{"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/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": "10.1023/a:1004518730970", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:18:07Z", "type": "Journal Article", "created": "2002-12-21", "description": "Elevated atmospheric CO2 has the potential to change below-ground nutrient cycling and thereby alter the soil-atmosphere exchange of biogenic trace gases. We measured fluxes of CH4 and N2O in trembling aspen (Populus tremuloides Michx.) stands grown in open-top chambers under ambient and twice-ambient CO2 concentrations crossed with \u2018high\u2019 and low soil-N conditions.", "keywords": ["measurement-", "nitrous-oxide", "flux-", "Vascular-Plants", "poplars-", "carbon-dioxide-enrichment", "photosynthesis-", "Nutrition-", "carbon-dioxide: atmospheric-concentration", "stand-growth", "nitrogen-cycle", "michigan-", "methane-: flux-", "soil-", "nitrogen-", "Populus-tremuloides [aspen-] (Salicaceae-)", "carbon-cycle", "methane-production", "soil-fertility", "Salicaceae-: Dicotyledones-", "populus-tremuloides", "cycling-", "Spermatophytes-", "Spermatophyta-", "Plantae-", "biological-activity-in-soil", "Climatology- (Environmental-Sciences)", "Angiosperms-", "Angiospermae-", "Plants-", "gases-", "oxidation-", "forest-soils", "methane-", "04 agricultural and veterinary sciences", "GLOBAL-ECOLOGY", "15. Life on land", "enzyme-activity", "gas-exchange", "nitrous-oxide: emission-", "soil-water", "13. Climate action", "denitrification-", "0401 agriculture", " forestry", " and fisheries", "soil-bacteria", "Dicots-", "efflux-"]}, "links": [{"href": "https://doi.org/10.1023/a:1004518730970"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%20and%20Soil", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1023/a:1004518730970", "name": "item", "description": "10.1023/a:1004518730970", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1023/a:1004518730970"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1999-02-01T00:00:00Z"}}, {"id": "10.1046/j.1365-2486.2001.00388.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:18:34Z", "type": "Journal Article", "created": "2003-03-11", "title": "Chemistry And Decomposition Of Litter From Populus Tremuloides Michaux Grown At Elevated Atmospheric Co2 And Varying N Availability", "description": "Summary<p>It has been hypothesized that greater production of total nonstructural carbohydrates (TNC) in foliage grown under elevated atmospheric carbon dioxide (CO2) will result in higher concentrations of defensive compounds in tree leaf litter, possibly leading to reduced rates of decomposition and nutrient cycling in forest ecosystems of the future. To evaluate the effects of elevated atmospheric CO2on litter chemistry and decomposition, we performed a 111 day laboratory incubation with leaf litter of trembling aspen (Populus tremuloidesMichaux) produced at 36\uffe2\uff80\uff83Pa and 56\uffe2\uff80\uff83Pa CO2and two levels of soil nitrogen (N) availability. Decomposition was quantified as microbially respired CO2and dissolved organic carbon (DOC) in soil solution, and concentrations of nonstructural carbohydrates, N, carbon (C), and condensed tannins were monitored throughout the incubation. Growth under elevated atmospheric CO2did not significantly affect initial litter concentrations of TNC, N, or condensed tannins. Rates of decomposition, measured as both microbially respired CO2and DOC did not differ between litter produced under ambient and elevated CO2. Total C lost from the samples was 38\uffe2\uff80\uff83mg\uffe2\uff80\uff83g\uffe2\uff88\uff921litter as respired CO2and 138\uffe2\uff80\uff83mg\uffe2\uff80\uff83g\uffe2\uff88\uff921litter as DOC, suggesting short\uffe2\uff80\uff90term pulses of dissolved C in soil solution are important components of the terrestrial C cycle. We conclude that litter chemistry and decomposition in trembling aspen are minimally affected by growth under higher concentrations of CO2.</p>", "keywords": ["Ecology and Evolutionary Biology", "carbohydrates", "Quaking aspen", "forest-soil", "litter-plant", "nitrogen", "nitrogen-", "Microlysimeter", "soil-chemistry", "cycling-", "populus-tremuloides", "Geology and Earth Sciences", "Soil Carbon", "Microbiology of soils", "Carbon cycle", "04 agricultural and veterinary sciences", "GLOBAL-ECOLOGY", "chemical-composition", "Organic-matter", "soil-solution", "nutrient-availability", "Tannin", "leaf-litter", "Science", "decomposition-", "Nutrient enrichment", "Carbohydrates", "carbohydrates-", "respiration-", "carbon-dioxide-enrichment", "Nitrogen in soil", "michigan-", "carbon sinks", "C", "Nutrient budget of forests", "Litter", "Populus tremuloides", "Global Change", "tannins-", "Decomposition", "forest-litter", "Foliage", "Carbon dioxide effects on forest litter", "Climatic changes", "15. Life on land", "carbon-nitrogen-ratio", "Forest litter decomposition", "N Ratio", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "microbial-activities", "nitrogen-content"]}, "links": [{"href": "https://doi.org/10.1046/j.1365-2486.2001.00388.