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2,078 results for “soil data”
Data from: Phosphorus release from unamended and gypsum-or biochar-amended soils under simulated spring snowmelt and summer flooding conditions
<p>Prolonged flooding changes the oxidation–reduction status of soils, often enhancing phosphorus (P) release to overlying floodwater. We studied P release from unamended, gypsum-amended and biochar- amended soils under simulated snowmelt flooding (previously frozen, cold flooding at +4°C) and summer flooding (unfrozen, warm flooding at +22°C), using two soils, Fyala clay (FYL-Cl) and Neuenberg sandy loam (NBG-SL) from Manitoba, Canada. Amended and unamended soils were packed into vessels and flooded under cold and warm temperatures in the laboratory. Pore water and floodwater samples were taken weekly for 6 weeks after flooding (WAF) and thereafter biweekly for 10 WAF, and analyzed for dissolved reactive P (DRP), pH and cation concentrations. NBG-SL showed a significantly higher DRP concentration in pore water and floodwater despite its low Olsen P content. Redox potential (Eh) decreased slowly under cold compared to warm flooding; hence redox-induced P release was substantially lower under cold flooding. Gypsum amendment significantly decreased the floodwater DRP concentrations in NBG-SL by 38% and 35% under cold and warm flooding, respectively, but had no significant effect in FYL-Cl, which had low DRP concentrations (<1.2 mg L-1) throughout flooding period. Biochar amendment significantly increased floodwater DRP concentrations by 27 to 68% in FYL-Cl under cold and warm flooding, respectively, but had no significant effect in NBG-SL. The results indicate substantially less P release under cold, than under warm flooding. Gypsum was effective in reducing floodwater DRP concentrations only at high DRP concentrations; thus the effectiveness was greater under warm, than under cold flooding conditions.</p>
Data from: Mosses reduce soil nitrogen availability in a subarctic birch forest via effects on soil thermal regime and sequestration of deposited nitrogen
<p>In high-latitude ecosystems, bryophytes are important drivers of ecosystem functions. Alterations in abundance of mosses due to global change may thus strongly influence carbon (C) and nitrogen (N) cycling and hence cause feedback on climate. The effects of mosses on soil microbial activity are, however, still poorly understood. Our study aims at elucidating how and by which mechanisms bryophytes influence microbial decomposition processes of soil organic matter and thus soil nutrient availability. We present results from a field experiment in a subarctic birch forest in northern Sweden, where we partly removed the moss cover and replaced it with an artificial soil cover for simulating moss effects on soil temperature and moisture. We combined this with a fertilization experiment with 15N-labelled N for analyzing the effects of moss N-sequestration on soil processes. Our results demonstrate the capacity of mosses to reduce soil N availability and retard N cycling. The comparison with artificial soil cover plots suggests that the effect of mosses on N cycling is linked to the thermal insulation capacity of mosses causing low average soil temperature in summer and strongly reduced soil temperature fluctuations, the latter also leading to a decreased frequency of freeze-thaw events in autumn and spring. Our results also showed, however, that the negative temperature effect of mosses on soil microbial activity was in part compensated by stimulatory effects of the moss layer, possibly linked to leaching of labile substrates from the moss. Furthermore, our results revealed that bryophytes efficiently sequester added N from wet deposition and thus prevent effects of increased atmospheric N deposition on soil N availability and soil processes.</p> <p><em>Synthesis.</em> Our study emphasizes the important role of mosses in carbon and nutrient cycling in high latitude ecosystems and the potential strong impacts of reductions in moss abundance on microbial decomposition processes and nutrient availability in subarctic and boreal forests.</p>
Data on universities offering undergraduate degrees that train students for soil science careers at universities in the USA and its territories
