Forests and abundance of water −focus on boreal forests and peatlands Abstracts and Programme of the COST Action FP0601 FORMAN Workshop at the Finnish Environment Institute, Helsinki and Hyytiälä Forestry Field Station, Finland 6.−8.9.2010 Leena Finér, Pirkko Kortelainen, Elve Lode and Markus Lier (eds.) Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm ISBN 978-951-40-2247-0 (PDF) ISBN 978-951-40-2248-7 (paperback) ISSN 1795-150X www.metla.fi Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 2 Working Papers of the Finnish Forest Research Institute publishes preliminary research results and conference proceedings. The papers published in the series are not peer-reviewed. The papers are published in pdf format on the Internet only. http://www.metla.fi/julkaisut/workingpapers/ ISSN 1795-150X Office P.O. Box 18 FI-01301 Vantaa, Finland tel. +358 10 2111 fax +358 10 211 2101 e-mail julkaisutoimitus@metla.fi Publisher Finnish Forest Research Institute P.O. Box 18 FI-01301 Vantaa, Finland tel. +358 10 2111 fax +358 10 211 2101 e-mail info@metla.fi http://www.metla.fi/ Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 3 Authors Finér, Leena, Kortelainen, Pirkko, Lode, Elve & Lier, Markus (eds.) Title Forests and abundance of water -focus on boreal forests and peatlands. Abstracts and Programme of the COST Action FP0601 FORMAN Workshop at the Finnish Environment Institute, Helsinki and Hyytiälä Forestry Field Station, Finland 6.−8.9.2010 Year 2010 Pages 58 ISBN 978-951-40-2247-0 (PDF) 978-951-40-2248-7 (paperback) ISSN 1795-150X Unit / Research programme / Projects Finnish Forest Research Institute, Metla, Joensuu Research Unit / 3506 Accepted by Pasi Puttonen, Director of Research, 17.8.2010 Abstract This paper compiles the programme and abstracts of the international scientific workshop, Forests and abundance of water boreal forests and peatlands, organised in the premises of the Finnish Environment Institute, Helsinki and the Hyytiälä Forestry Field Station of the University of Helsinki from the 6th to 8th of September 2010. It is the 7th workshop of the COST Action FP0601 Forest management and water cycle (FORMAN). The main objectives of FORMAN are to enhance the knowledge on forest-water interactions in Europe and to elaborate science-based guidelines for the improvement of the management of forests predominantly designed for the production and storage of water. FORMAN will scientifically address the manifold aspects of managing forest-water interactions under rapidly changing environmental constraints. The main organizers of this Workshop are the Finnish Forest Research Institute, the Finnish Environment Institute, together with the Institute of Ecology from the Tallinn University, the Department of Soil and Environment from the Swedish University of Agricultural Sciences and the COST Action FP0601. Over 50 scientists from 19 different countries attend the workshop. Keywords abundance of water, boreal forests, peatlands Available at http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm Replaces Is replaced by Contact information Leena Finér, Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland. E-mail:leena.finer@metla.fi Other information Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 4 Contents Welcome to the conference ......................................................................................................................7 Practical Information ...............................................................................................................................8 Programme ...............................................................................................................................................9 List of participants ..................................................................................................................................12 Session 1: Water relations in boreal forests and peatlands ...................................15 Chair: Elve Lode, Tallinn University, Estonia & Swedish University of Agricultural Sciences, Sweden Keynote: Water relations in boreal forests and peatlands .....................................................................16 Leena Finér Managing erosion, sediment transport and water quality in drained peatland catchments ...................17 Hannu Marttila, Kari-Matti Vuori, Hannu Hökkä, Juha Jämsen and Bjørn Kløve Forestry operations have a small impact on the groundwater quality in aquifers ..................................18 Sirpa Piirainen, Leena Finér, Marja-Liisa Juntunen, Hannu Mannerkoski, Mirella Miettinen and Michael Starr Keynote: The role of water for carbon sequestration and GHG emissions in boreal forests ................19 Mats Olsson Drought-induced changes in Scots pine and Norway spruce stands estimated on the evidence to artificial drought experiments........................................................................................................20 Rasa Buozyte, Vidas Stakenas, Remigijus Ozolincius and Jurate Aleinikoviene The impact of drought on young spruce trees stem circumference changes and sap flow rate ..............21 Střelcová Katarína, Ježík Marek, Blaženec Miroslav, Frič Michal and Končír Matej Forest and permanent excess of water – peatland forestry .....................................................................22 Ari Laurén, Samuli Launiainen and Harri Koivusalo Use of natural and restored peatland buffers to reduce sediment and nutrient transport from forested catchments − Finnish experiences ...................................................................................23 Mika Nieminen, Anu Vikman, Sakari Sarkkola, Harri Koivusalo, Ari Lauren, Hannu Fritze Session 2: Water fluxes at different scales ...............................................................25 Chair: Patrick Schleppi, WSL, Switzerland Significance of tree roots to preferential flow in soil horizons with different degrees of hydromorphy .................................................................................................................................26 Benjamin Lange, Peter Lüscher and Peter F. Germann FOREST stony soil: The contribution of rock fragments to soil water retention ..................................27 Viliam Novák and Peter Šurda Development of a physics-based, dual-permeability model for subsurface stormflow and solute transport in a forested hillslope .....................................................................................................28 Hanne Laine-Kaulio and Harri Koivusalo GIS analysis of peatland topo-hydrological