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Shibata H, Branquinho C, McDowell WH, Mitchell MJ, Monteith DT, Tang J, Arvola L, Cruz C, Cusack DF, Halada L, Kopáček J, Máguas C, Sajidu S, Schubert H, Tokuchi N, Záhora J. Consequence of altered nitrogen cycles in the coupled human and ecological system under changing climate: The need for long-term and site-based research. AMBIO 2015; 44:178-93. [PMID: 25037589 PMCID: PMC4357624 DOI: 10.1007/s13280-014-0545-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/24/2014] [Accepted: 06/30/2014] [Indexed: 05/02/2023]
Abstract
Anthropogenically derived nitrogen (N) has a central role in global environmental changes, including climate change, biodiversity loss, air pollution, greenhouse gas emission, water pollution, as well as food production and human health. Current understanding of the biogeochemical processes that govern the N cycle in coupled human-ecological systems around the globe is drawn largely from the long-term ecological monitoring and experimental studies. Here, we review spatial and temporal patterns and trends in reactive N emissions, and the interactions between N and other important elements that dictate their delivery from terrestrial to aquatic ecosystems, and the impacts of N on biodiversity and human society. Integrated international and long-term collaborative studies covering research gaps will reduce uncertainties and promote further understanding of the nitrogen cycle in various ecosystems.
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Affiliation(s)
- Hideaki Shibata
- />Field Science Center for Northern Biosphere, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-0809 Japan
| | - Cristina Branquinho
- />Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Bloco C2, 5° Piso, sala 37, 1749-016 Lisbon, Portugal
| | - William H. McDowell
- />Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd., Durham, NH 03824 USA
| | - Myron J. Mitchell
- />College of Environmental Science and Forestry, State University of New York, 1 Forestry Drive, Syracuse, NY 13210 USA
| | - Don T. Monteith
- />NERC Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP UK
| | - Jianwu Tang
- />Ecosystems Center, Marine Biological Laboratory, 7 MBL St., Woods Hole, MA 02543 USA
| | - Lauri Arvola
- />Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900 Lammi, Finland
| | - Cristina Cruz
- />Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Bloco C2, 5° Piso, sala 37, 1749-016 Lisbon, Portugal
| | - Daniela F. Cusack
- />Department of Geography, University of California - Los Angeles, 1255 Bunche Hall, Box 951524, Los Angeles, CA 90095 USA
| | - Lubos Halada
- />Institute of Landscape Ecology SAS, Branch Nitra, Akademicka 2, POB 22, 949 10 Nitra, Slovakia
| | - Jiří Kopáček
- />Institute of Hydrobiology, Biology Centre ASCR, Na Sádkách 7, 37005 České Budějovice, Czech Republic
| | - Cristina Máguas
- />Center for Environmental Biology, SIIAF - Stable Isotopes and Instrumental Analysis Facility, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Bloco C2, 5° Piso, sala 12, 1749-016 Lisbon, Portugal
| | - Samson Sajidu
- />Chemistry Department, Chancellor College, University of Malawi, P.O Box 280, Zomba, Malawi
| | - Hendrik Schubert
- />Institut für Biowissenschaften, Lehrstuhl Ökologie, Universität Rostock, Albert-Einsteinstraße 3, 18051 Rostock, Germany
| | - Naoko Tokuchi
- />Field Science Education and Research Center, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502 Japan
| | - Jaroslav Záhora
- />Mendel University in Brno, Zemědělská 1/1665, 613 00 Brno, Czech Republic
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Lepistö A, Futter MN, Kortelainen P. Almost 50 years of monitoring shows that climate, not forestry, controls long-term organic carbon fluxes in a large boreal watershed. GLOBAL CHANGE BIOLOGY 2014; 20:1225-1237. [PMID: 24501106 DOI: 10.1111/gcb.12491] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 11/02/2013] [Indexed: 05/28/2023]
Abstract
Here, we use a unique long-term data set on total organic carbon (TOC) fluxes, its climatic drivers and effects of land management from a large boreal watershed in northern Finland. TOC and runoff have been monitored at several sites in the Simojoki watershed (3160 km(2) ) since the early 1960s. Annual TOC fluxes have increased significantly together with increased inter-annual variability. Acid deposition in the area has been low and has not significantly influenced losses of TOC. Forest management, including ditching and clear felling, had a minor influence on TOC fluxes - seasonal and long-term patterns in TOC were controlled primarily by changes in soil frost, seasonal precipitation, drought, and runoff. Deeper soil frost led to lower spring TOC concentrations in the river. Summer TOC concentrations were positively correlated with precipitation and soil moisture not temperature. There is some indication that drought conditions led to elevated TOC concentrations and fluxes in subsequent years (1998-2000). A sensitivity analysis of the INCA-C model results showed the importance of landscape position, land-use type, and soil temperature as controls of modeled TOC concentrations. Model predictions were not sensitive to forest management. Our results are contradictory to some earlier plot-scale and small catchment studies that have shown more profound forest management impacts on TOC fluxes. This shows the importance of scale when assessing the mechanisms controlling TOC fluxes and concentrations. The results highlight the value of long-term multiple data sets to better understand ecosystem response to land management, climate change and extremes in northern ecosystems.