<p>Several soil science education studies over the last 15 years have focused on the number of students enrolled in soil science programs. However, no studies have quantitatively addressed the number of undergraduate soil science preparatory programs that exist in the United States, which means we do not have solid data concerning whether overall program numbers are declining, rising, or holding steady. This also means we do not have complete data on the same trends for total undergraduate soil science students in the United States. This study used the US Office of Personnel Management (OPM) Soil Science Series 0470 standards to determine if a bachelor's degree met soil science preparatory criteria. Lists of the approximately 3,500 regionally accredited colleges and universities were obtained from the regional accrediting agencies and the website of each of the colleges and universities was visited to determine if they had a degree program that met the OPM 0470 criteria. A total of 92 soil science preparatory degree programs were identified at 86 colleges and universities. These programs were primarily linked to 1) agriculture, 2) environmental science, and 3) soil and water science based on number of degree occurrences. This study creates a baseline for future studies that can investigate trends in soil science programs. It also provides insight into the institutions and degree programs that should be included in soil science education studies.</p>
Data from Soil chemistry turned upside down: a meta-analysis of invasive earthworm effects on soil chemical properties
<p>Recent studies have shown that invasive earthworms can dramatically reduce native biodiversity, both above and below the ground. <a name="_Hlk9515878">However, we still lack a synthetic understanding of the underlying mechanisms behind these changes, such as whether earthworm effects on soil chemical properties drive such relationships</a>. Here, we investigated the effects of invasive earthworms on soil chemical properties (pH, water content, and the stocks and fluxes of carbon, nitrogen, and phosphorus) by conducting a meta-analysis. Invasive earthworms generally increased soil pH, indicating that the removal of organic layers and the upward transport of more base-rich mineral soil caused a shift in soil pH. Moreover, earthworms significantly decreased soil water content, suggesting that the burrowing activities of earthworms may have increased water infiltration of and/or increased evapo-transpiration from soil. Notably, invasive earthworms had opposing effects on organic and mineral soil for carbon and nitrogen stocks, with decreases in organic, and increases in mineral soil. Nitrogen fluxes were higher in mineral soil, whereas fluxes in organic soil were not significantly affected by the presence of invasive earthworms, indicating that earthworms mobilize and redistribute nutrients among soil layers and increase overall nitrogen loss from the soil. Invasive earthworm effects on element stocks increased with ecological group richness only in organic soil. Earthworms further decreased ammonium stocks with negligible effects on nitrate stocks in organic soil, whereas they increased nitrate stocks but not ammonium stocks in mineral soil. Notably, all of these results were consistent across forest and grassland ecosystems underlining the generality of our findings. However, we found some significant differences between studies that were conducted in the field (observational and experimental settings) and in the lab, such as that the effects on soil pH decreased from field to lab settings, calling for a careful interpretation of lab findings. Our meta-analysis provides strong empirical evidence that earthworm invasion may lead to substantial changes in soil chemical properties and element cycling in soil. Furthermore, our results can help explain the dramatic effects of invasive earthworms on native biodiversity, e.g., shifts towards the dominance of grass species over herbaceous ones, as shown by recent meta-analyses.</p>
Data from: Niche differentiation of bacterial versus archaeal soil nitrifiers induced by ammonium inhibition along a management gradient
<p>Soil nitrification, mediated mainly by ammonia oxidizing archaea (AOA) and bacteria (AOB), converts ammonium (NH4+) to nitrite (NO2−) and thence nitrate (NO3−). To better understand ecological differences between AOA and AOB, we investigated the nitrification kinetics of AOA and AOB under eight replicated cropped and unmanaged ecosystems (including two fertilized natural systems) along a long-term management intensity gradient in the upper U.S. Midwest. For five of eight ecosystems, AOB but not AOA exhibited Haldane kinetics (inhibited by high NH4+ additions), especially in perennial and successional systems. In contrast, AOA predominantly exhibited Michaelis-Menten kinetics, suggesting greater resistance to high nitrogen inputs than AOB. These responses suggest the potential for NH4+-induced niche differentiation between AOA and AOB. Additionally, long-term fertilization significantly enhanced maximum nitrification rates (Vmax) in the early successional systems for both AOA and AOB, but not in the deciduous forest systems. This was likely due to pH suppression of nitrification in the acidic forest soils, corroborated by a positive correlation of Vmax with soil pH but not with amoA gene abundance. Results also demonstrated that soil nitrification potentials were relatively stable, as there were no seasonal differences. Overall, results suggest that (1) NH4+ inhibition of AOB but not AOA could be another factor contributing to niche differentiation between AOA and AOB in soil, and (2) nitrification by both AOA and AOB can be significantly promoted by long-term nitrogen inputs.</p>
