{"type": "FeatureCollection", "features": [{"id": "10.1016/j.agee.2017.06.003", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:15:29Z", "type": "Journal Article", "created": "2017-06-10", "title": "Effects Of Shade-Tree Species And Spacing On Soil And Leaf Nutrient Concentrations In Cocoa Plantations At 8 Years After Establishment", "description": "Intercropping in agroforestry systems improves ecosystem services. Appropriate species compositions and spacing regimes are critical to achieve ecosystem benefits and improve yields of all the component crops. Cocoa (Theobroma cacao) is an important cash crop globally but it requires shade for survival and growth. However, the effects of shade-tree species composition and spacing regime on nutrient cycling in cocoa plantations are not well understood. This study investigated the effects of shade tree species and spacing regimes on soil and plant nutrient availability at 8 years after plantation establishment in Papua New Guinea. Three cocoa intercropping systems were established in which T. cacao was planted with either a non-legume timber tree, Canarium indicum, or a legume non-timber tree, Gliricidia sepium. The shade-tree spacing regimes included either 8 m \u00d7 16 m or 8 m \u00d7 8 m in the Theobroma + Canarium plantations. There was an ongoing thinning regime in the Theobroma + Gliricidia plantation, with a final shade-tree spacing of 12 m \u00d7 12 m. Soil total carbon (TC) and total nitrogen (TN) were significantly higher in the Theobroma + Gliricidia plantation with 12 m \u00d7 12 m spacing and the Theobroma + Canarium plantation with 8 m \u00d7 16 m spacing than in the Theobroma + Canarium plantation with 8 m \u00d7 8 m spacing. Foliar TN and P were correlated with soil TN and P, respectively, whereas no correlation was detected between soil and leaf K concentrations. Foliar TN, P and K were under ideal concentrations for T. cacao in all of the plantations. The Theobroma + Gliricidia plantation had higher soil water extractable phosphorus (P) than the two Theobroma + Canarium plantations, probably due to frequent pruning of the G. sepium trees. Foliar C isotope composition (\u03b413C) of T. cacao suggested that T. cacao close to G. sepium or close to C. indicum with spacing of 8 m \u00d7 16 m and 8 m \u00d7 8 m had similar light interception. However, increased C. indicum spacing increased the light interception of T. cacao trees that were not planted next to C. indicum. This study indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T. cacao. However, our study indicated all three plantations required fertilisation and better nutrient management.", "keywords": ["571", "stable isotopes", "FoR 16 (Studies in Human Society)", "Canarium indicum", "Soil fertility", "Gliricidia sepium", "333", "630", "Papua New Guinea", "veterinary and food sciences", "Stable isotopes", "2. Zero hunger", "Field organic and low chemical input horticulture", "Agricultural", "Science & Technology", "Multidisciplinary", "Ecology", "soil fertility", "FoR 07 (Agricultural and Veterinary Sciences)", "Human society", "Agriculture", "04 agricultural and veterinary sciences", "15. Life on land", "Environmental sciences", "260516 Tropical fruit", "gliricidia sepium", "Intercropping", "070501 Agroforestry", "0401 agriculture", " forestry", " and fisheries", "FoR 05 (Environmental Sciences)", "intercropping", "Life Sciences & Biomedicine"]}, "links": [{"href": "https://doi.org/10.1016/j.agee.2017.06.003"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agriculture%2C%20Ecosystems%20%26amp%3B%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.agee.2017.06.003", "name": "item", "description": "10.1016/j.agee.2017.06.003", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.agee.2017.06.003"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-08-01T00:00:00Z"}}, {"id": "10.1007/s00468-008-0293-9", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:14:33Z", "type": "Journal Article", "created": "2008-12-12", "title": "Nitrogen Availability Patterns In White-Sand Vegetations Of Central Brazilian Amazon", "description": "Addressing spatial variability in nitrogen (N) availability in the Central Brazilian Amazon, we hypothesized that N availability varies among white-sand vegetation types (campina and campinarana) and lowland tropical forests (dense terra-firme forests) in the Central Brazilian Amazon, under the same climate conditions. Accordingly, we measured soil and foliar N concentration and N isotope ratios (\u03b415N) throughout the campina-campinarana transect and compared to published dense terra-firme forest results. There were no differences between white-sand vegetation types in regard to soil N concentration, C:N ratio and \u03b415N across the transect. Both white-sand vegetation types showed very low foliar N concentrations and elevated foliar C:N ratios, and no significant difference between site types was observed. Foliar \u03b415N was depleted, varying from \u22129.6 to 1.6\u2030 in the white-sand vegetations. The legume Aldina heterophylla had the highest average \u03b415N values (\u22121.5\u2030) as well as the highest foliar N concentration (2.1%) while the non-legume species had more depleted \u03b415N values and the average foliar N concentrations varied from 0.9 to 1.5% among them. Despite the high variation in foliar \u03b415N among plants, a significant and gradual 15N-enrichment in foliar isotopic signatures throughout the campina\u2013campinarana transect was observed. Individual plants growing in the campinarana were significantly enriched in 15N compared to those in campina. In the white-sand N-limited ecosystems, the differentiation of N use seems to be a major cause of variations observed in foliar \u03b415N values throughout the campina\u2013campinarana transect.", "keywords": ["0106 biological sciences", "Concentration", "Vegetation", "Concentration (process)", "Nitrogen", "Nitrogen Availability", "Forestry", "04 agricultural and veterinary sciences", "Plants", "15. Life on land", "01 natural sciences", "Ecosystems", "Aldina Heterophylla", "Campinarana", "Soil", "Isotopes", "Sand", "Soils", "0401 agriculture", " forestry", " and fisheries", "Campina", "White-sand Vegetation", "Nitrogen Stable Isotopes"]}, "links": [{"href": "https://doi.org/10.1007/s00468-008-0293-9"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Trees", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s00468-008-0293-9", "name": "item", "description": "10.1007/s00468-008-0293-9", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s00468-008-0293-9"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2008-12-13T00:00:00Z"}}, {"id": "10.1007/s10021-009-9252-6", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:14:36Z", "type": "Journal Article", "created": "2009-05-04", "title": "Sheep Grazing Decreases Organic Carbon And Nitrogen Pools In The Patagonian Steppe: Combination Of Direct And Indirect Effects", "description": "We explored the net effects of grazing on soil C and N pools in a Patagonian shrub\u2013grass steppe (temperate South America). Net effects result from the combination of direct impacts of grazing on biogeochemical characteristics of microsites with indirect effects on relative cover of vegetated and unvegetated microsites. Within five independent areas, we sampled surface soils in sites subjected to three grazing intensities: (1) ungrazed sites inside grazing exclosures, (2) moderately grazed sites adjacent to them, and (3) intensely grazed sites within the same paddock. Grazing significantly reduced soil C and N pools, although this pattern was clearest in intensely grazed sites. This net effect was due to the combination of a direct reduction of soil N content in bare soil patches, and indirect effects mediated by the increase of the cover of bare soil microsites, with lower C and N content than either grass or shrub microsites. This increase in bare soil cover was accompanied by a reduction in cover of preferred grass species and standing dead material. Finally, stable isotope signatures varied significantly among grazed and ungrazed sites, with \u03b415N and \u03b413C significantly depleted in intensely grazed sites, suggesting reduced mineralization with increased grazing intensity. In the Patagonian steppe, grazing appears to exert a negative effect on soil C and N cycles; sound management practices must incorporate the importance of species shifts within life form, and the critical role of standing dead material in maintaining soil C and N stocks and biogeochemical processes.", "keywords": ["0106 biological sciences", "2. Zero hunger", "ARGENTINA", "SEMIARID ECOSYSTEMS", "STABLE ISOTOPES", "DESERTIFICATION", "\u039413C", "SHRUB-GRASS STEPPE", "04 agricultural and veterinary sciences", "15. Life on land", "BIOGEOCHEMISTRY", "Δ13C", "01 natural sciences", "LIFE FORMS", "https://purl.org/becyt/ford/4.5", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "https://purl.org/becyt/ford/4", "\u03b415N"]}, "links": [{"href": "https://doi.org/10.1007/s10021-009-9252-6"}, {"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/s10021-009-9252-6", "name": "item", "description": "10.1007/s10021-009-9252-6", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10021-009-9252-6"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2009-05-05T00:00:00Z"}}, {"id": "10.1016/j.agee.2015.10.017", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:15:27Z", "type": "Journal Article", "created": "2015-11-10", "title": "Land Use Changes Affecting Soil Organic Carbon Storage Along A Mangrove Swamp Rice Chronosequence In The Cacheu And Oio Regions (Northern Guinea-Bissau)", "description": "Abstract Guinea-Bissau has the largest area of mangrove swamp rice, an important cropping system that significantly contribute to the food security of the nation. Attempts to reclaim mangrove swamps for rice growing have shown the importance of a greater knowledge on the effects of land use change on soil properties and soil carbon storage. To address this problem, a study was undertaken within Cacheur and Oio regions in Northern Guinea-Bissau, along the following chronosequence: mangrove, rice and abandoned fields. Changes in C/N ratio, \u03b4 13 C and \u03b4 15 N values were used to study the dynamics of C 3 plant-derived and marine-derived carbon (C) in order to analyze the origin of soil organic matter (SOM) and estimate the impact of marine contribution to SOC. Isotopic signatures within the mangrove swamp rice soils suggested the inwelling of marine derived C. SOC stock was estimated in 0\u201310, 0\u201320, 0\u201340 and 0\u201380\u00a0cm soil layers using fixed soil depth (FD) and fixed soil mass (FM) approaches. The significantly highest values were found in mangrove soils and the lowest in the abandoned fields for both sites, while no significant differences were recorded for the topsoil (0\u201310\u00a0cm) between mangrove and rice fields. The results of this study revealed that conversion of mangrove to rice cropping has technical potential of SOC sequestration in the upper part of the soil (0\u201340\u00a0cm). On the other hand, the abandonment of the fields caused decreases in carbon storage along the whole soil depth. These findings may have important implications for national forest carbon monitoring systems and regional level reducing emission from deforestation and forest degradation (REDD+) strategies.", "keywords": ["Land-use change; Mangrove; Paddy soils; Soil carbon stock; Stable isotopes", "2. Zero hunger", "Soil carbon stock", "13. Climate action", "Land-use change", "Paddy soils", "15. Life on land", "Mangrove", "01 natural sciences", "6. Clean water", "Stable