Forest ecosystems are important sinks for rising concentrations of atmospheric CO 2 . In previous research, we showed that net primary production (NPP) increased by 23 \uffc2\uffb1 2% when four experimental forests were grown under atmospheric concentrations of CO 2 predicted for the latter half of this century. Because nitrogen (N) availability commonly limits forest productivity, some combination of increased N uptake from the soil and more efficient use of the N already assimilated by trees is necessary to sustain the high rates of forest NPP under free-air CO 2 enrichment (FACE). In this study, experimental evidence demonstrates that the uptake of N increased under elevated CO 2 at the Rhinelander, Duke, and Oak Ridge National Laboratory FACE sites, yet fertilization studies at the Duke and Oak Ridge National Laboratory FACE sites showed that tree growth and forest NPP were strongly limited by N availability. By contrast, nitrogen-use efficiency increased under elevated CO 2 at the POP-EUROFACE site, where fertilization studies showed that N was not limiting to tree growth. Some combination of increasing fine root production, increased rates of soil organic matter decomposition, and increased allocation of carbon (C) to mycorrhizal fungi is likely to account for greater N uptake under elevated CO 2 . Regardless of the specific mechanism, this analysis shows that the larger quantities of C entering the below-ground system under elevated CO 2 result in greater N uptake, even in N-limited ecosystems. Biogeochemical models must be reformulated to allow C transfers below ground that result in additional N uptake under elevated CO 2 .
", "keywords": ["rotation poplar plantation", "0106 biological sciences", "Nitrogen", "Climate", "atmospheric carbon-dioxide", "enrichment face", "organic nitrogen", "Biological Transport", "deciduous forest", "04 agricultural and veterinary sciences", "Carbon Dioxide", "15. Life on land", "01 natural sciences", "Trees", "Kinetics", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "populus-tremuloides", "community composition", "soil-n availability", "fine-root production", "Ecosystem", "ecosystem responses"]}, "links": [{"href": "https://doi.org/10.1073/pnas.0706518104"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Proceedings%20of%20the%20National%20Academy%20of%20Sciences", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1073/pnas.0706518104", "name": "item", "description": "10.1073/pnas.0706518104", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1073/pnas.0706518104"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2007-08-28T00:00:00Z"}}, {"id": "10.1371/journal.pone.0070224", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:20:14Z", "type": "Journal Article", "created": "2013-07-16", "title": "Effects Of Added Organic Matter And Water On Soil Carbon Sequestration In An Arid Region", "description": "Open AccessEn general, se predice que el calentamiento global estimular\u00e1 la producci\u00f3n primaria y conducir\u00e1 a m\u00e1s aportes de carbono (C) al suelo. Sin embargo, muchos estudios han encontrado que el suelo C no necesariamente aumenta con el aumento de la entrada de basura vegetal. Las precipitaciones han aumentado en Asia central \u00e1rida y se prev\u00e9 que aumenten m\u00e1s, por lo que probamos los efectos de la adici\u00f3n de materia org\u00e1nica fresca (FOM) y agua en el secuestro de C del suelo en una regi\u00f3n \u00e1rida en el noroeste de China. Los resultados sugirieron que el FOM a\u00f1adido se descompuso r\u00e1pidamente y tuvo efectos menores en el dep\u00f3sito de carbono org\u00e1nico del suelo (SOC) a una profundidad de 30 cm. Tanto la FOM como la adici\u00f3n de agua tuvieron efectos significativos en la biomasa microbiana del suelo. La biomasa microbiana del suelo aument\u00f3 con la adici\u00f3n de FOM, alcanz\u00f3 un m\u00e1ximo y luego disminuy\u00f3 a medida que la FOM se descompon\u00eda. El