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Pihl Karlsson G, Akselsson C, Hellsten S, Karlsson PE. Atmospheric deposition and soil water chemistry in Swedish forests since 1985 - Effects of reduced emissions of sulphur and nitrogen. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169734. [PMID: 38163609 DOI: 10.1016/j.scitotenv.2023.169734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Trends for the atmospheric deposition of sulphur (S) and inorganic nitrogen (inorg-N) to forests and changes in the forest soil water chemistry in Sweden have been assessed since 1985, with special focus on the last 25 years, based on measurements within the Swedish Throughfall Monitoring Network (SWETHRO). The reductions in the deposition of S and inorg-N in the southern part of Sweden corresponded relatively well with the pollutant emission reductions for S and inorg-N from both EU27 + UK and Sweden during 1996/97-2021/22. For northern Sweden the deposition of S and inorg-N decreased to a lesser extent than both European and Swedish emissions. The bulk deposition of NO3-N has decreased more than the deposition of NH4-N over the last 25-year period, which is consistent with the much larger emission reductions for NOx compared to NH3 from EU27 + UK and Sweden. The S concentrations in the soil water, at 50 cm below soil surface, have decreased during the last 25 years, however somewhat less than the S deposition. At sites with low ANC and pH in the beginning of the period, the increase in ANC was generally greater and the increase in pH was smaller, but at sites with high pH and ANC above zero, the increase in pH was dominant, in line with the nonlinear relationship between pH and ANC in the soil water. The incidence of elevated concentrations of NO3-N in the soil water was highest in southwest Sweden, ranging between 4 and 19 % of all measuring occasions since 1985/86. The reduced deposition of N over the 35-year period was not reflected in the incidence of elevated concentrations of NO3-N in the soil water over time.
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Affiliation(s)
- G Pihl Karlsson
- IVL Swedish Environmental Research Institute, P.O. Box 53021, SE-40014 Gothenburg, Sweden.
| | - C Akselsson
- Lund University, Department of Physical Geography and Ecosystems Science, Sölvegatan 12, SE-223 62 Lund, Sweden
| | - S Hellsten
- IVL Swedish Environmental Research Institute, P.O. Box 53021, SE-40014 Gothenburg, Sweden
| | - P E Karlsson
- IVL Swedish Environmental Research Institute, P.O. Box 53021, SE-40014 Gothenburg, Sweden
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Hedwall PO, Gustafsson L, Brunet J, Lindbladh M, Axelsson AL, Strengbom J. Half a century of multiple anthropogenic stressors has altered northern forest understory plant communities. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01874. [PMID: 30761647 DOI: 10.1002/eap.1874] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 01/14/2019] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
Boreal forests form the largest and least disturbed forest biome in the northern hemisphere. However, anthropogenic pressure from intensified forest management, eutrophication, and climate change may alter the ecosystem functions of understory vegetation and services boreal forests provide. Swedish forests span long gradients of climate, nitrogen deposition, and management intensity. This makes them ideal to study how the species composition and functions of other, more pristine, boreal forests might change under increased anthropogenic pressure. Moreover, the National Forest Inventory (NFI) has collected systematic data on Swedish forest vegetation since the mid-20th century. We use this data to quantify changes in vegetation types between two periods, 1953-1962 and 2003-2012. The results show changes in forest understory vegetation since the 1950s at scales not previously documented in the boreal biome. The spatial extent of most vegetation types changed significantly. Shade-adapted and nutrient-demanding species (those with high specific leaf area) have become more common at the expense of light-demanding and nutrient-conservative (low specific leaf area) species. The cover of ericaceous dwarf shrubs decreased dramatically. These effects were strongest where anthropogenic impacts were greatest, suggesting links to drivers such as nitrogen deposition and land-use change. These changes may impact ecosystem functions and services via effects on higher trophic levels and faster plant litter decomposition in the expanding vegetation types. This, in turn, may influence nutrient dynamics, and consequently ecosystem productivity and carbon sequestration.