isotopes", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.agee.2015.10.017"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Agriculture%2C%20Ecosystems%20%26amp%3B%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.agee.2015.10.017", "name": "item", "description": "10.1016/j.agee.2015.10.017", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.agee.2015.10.017"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-01-01T00:00:00Z"}}, {"id": "10.1007/s11104-016-3052-5", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:15:02Z", "type": "Journal Article", "created": "2016-09-10", "title": "Effects Of Forest Thinning On Soil-Plant Carbon And Nitrogen Dynamics", "description": "Corymbia spp. (previously included in the genus Eucalyptus) are common species in sub/tropical Australia and produce high quality timber and round logs. Thinning of native forests helps to preserve native tree species and is more sustainable than replacing native forest stands with mono-species plantations to produce timber. This study aimed to explore the effects of native forest thinning on soil-plant carbon (C) and nitrogen (N) dynamics in two experimental sites, Esk (5\u00a0years post-thinning) and Herberton (7\u00a0years post-thinning), situated in Queensland, Australia. The two sites had different thinning regimes. The final stocking rates varied between 75 and 200 stems ha\u22121 at Esk and between 250 and 400 stems ha\u22121 at Herberton. The thinned plots were compared to un-thinned plots. Soil samples were collected to measure labile C and N. Leaf samples were collected from C. variegata and C. citriodora in Esk and Herberton respectively. Thinning did not change soil total C, total N, \u03b415N and inorganic N at either Esk or Herberton. However, at Esk, intensive thinning resulted in decreases in water soluble total N (WSTN). Foliar \u03b413C did not vary with respect to thinning whereas foliar \u03b415N values were more enriched in thinned areas than those of un-thinned plots. The stepwise linear regression indicated that both foliar total N and \u03b415N were explained mainly by soil TN and WSTN. Thinning did not change soil C and N most likely due to the retention of thinned materials on site and their incorporation into soil. Foliar \u03b413C was not thinning-dependent due to homeostatic maintenance of the ratio of intercellular to ambient CO2 concentrations during photosynthesis. In our study, soil N was not a limiting factor for foliar N, however, foliar N was mainly driven by WSTN which may foreshadow a possible N limitation in severely thinned plots in the long term. We conclude that forest thinning does not decrease soil C and N availability in native Corymbia forests for several years post-thinning if the thinned materials are retained on site.", "keywords": ["570", "Corymbia spp", "Inorganic nitrogen", "stable isotopes", "veterinary and food sciences", "eucalyptus spp", "Other environmental sciences not elsewhere classified", "FoR 06 (Biological Sciences)", "Stable isotopes", "Farm forestry", "580", "Agricultural", "farm forestry", "FoR 07 (Agricultural and Veterinary Sciences)", "inorganic nitrogen", "04 agricultural and veterinary sciences", "15. Life on land", "corymbia spp", "Environmental sciences", "Biological sciences", "Eucalyptus spp", "070501 Agroforestry", "Water soluble total N and C", "0401 agriculture", " forestry", " and fisheries", "water soluble total N and C", "FoR 05 (Environmental Sciences)"]}, "links": [{"href": "https://doi.org/10.1007/s11104-016-3052-5"}, {"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": "10.1007/s11104-016-3052-5", "name": "item", "description": "10.1007/s11104-016-3052-5", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11104-016-3052-5"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-09-10T00:00:00Z"}}, {"id": "10.1016/j.apsoil.2009.03.003", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:15:40Z", "type": "Journal Article", "created": "2009-04-30", "title": "Soil Priming By Sugar And Leaf-Litter Substrates: A Link To Microbial Groups", "description": "The impact of elevated CO2 on leaf-litter and root exudate production may alter soil carbon storage capacities for the future. In particular when so-called \u2018priming effects\u2019, the counterintuitive loss of soil carbon following input of organic carbon substrates, are taken into consideration. Here we investigate the dynamics of priming effects and ask whether the source of primed carbon is microbial biomass or soil organic matter and whether specific microbial groups, as identified by phospholipid fatty acid (PLFA) biomarkers, may be important in causing them. We measured \u03b413C within soil CO2 efflux and PLFA biomarkers following C3 soil priming effects caused by additions of C4 sugar-cane sucrose and maize (Zea mays L.) leaf-litter chopped and ground. All additions caused an initial pulse of priming effect CO2 and a later pulse of substrate-derived CO2, showing that priming effects can be induced rapidly following changes in substrate supply. Priming effects persisted over 32 days and led to a loss of soil carbon, with an increase in soil carbon decomposition of 169% following sucrose addition, 44% following chopped maize and 67% following ground maize additions. An increased concentration of soil-derived carbon within specific PLFA biomarkers provided evidence that a source of the primed carbon was soil organic matter. Certain Gram negative bacteria, identified by PLFA biomarkers (16:1\u03c95, 16:1\u03c97), showed increased uptake of soil carbon for both sucrose and maize treatments and may be directly linked to priming effects. Our study provides evidence that substrate carbon inputs to soil induce rapid changes in specific microbial groups, which in turn increase soil carbon metabolism.", "keywords": ["priming effect", "2. Zero hunger", "decomposition", "leaf-litter", "13. Climate action", "PLFA", "stable isotopes", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "soil carbon", "15. Life on land", "6. Clean water"], "contacts": [{"organization": "Nottingham, Andrew T., Griffiths, Howard, Chamberlain, Paul M., Stott, Andrew W., Tanner, Edmund V. J.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1016/j.apsoil.2009.03.003"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Applied%20Soil%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.apsoil.2009.03.003", "name": "item", "description": "10.1016/j.apsoil.2009.03.003", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.apsoil.2009.03.003"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2009-07-01T00:00:00Z"}}, {"id": "10.1016/j.chemgeo.2019.119279", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:15:52Z", "type": "Journal Article", "created": "2019-08-15", "title": "Volatile loss under a diffusion-limited regime in tektites: Evidence from tin stable isotopes", "description": "Abstract Tektites are glasses derived from near-surface continental crustal rocks that were molten and ejected from the Earth's surface during hypervelocity meteorite impacts. They are among the driest terrestrial samples, although the exact mechanism of water loss and the behaviour of other volatile species during these processes are debated. Based on the difference in magnitude of the Cu and Zn isotopic fractionations in tektites, and the difference of diffusivity between these elements, it was suggested that volatile loss was diffusion-limited. Tin is potentially well suited to testing this model, as it has a lower diffusivity in silicate melts than both Cu and Zn, but a similar volatility to Zn. Here, we analysed the Sn stable isotopic composition in a suite of seven tektites, representing three of the four known tektite strewn fields, and for which Zn and Cu isotopes were previously reported. Tin is enriched in the heavier isotopes (\u22652.5\u2030 on the 122Sn/118Sn ratio) in tektites, correlated with the degree of Sn elemental depletion in their respective samples as well as with Cu and Zn isotope ratios, implying a common control. While the isotope fractionation of Sn, Cu and Zn is a result of volatility, the magnitude of isotope fractionation is strongly moderated by their relative rates of diffusion in the molten tektite droplets. An Australasian Muong Nong-type tektite analysed has the least Sn depletion and Sn isotope fractionation, consistent with these samples being more proximal to the source and experiencing a shorter time at high temperatures.", "keywords": ["Volatiles", "ORIGIN", "FRACTIONATION", "01 natural sciences", "Tektites", "[SDU] Sciences of the Universe [physics]", "EVAPORATION", "ZINC", "105105 Geochemistry", "SILICATE MELTS", "Tin", "DISSOLUTION", "13. Climate action", "Impacts", "105105 Geochemie", "GEOCHEMISTRY", "CU", "GEOLOGICAL-MATERIALS", "Stable isotopes", "IMPACT GLASSES", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.chemgeo.2019.119279"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Chemical%20Geology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.chemgeo.2019.119279", "name": "item", "description": "10.1016/j.chemgeo.2019.119279", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.chemgeo.2019.119279"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-12-01T00:00:00Z"}}, {"id": "10.1016/j.gca.2017.04.040", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:18Z", "type": "Journal Article", "created": "2017-05-08", "title": "Tracing metal\u2013silicate segregation and late veneer in the Earth and the ureilite parent body with palladium stable isotopes", "description": "Abstract Stable isotope studies of highly siderophile elements (HSE) have the potential to yield valuable insights into a range of geological processes. In particular, the strong partitioning of these elements into metal over silicates may lead to stable isotope fractionation during metal\u2013silicate segregation, making them sensitive tracers of planetary differentiation processes. We present the first techniques for the precise determination of palladium stable isotopes by MC-ICPMS using a 106Pd\u2013110Pd double-spike to correct for instrumental mass fractionation. Results are expressed as the per mil (\u2030) difference in the 106Pd/105Pd ratio (\u03b4106Pd) relative to an in-house solution standard (Pd_IPGP) in the absence of a certified Pd isotopic standard. Repeated analyses of the Pd isotopic composition of the chondrite Allende demonstrate the external reproducibility of the technique of \u00b10.032\u2030 on \u03b4106Pd. Using these techniques, we have analysed Pd stable isotopes from a range of terrestrial and extraterrestrial samples. We find that chondrites define a mean \u03b4106Pdchondrite\u00a0=\u00a0\u22120.19\u00a0\u00b1\u00a00.05\u2030. Ureilites reveal a weak trend towards heavier \u03b4106Pd with decreasing Pd content, similar to recent findings based on Pt stable isotopes (Creech et al., 2017), although fractionation of Pd isotopes is significantly less than for Pt, possibly related to its weaker metal\u2013silicate partitioning behaviour and the limited field shift effect. Terrestrial mantle samples have a mean \u03b4106Pdmantle\u00a0=\u00a0\u22120.182\u00a0\u00b1\u00a00.130\u2030, which is consistent with a late-veneer of chondritic material after core formation.", "keywords": ["[SDU] Sciences of the Universe [physics]", "Terrestrial planet accretion", "13. Climate action", "01 natural sciences", "Late-veneer", "Palladium", "Meteorites", "Stable isotopes", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.gca.2017.04.040"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geochimica%20et%20Cosmochimica%20Acta", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.gca.2017.04.040", "name": "item", "description": "10.1016/j.gca.2017.04.040", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.gca.2017.04.040"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-11-01T00:00:00Z"}}, {"id": "10.1016/j.quascirev.2019.106130", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:38Z", "type": "Journal