FOM tuvo un efecto estimulante m\u00e1s significativo sobre la biomasa microbiana con la adici\u00f3n de agua. Bajo los rangos de humedad del suelo utilizados en este experimento (21.0% -29.7%), el aporte de FOM fue m\u00e1s importante que la adici\u00f3n de agua en el proceso de mineralizaci\u00f3n del suelo C. Concluimos que la entrada de FOM a corto plazo en el suelo subterr\u00e1neo y la adici\u00f3n de agua no afectan la piscina de SOC en los matorrales en una regi\u00f3n \u00e1rida.", "keywords": ["Carbon sequestration", "550", "Arid", "Growth", "630", "Agricultural and Biological Sciences", "Soil", "Agricultural soil science", "Tropical forest", "Soil water", "Carbon fibers", "Biomass", "Land-use", "2. Zero hunger", "Analysis of Land Cover and Ecosystems", "Ecology", "Respiration", "Q", "Temperature", "R", "Soil Chemical Properties", "Life Sciences", "Composite number", "04 agricultural and veterinary sciences", "Soil carbon", "6. Clean water", "Chemistry", "Physical Sciences", "Environmental chemistry", "Medicine", "Organic matter", "Research Article", "Composite material", "Carbon Sequestration", "China", "Desert shrubs", "Science", "Soil Science", "Ecosystems", "Environmental science", "Meta-analysis in Ecology and Agriculture Research", "Organic Matter Dynamics", "Climate-change", "Soil Carbon Sequestration", "Biology", "Ecology", " Evolution", " Behavior and Systematics", "Soil science", "Soil organic matter", "Soil Fertility", "Water", "Soil Properties", "15. Life on land", "Soil biodiversity", "Materials science", "Microbial activity", "Carbon dioxide", "13. Climate action", "FOS: Biological sciences", "Environmental Science", "Fine-root", "0401 agriculture", " forestry", " and fisheries", "Soil Carbon Dynamics and Nutrient Cycling in Ecosystems", "CO2 flux"]}, "links": [{"href": "https://doi.org/10.1371/journal.pone.0070224"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/PLoS%20ONE", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1371/journal.pone.0070224", "name": "item", "description": "10.1371/journal.pone.0070224", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1371/journal.pone.0070224"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2013-07-16T00:00:00Z"}}, {"id": "10.2136/sssaj2006.0069", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:21:06Z", "type": "Journal Article", "created": "2007-06-30", "description": "We resampled one of the earliest replicated experimental sites used to investigate the impacts of native tropical tree species on soil properties, to examine longer term effects to 1\uffe2\uff80\uff90m depth. The mono\uffe2\uff80\uff90dominant stands, established in abandoned pasture in 1988 at La Selva Biological Station, Costa Rica, contained six species, including one exotic, Pinus patula ssp. tecunumanii (Eguiluz & J.P. Perry) Styles, and five native species: Pentaclethra macroloba (Willd.) Ktze (N2\uffe2\uff80\uff90fixing); Hyeronima alchorneoides Allemao; Virola koschnyi Warb.; Vochysia ferruginea Mart.; and Vochysia guatemalensis J.D. Smith. Soil organic carbon (SOC) differed significantly among species in the surface (0\uffe2\uff80\uff9315\uffe2\uff80\uff90cm) layer, ranging from 44.5 to 55.1 g kg\uffe2\uff88\uff921, compared with 46.6 and 50.3 g kg\uffe2\uff88\uff921 in abandoned pasture and mature forest, respectively. The change in surface SOC over 15 yr ranged from \uffe2\uff88\uff920.03 to 0.66 Mg C ha\uffe2\uff88\uff921 yr\uffe2\uff88\uff921 The species differed in the quantity and chemical composition of their detrital production. Soil organic C was significantly correlated with fine\uffe2\uff80\uff90root growth, but not with aboveground detrital inputs. Soil organic C increased with potential C mineralization on a grams of C basis, indicating that species influenced both the quality and quantity of SOC. Contrary to expectations, SOC declined with increasing fine\uffe2\uff80\uff90root lignin concentrations, indicating that lignin\uffe2\uff80\uff90derived C did not dominate refractory SOC pools. We hypothesize that differences among species in the capacity to increase SOC stocks involved fine\uffe2\uff80\uff90root traits that promoted soil microbial turnover and, thus, greater production of recalcitrant, microbial\uffe2\uff80\uff90derived C fractions.