features .............................................................................30 Elve Lode and Meelis Leivits Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 5 Session 3: Hydrological fluxes in different climatic conditions .............................33 Chair: Viliam Pichler, Slovak Academy of Sciences, Bratislava, Slovakia Forest – Water Interactions: A Reply to the Water Yield Debate ..........................................................34 David Ellison, Martyn Futter and Kevin Bishop Carbon and nitrogen pathways from boreal headwater catchments downstream to the coast along variable land use cover ........................................................................................................35 Tuija Mattsson and Pirkko Kortelainen Stable isotopes studies to increase knowledge from the role of peatlands in catchment hydrology ......36 Anna-Kaisa Ronkanen, Hannu Marttila, Juha Siekkinen and Bjørn Kløve Runoff generation across spatial and temporal scales following wildfire ..............................................37 Jan Jacob Keizer, João Pedro Nunes, Maruxa Malvar, Sergio Prats, Raquel Ferreira, Diana Vieira, María Eufemia Varela, Isabel Fernandes and Silvia Faria Poster presentations ..................................................................................................39 New methods to control acid sulfate and organic acid leaching from peatland forestry drainage areas ................................................................................................................................40 Kaisa Heikkinen, Simo Tammela, Hannu Marttila, Tuomas Saarinen, Kati Martinmäki, Raimo Ihme, Mika Visuri, Jaakko Saukkoriipi, Jermi Tertsunen, Timo Yrjänä, Jukka Tuohino and Bjørn Kløve Participation of aquatic fungi in litter decomposition in Lithuanian woodland streams........................41 Svetlana Markovskaja and Jurga Motiejunaite Hydrological and protective services of forests – modelling on watershed level ..................................42 Špela Planinšek, Andreja Ferreira and Anže Japelj Stream ecohydrologic surveys to evaluate the impacts of watershed land use ......................................43 Semih Ediş, Betül Uygur and Yusuf Serengil Litterfall Production in Forests located at the Pre-delta Area of the Paraná River (Argentina) .............44 Pablo G. Aceñolaza, Lisandra P. Zamboni, Estela E. Rodríguez, Juan. F. Gallardo and M. Isabel González Ethylene and ABA responses to water stress in young Poplar ...............................................................45 Alessio Fortunati, Emanuele Pallozzi, Giovanni Marino and Mauro Centritto Upscaling water and carbon fluxes from leaf to canopy: role of stomatal control models ....................46 Samuli Launiainen Carbon emissions from bogs along a human-impact gradient in Estonia ..............................................47 Margus Pensa and Helen Karu Influence of woodland on the modification of the albedo and water distributions in an insular environment. Case study on Tenerife, Canary Islands, Spain .......................................................48 Juan Carlos Santamarta Cerezal and Luis Santana Pérez Scientific excursion, Wednesday 8th September 2010 ............................................49 EXCURSION SITE 1: SMEAR II – research station in Hyytiälä, Finland ...........................................50 Samuli Launiainen and Timo Vesala EXCURSION SITE 2: Lakkasuo - A diverse mire nature and research area in Central Finland .........52 Sakari Sarkkola and Harri Vasander EXCURSION SITE 3, a: Peatland water balance experiment in Jaakkoinsuo, Vilppula ......................55 Hannu Hökkä, Sakari Sarkkola, Harri Koivusalo, Eero Nikinmaa, and Mika Nieminen EXCURSION SITE 3, b: Jaakkoinsuo experimental drainage area ......................................................57 Hannu Hökkä and Sakari Sarkkola Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 6 Sponsors Organizers Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 7 Welcome to the conference Boreal forests are natural an essential element of the Northern European landscape. They cover 40−70% of the land area of the Nordic countries. With respect to abundant water conditions on that part of Europe, forests have an important stabilizer role both from water quality and quantity point of view, as well as from water basin and landscape point of view. The European boreal forest are important natural resource accompanied with intensive management, where forestry operations such as cutting, soil scarification and drainage have both internal and external forest and water impact interactions. The main concern is the increase in the export of elements after forestry operations. Changed element load will deteriorate surface water ecosystems and active measures are taken to mitigate these harmful effects on the watercourses. In the future one of the biggest challenges is to adapt forest management to the changing climatic and hydrological conditions. The focus of this three-day international scientific workshop, Forests and abundance of water, is in the water relations of boreal forests and peatlands and it is the 7th workshop of the COST Action FP0601 Forest management and water cycle (FORMAN). The main objectives of FORMAN are to enhance the knowledge on forest-water interactions in Europe and to elaborate science- based guidelines for the improvement of the management of forests predominantly designed for the production and storage of water. FORMAN will scientifically address the manifold aspects of managing forest-water interactions under rapidly changing environmental constraints. The previous six workshops have been arranged in the Mediterranean or temperate parts of Europe and this is the first workshop in the cooler climatic conditions, rich of water and forests. The workshop is organised in the premises of the Finnish Environment Institute (SYKE), Helsinki and the Hyytiälä Forestry Field Station of the University of Helsinki from the 6th to 8th of September 2010. The main organizers of this conference are the Finnish Forest Research Institute, Metla, SYKE, together with the Institute of Ecology from the Tallinn University, the Department of Soil and Environment from the Swedish University of Agricultural Sciences (SLU) and the COST Action FP0601. Over 50 scientists from 19 different countries attend the workshop. Scientific Committee of the Conference Michael Bredemeier, Leena Finér, Shabtai Cohen, Pirkko Kortelainen, Elve Lode, Viliam Pichler, Patrick Schleppi and Markus Lier Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 8 Practical Information The conference is organised in the premises of the Finnish Environment Institute (SYKE), Mechelininkatu 34a, Helsinki (on the 6.9.