Article", "created": "2020-01-06", "title": "Latest Pleistocene to Holocene loess in the central Great Plains: Optically stimulated luminescence dating and multi-proxy analysis of the enders loess section (Nebraska, USA)", "description": "Loess deposits of the central Great Plains, USA, and their intercalated soils provide a detailed record of climatically driven changes within the aeolian system during the Pleistocene-Holocene transition and the Holocene. Here we present a detailed optically stimulated luminescence (OSL) chronology as well as multi-proxy analysis obtained for the first time on the Enders section, located in southwestern Nebraska, central Great Plains. The section records multiple episodes of rapid loess deposition alternating with soil formation. Rapid accumulation of Late Pleistocene Peoria Loess was replaced around 13-14 ka by formation of the Brady Soil until 9.5 \u00b1 0.6 ka. The Holocene Bignell Loess then buried the Brady Soil and accumulated episodically throughout the Holocene. The loess-paleosol stratigraphy since the Late Pleistocene at the Enders site is very similar to that at other sites in western Nebraska, and the newly developed OSL chronology (based on three grain size classes) adds new confidence to earlier dating. The high-resolution grain size profile from Enders shares many features with similar data from the previously studied Wauneta site, including three peaks of fine-grained material just above and within the Brady Soil, likely representing response to millennial-scale climatic changes during the Pleistocene-Holocene transition. This study demonstrates the potential for developing high-resolution, well-dated paleoclimatic records from the loess of the central Great Plains. Contrasts between Great Plains and Eurasian loess records reflect differences in the Late Pleistocene to Holocene climatic evolution and other factors influencing the loess system.", "keywords": ["15. Life on land", "01 natural sciences", "Holocene; loess; optically stimulated luminescence dating; grain size; magnetic susceptibility; stable isotopes; Brady Soil", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.quascirev.2019.106130"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Quaternary%20Science%20Reviews", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.quascirev.2019.106130", "name": "item", "description": "10.1016/j.quascirev.2019.106130", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.quascirev.2019.106130"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-02-01T00:00:00Z"}}, {"id": "10.1016/j.scitotenv.2015.12.107", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:41Z", "type": "Journal Article", "created": "2016-01-09", "title": "Partitioning Of Carbon Sources Among Functional Pools To Investigate Short-Term Priming Effects Of Biochar In Soil: A C-13 Study", "description": "Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from several years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. This laboratory study was set up to evaluate effects of biochar on C-mineralization with due attention to source appointment by using (13)C isotope signatures. An arable soil (S) (7.9 g organic C, OC kg(-1)) was amended (single dose of 10 g kg(-1) soil) with dried, grinded maize stover (leaves and stalks), either natural (R) or (13)C enriched (R*), and/or biochar (B/B*) prepared from the maize stover residues (450 \u00b0C). Accordingly, seven different combinations were set up (S, SR, SB, SR*, SB*, SRB*, SR*B) to trace the source of C in CO2 (180 days), dissolved organic-C (115 days) and OC in soil aggregate fractions (90 days). The application of biochar to soil reduced the mineralization of native soil organic C but the effect on maize stover-C mineralization was not consistent. Biochar application decreased the mineralization of the non-enriched maize stover after 90 days, this being consistent with a significant reduction of dissolved organic C concentration from 45 to 18 mg L(-1). However, no significant effect was observed for the enriched maize stover, presumably due to differences between the natural and enriched materials. The combined addition of biochar and enriched maize stover significantly increased (twofold) the presence of native soil organic C or maize derived C in the free microaggregate fraction relative to soil added only with stover. Although consistent effects among C sources and biochar materials remains elusive, our outcomes indicate that some biochar products can reduce mineralization and solubilization of other sources of C while promoting their physical protection in soil particles.", "keywords": ["2. Zero hunger", "550", "Soil organic carbon", "Stable Isotopes", "04 agricultural and veterinary sciences", "15. Life on land", "630", "6. Clean water", "2311 Waste Management and Disposal", "Biochar", "2305 Environmental Engineering", "Priming", "2304 Environmental Chemistry", "2310 Pollution", "0401 agriculture", " forestry", " and fisheries", "Soil aggregates"]}, "links": [{"href": "https://doi.org/10.1016/j.scitotenv.2015.12.107"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.scitotenv.2015.12.107", "name": "item", "description": "10.1016/j.scitotenv.2015.12.107", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.scitotenv.2015.12.107"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-03-01T00:00:00Z"}}, {"id": "10.1016/j.soilbio.2014.09.012", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:53Z", "type": "Journal Article", "created": "2014-09-30", "title": "Nitrogen And Phosphorus Constrain Labile And Stable Carbon Turnover In Lowland Tropical Forest Soils", "description": "Tropical forests contain a large stock of soil carbon, but the factors that constrain its mineralization remain poorly understood. Microorganisms, when stimulated by the presence of new inputs of labile organic carbon, can mineralize (\u2018prime\u2019) soil organic matter to acquire nutrients. We used stable carbon isotopes to assess how nutrient demand and soil properties constrain mineralization of added labile (sucrose) carbon and pre-existing (primed) soil carbon in tropical forest soils. In a series of lowland tropical forest soils from Panama, we found that the mineralization of fresh labile carbon was accelerated foremost by phosphorus addition, whereas the mineralization of pre-existing soil carbon was constrained foremost by nitrogen addition. However, there was variation in the relative importance of these nutrients in different soils and the largest effects on the acceleration of sucrose metabolism and constraint of priming occurred following the addition of nitrogen and phosphorus together. The respiration responses due to sucrose or primed soil carbon mineralization were reduced at pH below 4.8 and above 6.0. We conclude that in these tropical forest soils, phosphorus availability is more important in promoting microbial mineralization of sucrose carbon, whereas nitrogen availability is more important in constraining the priming of pre-existing soil organic carbon. This response likely arises because nitrogen is more closely coupled to organic matter cycling, whereas phosphorus is abundant in both organic and inorganic forms. These results suggest that the greatest impact of priming on soil carbon stocks will occur in moderately acidic tropical forest soils of low nitrogen availability. Given long-term changes in both atmospheric carbon dioxide and nitrogen deposition, the impact of priming effects on soil carbon in tropical forest soils may be partially constrained by the abundance of nitrogen.", "keywords": ["2. Zero hunger", "tropical", "carbon dioxide", "stable isotopes", "04 agricultural and veterinary sciences", "15. Life on land", "01 natural sciences", "nitrogen", "carbon isotopes", "13. Climate action", "0401 agriculture", " forestry", " and fisheries", "priming effects", "phosphorus", "priming", "microorganisms", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.soilbio.2014.09.012"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Soil%20Biology%20and%20Biochemistry", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.soilbio.2014.09.012", "name": "item", "description": "10.1016/j.soilbio.2014.09.012", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.soilbio.2014.09.012"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2015-01-01T00:00:00Z"}}, {"id": "10.1023/b:plso.0000020975.75850.ca", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:17:24Z", "type": "Journal Article", "created": "2004-03-24", "title": "Isotopic Estimates Of New Carbon Inputs Into Litter And Soils In A Four-Year Climate Change Experiment With Douglas-Fir", "description": "Because soil is a major reservoir of terrestrial carbon and a potential sink for atmospheric CO2, determining plant inputs to soil carbon is critical for understanding ecosystem carbon dynamics. We present a modified method to quantify the effects of global climate change on plant inputs of carbon to soil based on 13C:12C ratio (\u03b413C) analyses that accounts for isotopic fractionation between inputs and newly created soil carbon. In a four-year study, the effects of elevated CO2 and temperature were determined for reconstructed Douglas-fir (Pseudotsuga mensiezii (Mirb.) Franco) ecosystems in which native soil of low nitrogen content was used. The \u03b413C patterns in litter and mineral soil horizons were measured and compared to \u03b413C patterns in live needles, fine roots, and coarse roots. From regression analyses, we calculated the isotopic enrichment in 13C of newly incorporated soil carbon relative to needle and root carbon at 4\u2030 and 2\u2030, respectively. These enrichments must be considered when using shifts in soil \u03b413C to calculate inputs of plant carbon into the soil, and are probably a major factor in the progressive enrichment in 13C with increasing depth in soil profiles. Relative to the total carbon in each layer, the proportion of new carbon from recent photosynthate in each soil layer was 13\u201315% in the A horizon, 7\u20139% in litter layers, and 4% in the B2 and C horizons. New carbon in the A horizon was estimated at 370\u00a0g C\u00a0m\u22122. Carbon concentrations and new carbon in A horizons were correlated (r 2=0.78, n=12), but with a slope of 0.356, indicating that about 36% of net carbon accumulation in the A horizon was from inputs via roots, root exudates or mycorrhizal fungi and 64% of carbon was derived from surface litter decomposition. Under the nitrogen-limited growth conditions used in this study, neither elevated CO2 nor temperature affected soil carbon sequestration patterns.", "keywords": ["elevated temperature", "13. Climate action", "soil carbon turnover", "elevated carbon dioxide", "stable isotopes", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "mesocosms", "15. Life on land", "global change", "isotopic discrimination"], "contacts": [{"organization": "Hobbie, Erik A., Johnson, M. G., Rygiewicz, Paul T., Tingey, David T., Olszyk, David M.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1023/b:plso.0000020975.75850.ca"}, {"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/b:plso.0000020975.75850.ca", "name": "item", "description": "10.1023/b:plso.0000020975.75850.ca", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1023/b:plso.0000020975.75850.ca"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-02-01T00:00:00Z"}}, {"id": "10.1029/2019jd030387", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:17:26Z", "type": "Journal Article", "created": "2019-06-19", "title": "Global 3-D Simulations of the Triple Oxygen Isotope Signature \u0394 17 O in Atmospheric CO 2", "description": "Abstract