", "keywords": ["soil organic carbon", "580", "Ecology and Evolutionary Biology", "Organic Chemistry", "Natural Resources Management and Policy", "lignin", "0401 agriculture", " forestry", " and fisheries", "Forest Biology", "tropical tree", "04 agricultural and veterinary sciences", "15. Life on land", "630", "fine-root growth"]}, "links": [{"href": "https://doi.org/10.2136/sssaj2006.0069"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Soil%20Science%20Society%20of%20America%20Journal", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.2136/sssaj2006.0069", "name": "item", "description": "10.2136/sssaj2006.0069", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.2136/sssaj2006.0069"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2007-07-01T00:00:00Z"}}, {"id": "10.5061/dryad.b8gtht7kg", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:22:15Z", "type": "Dataset", "created": "2023-11-27", "title": "Data from: The effect of drainage on the fine root biomass, production, and turnover in hemiboreal old-growth forests on organic soils", "description": "Open Access# The effect of drainage on the fine root biomass, production, and turnover in hemiboreal old-growth forests on organic soils ## #GWL _temp.csv This file contains data on study site soil temperature and groundwater level ## Description of the data and file structure Date - Sampling date Site - Study object name FT - Forest type (ND - not drained, KS - drained) Year - Sampling year Cycle - Sampling campaign number in specific sampling year PL - Sample plot of study object (1-3) Groundwater - Groundwater level depth from the ground surface, cm Soil_temp_10cm - Soil temperature at 10cm depth, \u00b0C Soil_temp_20cm - Soil temperature at 20cm depth, \u00b0C Soil_temp_30cm - Soil temperature at 30cm depth, \u00b0C Soil_temp_40cm - Soil temperature at 40cm depth, \u00b0C --- ## #Soil _data.csv This file contains data of study site soil analysis ## Description of the data and file structure Year - Sampling year Date - Sampling date Place - Study objects name FT - Forest type (ND - not drained, KS - drained) Soil_cm - Soil sampling depth Repetition - Number of repetitions (1-2) Soil_density - Soil bulk density, g/kg C_g_kg - Carbon content in sample, g/kg N_g_kg - Nitrogen content in sample, g/kg C_N - Carbon and Nitrogen ratio in sample pHKCl - Soil pH Pkop_g_kg - Total Phosphorus content in sample, g/kg K_mg_kg - Total Potassium content in sample, g/kg Ca_mg_kg - Total Calcium content in sample, g/kg Mg_mg_kg - Total Magnesium content in sample, g/kg --- ## #FRP _data.csv This file contains data of study site fine-root biomass, stand taxation indices and soil analysis per study object sample plot and fine-root fraction ## Description of the data and file structure ID - Study site ID Place - Study object name FT - Forest type (ND - not drained, KS - drained) Cycle - Sampling campaign number in specific sampling year PL - Sampling plot number Fraction - Fine-root fraction by name FRB - Fine-root biomass, t/ha FRB_BA - Fine-root biomass per basal area Pine_yield - Pine tree growing stock, m3/ha N_ha - Tree count per ha Spruce_yield - Spruce tree growing stock, m3/ha Shrub_percentage - Percentage of shrubs in ground vegetation Herb_percentage - Percentage of herbacous plants in ground vegetation D - Diameter at breast height, cm G_m2ha - basal area, m2/ha CN - soil C and N ratio pHKCl - soil pH CgKg - Soil Carbon (C) content, g/kg NgKg - Soil Nitrogen (N) content, g/kg --- ## #Mean _FRB _pa _frakcijam.csv This file contains data of study site average fine-root biomass per study object sample