-7.9.2010) and the Hyytiälä Forestry Field Station (7.9.-8.9.2010), Finland. Sunday 5.9.2010 19:00–21:00 Ice breaker and sauna, Finnish Environment Institute (SYKE). Monday 6.9.2010 08:30–09:00 Registration 09:00–18:00 Conference day 1 (see programme for more detailed information) 19:30–22:00 Dinner at restaurant Savu, Tervasaarenkannas 3, 00170 Helsinki (at 18:30 public transport with bus no 18 from SYKE to the restaurant) Tuesday 7.9.2010 09:00–14:00 Conference day 2 (see programme for more detailed information) 14:30 Departure to Hyytiälä Forestry Field Station by bus in front of SYKE 17:30 Arrival to Hyytiälä, accommodation 18:00-19:30 Sauna (optional) 20:00 Dinner Wednesday 8.9.2010 07:30–17:30 Scientific excursion (see scientific excursion for more detailed information) Coffee and lunch break Coffee and lunch is included in the participation fee. Coffee will be served during breaks in the lobby and lunches at SYKE restaurant. Internet A wireless Internet connection is available in the conference venue. Please ask for the password from the registration desk. Important phone numbers: Scandic Hotel Continental + 358 9 473 71 Emergency number 112 Taxi Helsinki +358 100 060 0 Finnair +358 600 140 140 Markus Lier, Metla +358 50 391 3063 Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 9 Programme Sunday 5.9.2010 Arrival to Helsinki 18:30 Registration 19:00–21:00 Ice breaker and sauna, Finnish Environment Institute (SYKE) Monday 6.9.2010 8:30–9:00 Registration 9:00–9:15 Opening of the workshop Michael Bredemeier, chairman COST FORMAN Session 1: Water relations in boreal forests and peatlands Chair: Elve Lode, Tallinn University, Estonia & Swedish University of Agricultural Sciences, Sweden 9:15 Keynote:Water relations in boreal forests and peatlands Leena Finér, Finnish Forest Research Institute, Metla, Finland 9:45 Managing erosion, sediment transport and water quality in drained peatland catchments Hannu Marttila, University of Oulu, Finland 10:10 Forestry operations have a small impact on the groundwater quality in aquifers Sirpa Piirainen, Finnish Forest Research Institute, Metla, Finland 10:35 Coffee break and posters (see page 11) 11:00 Keynote: The role of water for carbon sequestration and GHG emissions in boreal forests Mats Olsson, SLU, Sweden 11:30 Drought-induced changes in Scots pine and Norway spruce stands estimated on the evidence to artificial drought experiments Jurate Aleinikoviene, Lithuanian Research Centre for Agriculture and Forestry, Lithuania 11:55 The impact of drought on young spruce trees stem circumference changes and sap flow rate Katarina Střelcová, Technical Univeristy of Zvolen, Slovakia 12:20 Forest and permanent excess of water – peatland forestry Ari Laurén, Finnish Forest Research Institute, Metla, Finland 12:45 Use of natural and restored peatland buffers to reduce sediment and nutrient transport from forested catchments - Finnish experiences Mika Nieminen, Finnish Forest Research Institute, Metla, Finland 13:05-13:45 Lunch continue on the next page... Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 10 Session 2: Water fluxes at different scales (modeling, upscaling etc.) Chair: Patrick Schleppi, WSL, Switzerland 13:45 Significance of tree roots to preferential flow in soil horizons with different degrees of hydromorphy Benjamin Lange, WSL, Switzerland 14:10 FOREST stony soil: The contribution of rock fragments to soil water retention Viliam Novák, Slovak Academy of Sciences, Slovakia 14:35 Development of a physic-based, dual-permeability model for subsurface strormflow and conservative transport and a forested hillslope Hanne Laine-Kaulio, Aalto University, Finland 15:00 GIS analysis of peatland topo-hydrological features Elve Lode, Tallinn University, Estonia & Swedish University of Agricultural Sciences, Sweden 15:25 Coffee break and posters (see page 11) 16:00–18:00 Meetings of COST Action FORMAN working groups 19:30 Dinner Tuesday 7.9.2010 Session 3: Hydrological fluxes in different climatic conditions Chair: Viliam Pichler, Slovak Academy of Sciences, Bratislava, Slovakia 9:00 Forest – Water Interactions: A Reply to the Water Yield Debate David Ellison, Institute of World Economics, Hungary 9:30 Carbon and nitrogen pathways from boreal headwater catchments downstream to the coast along variable land use cover Pirkko Kortelainen Finnish Environment Institute, SYKE, Finland 9:55 Stable isotopes studies to increase knowledge from the role of peatland in catchment hydrology Anna-Kaisa Ronkainen, University of Oulu, Finland 10:20 Runoff generation across spatial and temporal scales following wildfire Jan Jacob Keizer, CESAM, Dept. Environment, U. Aveiro, Portugal 10.45 Soil and water in managed forests - sustainable production and environmental quality. Final conference in Santiago de Compostela, 9.5.-13.5.2011 Agustín Merino, University of Santiago de Compostela, Lugo, Spain 11:00 Coffee break 11:15 Conclusions of COST Action FORMAN working groups 11:50 COST Action FORMAN MC meeting 13:00–14:00 Lunch 14:30 Departure to Hyytiälä Forestry Field Station 17:30 Arrival to Hyytiälä, accommodation 18:00-19:30 Sauna (optional) 20:00 Dinner Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 11 Wednesday 8.9.2010 Scientific excursion 7:30 Breakfast at Hyytiälä 9:00 SITE 1: Visiting at SMEAR- research station. Measuring the relationship of atmosphere and forest in boreal climate zone. (Samuli Launiainen, Finnish Forest Research Institute, Metla) 10:00 Bus transfer to Lakkasuo 10:20 SITE 2: Demonstration of Lakkasuo pristine and drained peatland. (Sakari Sarkkola, Finnish Forest Research Institute, Metla) 11:40 Bus transfer to lunch 12:00 Lunch at Hyytiälä 13:00 Bus transfer to Vilppula 13:30 SITE 3: Vilppula peatland water balance experiment site at Jaakkoinsuo experimental drainage area. (Hannu Hökkä and Sakari Sarkkola, Finnish Forest Research Institute, Metla) 14:30–17:30 Bus transfer to Helsinki-Vantaa airport and Helsinki city centre Monday 6.9.2009, 10:35 and 15:25 during coffee break Poster presentations New methods to control acid sulfate and organic acid leaching from peatland forestry drainage areas Kaisa Heikkinen, SYKE, Simo Tammela, Hannu Marttila, Tuomas Saarinen, University of Oulu, Finland, Kati Martinmäki, Raimo Ihme, Mika Visuri, Jaakko Saukkoriipi, SYKE, Jermi Tertsunen, Timo Yrjänä, Jukka Tuohino, Centre for Economic Development, Oulu, Finland and