The mountain birch [Betula pubescens var. pumila (L.)] forest in the Subarctic is periodically exposed to insect outbreaks, which are expected to intensify due to climate change. To mitigate abiotic and biotic stresses, plants have evolved chemical defenses, including volatile organic compounds (VOCs) and non-volatile specialized compounds (NVSCs). Constitutive and induced production of these compounds, however, are poorly studied in Subarctic populations of mountain birch. Here, we assessed the joint effects of insect herbivory, elevation and season on foliar VOC emissions and NVSC contents of mountain birch. The VOCs were sampled in situ by an enclosure technique and analyzed by gas chromatography\uffe2\uff80\uff93mass spectrometry. NVSCs were analyzed by liquid chromatography\uffe2\uff80\uff93mass spectrometry using an untargeted approach. At low elevation, experimental herbivory by winter moth larvae (Operophtera brumata) increased emissions of monoterpenes and homoterpenes over the 3-week feeding period, and sesquiterpenes and green leaf volatiles at the end of the feeding period. At high elevation, however, herbivory augmented only homoterpene emissions. The more pronounced herbivory effects at low elevation were likely due to higher herbivory intensity. Of the individual compounds, linalool, ocimene, 4,8-dimethylnona-1,3,7-triene, 2-methyl butanenitrile and benzyl nitrile were among the most responsive compounds in herbivory treatments. Herbivory also altered foliar NVSC profiles at both low and high elevations, with the most responsive compounds likely belonging to fatty acyl glycosides and terpene glycosides. Additionally, VOC emissions from non-infested branches were higher at high than low elevation, particularly during the early season, which was mainly driven by phenological differences. The VOC emissions varied substantially over the season, largely reflecting the seasonal variations in temperature and light levels. Our results suggest that if insect herbivory pressure continues to rise in the mountain birch forest with ongoing climate change, it will significantly increase VOC emissions with important consequences for local trophic interactions and climate.
", "keywords": ["0301 basic medicine", "Volatile Organic Compounds", "0303 health sciences", "secondary metabolites", "VDP::Zoologiske og botaniske fag: 480", "plant\u2013insect interactions", "Moths", "15. Life on land", "geometrid moth", "Plant Leaves", "03 medical and health sciences", "biotic stress", "13. Climate action", "volatile organic compounds", "Larva", "8. Economic growth", "11. Sustainability", "VDP::Zoology and botany: 480", "Animals", "Herbivory", "Seasons", "global change", "Betula", "Research Paper"]}, "links": [{"href": "http://academic.oup.com/treephys/article-pdf/41/6/1019/38497290/tpab023.pdf"}, {"href": "https://doi.org/10.1093/treephys/tpab023"}, {"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/tpab023", "name": "item", "description": "10.1093/treephys/tpab023", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/treephys/tpab023"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-02-18T00:00:00Z"}}, {"id": "10.1139/as-2021-0058", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:19:13Z", "type": "Journal Article", "created": "2022-05-05", "title": "Monitoring litter and microplastics in Arctic mammals and bird", "description": "Plastic pollution has been reported to affect Arctic mammals and birds. There are strengths and limitations to monitoring litter and microplastics using Arctic mammals and birds. One strength is the direct use of these data to understand the potential impacts on Arctic biodiversity as well as effects on human health, if selected species are consumed. Monitoring programs must be practically designed with all purposes in mind, and a spectrum of approaches and species will be required. Spatial and temporal trends of plastic pollution can be built on the information obtained from studies on northern fulmars ( Fulmarus glacialis (Linnaeus, 1761)), a species that is an environmental indicator. To increase our understanding of the potential implications for human health, the species and locations chosen for monitoring should be selected based on the priorities of local communities. Monitoring programs under development should examine species for population level impacts in Arctic mammals and birds. Mammals and birds can be useful in source and surveillance monitoring via locally designed monitoring programs. We recommend future programs consider a range of monitoring objectives with mammals and birds as part of the suite of tools for monitoring litter and microplastics, plastic chemical additives, and effects, and for understanding sources.