The triple oxygen isotope signature \uffce\uff9417O in atmospheric CO2, also known as its \uffe2\uff80\uff9c17O excess,\uffe2\uff80\uff9d has been proposed as a tracer for gross primary production (the gross uptake of CO2 by vegetation through photosynthesis). We present the first global 3\uffe2\uff80\uff90D model simulations for \uffce\uff9417O in atmospheric CO2 together with a detailed model description and sensitivity analyses. In our 3\uffe2\uff80\uff90D model framework we include the stratospheric source of \uffce\uff9417O in CO2 and the surface sinks from vegetation, soils, ocean, biomass burning, and fossil fuel combustion. The effect of oxidation of atmospheric CO on \uffce\uff9417O in CO2 is also included in our model. We estimate that the global mean \uffce\uff9417O (defined as with \uffce\uffbbRL = 0.5229) of CO2 in the lowest 500\uffc2\uffa0m of the atmosphere is 39.6\uffc2\uffa0per meg, which is \uffe2\uff88\uffbc20\uffc2\uffa0per meg lower than estimates from existing box models. We compare our model results with a measured stratospheric \uffce\uff9417O in CO2 profile from Sodankyl\uffc3\uffa4 (Finland), which shows good agreement. In addition, we compare our model results with tropospheric measurements of \uffce\uff9417O in CO2 from G\uffc3\uffb6ttingen (Germany) and Taipei (Taiwan), which shows some agreement but we also find substantial discrepancies that are subsequently discussed. Finally, we show model results for Zotino (Russia), Mauna Loa (United States), Manaus (Brazil), and South Pole, which we propose as possible locations for future measurements of \uffce\uff9417O in tropospheric CO2 that can help to further increase our understanding of the global budget of \uffce\uff9417O in atmospheric CO2.