Bjørn Kløve, University of Oulu, Finland Participation of aquatic fungi in litter decomposition in Lithuanian woodland streams Svetlana Markovskaja and Jurga Motiejûnaité, Institute of Botany, Lithuania Hydrological and protective services of forests –modeling on watershed level Špela Planinšek, Andreja Ferreira and Anže Japelj, Slovenian Forestry Institute Stream ecohydrological surveys to evaluate the impacts of watershed land use Semih Ediş Betűl Uygur and Ysuf Serengil, Turkey Litterfall production in forests located at the pre-delta area of the Paraná River (Argentina) Pablo G. Aceñolaza, CICyTTP-CONICET, Argentina,Lisandra P. Zamboni, Universidad Autónoma de Entre Ríos, Argentina, Estela E. Rodríguez, CICyTTP-CONICET, Argentina, Juan. F. Gallardo, C.S.I.C., IRNAS, Spain, and M. Isabel González, University of Salamanca, Spain Ethylene and ABA responses to water stress in young Poplar, Alessio Fortunati Emanuele Palozzi, Giovanni Marino and Mauro Centritto, Institute of AgroEnvironmental and Forest Biology, National Research Council, Italy Upscaling water and carbon fluxes from leaf to canopy: role of stomatal control models Samuli Launiainen, University of Helsinki and METLA Carbon emission from bogs along a human-impact gradient in Estonia Margus Pensa, University of Tallinn, Estonia and Helen Karu, University of Tartu, Estonia Influence of woodland on the modification of the albedo and water distributions in an insular environment. Case study on Tenerife, Canary Islands, Spain Juan Carlos Santamarta Cerezal, Universidad de La Laguna, Spain and Luis Santa Pérez, Agrocabildo technical advisor (Tenerife island Council), Spain Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 12 Lastname Firstname Address E-mail 1 Aleinikoviene Jurate Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepu str. 1, 53101/Kaunas, Lithuania j.aleinikoviene@mi.lt 2 Ben-Hur Meni Institute of Soil, Water and Environmental Sciences, Volcani Center, P.O.Box 6, Bet-Dagan, 50-250, Israel meni@volcani.agri.gov.il 3 Bredemeier Michael University of Goettingen, Forest Ecosystems Res. Ctr., Buesgenweg 2, 37077 Goettingen, Germany mbredem@gwdg.de 4 Buozyte Rasa Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepu str. 1, 53101/Kaunas, Lithuania r.buozyte@mi.lt 5 Centritto Mauro National Research Council - Institute of Agro- Environmental & Forest Biology, Via Salaria km 29, 300, 00015 Monterotondo Scalo (RM), Italy mauro.centritto@cnr.it 6 Cohen Shabtai ARO Volcani Center, POB 6, Bet Dagan, Israel vwshep@agri.gov.il 7 Dimitrov Dimitar Forest Research Institute, Sofia, 132 “St. Kliment Ohridski” Blvd., 1756 Sofia, Bulgaria dimitrov_117@abv.bg 8 Eastaugh Chris BOKU, Peter Jordan Strasse 82, 1190 Vienna, Austria chris.eastaugh@boku.ac.at 9 EDİŞ Semih Cankiri Karatekin University, Orman Fakültesi Yeni Mah. Bademlik Cad., 18200/Cankiri, Turkey semihedis@karatekin.edu.tr 10 Ellison David Institute for World Economics, Orszaghaz utca 30, 1014 Budapest, Hungary ellisondl@gmail.com 11 Finér Leena Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, 80101 Joensuu, Finland leena.finer@metla.fi 12 Fortunati Alessio Institute of Agroenvironmental and Forest Biology (IBAF) of CNR, Via Salaria Km 29,300, 00016 / Monterotondo (RM), Italy alessio.fortunati@ibaf.cnr.it 13 Gallardo Lancho Juan Fernando Spanish C.S.I.C., IRNASa, Aptado. 257, Salamanca 37071, Spain jgallard@usal.es 14 Gislason Gisli Mar Life- and Environmental Sciences, University, Askja - Sturlugata 7, IS-107 Reykjavik, Iceland gmg@hi.is 15 Godbold Douglas Bangor University, Deniol Road, LL 57 1 BZ Bangor, UK d.l.godbold@bangor.ac.uk 16 Gonzalez Hernandez M. Isabel University of Salamanca, Facultad Ciencias Agrarias y Ambientales, Area Edafología, 37007 Salamanca,Spain mimg@usal.es 17 Heikkinen Kaisa Finnish Environment Institute SYKE, Freshwater Centre, River Basin Management Unit, the Oulu Office, Finland kaisa.heikkinen@ymparisto.fi 18 Hökkä Hannu Finnish Forest Research Institute, Metla, Rovaniemi Research Unit, P.O. Box 16, 96301 Rovaniemi, Finland hannu.hokka@metla.fi 19 Keizer Jan CESAM, University of Aveiro, Dept. Environment, Campus Universitario de Santiago, 3810-193/Aveiro, Portugal jjkeizer@ua.pt 20 Koivusalo Harri Aalto University, School of Science and Technology, PO Box 15200, 00076 Aalto, Finland harri.koivusalo@tkk.fi List of participants Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 13 21 Kortelainen Pirkko Finnish Environment Institute, P.O. Box 140, 00251 Helsinki, Finland pirkko.kortelainen@ymparisto.fi 22 Laine-Kaulio Hanne Aalto University School of Science and Technology, Water Research Unit, PO Box 15200, 00076 Aalto, Finland hanne.laine@tkk.fi 23 Lange Benjamin Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland benjamin.lange@wsl.ch 24 Launiainen Samuli Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, 80101 Joensuu, Finland samuli.launiainen@metla.fi 25 Lauren Ari Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, 80101 Joensuu, Finland air.lauren@metla.fi 26 Leitgeb Ernst Federal Research Centre for Forests (BFW), Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria ernst.leitgeb@bfw.gv.at 27 Lier Markus Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, 80101 Joensuu, Finland markus.lier@metla.fi 28 Lode Elve Institute of Ecology, Tallinn University, Uus- Sadama 5, 101 20 Tallinn, Estonia elve.lode@tlu.ee 29 Marino Giovanni Institute of Agroenvironmental and Forest Biology (IBAF) of CNR, Via Salaria Km 29,300, 00016 / Monterotondo (RM), Italy giovanni.marino@ibaf.cnr.it 30 Markovskaja Svetlana Institute of Botany, Zaliuju ezeru 49, 08406 Vilnius, Lithuania svetlana.markovskaja@ botanika.lt 31 Marttila Hannu University of Oulu, Water Resources and Environmental Engineering Laboratory, PO Box 4300, 90014 University of Oulu, Finland hannu.marttila@oulu.fi 32 Merino Augustin University of Santiago de Compostela, Escuela Politécnica Superior, E-27002 / Lugo, Spain agustín.merino@usc.es 33 Motiejunaite Jurga Institute of Botany, Zaliuju ezeru 49, 08406 Vilnius, Lithuania jurga.motiejunaite@botanika.lt 34 Nieminen Mika Finnish Forest Research Institute, Metla, Vantaa Research Unit, P.O. Box 18, 01301 Vantaa, Finland mika.nieminen@metla.fi 35 Novák Viliam Institute of Hydrology, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava, Slovakia novak@uh.savba.sk 36 Oddsdottir Edda Icelandic Forestry Research, Mogilsa, Reykjavik, Iceland edda@skogur.is 37 Olafsson Jon S. Institut of Freshwater Fisheries, Keldnaholt, 112 Reykjavik, Iceland jsol@veidimal.is 38 Olsson Mats SLU, 75007 Uppsala,Sweden mats.olsson@mark.slu.se 39 