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Global%20Change%20Biology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1046/j.1365-2486.2001.00388.x", "name": "item", "description": "10.1046/j.1365-2486.2001.00388.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1046/j.1365-2486.2001.00388.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2001-01-01T00:00:00Z"}}, {"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": "10.2307/2656979", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:21:18Z", "type": "Journal Article", "created": "2006-04-21", "title": "Genotypic Variation For Condensed Tannin Production In Trembling Aspen (Populs Tremuloides, Salicaceae) Under Elevated Co2 And In High- And Low-Fertility Soil", "description": "<p>The carbon/nutrient balance hypothesis suggests that leaf carbon to nitrogen ratios influence the synthesis of secondary compounds such as condensed tannins. We studied the effects of rising atmospheric carbon dioxide on carbon to nitrogen ratios and tannin production. Six genotypes of Populus tremuloides were grown under elevated and ambient CO2 partial pressure and high\uffe2\uff80\uff90 and low\uffe2\uff80\uff90fertility soil in field open\uffe2\uff80\uff90top chambers in northern lower Michigan, USA. During the second year of exposure, leaves were harvested three times (June, August, and September) and analyzed for condensed tannin concentration. The carbon/nutrient balance hypothesis was supported overall, with significantly greater leaf tannin concentration at high CO2 and low soil fertility compared to ambient CO2 and high soil fertility. However, some genotypes increased tannin concentration at elevated compared to ambient CO2, while others showed no CO2 response. Performance of lepidopteran leaf miner (Phyllonorycter tremuloidiella) larvae feeding on these plants varied across genotypes, CO2, and fertility treatments. These results suggest that with rising atmospheric CO2, plant secondary compound production may vary within species. This could have consequences for plant\uffe2\uff80\uff93herbivore and plant\uffe2\uff80\uff93microbe interactions and for the evolutionary response of this species to global climate change.</p>", "keywords": ["0106 biological sciences", "Salicaceae", "genotype", "plant\u2013herbivore interaction", "Phyllonorycter-tremuloidiella", "Quaking aspen", "01 natural sciences", "plant-composition", "tannin", "nitrogen-", "carbon-dioxide: elevation-", "124-38-9: CARBON DIOXIDE", "Spermatophytes-", "Spermatophyta-", "genotypic-variation", "Population-Genetics (Population-Studies)", "2. Zero hunger", "carbon-", "Climatology- (Environmental-Sciences)", "Angiosperms-", "Angiospermae-", "Plants-", "GLOBAL-ECOLOGY", "Populus-tremuloides", "plant-pests", "climate-change", "genetic-variation", "forest-trees", "condensed tannins", "Nitrogen", "Science", "Vascular-Plants", "carbon-dioxide-enrichment", "Nutrition-", "genotypes-", "Phyllonorycter tremuloidiella", "Populus-tremuloides [trembling-aspen] (Salicaceae-)", "soil-fertility", "Populus tremuloides", "Salicaceae-: Dicotyledones-", "Biology", "Plantae-", "global change", "tannins-", "condensed-tannin: production-", "foliage-", "forest-pests", "Tannic acid", "Metabolism-", "Botany", "carbon dioxide", "forest-soils", "15. Life on land", "Carbon", "climate-", "Carbon dioxide", "13. Climate action", "Dicots-", "insect-pests"], "contacts": [{"organization": "Donald R. Zak, Jennifer L Mansfield, Kurt S. Pregitzer, Kurt S. Pregitzer, Peter S. Curtis, Peter S. Curtis,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.2307/2656979"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/American%20Journal%20of%20Botany", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2307/2656979", "name": "item", "description": "10.2307/2656979", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2307/2656979"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1999-08-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=carbon-dioxide-enrichment&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=carbon-dioxide-enrichment&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=carbon-dioxide-enrichment&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=carbon-dioxide-enrichment&offset=6", "hreflang": "en-US"}], "numberMatched": 6, "numberReturned": 6, "distributedFeatures": [], "timeStamp": "2026-06-24T14:14:05.703456Z"}