Data from: Plant community composition steers grassland vegetation via soil legacy effects
<p>Soil legacy effects are commonly highlighted as drivers of plant community dynamics and species co-existence. However, experimental evidence for soil legacy effects of conditioning plant communities on responding plant communities under natural conditions is lacking. We conditioned 192 grassland plots using six different plant communities with different ratios of grasses and forbs and for different durations. Soil microbial legacies were evident for soil fungi, but not for soil bacteria, while soil abiotic parameters did not significantly change in response to conditioning. The soil legacies affected the composition of the succeeding vegetation. Plant communities with different ratios of grasses and forbs left soil legacies that negatively affected succeeding plants of the same functional type. We conclude that fungal-mediated soil legacy effects play a significant role in vegetation assembly of natural plant communities.</p>
Data from: Drought and soil nutrients effects on symbiotic nitrogen fixation in seedlings from eight Neotropical legume species
<p>Symbiotic nitrogen fixation is a dominant source of nitrogen to many terrestrial ecosystems, and thus may influence their responses to global change. High legume species diversity and abundance are thought to lead to high rates of symbiotic nitrogen fixation in Neotropical forests. However, how changes in water and nutrient availability will affect symbiotic nitrogen fixation have only recently been explored, even as droughts begin to increase in severity and frequency in the Neotropics. To explore these effects, we grew eight species of Neotropical woody legume seedlings in a shadehouse for four months while manipulating soil water, phosphorus and molybdenum availability. Overall, drought reduced nodule biomass, nitrogenase activity (acetylene reduction g<sup>-1</sup> nodule), and acetylene reduction per seedling by 33%, 27%, and 41%, respectively, but reduced seedling biomass by only 18%. Species varied in the manifestation of drought effects. For example, drought reduced the probability that nodules formed in some species, but in others reduced the nitrogenase activity or acetylene reduction per seedling. In contrast, the effects of phosphorus and molybdenum availability were more species-specific. However, fertilization did affect (both positively and negatively) one or more symbiotic nitrogen fixation response variables in two of the eight species. Our results indicate drought reduces symbiotic nitrogen fixation in Neotropical legume seedlings, but the mechanism of response may be species-specific. Therefore, predicting the response of symbiotic nitrogen fixation in the Neotropics to a changing climate, with expected increases in drought frequency and severity, may require grappling with the diversity of responses among nitrogen-fixing legumes.</p>
Data from: Multiple constraints cause positive and negative feedbacks limiting grassland soil CO2 efflux under CO2 enrichment
<p>Terrestrial ecosystems are increasingly enriched with resources such as atmospheric CO<sub>2</sub> that limit ecosystem processes. The consequences for ecosystem carbon cycling depend on the feedbacks from other limiting resources and plant community change, which remain poorly understood for soil CO<sub>2</sub> efflux, J<sub>CO2</sub>, a primary carbon flux from the biosphere to the atmosphere. We applied a unique CO<sub>2</sub> enrichment gradient (250 to 500 µL L<sup>-1</sup>) for eight years to grassland plant communities on soils from different landscape positions. We identified the trajectory of J<sub>CO2</sub> responses and feedbacks from other resources, plant diversity (effective species richness, exp(H)), and community change (plant species turnover). We found linear increases in J<sub>CO2</sub> on an alluvial sandy loam and a lowland clay soil, and an asymptotic increase on an upland silty clay soil. Structural equation modelling identified CO<sub>2</sub> as the dominant limitation on J<sub>CO2</sub> on the clay soil. In contrast with theory predicting limitation from a single limiting factor, the linear J<sub>CO2</sub> response on the sandy loam was reinforced by positive feedbacks from aboveground net primary productivity and exp(H), while the asymptotic J<sub>CO2</sub> response on the silty clay arose from a net negative feedback among exp(H), species turnover, and soil water potential. These findings support a multiple resource limitation view of the effects of global change drivers on grassland ecosystem carbon cycling and highlight a crucial role for positive or negative feedbacks between limiting resources and plant community structure. Incorporating these feedbacks will improve models of terrestrial carbon sequestration and ecosystem services.</p>