", "keywords": ["0106 biological sciences", "570", "marine litter", "d\u00e9chet marin", ":Zoology and botany: 480 [VDP]", "VDP::Zoologiske og botaniske fag: 480", "590", "Forurensing", "Environmental engineering", "Environmental pollutants in the Arctic", "01 natural sciences", "contamination", "plastic", "GE1-350", "14. Life underwater", "wild food", ":Zoologiske og botaniske fag: 480 [VDP]", "Microplastic", "TA170-171", "15. Life on land", "Mikroplast", "Pollution", "3. Good health", "Environmental sciences", "13. Climate action", "VDP::Zoology and botany: 480", "Milj\u00f8gifter i Arktis", "debris"]}, "links": [{"href": "https://cdnsciencepub.com/doi/pdf/10.1139/as-2021-0058"}, {"href": "https://doi.org/10.1139/as-2021-0058"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Arctic%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1139/as-2021-0058", "name": "item", "description": "10.1139/as-2021-0058", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1139/as-2021-0058"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2022-05-05T00:00:00Z"}}, {"id": "10.3389/fpls.2020.558979", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:20:50Z", "type": "Journal Article", "created": "2020-10-27", "title": "Insect Herbivory Strongly Modifies Mountain Birch Volatile Emissions", "description": "Insect herbivory is known to augment emissions of biogenic volatile organic compounds (BVOCs). Yet few studies have quantified BVOC responses to insect herbivory in natural populations in pan-Arctic regions. Here, we assess how quantitative and qualitative BVOC emissions change with increasing herbivore feeding intensity in the Subarctic mountain birch (Betula pubescens var pumila (L.)) forest. We conducted three field experiments in which we manipulated the larval density of geometrid moths (Operophtera brumata and Epirrita autumnata), on branches of mountain birch and measured BVOC emissions using the branch enclosure method and gas chromatography-mass spectrometry. Our study showed that herbivory significantly increased BVOC emissions from the branches damaged by larvae. BVOC emissions increased due to insect herbivory at relatively low larvae densities, causing up to 10% of leaf area loss. Insect herbivory also changed the blend composition of BVOCs, with damaged plants producing less intercorrelated BVOC blends than undamaged ones. Our results provide a quantitative understanding of the relationship between the severity of insect herbivore damage and emissions of BVOCs at larvae densities corresponding to background herbivory levels in the Subarctic mountain birch. The results have important and practical implications for modeling induced and constitutive BVOC emissions and their feedbacks to atmospheric chemistry.", "keywords": ["0301 basic medicine", "0303 health sciences", "VDP::Zoologiske og botaniske fag: 480", "insect herbivory", "Plant culture", "Plant Science", "15. Life on land", "geometrid moth", "SB1-1110", "03 medical and health sciences", "biotic stress", "mountain birch", "stress severity", "13. Climate action", "volatile organic compounds", "11. Sustainability", "arctic", "VDP::Zoology and botany: 480"]}, "links": [{"href": "https://doi.org/10.3389/fpls.2020.558979"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Plant%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/fpls.2020.558979", "name": "item", "description": "10.3389/fpls.2020.558979", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/fpls.2020.558979"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-10-27T00:00:00Z"}}, {"id": "1893/33794", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:25:19Z", "type": "Journal Article", "created": "2021-12-30", "title": "Global maps of soil temperature", "description": "AbstractResearch in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2\uffc2\uffa0m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1\uffe2\uff80\uff90km2resolution for 0\uffe2\uff80\uff935 and 5\uffe2\uff80\uff9315\uffc2\uffa0cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1\uffe2\uff80\uff90km2pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse\uffe2\uff80\uff90grained air temperature estimates from ERA5\uffe2\uff80\uff90Land (an atmospheric reanalysis by the European Centre for Medium\uffe2\uff80\uff90Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10\uffc2\uffb0C (mean\uffc2\uffa0=\uffc2\uffa03.0\uffc2\uffa0\uffc2\uffb1\uffc2\uffa02.1\uffc2\uffb0C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6\uffc2\uffa0\uffc2\uffb1\uffc2\uffa02.3\uffc2\uffb0C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (\uffe2\uff88\uff920.7\uffc2\uffa0\uffc2\uffb1\uffc2\uffa02.3\uffc2\uffb0C). The observed substantial and biome\uffe2\uff80\uff90specific offsets emphasize that the projected impacts of climate and climate change on near\uffe2\uff80\uff90surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil\uffe2\uff80\uff90related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.