{"type": "FeatureCollection", "features": [{"id": "10.1007/pl00008869", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:14:55Z", "type": "Journal Article", "created": "2006-04-10", "title": "Combined Effects Of Atmospheric Co2 And N Availability On The Belowground Carbon And Nitrogen Dynamics Of Aspen Mesocosms", "description": "It is uncertain whether elevated atmospheric CO2 will increase C storage in terrestrial ecosystems without concomitant increases in plant access to N. Elevated CO2 may alter microbial activities that regulate soil N availability by changing the amount or composition of organic substrates produced by roots. Our objective was to determine the potential for elevated CO2 to change N availability in an experimental plant-soil system by affecting the acquisition of root-derived C by soil microbes. We grew Populus tremuloides (trembling aspen) cuttings for 2 years under two levels of atmospheric CO2 (36.7 and 71.5 Pa) and at two levels of soil N (210 and 970 \u00b5g N g-1). Ambient and twice-ambient CO2 concentrations were applied using open-top chambers, and soil N availability was manipulated by mixing soils differing in organic N content. From June to October of the second growing season, we measured midday rates of soil respiration. In August, we pulse-labeled plants with 14CO2 and measured soil 14CO2 respiration and the 14C contents of plants, soils, and microorganisms after a 6-day chase period. In conjunction with the August radio-labeling and again in October, we used 15N pool dilution techniques to measure in situ rates of gross N mineralization, N immobilization by microbes, and plant N uptake. At both levels of soil N availability, elevated CO2 significantly increased whole-plant and root biomass, and marginally increased whole-plant N capital. Significant increases in soil respiration were closely linked to increases in root biomass under elevated CO2. CO2 enrichment had no significant effect on the allometric distribution of biomass or 14C among plant components, total 14C allocation belowground, or cumulative (6-day) 14CO2 soil respiration. Elevated CO2 significantly increased microbial 14C contents, indicating greater availability of microbial substrates derived from roots. The near doubling of microbial 14C contents at elevated CO2 was a relatively small quantitative change in the belowground C cycle of our experimental system, but represents an ecologically significant effect on the dynamics of microbial growth. Rates of plant N uptake during both 6-day periods in August and October were significantly greater at elevated CO2, and were closely related to fine-root biomass. Gross N mineralization was not affected by elevated CO2. Despite significantly greater rates of N immobilization under elevated CO2, standing pools of microbial N were not affected by elevated CO2, suggesting that N was cycling through microbes more rapidly. Our results contained elements of both positive and negative feedback hypotheses, and may be most relevant to young, aggrading ecosystems, where soil resources are not yet fully exploited by plant roots. If the turnover of microbial N increases, higher rates of N immobilization may not decrease N availability to plants under elevated CO2.", "keywords": ["0106 biological sciences", "root-: biomass-", "Ecology and Evolutionary Biology", "nitrogen-fixation", "Environmental-Sciences)", "01 natural sciences", "nitrogen", "biomass-", "nitrogen-cycle", "nitrogen-", "Microorganisms-", "carbon-14", "124-38-9: CARBON DIOXIDE", "C Cycle", "Spermatophytes-", "Spermatophyta-", "Key Words Atmospheric CO2", "Cellular and Developmental Biology", "Populus Tremuloides Michx", "2. Zero hunger", "carbon-dioxide: atmospheric-", "plant-nutrition", "Climatology- (Environmental-Sciences)", "Angiosperms-", "Angiospermae-", "Plants-", "Natural Resources and Environment", "04 agricultural and veterinary sciences", "global-climate-change", "microbe- (Microorganisms-)", "7727-37-9: NITROGEN", "chemical-composition", "carbon-sequestration", "mineral-uptake", "soil-biology", "Science", "Vascular-Plants", "poplars-", "respiration-", "carbon-dioxide-enrichment", "carbon-dioxide", "Populus-tremuloides [trembling-aspen] (Salicaceae-)", "carbon-cycle", "Health Sciences", "Salicaceae-: Dicotyledones-", "soil-respiration", "content", "Plantae-", "14762-75-5: CARBON-14", "mineralization-", "Molecular", "forest-soils", "15. Life on land", "Rhizodeposition", "soil-flora", "N Cycle", "13. Climate action", "cuttings-", "roots-", "Legacy", "Terrestrial-Ecology (Ecology-", "0401 agriculture", " forestry", " and fisheries", "Dicots-", "ecosystems-"], "contacts": [{"organization": "Mikan, Carl J., Zak, Donald R., Kubiske, Mark E., Pregitzer, Kurt S.