Soil water retention and water flow simulation data
<p>The data is for the manuscript of a paper entitled "<strong>Simulation of water flow and calculation of </strong><strong>the related physical quality indices as influenced by soil water retention curve fitting methods".</strong></p> <p>Accurate fitting of soil water retention curve (SWRC) parameters is crucial in the modeling of soil water flow and the assessment of soil quality. The un-weighted least squares regression (ULS) is the most common approach applied for fitting the SWRC functions to the observed data-points in order to optimize their parameters. However, the variance of SWRC data varies in different water contents; therefore, unlike the wet-end of the SWRC, the ULS method may not be sufficiently effective in estimating its dry-end. This study examined the differences between parameter approximations achieved by the ULS and the weighted least-squares (WLS) in the SWRC. Then, an analysis of both approaches in the simulation of water redistribution and the related soil physical quality indicators (SPQIs) was done. Accordingly</p>
Data from: With a little help from my friends – Physiological integration facilitates invasion of wetland grass Elymus athericus into flooded soils
<p>Tidal wetlands worldwide are undergoing rapid invasions by tall-growing clonal grasses. Prominent examples are invasions by species of the genera <i>Spartina, Phragmites,</i> and <i>Elymus</i>. The responsible physiological and ecological drivers of these invasions are poorly understood. Physiological integration (PI) is a key trait of clonal plants, which enables the exchange of resources among ramets. We investigated PI in <i>Elymus athericus,</i> which has been rapidly spreading from high-marsh into low-marsh environments of European salt marshes during the last decades. We applied a nitrogen-stable-isotope approach to trace nutrient translocation between ramets in a factorial mesocosm experiment. The experiment was set up to mimic an invasion pattern commonly found in tidal wetlands, i.e. from high-elevated and rarely flooded into low-elevated and frequently flooded microenvironments. We tested for intraspecific variability in PI by including two genotypes of <i>Elymus </i>that naturally occur at different elevations within the tidal frame, a high-marsh (HM) and a low-marsh (LM) genotype. PI strongly increased offspring ramet aboveground and belowground biomass by 62 and 81%, respectively. Offspring ramets under drained conditions had 95% greater belowground biomass than those under flooded conditions. LM genotype offspring ramets produced 27% more aboveground biomass than HM genotypes. Offspring ramets were clearly more enriched in <sup>15</sup>N under flooded vs. drained conditions; however, this positive effect of flooding on δ<sup>15</sup>N was only significant in the LM genotype. Our findings demonstrate the importance of PI for the growth of <i>Elymus</i> offspring ramets and thereby for the species' capacity for fast vegetative spread. We show that offspring ramets under stressful flooded conditions are more dependent on nutrient supply from parent ramets than those under drained conditions. Our data furthermore suggest a higher degree of adaptation to flooding via PI in the LM vs. HM genotype. In conclusion, we highlight the importance of assessing PI and intraspecific trait variability to understand invasion processes within ecosystems.</p>
Data from: Variations in ratio and loads of soil nitrogen and phosphorus explain the coexistence of dominant tree species in a boreal forest of Xinjiang, northwest China
<p><span>The resource ratio hypothesis (RRH) and the nutrient-load hypothesis (NLH) state that species coexistence is driven by the ratios and loads (contents) of multiple limiting resources, respectively. However, roles of resource ratios and loads to mature forest ecosystems remains unclear. Data were collected within 300 quadrats (20m×20m) spread across a 12 ha plot of boreal forest in the Kanas of Xinjiang, northwest China. We used torus translation tests to analyze the associations of dominant tree species with specific microhabitats. The linear mixed models were used to assess effects of resource ratios and contents on abundance and basal area of specific species, as well as within different life stages. Two shade-tolerant species, <i>Picea obovata</i> and <i>Pinus sibirica</i>, exhibited opposite relationships to the spatial distribution of soil nitrogen (N) content and phosphorus (P) content. <i>Picea. obovata</i> was associated with microhabitats with high N:P ratio, while <i>P. sibirica</i> preferred microhabitats with low N:P ratio. The light-demanding trees, <i>Betula pendula</i> clustered at both low N and P sites. Another light-demanding trees, <i>Larix sibirica</i>, did not show any significant habitat preferences. Moreover, N:P ratio mainly affected species abundance, while their contents largely impacted basal area of species. And effects of N:P ratio or contents on species distribution showed a decreasing trend from sapling to adults. Overall, our findings indicate that niche partitioning caused by resource variations may alleviate interspecific competition and contribute to the species coexistence, providing convincing proof for the importance of resource ratio and load on maintaining diversity in boreal forests. </span></p>
