{"type": "FeatureCollection", "features": [{"id": "10.1007/s004420100656", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:07Z", "type": "Journal Article", "created": "2003-02-13", "title": "Fine-Root Biomass And Fluxes Of Soil Carbon In Young Stands Of Paper Birch And Trembling Aspen As Affected By Elevated Atmospheric Co2 And Tropospheric O3", "description": "Rising atmospheric CO2 may stimulate future forest productivity, possibly increasing carbon storage in terrestrial ecosystems, but how tropospheric ozone will modify this response is unknown. Because of the importance of fine roots to the belowground C cycle, we monitored fine-root biomass and associated C fluxes in regenerating stands of trembling aspen, and mixed stands of trembling aspen and paper birch at FACTS-II, the Aspen FACE project in Rhinelander, Wisconsin. Free-air CO2 enrichment (FACE) was used to elevate concentrations of CO2 (average enrichment concentration 535\u00a0\u00b5l l-1) and O3 (53\u00a0nl l-1) in developing forest stands in 1998 and 1999. Soil respiration, soil pCO2, and dissolved organic carbon in soil solution (DOC) were monitored biweekly. Soil respiration was measured with a portable infrared gas analyzer. Soil pCO2 and DOC samples were collected from soil gas wells and tension lysimeters, respectively, at depths of 15, 30, and 125\u00a0cm. Fine-root biomass averaged 263\u00a0g m-2 in control plots and increased 96% under elevated CO2. The increased root biomass was accompanied by a 39% increase in soil respiration and a 27% increase in soil pCO2. Both soil respiration and pCO2 exhibited a strong seasonal signal, which was positively correlated with soil temperature. DOC concentrations in soil solution averaged ~12\u00a0mg l-1 in surface horizons, declined with depth, and were little affected by the treatments. A simplified belowground C budget for the site indicated that native soil organic matter still dominated the system, and that soil respiration was by far the largest flux. Ozone decreased the above responses to elevated CO2, but effects were rarely statistically significant. We conclude that regenerating stands of northern hardwoods have the potential for substantially greater C input to soil due to greater fine-root production under elevated CO2. Greater fine-root biomass will be accompanied by greater soil C efflux as soil respiration, but leaching losses of C will probably be unaffected.", "keywords": ["0106 biological sciences", "Ecology and Evolutionary Biology", "Aspen-FACE-project", "root-", "USA-", "pollutants-", "Environmental-Sciences)", "tropospheric-ozone", "forest-productivity", "01 natural sciences", "biomass-", "northern-forests", "124-38-9: CARBON DIOXIDE", "soil-carbon-flux", "terrestrial-ecosystems", "populus-tremuloides", "Cellular and Developmental Biology", "soil-carbon", "7440-44-0: CARBON", "carbon-", "fine-root", "Bioenergetics- (Biochemistry-and-Molecular-Biophysics)", "Natural Resources and Environment", "04 agricultural and veterinary sciences", "GLOBAL-ECOLOGY", "North-America", "Nearctic-region)", "Rhinelander- (Wisconsin-", "carbon-sequestration", "atmosphere-", "biomass-production", "dissolved-organic-carbon [DOC-]", "Science", "respiration-", "carbon-dioxide-enrichment", "forest-plantations", "carbon-dioxide", "carbon-storage", "fine-root-biomass", "belowground-biomass", "United-States-Wisconsin-Rhinelander", "carbon-cycle", "Health Sciences", "ozone-", "soil-respiration", "air-pollution", "global-change", "atmospheric-carbon-dioxide", "biomass", "Molecular", "15. Life on land", "ozone", "13. Climate action", "roots-", "Legacy", "Terrestrial-Ecology (Ecology-", "free-air-carbon-dioxide-enrichment [FREE-]: experimental-method", "0401 agriculture", " forestry", " and fisheries", "Northern Forests Global Change Carbon Sequestration Soil Respiration Dissolved Organic Carbon Soil PCO2"]}, "links": [{"href": "https://doi.org/10.1007/s004420100656"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Oecologia", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s004420100656", "name": "item", "description": "10.1007/s004420100656", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s004420100656"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2001-07-01T00:00:00Z"}}, {"id": "10.1093/treephys/22.7.435", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:19:07Z", "type": "Journal Article", "created": "2012-01-20", "title": "Responses Of Deciduous Broadleaf Trees To Defoliation In A Co2 Enriched Atmosphere", "description": "Relatively little is known about the implications of atmospheric CO2 enrichment for tree responses to biotic disturbances such as folivory. We examined the combined effects of elevated CO2 concentration ([CO2]) and defoliation on growth and physiology of sugar maple (Acer saccharum Marsh.) and trembling aspen (Populus tremuloides Michx.). Seedlings were planted in the ground in eight open-top chambers. Four chambers were ventilated with CO2-enriched air (ambient + 283 micromol mol-1) and four chambers were supplied with ambient air. After 6 weeks of growth, half of the leaf area was removed on a subset of seedlings of each species in each CO2 treatment. We monitored subsequent biomass gain and allocation, along with leaf gas exchange and chemistry. Defoliation did not significantly affect final seedling biomass in either species or CO2 treatment. Growth recovery following defoliation was associated with increased allocation to leaf mass in maple and a slight enhancement of mean photosynthesis in