Drought periods are projected to become more severe and more frequent in many European regions. While effects of single strong droughts on plant and microbial carbon (C) dynamics have been studied in some detail, impacts of recurrent drought events are still little understood.
We tested whether the legacy of extreme experimental drought affects responses of plant and microbial C and nitrogen (N) turnover to further drought and rewetting. In a mountain grassland, we conducted a 13C pulse\uffe2\uff80\uff90chase experiment during a naturally occurring drought and rewetting event in plots previously exposed to experimental droughts and in ambient controls (AC). After labelling, we traced 13C below\uffe2\uff80\uff90ground allocation and incorporation into soil microbes using phospholipid fatty acid biomarkers.
Drought history (DH) had no effects on the standing shoot and fine root plant biomass. However, plants with experimental DH displayed decreased shoot N concentrations and increased fine root N concentrations relative to those in AC. During the natural drought, plants with DH assimilated and allocated less 13C below\uffe2\uff80\uff90ground; moreover, fine root respiration was reduced and not fuelled by fresh C compared to plants in AC.
Regardless of DH, microbial biomass remained stable during natural drought and rewetting. Although microbial communities initially differed in their composition between soils with and without DH, they responded to the natural drought and rewetting in a similar way: gram\uffe2\uff80\uff90positive bacteria increased, while fungal and gram\uffe2\uff80\uff90negative bacteria remained stable. In soils with DH, a strongly reduced uptake of recent plant\uffe2\uff80\uff90derived 13C in microbial biomarkers was observed during the natural drought, pointing to a smaller fraction of active microbes or to a microbial community that is less dependent on plant C.
Synthesis. Drought history can induce changes in above\uffe2\uff80\uff90 vs. below\uffe2\uff80\uff90ground plant N concentrations and affect the response of plant C turnover to further droughts and rewetting by decreasing plant C uptake and below\uffe2\uff80\uff90ground allocation. DH does not affect the responses of the microbial community to further droughts and rewetting, but alters microbial functioning, particularly the turnover of recent plant\uffe2\uff80\uff90derived carbon, during and after further drought periods.
", "keywords": ["0301 basic medicine", "plant-soil (below-ground) interactions", "NITROGEN TURNOVER", "Biomass Allocation", "microbial community composition", "Negibacteria", "drought", "phospholipid fatty acid", "nitrogen", "Microbial community composition", "Plant\u2013Soil (Below\u2010ground) Interactions", "Recovery", "ROOT RESPIRATION", "Plant-soil (below-ground) interactions", "CLIMATE EXTREMES", "C pulse labelling", "Below-ground carbon allocation", "2. Zero hunger", "106022 Mikrobiologie", "0303 health sciences", "SOIL INTERACTIONS", "below-ground carbon allocation", "C-13 pulse labelling", "Grassland", "6. Clean water", "Europe", "Phospholipid", "ORGANIC-MATTER", "Mountain Region", "Posibacteria", "DIOXIDE PULSES", "Phospholipid fatty acid", "106022 Microbiology", "Root/shoot Ratio", "Belowground Biomass", "Ecosystem Resilience", "Nitrogen", "Microbial Community", "Carbon Isotope", "Soil-vegetation Interaction", "recovery", "SUMMER DROUGHT", "03 medical and health sciences", "Rewetting", "Community Composition", "plant\u2013soil (below-ground) interactions", "WATER-STRESS", "resilience", "Drought", "Resilience", "RESILIENCE", "15. Life on land", "Turnover", "Microbial Activity", "13. Climate action", "Fatty Acid", "RESPONSES"]}, "links": [{"href": "https://doi.org/10.1111/1365-2745.12593"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/1365-2745.12593", "name": "item", "description": "10.1111/1365-2745.12593", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/1365-2745.12593"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-05-24T00:00:00Z"}}, {"id": "10.1111/j.1365-2486.2006.01118.