{"type": "FeatureCollection", "features": [{"id": "10.1007/s004420050619", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:14:50Z", "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": "10.1023/a:1004518730970", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:18:02Z", "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": "10.2307/2640985", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-27T16:21:20Z", "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=nitrification-&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=nitrification-&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=nitrification-&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=nitrification-&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-07-28T04:01:38.907142Z"}