Paasonen-Kivekäs Maija Sven Hallinin tutkimussäätiö, Simonkatu 12 A 11, 00100 Helsinki, Finland maija.paasonen@hallin.fi 40 Pallozzi Emanuele Institute of Agroenvironmental and Forest Biology (IBAF) of CNR, Via Salaria Km 29,300, 00016 / Monterotondo (RM), Italy emanuele.pallozzi@ibaf.cnr.it 41 Pensa Margus Tallinn University, Institute of Ecology, Uus- Sadama 5, 10120 Tallinn, Estonia margus@ecoviro.johvi.ee 42 Pichler Viliam Technical University Zvolen, Slovak Republic pichler@vsld.tuzvo.sk Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 14 43 Piirainen Sirpa Finnish Forest Research Institute, Metla, Joensuu Research Unit, P.O. Box 68, 80101 Joensuu, Finland sirpa.piirainen@metla.fi 44 Pilaš Ivan Croatian forest research institute, Cvjetno naselje 41, Jastrebarsko, Croatia ivanp@sumins.hr 45 Planinšek Špela Slovenian Forestry Institute, Večna pot 2, 1000 Ljubljana, Slovenia spela.planinsek@gozdis.si 46 Ronkanen Anna-Kaisa Water Resources and Environmental Engineering Laboratory, PL 4300, 90014, Oulun yliopisto, Finland anna-kaisa.ronkanen@oulu.fi 47 Santamarta Cerezal Juan Carlos Universidad De La Laguna, San Jose 2 2-B , 38201, Spain jcsanta@ull.es 48 Sarkkola Sakari Finnish Forest Research Institute, Metla, Vantaa Research Unit, P.O. Box 18, 01301 Vantaa, Finland sakari.sarkkola@metla.fi 49 Schleppi Patrick WSL, Zürcherstr. 111, CH-8903 Birmersdorf, Switzerland patrick.schleppi@wsl.ch 50 Strelcova Katarina Technical University in Zvolen, Masarykova 24, 960 53 Zvolen, Slovakia strelcov@vsld.tuzvo.sk 51 Thormann Jean- Jacques SHL, Länggasse 85, 3052 Zollikofen, Switzerland jean-jacques.thormann@bfh.ch 52 Tognetti Roberto Università del Molise, Ecogeofor, Contrada Fonte Lappone, Pesche, I-86090, Italy tognetti@unimol.it 53 Velichkov Ivaylo Forest Research Institute, Sofia, 132 “St. Kliment Ohridski” Blvd., 1756 Sofia, Bulgaria ivo_velichkov@abv.bg 54 Vrbek Boris Croatian forest research institute, Cvjetno naselje 41, Jastrebarsko, Croatia borisv@sumins.hr 55 Zlatanov Tzvetan Forest Research Institute, Sofia, 132 “St. Kliment Ohridski” Blvd., 1756 Sofia, Bulgaria tmzlatanov@gmail.com Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 15 Session 1 Water relations in boreal forests and peatlands Chair: Elve Lode, Tallinn University, Estonia & Swedish University of Agricultural Sciences, Sweden Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 16 Keynote: Water relations in boreal forests and peatlands Leena Finér Finnish Forest Research Institute, Metla, Finland Boreal regions of Europe are characterized by coniferous forests growing on upland mineral soils or peatlands developed after the last Ice Age about 10 000 years ago. Towards the north, the climate gets increasingly colder and humid. The precipitation exceeds the evapotranspiration leading to the formation of runoff. The water flows to lakes and streams and further to the sea, in case of Finland, mainly the Baltic Sea. In central and northern parts of boreal region a significant part of the annual precipitation falls as snow, which melts in spring within a relatively short period of time leading to a runoff peak comprising 40−60% of the annual runoff. In winter the soils, if not protected by snow, will get frozen at the surface layer affecting on water pathways during the thawing periods. In the boreal forest regions surface and ground water resources are ample and the quality is mostly high for the human use due to the filtering capacity of forests and forest soils. Boreal forests were earlier frequently disturbed by fire and had therefore an influence on forests and water. Nowadays the fire protection is effective in the Nordic countries, and the disturbances on forests are caused by forest management activities like cutting, soils scarification and forest drainage. These operations have mostly minor impacts on runoff, but can significantly increase the element export into the watercourses for a period of several years. Locally these impacts can deteriorate the water quality, and are of major concern, but on national scale the impacts are small compared to the diffuse load from the agricultural lands. Of the single forest management operations, forest drainage has probably had the most significant effects on the fresh water ecosystems by increasing dramatically the sediment load to the watercourses. In Finland the research on water and forests has mainly focused on the effects of forest management practices on water yield and quality, and for developing methods to mitigate the negative effects. One of the biggest challenges in the future is to couple with the interactions of forests and water in changing climatic conditions. The climate change scenarios for the boreal regions of Europe predict and increase in the annual mean temperature up to 4−6 °C by the 2080s. The temperature will increase in all seasons, but more in wintertime. The amount of precipitation will increase and mostly in winter. In summer the total amount of precipitation changes very little or might even decrease. In the northern parts of the boreal region snow cover period will shorten, whereas in the south is becomes horter and most of the annual precipitation falls as rain. Warming and changes in snow cover affect also on soil frost and water pathways in soil. Climate change is expected to increase the occurrence of extreme weather phenomena. Increased number of storms and heavy rainfalls is forecasted. These changes can have many both positive and negative effects on the interactions between forests and water. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 17 Managing erosion, sediment transport and water quality in drained peatland catchments Hannu Marttila1, Kari-Matti Vuori2, Hannu Hökkä3, Juha Jämsen4 and Bjørn Kløve1 1 Department of Process and Environmental Engineering, University of Oulu, Finland 2 Finnish Environment Institute, Finland 3 Finnish Forest Research Institute, Metla, Finland 4 Central Finland Forestry Centre, Finland Drainage-induced diffuse pollution and erosion are key water quality problems in peatland forestry. A major part of the pollutant load is transported during peak runoff periods after snowmelt or intense rainfall. This presentation represent possibilities to increase retention time of runoff waters in drained peatland catchments on purpose to diminish peak runoff and improve settling conditions of suspended solids (SS). To create retention, a peak runoff control (PRC) structure was developed and its functioning, dimensioning and practical applications were studied in seven partly or completely ditch-drained catchments in Central Finland. Also erosion and sediment transport processes were studied. Results clearly indicate that effective water quality management in drained peatland areas can be achieved using the PRC method in drainage areas. The main effect of PRC is on SS and SS-bound nutrients. The PRC structure is cheap and can easily be created with forest drainage machinery during the ditching and ditch network maintenance operations. Different issues relating to the sediment transport dynamics, structural design, water quality benefits, and impacts on forestry are discussed. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 18 Forestry operations have a small impact on the groundwater quality in aquifers Sirpa Piirainen1, Leena Finér1, Marja-Liisa Juntunen1, Hannu Mannerkoski2, Mirella Miettinen2 and Michael Starr3 1 Finnish Forest Research Institute, Meltla, Finland 2 University of Eastern Finland 3 University of Helsinki Groundwater is the main source (60 %) of water distributed by waterworks to households and industry in Finland. Groundwater aquifers are mainly located on forest land, thus forest fertilization and intensive soil preparation are not allowed on groundwater aquifers to maintain the good quality of groundwater. High nitrate leaching to groundwater after clear-cuttings has been observed in studies done in N-rich soils in southern Sweden and central Europe (Wiklander et al. 1991, Weis et al. 2001). However, the effects of different forestry operations on groundwater quality are not systematically studied. A monitoring study on the effects of forest cutting on the quality of groundwater in large aquifers (5.2−15.4 km2) showed that both thinning and clear- cutting (27−66 % of the recharge zone) increase nitrate concentrations for several years (Rusanen et al., 2004). However, even the maximum annual average concentrations remained very small < 2 mg L-1, well below the upper level (50 mg L-1) set for drinking water. The results from an other study (VALU) by Mannerkoski et al. (2005), on headwater catchments, where 10−30 % of the area were clear-cut and disc-plowed, showed also that influence of forestry to groundwater level and quality is small, although in some wells the maximum monthly concentration of nitrate increased to 6.3 mg L-1. In the VALU study it was clearly shown that leaching of nitrate was delayed for some years after forestry operations and the effect seemed to be long-lasting. In 2000 we started a new study to find out what is the effect of forest regeneration and soil harrowing on the quality of groundwater in the Class I groundwater recharge area. The area, called Silkunharju esker, locates in eastern Finland and the soil is glacial deposit with a texture of gravel. The main tree species was pine (Pinus sylvestris L.). 70 % of the area (2.47 km2) was cut in 2001 and we have monitored the groundwater quality, groundwater table level and climatic variables in the area. We will show the results from the Silkunharju study, which indicate that the effects of forest operations are small on groundwater quality and short lasting. We will also introduce the latest measurements from the VALU study where the influences are longer. References Mannerkoski, H., Finér, L., Piirainen, S. & Starr, M. 2005. Effects of clear-cutting and site preparation on the level and quality of groundwater in some headwater catchments in eastern Finland. Forest Ecology and Management 220: 107−117. Rusanen, K., Finér, L., Antikainen, M., Korkka-Niemi, K., Backman, B. & Britschgi, R. 2004. The effects of forest cut- ting on the quality of groundwater in large aquifers in Finland. Boreal Environment Research 9(3): 253−261. Weis, W., Huber, C. & Göttlein, A. 2001. Regeneration of mature Norway spruce stands: early effects of selective cut- ting on seepage water quality and soil fertility. The Scientific World Journal 1(2): 493−499. Wiklander, G., Nordlander, G. & Andersson, R. 1991. Leaching of nitrogen from a forest catchment at Söderåsen in southern Sweden. Water Air and Soil Pollution 55: 263−282. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 19 Keynote: The role of water for carbon sequestration and GHG emissions in boreal forests Mats Olsson Swedish University of Agricultural Sciences The accumulation of SOC (soil organic carbon) is the result of the dynamic balance between litter production and heterotrophic respiration, both of being strongly affected by water availability. Water effects on long- term SOC sequestration is evident from SOC content in soil types with different hydrological regimes. Hiederer (2009) reported for 0−100cm, based on an European data base: Histosols (73.9 kg C m-2) > Podzols (11.5 kg Cm-2) > Cambisols (3.3 kg Cm-2) > Chernozem (3.0 kg Cm-2) > Xerosols (1.7 kg Cm-2). This range is caused by differences in groundwater level and precipitation , but also in land use. Water saturation such as in the Histosol allows photosynthesis and litter production but retards decomposition resulting in peat accumulation. Dry conditions such as in Xerosols gives a very low litter production. Hiederer (2009) also showed that the drier soils has a higher proportion of total SOC in the lower part of the profile. Reasons to this may be a higher proportion of below-ground biomass, and forest floor carbon at dryer conditions may be lost through fires. Olsson et al. (2009) reported, based on the Swedish Forest Soil Inventory, a higher content of SOC to the depth of 50cm in well-drained Podzols at sites with high groundwater level (ca. 1m) than at sites with low groundwater level (> 2m). This difference was exclusively due to difference s in SOC stock in the O-horizons. Possible explanations for the higher stocks at slightly moist sites are lower decomposition losses due to occasional water saturation, production of litter from the field layer is higher, and that the litter quality is different. However, there are no major differences in tree-biomass production between slightly moist and fresh sites, and, presumably, no difference in tree-litter production. The deviating pattern in the O-horizon versus the mineral soil may be caused by the distribution of root litter. Berggren Kleja et al. (2008) showed that 0–2 mm root biomass in the O-horizon is higher at moist sites than at fresh and dry sites, whereas the root biomass in the mineral soil lower at moist sites. Callesen et al (2003) determined SOC pools in Nordic forest soils for forest floor and mineral soil to a depth of 100cm as functions of mean annual temperature and precipitation. They concluded that SOC stores in forest floor and forest floor+mineral soil were positively correlated with precipitation. Based on their regressions, an increase in precipitation with 50% from 600 to 900mm at 5oC would increase SOC stock with 75%. The short term SOC sequestration may deviate from the long term resulting in CO2 sinks or sources. Data from the Swedish Forest Soil Inventory did not show any net emissions for well-drained soils. Peatland, on the other hand, has been shown to emit large quantities of CO2, CH4 and N2O. Ojanen et al (2010) showed for drained boreal peatland that groundwater level affects CO2 and CH4 emissions, and hypothesised that soil nitrogen availability would correlate with N2O flux. References Berggren Kleja, D., Svensson, M., Majdi, H., Jansson, P.