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:18:45Z", "type": "Journal Article", "created": "2006-04-23", "title": "Woody Biomass Production During The Second Rotation Of A Bio-Energy Populus Plantation Increases In A Future High Co2 World", "description": "AbstractThe quickly rising atmospheric carbon dioxide (CO2)\uffe2\uff80\uff90levels, justify the need to explore all carbon (C) sequestration possibilities that might mitigate the current CO2increase. Here, we report the likely impact of future increases in atmospheric CO2on woody biomass production of three poplar species (Populus albaL. clone 2AS\uffe2\uff80\uff9011,Populus nigraL. clone Jean Pourtet andPopulus\uffc3\uff97euramericanaclone I\uffe2\uff80\uff90214). Trees were growing in a high\uffe2\uff80\uff90density coppice plantation during the second rotation (i.e., regrowth after coppice; 2002\uffe2\uff80\uff932004; POPFACE/EUROFACE). Six plots were studied, half of which were continuously fumigated with CO2(FACE; free air carbon dioxide enrichment of 550\uffe2\uff80\uff83ppm). Half of each plot was fertilized to study the interaction between CO2and nutrient fertilization. At the end of the second rotation, selective above\uffe2\uff80\uff90 and belowground harvests were performed to estimate the productivity of this bio\uffe2\uff80\uff90energy plantation. Fertilization did not affect growth of the poplar trees, which was likely because of the high rates of fertilization during the previous agricultural land use. In contrast, elevated CO2enhanced biomass production by up to 29%, and this stimulation did not differ between above\uffe2\uff80\uff90 and belowground parts. The increased initial stump size resulting from elevated CO2during the first rotation (1999\uffe2\uff80\uff932001) could not solely explain the observed final biomass increase. The larger leaf area index after canopy closure and the absence of any major photosynthetic acclimation after 6 years of fumigation caused the sustained CO2\uffe2\uff80\uff90induced biomass increase after coppice. These results suggest that, under future CO2concentrations, managed poplar coppice systems may exhibit higher potential for C sequestration and, thus, help mitigate climate change when used as a source of C\uffe2\uff80\uff90neutral energy.
", "keywords": ["2. Zero hunger", "580", "0106 biological sciences", "570", "atmospheric co2", "elevated co2", "n-fertilization", "Global and Planetary Change", "Ecology", "growth", "enrichment face", "hybrid poplar", "04 agricultural and veterinary sciences", "15. Life on land", "7. Clean energy", "01 natural sciences", "pinus-taeda", "poplar plantation", "Bio-energy; Biomass distribution; EUROFACE; FACE; Fertilization; Leaf area index; Photosynthesis; Populus; Short rotation coppice; Woody biomass", "13. Climate action", "no3 availability", "Environmental Chemistry", "0401 agriculture", " forestry", " and fisheries", "water-stress", "General Environmental Science"]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2486.2006.01118.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": "10.1111/j.1365-2486.2006.01118.x", "name": "item", "description": "10.1111/j.1365-2486.2006.01118.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2486.2006.01118.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-04-13T00:00:00Z"}}, {"id": "10.1111/nph.15516", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-25T16:19:01Z", "type": "Journal Article", "created": "2018-10-06", "title": "Imaging microstructure of the barley rhizosphere: particle packing and root hair influences", "description": "Summary
Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three\uffe2\uff80\uff90dimensional pore structure at a fine scale is scarce and often contradictory.
Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (<250\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm of the root surface.
Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions.
A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.
Soil adjacent to roots has distinct structural and physical properties from bulk soil, affecting water and solute acquisition by plants. Detailed knowledge on how root activity and traits such as root hairs affect the three\uffe2\uff80\uff90dimensional pore structure at a fine scale is scarce and often contradictory.
Roots of hairless barley (Hordeum vulgare L. cv Optic) mutant (NRH) and its wildtype (WT) parent were grown in tubes of sieved (<250\uffc2\uffa0\uffce\uffbcm) sandy loam soil under two different water regimes. The tubes were scanned by synchrotron\uffe2\uff80\uff90based X\uffe2\uff80\uff90ray computed tomography to visualise pore structure at the soil\uffe2\uff80\uff93root interface. Pore volume fraction and pore size distribution were analysed vs distance within 1\uffc2\uffa0mm of the root surface.
Less dense packing of particles at the root surface was hypothesised to cause the observed increased pore volume fraction immediately next to the epidermis. The pore size distribution was narrower due to a decreased fraction of larger pores. There were no statistically significant differences in pore structure between genotypes or moisture conditions.
A model is proposed that describes the variation in porosity near roots taking into account soil compaction and the surface effect at the root surface.