High soil organic carbon content, extensive root biomass, and low nutrient availability make alpine grasslands an important ecosystem for assessing the influence of nutrient enrichment on soil respiration (SR). We conducted a four-year (2009\uffe2\uff80\uff932012) field experiment in an alpine grassland on the Qinghai-Tibetan Plateau to examine the individual and combined effects of nitrogen (N, 100\uffe2\uff80\uff89kg ha\uffe2\uff88\uff921year\uffe2\uff88\uff921) and phosphorus (P, 50\uffe2\uff80\uff89kg ha\uffe2\uff88\uff921year\uffe2\uff88\uff921) addition on SR. We found that both N and P addition did not affect the overall growing-season SR but effects varied by year: with N addition SR increased in the first year but decreased during the last two years. However, while P addition did not affect SR during the first two years, SR increased during the last two years. No interactive effects of N and P addition were observed, and both N addition and P addition reduced heterotrophic respiration during the last year of the experiment. N and P addition affected SR via different processes: N mainly affected heterotrophic respiration, whereas P largely influenced autotrophic respiration. Our results highlight the divergent effects of N and P addition on SR and address the important potential of P enrichment for regulating SR and the carbon balance in alpine grasslands.
", "keywords": ["Biomass (ecology)", "0106 biological sciences", "Mechanics and Transport in Unsaturated Soils", "Nitrogen", "Soil Science", "Organic chemistry", "Plant Science", "Thermal Effects on Soil", "01 natural sciences", "Article", "Environmental science", "Agricultural and Biological Sciences", "Engineering", "Soil water", "Genetics", "Biology", "Ecosystem", "Civil and Structural Engineering", "2. Zero hunger", "Soil Fertility", "Ecology", "Bacteria", "Respiration", "Botany", "Life Sciences", "Plant Nutrient Uptake and Signaling Pathways", "Phosphorus", "Soil respiration", "04 agricultural and veterinary sciences", "15. Life on land", "Grassland", "Soil carbon", "Agronomy", "Chemistry", "13. Climate action", "FOS: Biological sciences", "Physical Sciences", "Heterotroph", "Growing season", "0401 agriculture", " forestry", " and fisheries", "Soil Carbon Dynamics and Nutrient Cycling in Ecosystems", "Animal science", "Nutrient"]}, "links": [{"href": "https://doi.org/10.1038/srep34786"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Scientific%20Reports", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1038/srep34786", "name": "item", "description": "10.1038/srep34786", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1038/srep34786"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-10-10T00:00:00Z"}}, {"id": "10.1073/pnas.2201072119", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:18:46Z", "type": "Journal Article", "created": "2022-07-18", "title": "Ethylene inhibits rice root elongation in compacted soil via ABA- and auxin-mediated mechanisms", "description": "Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8 . Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil. Abstract. Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the ORCHIDEE land surface model, and evaluate it with data from nutrient manipulation experiments along a\uffc2\uffa0soil formation chronosequence in Hawaii. ORCHIDEE accounts for the influence of the nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated) mineralization, and biological nitrogen fixation. Changes in the nutrient content (quality) of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from the soil to the root surface. The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300-year) and a late (4.1\uffe2\uff80\uffafMyr) stage of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus, or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower than observed primarily due to biases in the nutrient content and turnover of woody biomass. We conclude that ORCHIDEE is able to reproduce the shift from nitrogen to phosphorus limited net primary productivity along the soil development chronosequence, as well as the contrasting responses of net primary productivity to nutrient addition.
", "keywords": ["Biomass (ecology)", "Chronosequence", "Organic chemistry", "chronos\u00e9quence", "Plant Science", "mod\u00e8le", "Nitrogen cycle", "01 natural sciences", "Nutrient cycle", "Agricultural and Biological Sciences", "Soil water", "Pathology", "2. Zero hunger", "QE1-996.5", "Global and Planetary Change", "Orchidee", "Ecology", "Physics", "Life Sciences", "Geology", "Phosphorus", "Carbon cycle", "Chemistry", "nutrition", "Physical Sciences", "Medicine", "[SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]", "Ecosystem Functioning", "Vegetation (pathology)", "cycle du carbone", "570", "[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]", "Nitrogen", "hawai", "Soil Science", "mod\u00e8le orchid\u00e9e", "Environmental science", "vegetation", "phosphore du sol", "Biology", "Ecosystem", "0105 earth and related environmental sciences", "Soil science", "Soil Fertility", "ddc:550", "Global Forest Drought Response and Climate Change", "surface terrestre", "Plant Nutrient Uptake and Signaling Pathways", "15. Life on land", "Agronomy", "hawaii", "13. Climate action", "FOS: Biological sciences", "Environmental Science", "Soil Carbon Dynamics and Nutrient Cycling in Ecosystems", "Nutrient"]}, "links": [{"href": "https://gmd.copernicus.org/articles/10/3745/2017/gmd-10-3745-2017.pdf"}, {"href": "https://doi.org/10.5194/gmd-10-3745-2017"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geoscientific%20Model%20Development", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.5194/gmd-10-3745-2017", "name": "item", "description": "10.5194/gmd-10-3745-2017", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.5194/gmd-10-3745-2017"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-10-12T00:00:00Z"}}, {"id": "11104/0341036", "type": "Feature", "geometry": null, "properties": {"updated": "2026-06-23T16:25:56Z", "type": "Journal Article", "created": "2022-07-18", "title": "Ethylene inhibits rice root elongation in compacted soil via ABA- and auxin-mediated mechanisms", "description": "Soil compaction represents a major agronomic challenge, inhibiting root elongation and impacting crop yields. Roots use ethylene to sense soil compaction as the restricted air space causes this gaseous signal to accumulate around root tips. Ethylene inhibits root elongation and promotes radial expansion in compacted soil, but its mechanistic basis remains unclear. Here, we report that ethylene promotes abscisic acid (ABA) biosynthesis and cortical cell radial expansion. Rice mutants of ABA biosynthetic genes had attenuated cortical cell radial expansion in compacted soil, leading to better penetration. Soil compaction-induced ethylene also up-regulates the auxin biosynthesis gene OsYUC8 . Mutants lacking OsYUC8 are better able to penetrate compacted soil. The auxin influx transporter OsAUX1 is also required to mobilize auxin from the root tip to the elongation zone during a root compaction response. Moreover, osaux1 mutants penetrate compacted soil better than the wild-type roots and do not exhibit cortical cell radial expansion. We conclude that ethylene uses auxin and ABA as downstream signals to modify rice root cell elongation and radial expansion, causing root tips to swell and reducing their ability to penetrate compacted soil.