aspen. Elevated [CO2] did not significantly affect aspen growth, and the observed stimulation of maple growth was significant only in mid-season. Correspondingly, simulated responses of whole-tree photosynthesis to elevated [CO2] were constrained by a decrease in photosynthetic capacity in maple, and were partially offset by reductions in specific leaf area and biomass allocation to foliage in aspen. There was a significant interaction between [CO2] and defoliation on only a few of the measured traits. Thus, the data do not support the hypothesis that atmospheric CO2 enrichment will substantially alter tree responses to folivory. However, our findings do provide further indication that regeneration-stage growth rates of certain temperate tree species may respond only moderately to a near doubling of atmospheric [CO2].", "keywords": ["defoliation-", "0106 biological sciences", "Ecophysiology", "Quaking aspen", "biomass-allocation", "growth-response", "Growth", "Environmental-Sciences)", "01 natural sciences", "plant-composition", "Trees", "biomass-", "Spermatophyta-", "Biomass", "Photosynthesis", "plant-physiology", "defoliation", "Angiospermae-", "leaf-area", "GLOBAL-ECOLOGY", "seedling-growth", "source-sink-relations", "Populus-tremuloides", "gas-exchange", "Populus", "broadleaves-", "deciduous-tree", "forest-trees", "atmosphere-", "trees-", "biomass-production", "Acer saccharum", "Nitrogen", "Carbohydrates", "Acer", "carbon-dioxide-enrichment", "photosynthesis-", "growth-", "species-differences", "seedlings-", "wisconsin-", "Populus tremuloides", "photosynthesis", "Climatic changes", "Carbon Dioxide", "15. Life on land", "Plant Leaves", "leaves-", "Aceraceae-: Dicotyledones-", "Carbon dioxide", "Sugar maple", "Seedlings", "Terrestrial-Ecology (Ecology-", "Acer-saccharum"], "contacts": [{"organization": "Volin, John C., Kruger, Eric L., Lindroth, Richard L.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1093/treephys/22.7.435"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Tree%20Physiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1093/treephys/22.7.435", "name": "item", "description": "10.1093/treephys/22.7.435", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/treephys/22.7.435"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2002-05-01T00:00:00Z"}}, {"id": "10.1175/jtech-d-21-0019.1", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:20:04Z", "type": "Journal Article", "created": "2021-09-13", "title": "Distributed sensing of wind direction using fiber-optic cables", "description": "Abstract<p>In the atmospheric boundary layer, phenomena exist with challenging properties such as spatial heterogeneity, particularly during stable weak wind situations. Studying spatially heterogeneous features requires spatially distributed measurements on fine spatial and temporal scales. Fiber-Optic Distributed Sensing (FODS) can provide spatially distributed measurements, simultaneously offering a spatial resolution on the order of decimeters and a temporal resolution on the order of seconds. While FODS has already been deployed to study various variables, FODS wind direction sensing has only been demonstrated in idealized wind tunnel experiments. We present the first distributed observations of FODS wind directions from field data. The wind direction sensing is accomplished by using pairs of actively heated fiber optic cables with cone-shaped microstructures attached to them. Here we present three different methods of calculating wind directions from the FODS measurements, two based on using combined wind speed and direction information and one deriving wind direction independently from FODS wind speed. For each approach, the effective temporal and spatial resolution is quantified using spectral coherence. With each method of calculating wind directions, temporal resolutions on the order of tens of seconds can be achieved. The accuracy of FODS wind directions was evaluated against a sonic anemometer, showing deviations of less than 15\uffc2\uffb0 most of the time. The applicability of FODS for wind direction measurements in different environmental conditions is tested by analysing the dependence of FODS wind direction accuracy and observable scales on environmental factors. Finally, we demonstrate the potential of this technique by presenting a period that displays spatial and temporal structures in the wind direction.</p>", "keywords": ["Spectral analysis/models/distribution", "550", "Atmosphere", "0207 environmental engineering", "Distributed Temperature Sensing", "02 engineering and technology", "Field experiments", "Wind effects", "530", "01 natural sciences", "Turbulence", "13. Climate action", "Atmosphere-land interaction", "0105 earth and related environmental sciences"], "contacts": [{"organization": "Freundorfer, Anita, Lapo, Karl, Schneider, Johann, Thomas, Christoph K.,", "roles": ["creator"]}]}, "links": [{"href": "https://journals.ametsoc.org/downloadpdf/journals/atot/aop/JTECH-D-21-0019.1/JTECH-D-21-0019.1.xml"}, {"href": "https://doi.org/10.1175/jtech-d-21-0019.1"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Atmospheric%20and%20Oceanic%20Technology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1175/jtech-d-21-0019.1", "name": "item", "description": "10.1175/jtech-d-21-0019.1", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1175/jtech-d-21-0019.1"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-09-13T00:00:00Z"}}, {"id": "10.2307/2640985", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:21:18Z", "type": "Journal