plot and fine-root fraction ## Description of the data and file structure ID - Study site ID Object - Study object name FT - Forest type (ND - not drained, KS - drained) PL - Sampling campaign number in specific sampling year Fraction - Fine-root fraction by name AvgFRB - Average fine-root biomass, t/ha FRB_BA - Average fine-root biomass per basal area Sd - Standarddeviation of average fine-root biomass n - sampling campaign count se - Standarderror of average fine-root biomass Basal_Area - basal area, m2/ha --- ## #PCA _analize.csv This file contains data of study site for PCA analysis containing fine-root biomass, production and turnover, taxation indices and soil data per sample plot ## Description of the data and file structure ID - Study site ID Site - Study object name FT - Forest type (ND - not drained, KS - drained) Plot - - Sampling plot number SP_FRB - Scots pine fine-root biomass, t/ha SP_FRP - Scots pine fine-root production, t/ha/yr SP_T - Scots pine fine-root turnover, t/yr PineFRB_BA - Scots pine fine-root biomass per stand basal area, t/m2 NS_FRB - Norway spruce fine-root biomass, t/ha NS_FRP - Norway spruce fine-root production, t/ha/yr NS_T - Norway spruce fine-root turnover, t/yr SpurceFRB_BA - Norway spruce fine-root biomass per stand basal area, t/m2 H_FRB - Herb fine-root biomass, t/ha DS_FRB - Dwarf shrub fine-root biomass, t/ha DS_FRP - Dwarf shub fine-root production, t/ha/yr TOT_FRP - Total fine-root production, t/ha/yr SP_dFRB - Scots pine fine-root necromass, t/ha NS_dFRB - Norway spruce fine-root necromass, t/ha C_g_kg - Soil Carbon content, g/kg N_g_kg - Soil Nitrogen content, g/kg C_N - Carbon and Nitrogen ratio in sample pHKCl - Soil pH Pkop - Total soil Phosphorous content, g/kg Aug_bl - Soil bulk density, g/kg Dg - Diameter at breast height, cm Hg - Tree height, m G - basal area, m2/ha Yield_1st - First layer tree growing stock, m3/ha N_ha - Tree count per ha SP_m3ha - Pine tree growing stock, m3/ha NS_m3ha - Spruce tree growing stock, m3/ha DS_m2 - Dwarf shrub coverage, m2 H_m2 - Herbacous plant coverage, m2 --- ## #R _frb.csv This file contains raw data of fine-root samples per site, sample plot, fraction and sampling depth ## Description of the data and file structure Place - Study objects name ID - Sample ID CM - Sampling depth, cm Fraction - Fine-root fraction ID Species - Fine-root fraction by name Status - Fine-root status (living/dead) Weight_g - Sample weight FT - Forest type (ND - not drained, KS - drained) FRB - Fine-root biomass, t/ja Cycle - Sampling campaign number ID_cycle - Sample ID per sampling cycle PL - Sampling plot number Place_pl_cm_cycle - ID containing study object name, forest type, sampling depth and sampling cycle ## Sharing/Access information Correspondence: Valters Samariks, Latvian State Forest Research Institute 'Silava', Latvia, Salaspils, R\u012bgas street 111, LV-2169, Email: ; ORCID: 0000-0001-9953-0455 ## Code Code for this data file is available in Fine_root_calculations_DRYAD.R", "keywords": ["hemiboreal", "Fine-root production", "forest drainage", "Peat", "fine-root turnover", "FOS: Agriculture", " forestry", " and fisheries"], "contacts": [{"organization": "Samariks, Valters", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.5061/dryad.b8gtht7kg"}, {"rel": "self", "type": "application/geo+json", "title": "10.5061/dryad.b8gtht7kg", "name": "item", "description": "10.5061/dryad.b8gtht7kg", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5061/dryad.b8gtht7kg"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-20T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=fine-root&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=fine-root&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=fine-root&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=fine-root&offset=6", "hreflang": "en-US"}], "numberMatched": 6, "numberReturned": 6, "distributedFeatures": [], "timeStamp": "2026-06-24T14:08:16.640840Z"}