Papers by Nicholas John Clarke
Source at http://hdl.handle.net/11250/2559230Skogens helsetilstand påvirkes i stor grad av klima ... more Source at http://hdl.handle.net/11250/2559230Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. Denne rapporten presenterer resultater fra skogskadeovervåkingen i Norge i 2017 og trender over tid for følgende temaer...Forest health is to a large extent affected by climate and weather conditions, either directly by e.g. drought, frost and wind, or indirectly when climatic conditions influence the occurrence and abundance of pests and diseases. Climate change and the expected increase in abiotic damage are a challenge to the management of future forest resources. The same is true for invasive dam...
Energy, Sustainability and Society, 2021
BackgroundBioenergy plays a key role in the transition to a sustainable economy in Europe, but it... more BackgroundBioenergy plays a key role in the transition to a sustainable economy in Europe, but its own sustainability is being questioned. We study the experiences of Sweden, Finland, Denmark and Norway, to find out whether the forest-based bioenergy chains developed in the four countries have led to unsustainable outcomes and how the countries manage the sustainability risks. Data were collected from a diversity of sources including interviews, statistical databases, the scientific literature, government planning documents and legislation.ResultsSustainability risks of deforestation, degradation of forests, reduced carbon pools in forests, expensive biopower and heat, resource competition, and lack of acceptance at the local level are considered. The experience of the four countries shows that the sustainability risks can to a high degree be managed with voluntary measures without resorting to prescriptive measures. It is possible to add to the carbon pools of forests along with hi...
The Integrated Monitoring Programme (ICP IM) is part of the effect-oriented activities under the ... more The Integrated Monitoring Programme (ICP IM) is part of the effect-oriented activities under the 1979 Convention on Long-range Transboundary Air Pollution, which covers the region of the United Nations Economic Commission for Europe (UNECE). The main aim of ICP IM is to provide a framework to observe and understand the complex changes occurring in natural/semi natural ecosystems. This report summarises the work carried out by the ICP IM Programme Centre and several collaborating institutes. The emphasis of the report is in the work done during the programme year 2019/2020 including: • A short summary of previous data assessments • A status report of the ICP IM activities, content of the IM database, and geographical coverage of the monitoring network • A report on temporal trends and input-output budgets of heavy metals in ICP IM catchments • An interim assessment of the impact of internal nitrogen-related parameters and exceedances of critical loads of eutrophication on long-term changes in the inorganic nitrogen output in European ICP Integrated Monitoring catchments • National Reports on ICP IM activities are presented as annexes.
Aas 10) 1) Soppsjukdommer i skog-, jord-og hagebruk, 2) Skogproduksjon og teknologi, 3) Bioteknol... more Aas 10) 1) Soppsjukdommer i skog-, jord-og hagebruk, 2) Skogproduksjon og teknologi, 3) Bioteknologi og molekylaer genetikk, 4) Terrestrisk økologi, 5) Skadedyr og ugras i skog-, jord-og hagebruk, 6) Skoggenetikk og biomangfold (NIBIO); 7) Vitenskapskomiteen for mat og miljø (VKM), 8) Norsk institutt for naturforskning (NINA), 9) UiT Norges Arktiske Universitet, 10) Norsk institutt for luftforskning (NILU)
Rapporten vurderer ut fra eksisterende litteratur og ved hjelp av modell-og prognosekjøringer kon... more Rapporten vurderer ut fra eksisterende litteratur og ved hjelp av modell-og prognosekjøringer konsekvensen av "hogstfredning" og ulike omløpstider i skog på karbonbinding. Resultatene antyder at høyest samlet karbonbinding i vegetasjon og jord vil oppnås ved lengre omløpstider (anslagsvis 30-50 år på middels bonitet) enn de såkalt "normale" omløpstider i skogbruket. Det knytter seg først og fremst usikkerhet til traernes vekst og avdøing ved utvidet omløpstid. Bledningshogst er vurdert til ikke å vaere et realistisk alternativ til ensalderskogbruket når det gjelder å øke karbonbinding i skog. Prognoser på landsbasis viser at den produktive skogen i Norge vil øke til en biomasse på ca. 2.1 milliarder tonn (i traer og jord) i løpet av 50 år, dersom den ble fredet fra hogst. Den årlige karbonbindingen ville da øke i en periode på 30 år for deretter gradvis å avta på grunn av skogens alderssammensetning. Med dagens hogstnivå i 50 år framover, vil biomassen i skog bygge seg opp til 1,5 milliarder tonn (i traer og jord). Høsting av GROT (greiner og topper) til energiformål vil bety lite for de totale karbonmengder i skog. Reduksjonen i CO 2-utslipp ved utstrakt bruk av GROT (60-70% av potensialet) til energiformål vil ligge i størrelsesorden 1,5-2% av de totale norske utslippene i dag. Dersom man skulle bruke 3 millioner m 3 tynningsvirke til bioenergiformål i tillegg til å nytte GROT, vil CO 2 besparelsene totalt ligge på 3,5-4,5% av dagens norske utslipp.