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/pl00008869"}, {"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/pl00008869", "name": "item", "description": "10.1007/pl00008869", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/pl00008869"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2000-08-23T00:00:00Z"}}, {"id": "10.1007/s004420050619", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:07Z", "type": "Journal Article", "created": "2002-08-25", "title": "Soil Carbon And Nitrogen In A Pine-Oak Sand Plain In Central Massachusetts: Role Of Vegetation And Land-Use History", "description": "Over the last 150 years much of the landscape of eastern North America has been transformed from predominantly agricultural lands to forest. Although cultivation strongly affects important ecosystem processes such as biomass accumulation, soil organic matter dynamics, and nitrogen cycling, recovery of these processes after abandonment is insufficiently understood. We examined soil carbon and nitrogen pools and nitrogen dynamics for 16 plots on a central Massachusetts sand plain, over 80% of which had been cultivated and subsequently abandoned at least 40 years ago. The two youngest old-field forests, located on sites abandoned 40-60 years prior to our sampling, had the lowest mineral soil carbon content (0-15\u2009cm), 31% less than the average of unplowed soils. Soil carbon concentration and loss-on-ignition were significantly higher in unplowed soils than in all plowed soils, but these differences were offset by the higher bulk density in formerly plowed soils, leading to no significant differences in C content between plowed and unplowed soil. Soil C:N ratios were lower in formerly plowed soils (26.2) than in unplowed soils (28.0). While soil N content was not affected by land-use history or vegetation type, net N mineralization showed much greater variation. In situ August net nitrogen mineralization varied nearly 40-fold between stand types: lowest in pitch pine and white pine stands (-0.13 and 0.10\u2009kg\u2009N\u2009ha-1\u200928\u2009day-1), intermediate in scrub oak stands (0.48\u2009kg\u2009N\u2009ha-1\u200928\u2009day-1) and highest in aspen and mixed oak stands (1.34-3.11\u2009kg\u2009N\u2009ha-1\u200928\u2009day-1). Mineralization was more strongly related to present vegetation than to land-use history or soil N content. Appreciable net nitrification was observed only in the most recently abandoned aspen plot (0.82\u2009kg\u2009N\u2009ha-1\u200928\u2009day-1), suggesting that recent disturbance and residual agricultural lime stimulated nitrification. Carbon:nitrogen ratios increased and pH declined with stand age. Higher bulk density, lower loss-on-ignition and C:N ratios, and slightly lower C concentrations in the surface mineral soil are the persistent legacies of agriculture on soil properties. Short-term agricultural use and the low initial C and N concentrations in these sandy soils appear to have resulted in less persistent impacts of agriculture on soil C and N content and N cycling.", "keywords": ["0106 biological sciences", "soil-properties", "Forests", "Environmental-Sciences)", "01 natural sciences", "nitrogen", "variation-", "Soil", "Quercus", "soil-nitrogen", "nitrogen-", "cultivation-", "cycling-", "soil-organic-matter", "vegetation-history", "sandy-soils", "soil-carbon", "2. Zero hunger", "7440-44-0: CARBON", "carbon-", "pines-", "Soil-studies", "land-use-history", "04 agricultural and veterinary sciences", "pine-oak-sand-plain", "Chemistry", "North-America", "Nearctic-region)", "Massachusetts", "agricultural-practice", "biomass-production", "trees-", "7727-37-9: Nitrogen", "nitrification-", "United-States", "forests-", "Agricultural ecosystems", "land-use", "Massachusetts- (USA-", "forest-lands", "Nutrient dynamics", "vegetation-type", "USA", "Vegetation", "mineralization-", "15. Life on land", "Pinus", "soil-types", "Terrestrial-Ecology (Ecology-", "0401 agriculture", " forestry", " and fisheries", "agricultural-land", "ecosystems-"], "contacts": [{"organization": "Campton, Jana E., Boone, Richard D., Motzkin, Glenn, Foster, David R.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/s004420050619"}, {"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/s004420050619", "name": "item", "description": "10.1007/s004420050619", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s004420050619"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1998-10-01T00:00:00Z"}}, {"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": "10.1007/s100210000025", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:15:12Z", "type": "Journal Article", "created": "2002-07-25", "title": "Controls On Soil Carbon Dioxide And Methane Fluxes In A Variety Of Taiga Forest Stands In Interior Alaska", "description": "CO2 and CH4 fluxes were monitored over 4 years in a range of taiga forests along the Tanana River in interior Alaska. Floodplain alder and white spruce sites and upland birch/aspen and white spruce sites were examined. Each site had control, fertilized, and sawdust amended plots; flux measurements began during the second treatment year. CO2 emissions decreased with successional age across the sites (alder, birch/aspen, and white spruce, in order