-E., Langvall, O., Bergkvist, B., Johansson, M.-B., Weslien, P., Truus, L., Lindroth, A. & Ågren, G.I.2008. Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden. Biogeochemistry 89(1): 7–25. Callesen, I., Liski, J., Rauland-Rasmussen, K., Olsson, M.T., Tau-Strands, L., Vesterdal, L. & Westman, C.J. 2003. Soil carbon stores in Nordic well-drained forest soils – relationships with climate and texture class. Global Change Biology 9(3): 358–370. Hiederer, R. (2009) Distribution of Organic Carbon in Soil Profile Data. EUR 23980 EN. Luxembourg: Office for Of- ficial Publications of the European Communities. 126 pp. Ojanen, P., Minkkinen, K., Alm, J. & Penttilä, T. 2010. Soil–atmosphere CO2, CH4 and N2O fluxes in boreal forestry- drained peatlands. Forest Ecology and Management, 260(3), 411−421. Olsson, M., Erlandsson, M., Lundin, L., Nilsson, T., Nilsson, Å. & Stendahl, J. 2009. Organic carbon stocks in Swed- ish Podzol soils in relation to soil hydrology and other site Characteristics. Silva Fennica 43(2): 209–222. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 20 Drought-induced changes in Scots pine and Norway spruce stands estimated on the evidence to artificial drought experiments Rasa Buozyte, Vidas Stakenas, Remigijus Ozolincius and Jurate Aleinikoviene Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Kaunas district, Lithuania Drought-induced changes on tree condition, ground vegetation cover, chemical and biological soil parameters were comparatively estimated in Scots pine (Pinus sylvestris L., 60 years old) and Norway spruce (Picea abies (L.) Karst., 40 years old) stands where the artificial drought was proceeded by installing the roof constructions below forest canopies. The artificial drought experiments were held permanently in Pinetum vaccinio-myrtillosum site in 2003−2005 and in Piceetum oxalidosum site in 2003−2004. Although the artificial drought experiments were kept 3 and 2 vegetation periods, respectively, in Scots pine and in Norway spruce stands, there were estimated drought-induced changes in both stands. The mean crown defoliation under the drought condition in Scots pine stands was by 6.3−17.5% higher as compared with that in the control. Though, the mean crown defoliation was not extensively increasing in Norway spruce stands under the drought and was only by 2.2−2.4% higher as compared with the control plots. Even though the crown defoliation in pine stands was high in drought plots, the increase in the litterfall mass was not well-defined over the experiment. Thus, in spruce stands the litterfall mass increased after the introducing the drought and remained by 1.5−2.0 times higher than in the control. However, under the drought conditions the tendencies in decreasing of the mean mass of tree fine-roots remained for both pine and spruce stands. In Scots pine stand as well as in Norway spruce stand under the drought conditions the ground vegetation cover significantly decreased. Thus, under the drought condition over the 3 years vegetation period in pine stands the cover of the mosses and vascular plants have decreased, respectively, from 89.5% to 0.5% and from 41.5% to 0.7%. In spruce stands, naturally with low ground vegetation cover, under the drought conditions over the 2 years vegetation period decrease in the cover of the mosses and vascular plants was estimated, respectively, from 7.2% to 0.1% and from 1.5% to 0.0%. The artificial drought influenced the changes in chemical and biological properties of O-layers and in some extent only in mineral soil of 0−2 cm deep layers in Scots pine and in Norway spruce stands. If to compare with the control plots the drought induced the increase in the contents of organic carbon in the O-layer and mineral soil of 0-2 cm deep layer in both sites, even though, these differences were statistically not significant. Thus, significantly increase of the contents of nitrogen (by 2−3 times in O-layer and mineral soil of 0−2 cm deep layer of the pine plantations, while, by 2 times only in O-layer of the spruce plantations) was estimated. Also, the significantly increase in the abundance of the ammonifiers and nitrifiers in organic soil (by 2 times in both sites) was found. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 21 The impact of drought on young spruce trees stem circumference changes and sap flow rate Střelcová Katarína1, Ježík Marek, Blaženec Miroslav2, Frič Michal1 and Končír Matej1 1 Faculty of Forestry, Technical University in Zvolen 2 Institute of Forest Ecology, Slovak Academy of Sciences, Zvolen, Slovakia In connection with the global climatic change, a considerable increase of the drought-induced damages over many regions of the world (IPCC Third Assessment Report 2000) is expected. Water stress limits the potential range of many species by affecting plant production potential and thus establishment and competitive success. The anticipated changes in climate, including changes in precipitation patterns in certain regions on the background of increasing temperatures and atmospheric demand for water, make it imperative to understand species responses to water stress. Considering the sensitivity of Picea abies [L.] Karst (Norway spruce) to soil water supply, and its ecological and economical importance in both natural and planted stands of Europe, it is not surprising that observations of P. abies stands showing clear signs of drought stress cause a wide concern. The contribution is aimed at identification of potential drought stress of spruce stand (30 years old) during vegetation period 2009. The response of stem circumference changes and sap flow rate were investigated in diurnal courses and seasonal courses in relation to meteorological parameters (global radiation, air temperature, potential evapotranspiration and soil water potential). During the second half of vegetation