Biogeosciences Discussions, 2019
Drained organic forest soils in boreal and temperate climate zones are believed to be significant... more Drained organic forest soils in boreal and temperate climate zones are believed to be significant sources of the greenhouse gases (GHG) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), but the annual fluxes are still highly uncertain. Drained organic soils exemplify systems where many studies are still carried out with relatively small 40 resources, several methodologies and manually operated systems, which further involve different options for the detailed design of the measurement and data analysis protocols for deriving the annual flux. It would be beneficial to set certain guidelines for how to measure and report the data, so that data from individual studies could also be used in synthesis work based on data collation and modelling. Such synthesis work is necessary for deciphering general patterns and trends related to, e.g., site types, climate, and management, and the development of corresponding emission factors, i.e., 45 estimates of the net annual soil GHG emission/removal, which can be used in GHG inventories. Development of specific emission factors also sets prerequisites for the background or environmental data to be reported in individual studies. We argue that wide applicability greatly increases the value of individual studies. An overall objective of this paper is to support future monitoring campaigns in obtaining high-value data. We analysed peer-reviewed publications presenting CO2, CH4 and N2O flux data for drained organic forest soils in boreal and temperate climate zones, focusing on data that 50 have been used, or have the potential to be used, for estimating net annual soil GHG emission/removals. We evaluated the methods used in data collection, and identified major gaps in background/environmental data. Based on these, we formulated recommendations for future research.
The Science of the total environment, 2018
The international Long-Term Ecological Research Network (ILTER) encompasses hundreds of long-term... more The international Long-Term Ecological Research Network (ILTER) encompasses hundreds of long-term research/monitoring sites located in a wide array of ecosystems that can help us understand environmental change across the globe. We evaluated long-term trends (1990-2015) for bulk deposition, throughfall and runoff water chemistry and fluxes, and climatic variables in 25 forested catchments in Europe belonging to the UNECE International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICP IM). Many of the IM sites form part of the monitoring infrastructures of this larger ILTER network. Trends were evaluated for monthly concentrations of non-marine (anthropogenic fraction, denoted as x) sulphate (xSO) and base cations x(Ca+Mg), hydrogen ion (H), inorganic N (NO and NH) and ANC (Acid Neutralising Capacity) and their respective fluxes into and out of the catchments and for monthly precipitation, runoff and air temperature. A significant decrease of ...
Global change biology, Aug 31, 2018
Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion a... more Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosystems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralising capacity (ANC), major ions, total aluminium (Al), and dissolved organic carbon (DOC) were determined for the period 1995-2012. Plots with at least 10 years of observations from the ICP Forests monitoring network were used. Trends were assessed for the upper mineral soil (10-20 cm, 104 plots) and subsoil (40-80 cm, 162 plots). There was a large decrease in the concentration of sulphate (SO42-)in soil solution; over a ten-year period (2000-2010), SO42- decreased by 52% at 10-20 cm and 40% at 40-80 cm. Nitrate was uncha...
Journal of Environmental Monitoring, 2009
A Working Ring Test (WRT) was organised in the framework of the EU Regulation (EC) No 2152/2003 (... more A Working Ring Test (WRT) was organised in the framework of the EU Regulation (EC) No 2152/2003 ("Forest Focus") and of the UN/ECE Program "ICP Forests" to evaluate the overall performance of the laboratories monitoring atmospheric deposition and soil solution in European Forests. Seven natural samples of atmospheric deposition and soil solutions and 5 synthetic solutions were distributed to 52 laboratories, which analysed them using their routine methods. Thirteen variables are considered in this paper: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulfate, nitrate, chloride, total alkalinity, total dissolved nitrogen and dissolved organic carbon. For each variable, the relative standard deviation of the results was evaluated, after outlier rejection, to estimate the analytical error of the measurements. The results are evaluated considering the Quality Assurance/Quality Control (QA/QC) procedure included in the ICP Forests monitoring manual: consistency check of the data and use of control charts and internal standards. A Data Quality Objective (DQO) is defined for each of the variables and the number of data meeting the DQOs are discussed in relation to the QA/QC procedures adopted. Although 38% of the results did not meet the DQO, the laboratories adopting QA/QC procedures produced a larger proportion of results meeting the objective and a consistent part of the outliers could be detected a posteriori checking analyses consistence.
Global Biogeochemical Cycles, 2014
Lateral transport of carbon plays an important role in linking the carbon cycles of terrestrial a... more Lateral transport of carbon plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. There is, however, a lack of information on the factors controlling one of the main C sources of this lateral flux, i.e., the concentration of dissolved organic carbon (DOC) in soil solution across large spatial scales and under different soil, vegetation, and climate conditions. We compiled a database on DOC in soil solution down to 80 cm and analyzed it with the aim, first, to quantify the differences in DOC concentrations among terrestrial ecosystems, climate zones, soil, and vegetation types at global scale and second, to identify potential determinants of the site‐to‐site variability of DOC concentration in soil solution across European broadleaved and coniferous forests. We found that DOC concentrations were 75% lower in mineral than in organic soil, and temperate sites showed higher DOC concentrations than boreal and tropical sites. The majority of the varia...
Sustainable Forest Management - Current Research, 2012
Scandinavian Journal of Forest Research, 2017
ABSTRACT Short-term (three to four years) effects of forest harvesting on soil solution chemistry... more ABSTRACT Short-term (three to four years) effects of forest harvesting on soil solution chemistry were investigated at two Norway spruce sites in southern Norway, differing in precipitation amount and topography. Experimental plots were either harvested conventionally (stem-only harvesting, SOH) or whole trees, including crowns, twigs and branches were removed (whole-tree harvesting, WTH), leaving residue piles on the ground for some months before removal. The WTH treatment had two sub-treatments: WTH-pile where there had been piles and WTH-removal, from where residues had been removed to make piles. Increased soil solution concentrations of NO3–N, total N, Ca, Mg and K at 30 cm depth, shown by peaks in concentrations in the years after harvesting, were found at the drier, less steep site in eastern Norway after SOH and WTH-pile, but less so after WTH-removal. At the wetter, steeper site in western Norway, peaks were often observed also at WTH-removal plots, which might reflect within-site differences in water pathways due largely to site topography.
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Papers by Nicholas John Clarke