of succession) regardless of landscape position. Although CO2 fluxes showed an exponential relationship with soil temperature, the response of CO2 production to moisture fit an asymptotic model. Of the manipulations, only N fertilization had an effect on CO2 flux, decreasing flux in the floodplain sites but increasing it in the birch/aspen site. Landscape position was the best predictor of CH4 flux. The two upland sites consumed CH4 at similar rates (approximately 0.5 mg C m\u22122 d\u22121), whereas the floodplain sites had lower consumption rates (0\u20130.3 mg C m\u22122 d\u22121). N fertilization and sawdust both inhibited CH4 consumption in the upland birch/aspen and floodplain spruce sites but not in the upland spruce site. The biological processes driving CO2 fluxes were sensitive to temperature, moisture, and vegetation, whereas CH4 fluxes were sensitive primarily to landscape position and biogeochemical disturbances. Hence, climate change effects on C-gas flux in taiga forest soils will depend on the relationship between soil temperature and moisture and the concomitant changes in soil nutrient pools and cycles.", "keywords": ["landscape-ecology", "Betulaceae-: Dicotyledones-", "flux-", "soil-nutrient-pools", "Coniferopsida-: Gymnospermae-", "Vascular-Plants", "forests-", "Environmental-Sciences)", "carbon-dioxide", "nitrogen-fertilizers", "01 natural sciences", "carbon-dioxide: emissions-", "nitrogen-: fertilization-", "vegetation-", "birch- (Betulaceae-)", "124-38-9: CARBON DIOXIDE", "Spermatophytes-", "Spermatophyta-", "74-82-8: METHANE", "Plantae-", "white-spruce (Coniferopsida-)", "successional-age", "boreal-forests", "environmental-temperature", "0105 earth and related environmental sciences", "taiga-forest-stands", "Angiosperms-", "Gymnosperms-", "Angiospermae-", "Plants-", "sawdust-", "methane-", "15. Life on land", "North-America", "Nearctic-region)", "floodplains-", "mathematical-models", "13. Climate action", "alder- (Betulaceae-)", "upland-sites", "Alaska- (USA-", "climate-change", "Terrestrial-Ecology (Ecology-", "7727-37-9: NITROGEN", "Dicots-", "methane-: consumption-", "moisture-", "climatic-change", "temperature-"]}, "links": [{"href": "https://doi.org/10.1007/s100210000025"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Ecosystems", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s100210000025", "name": "item", "description": "10.1007/s100210000025", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s100210000025"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2000-05-10T00:00:00Z"}}, {"id": "10.1046/j.1365-2745.1998.00278.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:18:35Z", "type": "Journal Article", "created": "2003-05-21", "title": "An Experimental Test Of Limits To Tree Establishment In Arctic Tundra", "description": "<p>1 Five treeline species had low seed germination rates and low survivorship and growth of seedlings when transplanted into Alaskan tundra. Seed germination of all species increased with experimental warming, suggesting that the present treeline may in part result from unsuccessful recruitment under cold conditions.</p><p> 2 Growth, biomass and survivorship of seedlings of treeline species transplanted into tundra were largely unaffected by experimental warming. However, transplanted seedlings of three species (Betula papyrifera, Picea glauca and Populus tremuloides) grew more when below\uffe2\uff80\uff90ground competition with the extant community was reduced. All three measures of transplant performance were greater in shrub tundra than in the less productive tussock or heath tundra. Establishment of trees in tundra may thus be prevented by low resource availability and competition.</p><p> 3 Two species (Alnus crispa and Populus balsamifera) had low seed germination and survivorship of germinated seeds; transplants of these species did not respond to the manipulations and lost biomass following transplanting into tundra. Isolated populations of these two species north of the present treeline in arctic Alaska probably became established during mid\uffe2\uff80\uff90Holocene warming rather than in recent times.</p><p> 4 Of all the species studied here, Picea glauca was the most likely to invade intact upland tundra. Its seeds had the highest germination rates and it was the only species whose seedlings survived subsequently. Furthermore, transplanted seedlings of Picea glauca had relatively high survivorship and positive growth in tundra, especially in treatments that increased air temperature or nutrient availability, two factors likely to increase with climate warming.