Nicholas Clarke
Research Professor
Biography
Authors
James Weldon Wenche Aas Barbara Albiniak Algirdas Augustaitis Ieva Baužienė Camilla Capelli Nicholas Clarke Thomas Cummins Heleen de Wit Thomas Dirnböck Ika Djukic Karin Eklöf Martin Forsius Martyn Futter Ulf Grandin Sergei Gromov Adéla Holubová Šmejkalová Ricardo Ibañez Iveta Indriksone Sara Jutterström Johannes Kobler Heidi Koger Angelika Kölbl Andrzej Kostrzewski Anna Koukhta Pavel Krám Robert Kruszyk Esther Lasheras Kairi Lõhmus Mikołaj Majewski Ulla Makkonen Hampus Markensten Rafael Miranda Michael Mirtl Filip Moldan Giancarlo Papitto Johannes Peterseil Ainis Pivoras Thomas Plha Gisela Pröll Pernilla Rönnback Carolina Santamaría Jesús Miguel Santamaría Krzysztof Skotak David Elustondo Mercedes Valerio Sarah Venier Lieke E. Vlaar Liisa Ukonmaanaho Jussi Vuorenmaa Nicole WellbrockAbstract
Abstract The International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM) presents a comprehensive long-term dataset of ongoing integrated ecosystem monitoring from European forested catchments. The dataset encompasses measurements from 46 monitoring stations across 14 European countries, with temporal coverage mostly extending from the early 1990s to 2020 (48 sites are currently active). The integrated monitoring approach applies over 20 monitoring subprogrammes to simultaneously measure physical, chemical, and biological properties across multiple ecosystem compartments including atmosphere, precipitation, throughfall, soil water, groundwater, runoff water, soil, vegetation, and biota. All measurements follow standardised protocols detailed in the ICP IM Manual, ensuring data quality and comparability across sites and time periods. The dataset supports research on ecosystem responses to air pollution, climate change impacts, and biogeochemical cycling. Data are available under a Creative Commons By Attribution (CC BY) licence, providing valuable long-term environmental monitoring data for the scientific community.
Authors
Jiajun Wu Bin Zhou Zhehao Huang Zichuan Li Jingyuan Pan Kaihao Zhang Cheng Liu Yanjun Chai Yan Li Muhammad Azeem Nicholas Clarke Shengdao ShanAbstract
No abstract has been registered
Abstract
We assessed soil organic carbon (SOC) stocks and changes across six upland forest sites with 13replicated plots, spanning bioclimatic regions from the boreonemoral to the northern borealzone. The sites included three ICP Forests Level II plots in older coniferous stands and threelong-term experiments focusing on thinning intensity, tree species effects (Norway spruce, Scotspine, silver birch), and mixtures of Norway spruce and downy birch, the latter two followingclear-cutting. Repeated soil surveys spanned 9–34 years. SOC stocks in the organic LFH horizonranged from 1.4 to 3.6 kg m−2, while total stocks down to 30 cm and 70–100 cm mineral soildepths ranged from 3.0 to 13.5 kg m−2 and 8.5 to 17.5 kg m−2, respectively. Annual SOC stockchanges in the LFH horizon ranged from −106 to 111 g m−2 yr−1, with significant changesobserved in five plots. Total SOC stock changes down to 15, 18 or 20 cm mineral soil depthranged from −77 to 154 g m−2 yr−1, with significant increases detected in two ICP level II plots.Sensitivity analyses supported these findings but highlighted inconsistencies in samplingmethods, hight spatial variability, and limited replicates, affecting estimates in the remaining 11plots.ARTICLE HISTORYReceived 31 March 2025Accepted 8 July 2025KEYWORDSBoreal forest; downy birch;Norway spruce; Scots pine;soil organic carbon; SOC;SOC stock changesIntroductionForest ecosystems are crucial biomes for carbon (C)storage, with boreal forests playing a significant role asa C sink (Pan et al. 2011; Watts et al. 2023). Globally,the soil organic carbon (SOC) pool contains more thanthree times as much C as the atmosphere (Schmidt etal. 2011). From a climate perspective, the importanceof SOC storage is tied to its overall size as well as itspotential as a long-term reservoir. Estimates of SOCstocks in boreal upland forests suggest 3–4 times moreC relative to the aboveground tree biomass (Scharle-mann et al. 2014; Bradshaw and Warkentin 2015). Thebiological stability of SOC is mediated by a broad setof environmental drivers, notably temperature and soilmoisture content (Soucémarianadin et al. 2018).Additionally, microbial communities play an importantrole in both decomposition and accumulation of SOC(Lindahl et al. 2021; Gundale et al. 2024), processesthat are further influenced by forest management prac-tices (Mayer et al. 2020; Jörgensen et al. 2022) and treespecies (Mundra et al. 2022, 2024). The effect of treespecies on SOC stocks may primarily influence the distri-bution of SOC within the soil profile rather than the totalSOC stock (Vesterdal et al. 2013; Kjønaas et al. 2021). Thisdistribution, however, affects the stability of SOC and itsvulnerability to decomposition, consequently impactingthe CO2 flux from the soil (James and Harrison 2016;Cotrufo et al. 2019; Georgiou et al. 2024).Estimated C allocation in Norwegian forests is approxi-mately 21% in vegetation and 79% in soil (Grønlund etal. 2010). SOC stocks in Norwegian forest soils are con-sidered higher compared to those of Sweden andFinland (Olsson et al. 2009; Rantakari et al. 2012; Strandet al. 2016). This disparity may partly stem from varyinginventory methods. However, differences in precipitationand temperature gradients account for approximately68% of the variability in SOC stocks across Nordic forests(Callesen et al. 2003), suggesting that climate factors alsoplay a significant role. On a European scale, coniferousforest soils represent one of the largest and most vulner-able SOC stocks (Lugato et al. 2021). The size and stabilityof the SOC stock may determine the magnitude of© 2025 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis GroupThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use,distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the AcceptedManuscript in a repository by the author(s) or with their consent.CONTACT O. Janne Kjønaas janne.kjonaas@nibio.noSupplemental data for this article can be accessed online at https://doi.org/10.1080/02827581.2025.2533379.SCANDINAVIAN JOURNAL OF FOREST RESEARCH2025, VOL. 40, NOS. 7–8, 321–356https://doi.org/10.1080/02827581.2025.2533379