", "keywords": ["CARBONIC-ANHYDRASE ACTIVITY", "550", "STRATOSPHERIC CO2", "STOMATAL CONDUCTANCE", "TRACER", "stable isotopes", "MASS", "carbon dioxide (CO)", "01 natural sciences", "7. Clean energy", "DIOXIDE EXCHANGE", "O excess (\u0394O)", "3-DIMENSIONAL SYNTHESIS", "carbon dioxide (CO2)", "carbon cycle", "O-17 excess (Delta O-17)", "SDG 13 - Climate Action", "SDG 14 - Life Below Water", "Research Articles", "0105 earth and related environmental sciences", "O-18 CONTENT", "info:eu-repo/classification/ddc/550", "mass-independent fractionation (MIF)", "ddc:550", "gross primary production (GPP)", "15. Life on land", "Earth sciences", "13. Climate action", "MODEL TM5", "17O excess (\u039417O)", "FIRE EMISSIONS"]}, "links": [{"href": "https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019JD030387"}, {"href": "https://doi.org/10.1029/2019jd030387"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Geophysical%20Research%3A%20Atmospheres", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1029/2019jd030387", "name": "item", "description": "10.1029/2019jd030387", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1029/2019jd030387"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2019-08-04T00:00:00Z"}}, {"id": "10.1088/1748-9326/aaeae7", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:18:05Z", "type": "Journal Article", "created": "2018-10-24", "title": "Using research networks to create the comprehensive datasets needed to assess nutrient availability as a key determinant of terrestrial carbon cycling", "description": "Open AccessA wide range of research shows that nutrient availability strongly influences terrestrial carbon (C) cycling and shapes ecosystem responses to environmental changes and hence terrestrial feedbacks to climate. Nonetheless, our understanding of nutrient controls remains far from complete and poorly quantified, at least partly due to a lack of informative, comparable, and accessible datasets at regional-to-global scales. A growing research infrastructure of multi-site networks are providing valuable data on C fluxes and stocks and are monitoring their responses to global environmental change and measuring responses to experimental treatments. These networks thus provide an opportunity for improving our understanding of C-nutrient cycle interactions and our ability to model them. However, coherent information on how nutrient cycling interacts with observed C cycle patterns is still generally lacking. Here, we argue that complementing available C-cycle measurements from monitoring and experimental sites with data characterizing nutrient availability will greatly enhance their power and will improve our capacity to forecast future trajectories of terrestrial C cycling and climate. Therefore, we propose a set of complementary measurements that are relatively easy to conduct routinely at any site or experiment and that, in combination with C cycle observations, can provide a robust characterization of the effects of nutrient availability across sites. In addition, we discuss the power of different observable variables for informing the formulation of models and constraining their predictions. Most widely available measurements of nutrient availability often do not align well with current modelling needs. This highlights the importance to foster the interaction between the empirical and modelling communities for setting future research priorities.", "keywords": ["Global vegetation models", "550", "manipulation experiments", "Terrestrial-Aquatic Linkages", "Kolefni", "01 natural sciences", "Nutrient cycle", "Agricultural and Biological Sciences", "Terrestrial ecosystem", "SDG 13 - Climate Action", "Climate change", "Jar\u00f0vegur", "Environmental resource management", "Global change", "General Environmental Science", "SDG 15 - Life on Land", "Carbon-nutrient cycle interactions", "2. Zero hunger", "Data syntheses", "Global and Planetary Change", "Ecology", "Geography", "Physics", "Life Sciences", "Application of Stable Isotopes in Trophic Ecology", "Cycling", "Carbon cycle", "04 agricultural and veterinary sciences", "Chemistry", "ORGANIC-MATTER", "Archaeology", "Physical Sciences", "Nutrient availability", "NET PRIMARY PRODUCTIVITY", "Ecosystem Functioning", "570", "LAND", "TROPICAL RAIN-FOREST", "carbon-nutrient cycle interactions", "data syntheses", "Soil Science", "Environmental science", "[SDU] Sciences of the Universe [physics]", "SOIL-PHOSPHORUS AVAILABILITY", "global vegetation models", "SDG 3 - Good Health and Well-being", "nutrients", "USE EFFICIENCY", "SDG 7 - Affordable and Clean Energy", "GLOBAL CHANGE", "Key (lock)", "Biology", "Ecosystem", "Manipulation experiments", "0105 earth and related environmental sciences", "Renewable Energy", " Sustainability and the Environment", "Ecosystem Structure", "Public Health", " Environmental and Occupational Health", "Nutrients", "15. Life on land", "Computer science", "[SDU]Sciences of the Universe [physics]", "13. Climate action", "ECOSYSTEM RESPONSES", "FOS: Biological sciences", "Global Methane Emissions and Impacts", "Environmental Science", "0401 agriculture", " forestry", " and fisheries", "NITROGEN-FIXATION", "Soil Carbon Dynamics and Nutrient Cycling in Ecosystems", "Nutrient Limitation", "ELEVATED CO2", "Nutrient"]}, "links": [{"href": "https://doi.org/10.1088/1748-9326/aaeae7"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Research%20Letters", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1088/1748-9326/aaeae7", "name": "item", "description": "10.1088/1748-9326/aaeae7", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1088/1748-9326/aaeae7"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-12-07T00:00:00Z"}}, {"id": "10.1046/j.1365-2486.1999.00211.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:17:42Z", "type": "Journal Article", "created": "2003-03-11", "title": "Elevated Co2 And Temperature Impacts On Different Components Of Soil Co2 Efflux In Douglas-Fir Terracosms", "description": "Abstract

