{"type": "FeatureCollection", "features": [{"id": "10.1007/s00442-002-0884-x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-27T16:15:38Z", "type": "Journal Article", "created": "2003-02-13", "title": "Forest Carbon Balance Under Elevated Co2", "description": "Free-air CO2 enrichment (FACE) technology was used to expose a loblolly pine (Pinus taeda L.) forest to elevated atmospheric CO2 (ambient + 200\u00a0\u00b5l l-1). After 4\u00a0years, basal area of pine trees was 9.2% larger in elevated than in ambient CO2 plots. During the first 3\u00a0years the growth rate of pine was stimulated by ~26%. In the fourth year this stimulation declined to 23%. The average net ecosystem production (NEP) in the ambient plots was 428\u00a0gC\u00a0m-2\u00a0year-1, indicating that the forest was a net sink for atmospheric CO2. Elevated atmospheric CO2 stimulated NEP by 41%. This increase was primarily an increase in plant biomass increment (57%), and secondarily increased accumulation of carbon in the forest floor (35%) and fine root increment (8%). Net primary production (NPP) was stimulated by 27%, driven primarily by increases in the growth rate of the pines. Total heterotrophic respiration (R h) increased by 165%, but total autotrophic respiration (R a) was unaffected. Gross primary production was increased by 18%. The largest uncertainties in the carbon budget remain in separating belowground heterotrophic (soil microbes) and autotrophic (root) respiration. If applied to temperate forests globally, the increase in NEP that we measured would fix less than 10% of the anthropogenic CO2 projected to be released into the atmosphere in the year 2050. This may represent an upper limit because rising global temperatures, land disturbance, and heterotrophic decomposition of woody tissues will ultimately cause an increased flux of carbon back to the atmosphere.", "keywords": ["Carbon sequestration", "Global carbon cycle", "0106 biological sciences", "Free-air CO enrichment 2", "Carbon dioxide", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "Pinus taeda", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences"]}, "links": [{"href": "https://doi.org/10.1007/s00442-002-0884-x"}, {"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/s00442-002-0884-x", "name": "item", "description": "10.1007/s00442-002-0884-x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s00442-002-0884-x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2002-04-01T00:00:00Z"}}, {"id": "10.1046/j.1469-8137.2003.00911.x", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-27T16:19:39Z", "type": "Journal Article", "created": "2003-11-17", "title": "Fine-Root Respiration In A Loblolly Pine And Sweetgum Forest Growing In Elevated Co2", "description": "\u2022\u2002 The loss of carbon below-ground through respiration of fine roots may be modified by global change. Here we tested the hypothesis that a reduction in N concentration of tree fine-roots grown in an elevated atmospheric CO2 concentration would reduce maintenance respiration and that more energy would be used for root growth and N uptake. We partitioned total fine-root respiration (RT ) between maintenance (RM ), growth (RG ), and N uptake respiration (RN ) for loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) forests exposed to elevated CO2 . \u2022\u2002 A substantial increase in fine-root production contributed to a 151% increase in RG for loblolly pine in elevated CO2 . Root specific RM for pine was 24% lower under elevated CO2 but when extrapolated to the entire forest, no treatment effect could be detected. \u2022\u2002 R G (<\u00a010%) and RN (<\u00a03%) were small components of RM in both forests. Maintenance respiration was the vast majority of RT , and contributed 92% and 86% of these totals at the pine and sweetgum forests, respectively. \u2022\u2002 The hypothesis was rejected because the majority of fine-root respiration was used for maintenance and was not reduced by changes in root N concentration in elevated CO2 . Because of its large contribution to RT and total soil CO2 efflux, changes in RM caused by warming may greatly alter carbon losses from forests to the atmosphere.", "keywords": ["0106 biological sciences", "Temperate forest", "Sweetgum (Liquidambar styeaciflua)", "Growth respiration", "Loblolly pine (Pinus taeda)", "Maintenance respiration", "Nitrogen uptake respiration", "15. Life on land", "Free-air CO enrichment (FACE) 2", "01 natural sciences", "Annual fine-root respiration"]}, "links": [{"href": "https://doi.org/10.1046/j.1469-8137.2003.00911.