Data from: Changes in soil microbial communities in post mine ecological restoration: implications for monitoring using high throughput DNA sequencing
<p>The ecological restoration of ecosystem services and biodiversity is a key intervention used to reverse the impacts of anthropogenic activities such as mining. Assessment of the performance of restoration against completion criteria relies on biodiversity monitoring. However, monitoring usually overlooks soil microbial communities (SMC), despite increased awareness of their pivotal role in many ecological functions. Recent advances in cost, scalability and technology has led to DNA sequencing being considered as a cost-effective biological monitoring tool, particularly for otherwise difficult to survey groups such as microbes. However, such approaches for monitoring complex restoration sites such as post-mined landscapes have not yet been tested. Here we examine bacterial and fungal communities across chronosequences of mine site restoration at three locations in Western Australia to determine if there are consistent changes in SMC diversity, community composition and functional capacity. Although we detected directional changes in community composition indicative of microbial recovery, these were inconsistent between locations and microbial taxa (bacteria or fungi). Assessing functional diversity provided greater understanding of changes in site conditions and microbial recovery than could be determined through assessment of community composition alone. These results demonstrate that <span>high-throughput amplicon sequencing of environmental DNA (eDNA)</span> is an effective approach for monitoring the complex changes in SMC following restoration. Future monitoring of mine site restoration using eDNA should consider archiving samples to provide improved understanding of changes in communities over time. Expansion to include other biological groups (e.g. soil fauna) and substrates would also provide a more holistic understanding of biodiversity recovery. </p>
Data from: The soil microbial community alters patterns of selection on flowering time and fitness related traits in Ipomoea purpurea
Premise of the study <p>Plant flowering time plays an important role in plant fitness and thus evolutionary processes. Soil microbial communities are diverse and have a large impact, both positive and negative, on the host plant. However, owing to few available studies, how the soil microbial community may influence the evolutionary response of plant populations is not well understood. Here we sought to uncover if below-ground microbial communities act as an agent of selection on flowering and growth traits in the common morning glory, <i>Ipomoea purpurea</i>.</p> Methods <p>We performed a controlled greenhouse experiment in which genetic lines of <i>I. purpurea</i> were planted into either sterilized soils, or soils that were sterilized and re-inoculated with the microbial community from original field soil. This allowed us to directly test the influence of alterations to the microbial community on plant growth, flowering, and fitness, as well as assess patterns of selection in both soil microbial environments.</p> Results <p>We found that a more complex soil microbial community resulted in larger plants that produced more flowers. Selection strongly favored earlier flowering when plants were grown in the complex microbial environment than compared to sterilized soil. Additionally, we uncovered a pattern of negative correlational selection on growth rate and flowering time, indicating that selection favored different combinations of growth and flowering traits in the simplified versus complex soil community.</p> Conclusions <p>Together these results suggest the soil microbial community is a selective agent on flowering time and ultimately that soil microbial community influences important plant evolutionary processes.</p>
Data from "Removal of grazers alters the response of tundra soil carbon to warming and enhanced nitrogen availability", Ecological Monograps in October 2019