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Affiliation(s)
- Per-Ola Hedwall
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, Alnarp, 230 53, Sweden
| | - Lena Gustafsson
- Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, Uppsala, 750 07, Sweden
| | - Jörg Brunet
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, Alnarp, 230 53, Sweden
| | - Matts Lindbladh
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, P.O. Box 49, Alnarp, 230 53, Sweden
| | - Anna-Lena Axelsson
- Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå, 901 83, Sweden
| | - Joachim Strengbom
- Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, Uppsala, 750 07, Sweden
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Perring MP, Diekmann M, Midolo G, Schellenberger Costa D, Bernhardt-Römermann M, Otto JCJ, Gilliam FS, Hedwall PO, Nordin A, Dirnböck T, Simkin SM, Máliš F, Blondeel H, Brunet J, Chudomelová M, Durak T, De Frenne P, Hédl R, Kopecký M, Landuyt D, Li D, Manning P, Petřík P, Reczyńska K, Schmidt W, Standovár T, Świerkosz K, Vild O, Waller DM, Verheyen K. Understanding context dependency in the response of forest understorey plant communities to nitrogen deposition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 242:1787-1799. [PMID: 30115529 DOI: 10.1016/j.envpol.2018.07.089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 07/03/2018] [Accepted: 07/20/2018] [Indexed: 05/17/2023]
Abstract
Understorey communities can dominate forest plant diversity and strongly affect forest ecosystem structure and function. Understoreys often respond sensitively but inconsistently to drivers of ecological change, including nitrogen (N) deposition. Nitrogen deposition effects, reflected in the concept of critical loads, vary greatly not only among species and guilds, but also among forest types. Here, we characterize such context dependency as driven by differences in the amounts and forms of deposited N, cumulative deposition, the filtering of N by overstoreys, and available plant species pools. Nitrogen effects on understorey trajectories can also vary due to differences in surrounding landscape conditions; ambient browsing pressure; soils and geology; other environmental factors controlling plant growth; and, historical and current disturbance/management regimes. The number of these factors and their potentially complex interactions complicate our efforts to make simple predictions about how N deposition affects forest understoreys. We review the literature to examine evidence for context dependency in N deposition effects on forest understoreys. We also use data from 1814 European temperate forest plots to test the ability of multi-level models to characterize context-dependent understorey responses across sites that differ in levels of N deposition, community composition, local conditions and management history. This analysis demonstrated that historical management, and plot location on light and pH-fertility gradients, significantly affect how understorey communities respond to N deposition. We conclude that species' and communities' responses to N deposition, and thus the determination of critical loads, vary greatly depending on environmental contexts. This complicates our efforts to predict how N deposition will affect forest understoreys and thus how best to conserve and restore understorey biodiversity. To reduce uncertainty and incorporate context dependency in critical load setting, we should assemble data on underlying environmental conditions, conduct globally distributed field experiments, and analyse a wider range of habitat types.
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Affiliation(s)
- Michael P Perring
- Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090, Melle-Gontrode, Belgium; Ecosystem Restoration and Intervention Ecology Research Group, School of Biological Sciences, The University of Western Australia, 35, Stirling Highway, Crawley, WA, 6009, Australia.
| | - Martin Diekmann
- Vegetation Ecology and Conservation Biology, Institute of Ecology, FB 2, University of Bremen, Leobener Str. 5, DE-28359, Bremen, Germany
| | - Gabriele Midolo
- Faculty of Science and Technology, Free University of Bozen/Bolzano, Piazza Università 5, 39100, Bozen/Bolzano, Italy
| | - David Schellenberger Costa
- Institute of Ecology and Evolution, Friedrich-Schiller-University Jena, Dornburger Str. 159, DE-07743, Jena, Germany
| | - Markus Bernhardt-Römermann
- Institute of Ecology and Evolution, Friedrich-Schiller-University Jena, Dornburger Str. 159, DE-07743, Jena, Germany
| | - Johanna C J Otto
- Institute of Ecology and Evolution, Friedrich-Schiller-University Jena, Dornburger Str. 159, DE-07743, Jena, Germany
| | - Frank S Gilliam
- Department of Biology, University of West Florida, Pensacola, FL, 32514, USA
| | - Per-Ola Hedwall
- Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, 230 53, Alnarp, Sweden
| | - Annika Nordin
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå Plant Science Centre, 901 83, Umeå, Sweden
| | | | - Samuel M Simkin
- National Ecological Observatory Network, 1685 38th St., Suite 100, Boulder, CO, 80301, USA
| | - František Máliš