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/New%20Phytologist", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1046/j.1469-8137.2003.00911.x", "name": "item", "description": "10.1046/j.1469-8137.2003.00911.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1046/j.1469-8137.2003.00911.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2003-11-17T00:00:00Z"}}, {"id": "10.1093/treephys/21.2-3.83", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-27T16:20:14Z", "type": "Journal Article", "created": "2012-01-20", "title": "Influence Of Elevated Co2 And Mycorrhizae On Nitrogen Acquisition: Contrasting Responses In Pinus Taeda And Liquidambar Styraciflua", "description": "An understanding of root system capacity to acquire nitrogen (N) is critical in assessing the long-term growth impact of rising atmospheric CO2 concentration ([CO2]) on trees and forest ecosystems. We examined the effects of mycorrhizal inoculation and elevated [CO2] on root ammonium (NH4+) and nitrate (NO3-) uptake capacity in sweetgum (Liquidambar styraciflua L.) and loblolly pine (Pinus taeda L.). Mycorrhizal treatments included inoculation of seedlings with the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck & Smith in sweetgum and the ectomycorrhizal (EM) fungus Laccaria bicolor (Maire) Orton in loblolly pine. These plants were then equally divided between ambient and elevated [CO2] treatments. After 6 months of treatment, root systems of both species exhibited a greater uptake capacity for NH4+ than for NO3-. In both species, mycorrhizal inoculation significantly increased uptake capacity for NO3-, but not for NH4+. In sweetgum, the mycorrhizal effect on NO3- and NH4+ uptake capacity depended on growth [C02]. Similarly, in loblolly pine, the mycorrhizal effect on NO3- uptake capacity depended on growth [CO2], but the effect on NH4+ uptake capacity did not. Mycorrhizal inoculation significantly enhanced root nitrate reductase activity (NRA) in both species, but elevated [CO2] increased root NRA only in sweetgum. Leaf NRA in sweetgum did not change significantly with mycorrhizal inoculation, but increased in response to [CO2]. Leaf NRA in loblolly pine was unaffected by either treatment. The results indicate that the mycorrhizal effect on specific root N uptake in these species depends on both the form of inorganic N and the mycorrhizal type. However, our data show that in addressing N status of plants under high [CO2], reliable prediction is possible only when information about other root system adjustments (e.g., biomass allocation to fine roots) is simultaneously considered.", "keywords": ["0106 biological sciences", "Nitrogen", "Basidiomycota", "Fungi", "Pinus taeda", "04 agricultural and veterinary sciences", "Carbon Dioxide", "15. Life on land", "Pinus", "Magnoliaceae", "Nitrate Reductase", "Plant Roots", "01 natural sciences", "Nitrate Reductases", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://doi.org/10.1093/treephys/21.2-3.83"}, {"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/21.2-3.83", "name": "item", "description": "10.1093/treephys/21.2-3.83", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/treephys/21.2-3.83"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2001-02-01T00:00:00Z"}}, {"id": "10.1093/treephys/tps051", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-27T16:20:16Z", "type": "Journal Article", "created": "2012-06-14", "title": "Effects Of Predicted Future And Current Atmospheric Temperature And [Co2] And High And Low Soil Moisture On Gas Exchange And Growth Of Pinus Taeda Seedlings At Cool And Warm Sites In The Species Range", "description": "Predicted future changes in air temperature and atmospheric CO(2) concentration ([CO(2)]), coupled with altered precipitation, are expected to substantially affect tree growth. Effects on growth may vary considerably across a species range, as temperatures vary