataset of treeline locations</span><span>. </span><span>Google Earth images</span><span> are available to everyone, but may not be automatically downloaded and processed according to Google's license terms. Since we only wanted to detect tree individuals, we evaluated the aerial images manually by hand.</span> </div> <div> </div> <div> <span>Doing so, we scaled Google Earth's GUI interface to a buffer size of approximately 6000 m from a perspective of 100 m (+/- 20 m) above Earth's surface. Within this buffer zone, we took coordinates and elevation of the highest </span><span>realized </span><span>treeline locations. In some remote areas of Russia and Canada, individual trees were not identifiable due to insufficient image resolution. If this was the case, no treeline was sampled, unless we detected another visible treeline within the 6,000 m buffer and took this next highest treeline</span><span>. We did not ap</span><span>p</span><span>ly an automated image processing approach. </span><span>We calculated mass elevation effect as the distance to the nearest mountain chain limits. Continentality was assessed by the distance to the nearest coastline. Isolation was calculated by the nearest distance of a mountain chain to another mountain chain within a comparable elevational band. </span> </div>
Data from: Sink limitation of plant growth determines treeline in the arid Himalayas
Open the record for dataset details and reuse information.
Data from: Global drivers of tree seedling establishment at alpine treelines in a changing climate
Open the record for dataset details and reuse information.
A global data set of realized treelines sampled from Google Earth aerial images
Open the record for dataset details and reuse information.
Data from: Ecological gradients drive insect wing loss and speciation: the role of the alpine treeline
Open the record for dataset details and reuse information.
Data from: Competitor or facilitator? The ambiguous role of alpine grassland for the early establishment of tree seedlings at treeline
Open the record for dataset details and reuse information.
Data from: Evidence of widespread topoclimatic limitation for lower treelines of the Intermountain West, U.S.A.
Open the record for dataset details and reuse information.
Data from: Insect wing loss is tightly linked to the treeline: evidence from a diverse stonefly assemblage
Open the record for dataset details and reuse information.
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.