<p>Here we present the data used in the manuscript "<em>Removal of grazers alters the response of tundra soil carbon to warming and enhanced nitrogen availability</em>", Ecological Monograps, Early view in October 2019 by H. Ylänne, E. Kaarlejärvi, M. Väisänen, M. K. Männistö, S. H. K. Ahonen, J. Olofsson & S. Stark. In this paper we studied, how five years of experimental warming and increased soil nitrogen availability interact with both long- and short-term differences in grazing intensity in shaping ecosystem carbon stocks and the processes underlying the changes. We used an over 50-year-old reindeer fence that separates a lightly grazed shrub-dominated tundra from a heavily grazed graminoid-dominated tundra, where the different grazing histories on the two sides of the fences have created different ecosystem states. In addition to the long-term grazing difference, we also established short-term grazer exclosures on the heavily grazed side of the fence to account for the effect of a sudden grazing cessation.</p> <p>This file includes data of ecosystem carbon stocks, soil properties, and fungal and bacterial copy numbers. It also provides data on development of the vegetation through the course of the experiment (2010-2014) and presents the activities of six extracellular enzymes measured on three occasions in 2013.</p>
Data from: Canopy soil greenhouse gas dynamics in response to indirect fertilization across an elevation gradient of tropical montane forests
Canopy soils can significantly contribute to aboveground labile biomass, especially in tropical montane forests. Whether they also contribute to the exchange of greenhouse gases is unknown. To examine the importance of canopy soils to tropical forest-soil greenhouse gas exchange, we quantified gas fluxes from canopy soil cores along an elevation gradient with 4 yr of nutrient addition to the forest floor. Canopy soil contributed 5–12 percent of combined (canopy + forest floor) soil CO2 emissions but CH4 and N2O fluxes were low. At 2000 m, phosphorus decreased CO2 emissions (>40%) and nitrogen slightly increased CH4 uptake and N2O emissions. Our results show that canopy soils may contribute significantly to combined soil greenhouse gas fluxes in montane regions with high accumulations of canopy soil. We also show that changes in fluxes could occur with chronic nutrient deposition.
Data from: Decay of ecosystem differences and decoupling of tree community-soil environment relationships at ecotones
Ecotones are important landscape features where there is a transition between adjoining ecosystems. However, there are few generalized hypotheses about the response of communities to ecotones, except for a proposed increase in species richness that receives varying empirical support. Based on the assumption that transport of abiotic material and dispersal of organism propagules across ecotones are independent processes, we propose the new hypothesis that ecotones decouple community-environment relationships, increasing the importance of spatial structure that is independent of the environment. We tested this hypothesis by examining the effects of ecotones on relationships between trees and soil properties in a temperate deciduous forest. The study area included different landforms defined by topography, hydrology, and geomorphology, which we designated upland, bottomland, and riparian forests. The site also included a mowed herbaceous corridor. We found that soil properties and tree community composition significantly differed among landforms, and thus they could be treated as differing ecosystem types. However, inclusion of plots near ecotones significantly reduced the variance explained by landform due to introduction of increased noise, increased similarity of ecotone plots in different landforms, or both. To examine tree community-soil environment relationships, factorial kriging analysis was used to decompose variation in soil properties into structures associated with differing spatial scales, which were then used as predictors of tree composition using redundancy analysis. In agreement with the ecotone-decoupling hypothesis, we found that ecotones introduced significant unexplained variation into correlations between tree community composition and soil properties. In addition, spatial variation in tree community composition that was independent of soil properties was only detected when ecotones were included in the analysis, and little variation in tree community composition was attributed to small-scale soil property structures. Together, these results indicate that dispersal limitation and mass effects in the tree community take on increased importance near ecotones. We found no consistent changes in tree species richness associated with ecotones, and suggest that the ecotone-decoupling hypothesis may correspond with a more general community-level pattern that warrants further testing. Decoupling of community-environment relationships near ecotones also has important implications for accuracy of models predicting community distributions from abiotic information.