</p>", "keywords": ["0106 biological sciences", "nutrient-availability", "air-temperature", "tundra", "-Alaska", "Betulaceae-: Dicotyledones-", "Arctic-tundra", "Coniferopsida-: Gymnospermae-", "natural-regeneration", "Environmental-Sciences)", "growth-", "01 natural sciences", "seedlings-", "Picea-glauca", "Betula-papyrifera", "tundra-", "soil-fertility", "Salicaceae-: Dicotyledones-", "Spermatophyta-", "treelines-", "Plantae-", "USA", "tree-establishment", "resource-availability", "Climatology- (Environmental-Sciences)", "Populus-balsamifera (Salicaceae-): seedling-", "Angiosperms-", "transplanting-", "Angiospermae-", "15. Life on land", "Plant-ecology:-communities", "Populus-balsamifera", "Betula-papyrifera (Betulaceae-): seedling-", "Populus-tremuloides", "climate-", "interspecific-competition", "germination", "Populus-tremuloides (Salicaceae-): seedling-", "Terrestrial-Ecology (Ecology-", "Picea-glauca (Coniferopsida-): seedling-", "Dicots-", "seed-germination", "Alnus-crispa", "plant-competition", "Alnus-crispa (Betulaceae-): seedling-", "survival-", "establishment-"]}, "links": [{"href": "https://doi.org/10.1046/j.1365-2745.1998.00278.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1046/j.1365-2745.1998.00278.x", "name": "item", "description": "10.1046/j.1365-2745.1998.00278.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1046/j.1365-2745.1998.00278.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1998-06-01T00:00:00Z"}}, {"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": "10.2307/2640985", "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"}}, {"id": "10.4141/s98-081", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:22:08Z", "type": "Journal Article", "created": "2011-04-23", "title": "Effects Of Forest Soil Compaction And Organic Matter Removal On Leaf Litter Decomposition In Central British Columbia", "description": "<p> As part of the long-term soil productivity study in central British Columbia, we examined the effect of soil compaction and organic matter removal on trembling aspen (Populus tremuloides Michx.) litter decomposition. We compared three levels of organic matter removal (stem-only, whole-tree harvest, and scalped mineral soil) and two levels of compaction (no compaction and heavy compaction) in a factorial design replicated as blocks on three sites. Whole-tree harvesting significantly increased litter decomposition rates compared to stem-only (by 36%) and scalped (by 41%) treatments. Soil compaction had inconsistent effects on decomposition rates (k) for forest floor and scalped treatments and, overall, did not significantly affect litter decomposition rates. Litter on scalped plots had higher rates of nutrient translocation than litter on forest floors. We found the treatments altered soil heat sums, so changes in temperatures at the soil surface might be partly responsible for the changes in decomposition rates. We could not detect differences in soil mesofauna populations collected from the litter bags, so treatment effects on fauna probably had less influence than microclimate on decomposition rates. The effects of these early changes in litter decomposition on biological productivity will be part of the ongoing long-term soil productivity study. Key words: Litter decomposition, soil compaction, scalping, whole-tree harvest, nutrient translocation </p>", "keywords": ["0106 biological sciences", "leaf-litter-decomposition: organic-matter-removal", "nutrients-", "Environmental-Sciences)", "01 natural sciences", "harvesting-", "translocation-", "populus-tremuloides", "soil-organic-matter", "Spermatophytes-", "Spermatophyta-", "Angiosperms-", "Angiospermae-", "Plants-", "heat-sums", "04 agricultural and veterinary sciences", "Soil-Science", "British-Columbia (Canada-", "North-America", "Nearctic-region)", "compaction-", "soil-compaction", "decomposition-", "microclimate-", "Vascular-Plants", "poplars-", "forests-", "movement-in-soil", "treatment-", "sustainability-", "Populus-tremuloides [trembling-aspen] (Salicaceae-)", "british-columbia", "Salicaceae-: Dicotyledones-", "land-productivity", "organic-matter", "Plantae-", "forest-litter", "productivity-", "forestry-practices", "forestry-", "mineralization-", "forest-soils", "mineral-soils", "removal-", "15. Life on land", "logging-effects", "Terrestrial-Ecology (Ecology-", "0401 agriculture", " forestry", " and fisheries", "Dicots-", "temperature-", "soil-fauna"], "contacts": [{"organization": "Kranabetter, J.M., Chapman, B.K.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.4141/s98-081"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Canadian%20Journal%20of%20Soil%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.4141/s98-081", "name": "item", "description": "10.4141/s98-081", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.4141/s98-081"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1999-11-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Terrestrial-Ecology+%28Ecology-&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=Terrestrial-Ecology+%28Ecology-&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=Terrestrial-Ecology+%28Ecology-&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Terrestrial-Ecology+%28Ecology-&offset=8", "hreflang": "en-US"}], "numberMatched": 8, "numberReturned": 8, "distributedFeatures": [], "timeStamp": "2026-06-24T14:13:59.585332Z"}