from sub-optimal to supra-optimal for growth. We performed an experiment simultaneously at two locations in the current range of loblolly pine, a cool site and a warm site, to examine the effect of future climate conditions on growth of loblolly pine seedlings in contrasting regions of the species range. At both sites 1-year-old loblolly pine seedlings were grown in current (local ambient temperature and [CO(2)]) and predicted future atmospheric conditions (ambient +2 \u00b0C temperature and 700 \u03bcmol mol(-1) [CO(2)]). Additionally, high and low soil moisture treatments were applied within each atmospheric treatment at each site by altering the amount of water provided to the seedlings. Averaged across water treatments, photosynthesis (A(net)) was 31% greater at the cool site and 34% greater at the warm site in elevated temperature and [CO(2)] compared with ambient temperature. Biomass accumulation was also stimulated by 38% at the cool site and by 24% at the warm site in that treatment. These results suggest that a temperature increase of 2 \u00b0C coupled with an increase in [CO(2)] (predicted future climate) will create conditions favorable for growth of this species. Reduced soil moisture decreased growth in both current and predicted atmospheric conditions. Biomass accumulation and A(net) were reduced by \u223c39 and 17%, respectively, in the low water treatment. These results suggest that any benefit of future atmospheric conditions may be negated if soil moisture is reduced by altered precipitation patterns.", "keywords": ["0106 biological sciences", "Analysis of Variance", "Atmosphere", "Temperature", "Humidity", "Pinus taeda", "Carbon Dioxide", "15. Life on land", "01 natural sciences", "6. Clean water", "Soil", "Species Specificity", "Seedlings", "13. Climate action", "Plant Stomata", "Biomass", "Seasons", "Photosynthesis"]}, "links": [{"href": "https://doi.org/10.1093/treephys/tps051"}, {"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/tps051", "name": "item", "description": "10.1093/treephys/tps051", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/treephys/tps051"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2012-06-12T00:00:00Z"}}, {"id": "10.1111/j.1365-3040.2008.01869.x", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-06-27T16:20:53Z", "type": "Journal Article", "created": "2008-08-05", "title": "Fine-Root Respiration In A Loblolly Pine (Pinus Taedal.) Forest Exposed To Elevated Co2and N Fertilization", "description": "ABSTRACT<p>Forest ecosystems release large amounts of carbon to the atmosphere from fine\uffe2\uff80\uff90root respiration (Rr), but the control of this flux and its temperature sensitivity (Q10) are poorly understood. We attempted to: (1) identify the factors limiting this flux using additions of glucose and an electron transport uncoupler (carbonyl cyanide m\uffe2\uff80\uff90chlorophenylhydrazone); and (2) improve yearly estimates of Rr by directly measuring its Q10in situ using temperature\uffe2\uff80\uff90controlled cuvettes buried around intact, attached roots. The proximal limits of Rr of loblolly pine (Pinus taeda L.) trees exposed to free\uffe2\uff80\uff90air CO2 enrichment (FACE) and N fertilization were seasonally variable; enzyme capacity limited Rr in the winter, and a combination of substrate supply and adenylate availability limited Rr in summer months. The limiting factors of Rr were not affected by elevated CO2 or N fertilization. Elevated CO2 increased annual stand\uffe2\uff80\uff90level Rr by 34% whereas the combination of elevated CO2 and N fertilization reduced Rr by 40%. Measurements of in situ Rr with high temporal resolution detected diel patterns that were correlated with canopy photosynthesis with a lag of 1\uffe2\uff80\uff83d or less as measured by eddy covariance, indicating a dynamic link between canopy photosynthesis and root respiration. These results suggest that Rr is coupled to daily canopy photosynthesis and increases with carbon allocation below ground.