Data from: Combined effects of seed and soil quality drive seedling performance of a late-successional canopy tree in a tropical forest
Habitat loss and fragmentation affect the structure and functioning of forested ecosystems worldwide, yet we lack an understanding of how species respond to environmental changes. Here, we examined reproductive success and seedling performance of Poulsenia armata (Moraceae) in continuous and fragmented forests of Los Tuxtlas, southern Mexico. We further investigated how maternal habitat and soil conditions manifested in the seedling stage. We determined seed quality and seedling performance by combining isotopic analyses in seed quality with field observations of P. armata fruit production and a common--garden experiment. Soil conditions in forest fragments negatively impacted P. armata reproductive success. Trees of P. armata in forest fragments were smaller in size and produced fewer fruits and smaller seeds with lower quality compared with trees from the continuous forest. The combined effects of maternal habitat and soil conditions determined seedling survival and growth of this tropical tree. Notably, seedlings had restricted plasticity for biomass allocation to roots, limiting the capacity of fragmented populations to compensate for the initial low N content in seeds. Trees in forest fragments at Los Tuxtlas produced offspring competitively inferior and potentially less resilient than counterparts in continuous forest, jeopardizing future persistence of this late-successional tree species.
Data from: Different roles of elevational and local environmental factors on abundance-based beta diversity of the soil Enchytraeidae on the Changbai Mountain
The elevational alpha biodiversity gradient in mountain regions is one of the well-known ecological patterns, but its beta diversity pattern remains poorly-known. Examining the beta diversity and its components could enhance the understanding of community assembly mechanism. We studied the beta diversity pattern of the soil enchytraeids along a distinct elevational gradient (705—2280 m) on the Changbai Mountain, the best-preserved mountain in northeastern China. The overall abundance-based community dissimilarity was relatively high (ca. 0.70), largely due to the balanced-variation component (85%). The overall dissimilarity and its balanced-variation (substitution) component were both related to local environmental heterogeneity and elevational distance, with the environmental relationships being stronger. In contrast, the abundance-gradient (subsets) component was not related to the two gradients. The same important spatial and environmental variables were detected in structuring overall dissimilarity and substitution component, different from that in subsets component. Variation partitioning analysis showed that environmental control played a more important role than spatial (vertical and horizontal) factors in structuring the patterns of overall beta diversity and its two components. The predictive power of multivariate analysis was higher for the substitution component (nearly 50%) and overall dissimilarity (35%), but much lower for subsets components (< 4%). These findings implied that abundance-based beta diversity patterns of the soil enchytraeids were the results of different ecological processes (e.g. environmental sorting and dispersal limitation), operating in the two antithetic components. Our study showed the substitution and loss of individuals reflecting different ecological processes and highlights the importance of partitioning beta diversity in assessing biodiversity patterns and their causes.
Data from: Defoliation of a grass by reindeer is compensated by the positive effects of its soil legacy, dung deposition, and moss removal
Herbivory is one of the key drivers shaping plant community dynamics. Herbivores can strongly influence plant productivity directly through defoliation and the return of nutrients in the form of dung and urine, but also indirectly by reducing the abundance of neighbouring plants and inducing changes in soil processes. However, the relative importance of these processes is poorly understood. We, therefore, established a common garden experiment to study plant responses to defoliation, dung addition, moss cover, and the soil legacy of reindeer grazing. We used an arctic tundra grazed by reindeer as our study system, and Festuca ovina, a common grazing-tolerant grass species as the model species. The soil legacy of reindeer grazing had the strongest effect on plants, and resulted in higher growth in soils originating from previously heavily-grazed sites. Defoliation also had a strong effect and reduced shoot and root growth and nutrient uptake. Plants did not fully compensate for the tissue lost due to defoliation, even when nutrient availability was high. In contrast, defoliation enhanced plant nitrogen concentrations. Dung addition increased plant production, nitrogen concentrations and nutrient uptake, although the effect was fairly small. Mosses also had a positive effect on aboveground plant production as long as the plants were not defoliated. The presence of a thick moss layer reduced plant growth following defoliation. This study demonstrates that grasses, even though they suffer from defoliation, can tolerate high densities of herbivores when all aspects of herbivores on ecosystems are taken into account. Our results further show that the positive effect of herbivores on plant growth via changes in soil properties is essential for plants to cope with a high grazing pressure. The strong effect of the soil legacy of reindeer grazing reveals that herbivores can have long-lasting effects on plant productivity and ecosystem functioning after grazing has ceased.
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.
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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.