Although numerous studies indicate that increasing atmospheric CO2 or temperature stimulate soil CO2 efflux, few data are available on the responses of three major components of soil respiration [i.e. rhizosphere respiration (root and root exudates), litter decomposition, and oxidation of soil organic matter] to different CO2 and temperature conditions. In this study, we applied a dual stable isotope approach to investigate the impact of elevated CO2 and elevated temperature on these components of soil CO2 efflux in Douglas\uffe2\uff80\uff90fir terracosms. We measured both soil CO2 efflux rates and the 13C and 18O isotopic compositions of soil CO2 efflux in 12 sun\uffe2\uff80\uff90lit and environmentally controlled terracosms with 4\uffe2\uff80\uff90year\uffe2\uff80\uff90old Douglas fir seedlings and reconstructed forest soils under two CO2 concentrations (ambient and 200 ppmv above ambient) and two air temperature regimes (ambient and 4 \uffc2\uffb0C above ambient). The stable isotope data were used to estimate the relative contributions of different components to the overall soil CO2 efflux. In most cases, litter decomposition was the dominant component of soil CO2 efflux in this system, followed by rhizosphere respiration and soil organic matter oxidation. Both elevated atmospheric CO2 concentration and elevated temperature stimulated rhizosphere respiration and litter decomposition. The oxidation of soil organic matter was stimulated only by increasing temperature. Release of newly fixed carbon as root respiration was the most responsive to elevated CO2, while soil organic matter decomposition was most responsive to increasing temperature. Although some assumptions associated with this new method need to be further validated, application of this dual\uffe2\uff80\uff90isotope approach can provide new insights into the responses of soil carbon dynamics in forest ecosystems to future climate changes.