- Technical University in Zvolen, Faculty of Forestry, T. G. Masaryka 24, 960 53, Zvolen, Slovakia; National Forest Centre, T. G. Masaryka 22, 960 92, Zvolen, Slovakia
| | - Haben Blondeel
- Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090, Melle-Gontrode, Belgium
| | - Jörg Brunet
- Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, 230 53, Alnarp, Sweden
| | - Markéta Chudomelová
- Department of Vegetation Ecology, Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, CZ-60200, Brno, Czech Republic
| | - Tomasz Durak
- Department of Ecology, University of Rzeszów, ul. Rejtana 16C, PL-35- 959, Rzeszów, Poland
| | - Pieter De Frenne
- Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090, Melle-Gontrode, Belgium
| | - Radim Hédl
- Department of Vegetation Ecology, Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, CZ-60200, Brno, Czech Republic; Department of Botany, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Martin Kopecký
- Department of GIS and Remote Sensing, Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 00, Prague 6, Suchdol, Czech Republic
| | - Dries Landuyt
- Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090, Melle-Gontrode, Belgium
| | - Daijiang Li
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - Peter Manning
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Frankfurt, Germany
| | - Petr Petřík
- Department of GIS and Remote Sensing, Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Kamila Reczyńska
- Department of Botany, Faculty of Biological Sciences, University of Wrocław, Kanonia 6/8, PL-50-328, Wrocław, Poland
| | - Wolfgang Schmidt
- Department of Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen, Büsgenweg 1, D-37077, Göttingen, Germany
| | - Tibor Standovár
- Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, Pázmány P. sétány 1/c, H-1117, Budapest, Hungary
| | - Krzysztof Świerkosz
- Museum of Natural History, University of Wrocław, Sienkiewicza 21, PL-50-335, Wroclaw, Poland
| | - Ondřej Vild
- Department of Vegetation Ecology, Institute of Botany, The Czech Academy of Sciences, Lidická 25/27, CZ-60200, Brno, Czech Republic
| | - Donald M Waller
- Department of Botany, University of Wisconsin - Madison, Madison, WI, 53706, USA
| | - Kris Verheyen
- Forest & Nature Lab, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Geraardsbergsesteenweg 267, 9090, Melle-Gontrode, Belgium
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Hedwall PO, Brunet J. Trait variations of ground flora species disentangle the effects of global change and altered land-use in Swedish forests during 20 years. GLOBAL CHANGE BIOLOGY 2016; 22:4038-4047. [PMID: 27111238 DOI: 10.1111/gcb.13329] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/07/2016] [Accepted: 04/17/2016] [Indexed: 05/22/2023]
Abstract
Northern forest ecosystems are exposed to a range of anthropogenic processes including global warming, atmospheric deposition, and changing land-use. The vegetation of northern forests is composed of species with several functional traits related to these processes, whose effects may be difficult to disentangle. Here, we combined analyses of spatio-temporal dynamics and functional traits of ground flora species, including morphological characteristics, responses to macro- and microclimate, soil conditions, and disturbance. Based on data from the Swedish National Forest Inventory, we compared changes in occurrence of a large number of ground flora species during a 20-year period (1994-2013) in boreal and temperate Sweden respectively. Our results show that a majority of the common ground flora species have changed their overall frequency. Comparisons of functional traits between increasing and declining species, and of trends in mean trait values of sample plots, indicate that current floristic changes are caused by combined effects of climate warming, nitrogen deposition and changing land-use. Changes and their relations with plant traits were generally larger in temperate southern Sweden. Nutrient-demanding species with mesotrophic morphology were favored by ongoing eutrophication due to nitrogen deposition in the temperate zone, while dwarf shrubs with low demands on nitrogen decreased in frequency. An increase of species with less northern and less eastern distribution limits was also restricted to temperate Sweden, and indicates effects of a moister and milder macroclimate. A trend toward dense plantation forests is mirrored by a decrease of light-demanding species in both vegetation zones, and a decrease of grassland species in the temperate zone. Although denser tree canopies may buffer effects of a warmer climate and of nitrogen deposition to some extent, traits related to these processes were weakly correlated in the group of species with changing frequency. Hence, our results indicate specific effects of these often confounded anthropogenic processes.
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Affiliation(s)
- Per-Ola Hedwall
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 49, 230 53, Alnarp, Sweden
| | - Jörg Brunet
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Box 49, 230 53, Alnarp, Sweden
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