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Affiliation(s)
- Ahti Lepistö
- Finnish Environment Institute SYKE, P.O. Box 140, FI-00251, Helsinki, Finland
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Stenberg M, Ulén B, Söderström M, Roland B, Delin K, Helander CA. Tile drain losses of nitrogen and phosphorus from fields under integrated and organic crop rotations. A four-year study on a clay soil in southwest Sweden. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 434:79-89. [PMID: 22264921 DOI: 10.1016/j.scitotenv.2011.12.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 12/09/2011] [Accepted: 12/14/2011] [Indexed: 05/26/2023]
Abstract
In order to explore the influence of site-specific soil properties on nitrogen (N) and phosphorus (P) losses between individual fields and crop sequences, 16 drained fields with clay soils were investigated in a four-year study. Mean total N (TN) loss was 6.6-11.1 from a conventional, 14.3-21.5 from an organic and 13.1-23.9 kg ha(-1) year(-1) from an integrated cropping system across a 4 year period, with 75% in nitrate form (NO(3)-N). Mean total P (TP) loss was 0.96-3.03, 0.99-4.63 and 0.76-2.67 kg ha(-1) year(-1), from the three systems respectively during the same period, with 25% in dissolved reactive form (DRP). Median N efficiency was calculated to be 70% including gains from estimated N fixation. According to principal component factor (PCA) analysis, field characteristics and cropping system were generally more important for losses of N and P than year. Accumulation of soil mineral N in the autumn and (estimated) N fixation was important for N leaching. No P fertilisers were used at the site in either cropping system. Total P concentration in drainage water from each of the fields was marginally significantly (p<0.05) correlated to TP concentration in the topsoil (r=0.52), measured in hydrochloric acid extract (P-HCl). Mean DRP concentrations were significantly (p<0.01) correlated to degree of P saturation (DPS-AL) and soil carbon (C) content in the topsoil (r=0.63). Good establishment of a crop with efficient nutrient uptake and good soil structure was general preconditions for low nutrient leaching. Incorporation of ley by tillage operations in the summer before autumn crop establishment and repeated operations in autumn as well, increased N leaching. Crop management in sequences with leguminous crops needs to be considered carefully when designing cropping systems high efficiency in N utilisation and low environmental impact.
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Affiliation(s)
- Maria Stenberg
- Swedish University of Agricultural Sciences, Department of Soil and Environment, Skara, Sweden.
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Erlandsson M, Laudon H, Fölster J. Spatiotemporal patterns of drivers of episodic acidification in Swedish streams and their relationships to hydrometeorological factors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:4633-4643. [PMID: 20637494 DOI: 10.1016/j.scitotenv.2010.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 06/07/2010] [Accepted: 06/09/2010] [Indexed: 05/29/2023]
Abstract
This study examined the spatiotemporal patterns of episodic acidification in 87 weakly buffered streams in Sweden at a monthly sampling frequency during a ten-year study period (1998-2007). Time series of pre-industrial pH (pH(0)) were reconstructed from the acidification model Meta(MAGIC), and the acidification impact was defined by the difference between the pH(0) and the contemporary pH (i.e., DeltapH=pH(0)-pH(t)). Acidification episodes were defined as observations for which the pH(t) was at least 0.4 units lower than average, in combination with a pH at least 0.2 units higher than average. Thus, only occasions in which the stream water was both more acidic and more acidified than average were characterized as acidification episodes. For each observed episode, the primary cause was identified from one of the following five possible drivers: dilution, increase in sulfate, nitrate or organic acids, or sea salt deposition. In total, 258 episodes were observed during the study period. The study showed that streams that were acidified during baseflow (DeltapH>0.4), but not chronically acidic (pH>5.2), were subjected to regular episodic acidification. Dilution was the single most important cause and the main driver for 58% of the identified episodes. Increases in sulfate concentrations were also relatively common (26% of episodes), whereas increases in nitrate and organic acids as well as sea salt deposition were of minor importance. The total number of dilution-related acidification episodes within a year had a significant (p=0.005) positive correlation (r=+0.83) with the average annual precipitation. Occurrences of sulfate episodes were related to droughts during the preceding summers. While the number of streams that are susceptible to episodic acidification will decrease as a consequence of recovery from acidification, the hydrological and meteorological consequences of future climate change may make episodic acidification more common.
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Affiliation(s)
- Martin Erlandsson
- Department of Environmental Assessment, Swedish University of Agricultural Sciences, Box 7050, 750 07, Uppsala, Sweden.
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