", "keywords": ["elevated CO2", "13. Climate action", "stable isotopes", "0401 agriculture", " forestry", " and fisheries", "04 agricultural and veterinary sciences", "forest ecosystem", "15. Life on land", "global warming", "soil respiration"], "contacts": [{"organization": "Guanghui Lin, Guanghui Lin, Mark Johnson, David T. Tingey, James R. Ehleringer, Paul T. Rygiewicz,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1046/j.1365-2486.1999.00211.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.1365-2486.1999.00211.x", "name": "item", "description": "10.1046/j.1365-2486.1999.00211.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1046/j.1365-2486.1999.00211.x"}, {"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": "10.1073/pnas.1905912116", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:17:52Z", "type": "Journal Article", "created": "2019-08-06", "title": "Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency", "description": "

Multiple lines of evidence suggest that plant water-use efficiency (WUE)\uffe2\uff80\uff94the ratio of carbon assimilation to water loss\uffe2\uff80\uff94has increased in recent decades. Although rising atmospheric CO 2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO 2 -induced reductions in stomatal conductance. The depletion of moderately volatile elements in the lunar interior, compared to the Earth\uffe2\uff80\uff99s interior, is accompanied by enrichment in heavy isotopes for most species. This has been explained by vapor loss from the protolunar disk, incomplete accretion of volatiles, or volatile degassing during crystallization of the lunar magma ocean. Importantly, these hypotheses have assumed that volatile depletion and associated isotope fractionations are relevant to the whole Moon. However, our lunar sample collections are biased, as Apollo and Luna samples come from within or around the anomalous Procellarum KREEP Terrane region on the lunar nearside. Here, we propose that these chemical and isotopic features could have resulted from a large-scale impact event on the nearside early in the Moon\uffe2\uff80\uff99s history.