Article", "created": "2006-04-17", "description": "Elevated atmospheric CO2 has the potential to increase the production and alter the chemistry of organic substrates entering soil from plant production, the magnitude of which is constrained by soil-N availability. Because microbial growth in soil is limited by substrate inputs from plant production, we reasoned that changes in the amount and chemistry of these organic substrates could affect the composition of soil microbial com- munities and the cycling of N in soil. We studied microbial community composition and soil-N transformations beneath Populus tremuloides Michx. growing under experimental atmospheric CO2 (35.7 and 70.7 Pa) and soil-N-availability (low N 5 61 ng N\u00b7g 21 \u00b7d 21 and high N 5 319 ng N\u00b7g 21 \u00b7d 21 ) treatments. Atmospheric CO2 concentration was modified in large, open-top chambers, and we altered soil-N availability in open-bottom root boxes by mixing different proportions of A and C horizon material. We used phospholipid fatty-acid analysis to gain insight into microbial community composition and coupled this analysis to measurements of soil-N transformations using 15 N-pool dilution techniques. The infor- mation presented here is part of an integrated experiment designed to elucidate the phys- iological mechanisms controlling the flow of C and N in the plant-soil system. Our ob- jectives were (1) to determine whether changes in plant growth and tissue chemistry alter microbial community composition and soil-N cycling in response to increasing atmospheric CO2 and soil-N availability and (2) to integrate the results of our experiment into a synthesis of elevated atmospheric CO2 and the cycling of C and N in terrestrial ecosystems. After 2.5 growing seasons, microbial biomass, gross N mineralization, microbial im- mobilization, and nitrification (gross and net) were equivalent at ambient and elevated CO2, suggesting that increases in fine-root production and declines in fine-root N concentration were insufficient to alter the influence of native soil organic matter on microbial physiology; this was the case in both low- and high-N soil. Similarly, elevated CO2 did not alter the proportion of bacterial, actinomycetal, or fungal phospholipid fatty acids in low-N or high-N soil, indicating that changes in substrate input from greater plant growth under elevated CO2 did not alter microbial community composition. Our results differ from a substantial number of studies reporting increases and decreases in soil-N cycling under elevated CO 2. From our analysis, it appears that soil-N cycling responds to elevated atmospheric CO 2 in experimental situations where plant roots have fully colonized the soil and root-associated C inputs are sufficient to modify the influence of native soil organic matter on microbial physiology. In young developing ecosystems where plant roots have not fully exploited the soil, microbial metabolism appears to be regulated by relatively large pools of soil organic matter, rather than by the additional input of organic substrates under elevated CO 2.", "keywords": ["measurement-", "soil microorganisms", "Ecology and Evolutionary Biology", "nitrogen-: cycling-", "feedback", "microbial community composition", "techniques-", "Environmental-Sciences)", "01 natural sciences", "litter-plant", "biomass-", "gross and net", "124-38-9: CARBON DIOXIDE", "Spermatophytes-", "cycling-", "soil-organic-matter", "mineralization", "Spermatophyta-", "responses-", "phospholipid-fatty-acids", "2. Zero hunger", "Climatology- (Environmental-Sciences)", "Angiosperms-", "Angiospermae-", "Plants-", "global climate change", "microbial immobilization", "nutrient-", "Soil-Science", "6. Clean water", "metabolism-", "soil-N transformations", "transformation-", "substrates-", "7727-37-9: NITROGEN", "atmosphere-", "elevated atmospheric", "570", "nitrification-", "nitrogen immobilization", "Science", "Vascular-Plants", "poplars-", "phospholipid fatty acids (PFLAs)", "carbon-dioxide", "growth-", "soil-microbial-community-composition", "Salicaceae-: Dicotyledones-", "microbial-flora", "Populus tremuloides", "Plantae-", "organic-matter", "consortia-", "0105 earth and related environmental sciences", "communities-", "ecosystem", "analysis-", "atmospheric CO2 and soil-N availability", "soil-availability", "mineralization-", "carbon dioxide", "fatty-acids", "15. Life on land", "substrate-input", "Populus-tremuloides (Salicaceae-)", "13. Climate action", "roots-", "Terrestrial-Ecology (Ecology-", "composition-", "Dicots-", "immobilization-", "seasons-", "ecosystems-"], "contacts": [{"organization": "Zak, Donald R., Pregitzer, Kurt S., Curtis, Peter S., Holmes, William E.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.2307/2640985"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Ecological%20Applications", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2307/2640985", "name": "item", "description": "10.2307/2640985", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2307/2640985"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2000-02-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=atmosphere-&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=atmosphere-&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=atmosphere-&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=atmosphere-&offset=4", "hreflang": "en-US"}], "numberMatched": 4, "numberReturned": 4, "distributedFeatures": [], "timeStamp": "2026-06-24T14:10:16.015045Z"}