</p>", "keywords": ["580", "0106 biological sciences", "Analysis of Variance", "Nitrates", "Atmosphere", "Nitrogen", "Cell Respiration", "Temperature", "Pinus taeda", "Carbon Dioxide", "15. Life on land", "Plant Roots", "01 natural sciences", "Carbon", "Trees", "Glucose", "Oxygen Consumption", "050101 - Ecological Impacts of Climate Change", "13. Climate action", "North Carolina", "Seasons", "Least-Squares Analysis", "Photosynthesis", "Fertilizers", "Ecosystem"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-3040.2008.01869.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Plant%2C%20Cell%20%26amp%3B%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1365-3040.2008.01869.x", "name": "item", "description": "10.1111/j.1365-3040.2008.01869.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-3040.2008.01869.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2008-10-06T00:00:00Z"}}, {"id": "10.1111/j.1461-0248.2010.01570.x", "type": "Feature", "geometry": null, "properties": {"license": "Closed Access", "updated": "2026-06-27T16:20:55Z", "type": "Journal Article", "created": "2010-12-22", "title": "Enhanced Root Exudation Induces Microbial Feedbacks To N Cycling In A Pine Forest Under Long-Term Co2 Fumigation", "description": "<p> Ecology Letters (2011) 14: 187\uffe2\uff80\uff93194</p>Abstract<p>The degree to which rising atmospheric CO2 will be offset by carbon (C) sequestration in forests depends in part on the capacity of trees and soil microbes to make physiological adjustments that can alleviate resource limitation. Here, we show for the first time that mature trees exposed to CO2 enrichment increase the release of soluble C from roots to soil, and that such increases are coupled to the accelerated turnover of nitrogen (N) pools in the rhizosphere. Over the course of 3\uffe2\uff80\uff83years, we measured in situ rates of root exudation from 420 intact loblolly pine (Pinus taeda L.) roots. Trees fumigated with elevated CO2 (200 p.p.m.v. over background) increased exudation rates (\uffce\uffbcg\uffe2\uff80\uff83C\uffe2\uff80\uff83cm\uffe2\uff88\uff921\uffe2\uff80\uff83root\uffe2\uff80\uff83h\uffe2\uff88\uff921) by 55% during the primary growing season, leading to a 50% annual increase in dissolved organic inputs to fumigated forest soils. These increases in root\uffe2\uff80\uff90derived C were positively correlated with microbial release of extracellular enzymes involved in breakdown of organic N (R2\uffe2\uff80\uff83=\uffe2\uff80\uff830.66; P\uffe2\uff80\uff83=\uffe2\uff80\uff830.006) in the rhizosphere, indicating that exudation stimulated microbial activity and accelerated the rate of soil organic matter (SOM) turnover. In support of this conclusion, trees exposed to both elevated CO2 and N fertilization did not increase exudation rates and had reduced enzyme activities in the rhizosphere. Collectively, our results provide field\uffe2\uff80\uff90based empirical support suggesting that sustained growth responses of forests to elevated CO2 in low fertility soils are maintained by enhanced rates of microbial activity and N cycling fuelled by inputs of root\uffe2\uff80\uff90derived C. To the extent that increases in exudation also stimulate SOM decomposition, such changes may prevent soil C accumulation in forest ecosystems.</p>", "keywords": ["0106 biological sciences", "Nitrogen", "Plant Exudates", "Pinus taeda", "04 agricultural and veterinary sciences", "15. Life on land", "Carbon Dioxide", "01 natural sciences", "Plant Roots", "Carbon", "Trees", "Soil", "13. Climate action", "Rhizosphere", "North Carolina", "0401 agriculture", " forestry", " and fisheries", "Soil Microbiology"]}, "links": [{"href": "https://doi.org/10.1111/j.1461-0248.2010.01570.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Ecology%20Letters", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1461-0248.2010.01570.x", "name": "item", "description": "10.1111/j.1461-0248.2010.01570.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1461-0248.2010.01570.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-12-22T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Pinus+taeda&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=Pinus+taeda&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=Pinus+taeda&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Pinus+taeda&offset=6", "hreflang": "en-US"}], "numberMatched": 6, "numberReturned": 6, "distributedFeatures": [], "timeStamp": "2026-06-27T17:33:32.471189Z"}