", "keywords": ["UAT:1692", "[SDU] Sciences of the Universe [physics]", "lunar samples", "13. Climate action", "stable isotopes", "Lunar volatiles; the Moon; Procellarum KREEP Terrane; Lunar samples; Stable isotopes", "lunar volatiles", "Procellarum KREEP Terrane", "01 natural sciences", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://pnas.org/doi/pdf/10.1073/pnas.2023023118"}, {"href": "https://doi.org/10.1073/pnas.2023023118"}, {"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.2023023118", "name": "item", "description": "10.1073/pnas.2023023118", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1073/pnas.2023023118"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-03-15T00:00:00Z"}}, {"id": "10.1093/aob/mcab107", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:18:07Z", "type": "Journal Article", "created": "2021-08-17", "title": "Disentangling water sources in a gypsum plant community. Gypsum crystallization water is a key source of water for shallow-rooted plants", "description": "AbstractBackground and Aims

Gypsum drylands are widespread worldwide. In these arid ecosystems, the ability of different species to access different water sources during drought is a key determining factor of the composition of plant communities. Gypsum crystallization water could be a relevant source of water for shallow-rooted plants, but the segregation in the use of this source of water among plants remains unexplored. We analysed the principal water sources used by 20 species living in a gypsum hilltop, the effect of rooting depth and gypsum affinity, and the interaction of the plants with the soil beneath them.

Methods

We characterized the water stable isotope composition, \uffce\uffb4\uffe2\uff80\uff8a2H and \uffce\uffb4\uffe2\uff80\uff8a18O, of plant xylem water and related it to the free and gypsum crystallization water extracted from different depths throughout the soil profile and the groundwater, in both spring and summer. Bayesian isotope mixing models were used to estimate the contribution of water sources to plant xylem sap.

Key Results

In spring, all species used free water from the top soil as the main source. In summer, there was segregation in water sources used by different species depending on their rooting depth, but not on their gypsum affinity. Gypsum crystallization water was the main source for most shallow-rooted species, whereas free water from 50 to 100 cm depth was the main source for deep-rooted species. We detected plant\uffe2\uff80\uff93soil interactions in spring, and indirect evidence of possible hydraulic lift by deep-rooted species in summer.

Conclusions

Plants coexisting in gypsum communities segregate their hydrological niches according to their rooting depth. Crystallization water of gypsum represents an unaccounted for, vital source for most of the shallow-rooted species growing on gypsum drylands. Thus, crystallization water helps shallow-rooted species to endure arid conditions, which eventually accounts for the maintenance of high biodiversity in these specialized ecosystems. Multiple lines of evidence suggest that plant water-use efficiency (WUE)\uffe2\uff80\uff94the ratio of carbon assimilation to water loss\uffe2\uff80\uff94has increased in recent decades. Although rising atmospheric CO 2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO 2 -induced reductions in stomatal conductance. Gypsum drylands are widespread worldwide. In these arid ecosystems, the ability of different species to access different water sources during drought is a key determining factor of the composition of plant communities. Gypsum crystallization water could be a relevant source of water for shallow-rooted plants, but the segregation in the use of this source of water among plants remains unexplored. We analysed the principal water sources used by 20 species living in a gypsum hilltop, the effect of rooting depth and gypsum affinity, and the interaction of the plants with the soil beneath them.

Methods

We characterized the water stable isotope composition, \uffce\uffb4\uffe2\uff80\uff8a2H and \uffce\uffb4\uffe2\uff80\uff8a18O, of plant xylem water and related it to the free and gypsum crystallization water extracted from different depths throughout the soil profile and the groundwater, in both spring and summer. Bayesian isotope mixing models were used to estimate the contribution of water sources to plant xylem sap.

Key Results

In spring, all species used free water from the top soil as the main source. In summer, there was segregation in water sources used by different species depending on their rooting depth, but not on their gypsum affinity. Gypsum crystallization water was the main source for most shallow-rooted species, whereas free water from 50 to 100 cm depth was the main source for deep-rooted species. We detected plant\uffe2\uff80\uff93soil interactions in spring, and indirect evidence of possible hydraulic lift by deep-rooted species in summer.

Conclusions

Plants coexisting in gypsum communities segregate their hydrological niches according to their rooting depth. Crystallization water of gypsum represents an unaccounted for, vital source for most of the shallow-rooted species growing on gypsum drylands. Thus, crystallization water helps shallow-rooted species to endure arid conditions, which eventually accounts for the maintenance of high biodiversity in these specialized ecosystems.Gypsum drylands are widespread worldwide. In these arid ecosystems, the ability of different species to access different water sources during drought is a key determining factor of the composition of plant communities. Gypsum crystallization water could be a relevant source of water for shallow-rooted plants, but the segregation in the use of this source of water among plants remains unexplored. We analysed the principal water sources used by 20 species living in a gypsum hilltop, the effect of rooting depth and gypsum affinity, and the interaction of the plants with the soil beneath them.

Methods

We characterized the water stable isotope composition, \uffce\uffb4\uffe2\uff80\uff8a2H and \uffce\uffb4\uffe2\uff80\uff8a18O, of plant xylem water and related it to the free and gypsum crystallization water extracted from different depths throughout the soil profile and the groundwater, in both spring and summer. Bayesian isotope mixing models were used to estimate the contribution of water sources to plant xylem sap.

Key Results

In spring, all species used free water from the top soil as the main source. In summer, there was segregation in water sources used by different species depending on their rooting depth, but not on their gypsum affinity. Gypsum crystallization water was the main source for most shallow-rooted species, whereas free water from 50 to 100 cm depth was the main source for deep-rooted species. We detected plant\uffe2\uff80\uff93soil interactions in spring, and indirect evidence of possible hydraulic lift by deep-rooted species in summer.

Conclusions

Plants coexisting in gypsum communities segregate their hydrological niches according to their rooting depth. Crystallization water of gypsum represents an unaccounted for, vital source for most of the shallow-rooted species growing on gypsum drylands. Thus, crystallization water helps shallow-rooted species to endure arid conditions, which eventually accounts for the maintenance of high biodiversity in these specialized ecosystems.