period the decrease of soil water potential was observed and irrigation was applied in control group of spruce trees (6 samples), while second group of 6 samples was treated under natural soil drought. The atmospheric parameters were measured continually using digital meteorological station, stem circumference using digital dendrometer DRL 26 and sap flow rate using thermal heat balance method (EMS Brno, CZ). The decreasing sap flow rate was observed in tree samples treated under mild drought stress during noon and afternoon period. Diurnal courses of transpiration rate in these trees are different from those one in irrigated trees showing the noon depression of transpiration which continues afternoon. During drought stress conditions the decrease of dependency to global radiation, water pressure deficit and potential evapotranspiration has occurred. Under stress the determining factor of transpiration is soil water content. Model trees growing under water stress showed circumference changes characterized mainly by diurnal and inter-daily shrinkage and swelling, which reflected particularly irradiation, air water potential deficit, soil water potential and precipitation regime. On the other hand circumference changes of irrigated trees were characterized by diurnal shrinkage and swelling, but continuous inter-daily increase of circumference were observed. The strong impact of meteorological parameters and soil moisture on stem circumference changes during the diurnal and seasonal level was found. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 22 Forest and permanent excess of water – peatland forestry Ari Laurén1, Samuli Launiainen1 and Harri Koivusalo2 1 Finnish Forest Research Institute, Metla, Finland 2 Aalto University, Finland About one third of land surface area in Finland is peatland, where ground vegetation is characterized by mire species, or where the thickness of the peat layer on the mineral soil is more than 30 cm. Traditionally, peatlands have been considered as wastelands with inferior utilisation value, because they are not suitable for agricultural or forest production as such. The main problem that restricts plant production in peatlands is the excess water in rooting zone. When water content in soil is near saturation, soil water blocks the flux of atmospheric oxygen to the roots, and carbon dioxide flux from the root zone to the atmosphere. As a rule of thumb, excess water restricts gas transfer if air filled porosity is less than 10 % of volume. Growth conditions in peatlands can be improved by draining the rooting zone. In forestry, drainage is conducted using open ditch network with 60−100 cm depth and 30−60 m spacing. In peatlands the excess water in the rooting zone is a result of climatic and soil related factors. In boreal zone the annual rainfall typically exceeds evapotranspiration and hence the drainage is an important component of water balance. Draining water accumulates to depressions in the topography promoting formation of peat, whose physical characteristics support retention of water in the soil. Peat profile typically consists of low-humified top layer and a well humified bottom peat layer, underlain by mineral soil. Both low-humified and well-humified peat materials have a high porosity, but saturated hydraulic conductivity in well-humified layer is several orders of magnitude lower than that in low-humified peat. Because of the low hydraulic conductivity, well-humified peat material typically remains wet throughout the growing season keeping the air filled porosity in the soil too low to support forest growth. Ditching changes the physical conditions in the rooting zone which in peat soils typically extends ca. 10−20 cm below the surface. Water can be removed from the low-humified layer easily by ditch drainage, but the impact of the drainage on the humified layers is much smaller. Hydrologically the success of the drainage operations depends on the depth and spacing of the ditches, and on the depth of the permeable peat layer at the surface. During growing season, transpiring vegetation extracts the water from the rooting zone and air filled porosity increases accordingly. When transpiration and evaporation are strong, also the water content in well- humified layers may decrease. From the drainage viewpoint, it is crucial whether the excess water restrict s transpiration, which occurs in saturated soils. Field experiments have shown that if the volume of the growing stock exceeds 100 −150 m3 ha-1, the evapotranspiration can be more important for the results of drainage operations than the ditch flow. About half of the peatland area in Finland has been ditched to enhance forest growth. In this respect, the ditching campaign has been a very successful: it has increased the annual forest growth in national scale by ca. 15 millions of cubic meters, while the total growth is presently ca. 100 millions of cubic meters. The length of forest ditches − ca. 1 300 000 km − reveals the scale of the Finnish ditching operation: the total length of natural rivers isonly 53 000 km. The large scale alteration of peatland hydrology has, however, caused several drawbacks including deterioration of water quality in the recipient water courses. Ditching and ditch network maintenance increase especially export load of suspended sediments and organic matter. Wood harvesting and water protection are the future challenges of peatland forestry in Finland. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 23 Use of natural and restored peatland buffers to reduce sediment and nutrient transport from forested catchments − Finnish experiences Mika Nieminen1, Anu Vikman1, Sakari Sarkkola1, Harri Koivusalo2, Ari Lauren1, Hannu Fritze1 1 Finnish Forest Research Institute, Metla, Finland 2 Aalto University, Finland Sediment and nutrient losses from forested catchments are typically low, but can increase especially in drained peatland-dominated catchments when forests are harvested or fertilized, or when the ditch networks are maintained. To prevent the increased sediment and nutrient transport to reach recipient water courses, use of sedimentation ponds was a subject of active research in the 1990s. Ponds were shown to efficiently remove coarse-textured sediment particles from discharge waters, but their effect on fine-textured materials, light organic particles and soluble nutrients was negligible. It is presently recommended that nutrient-rich drainage waters from forested catchments are conveyed to receiving surface waters through either natural or restored peatland buffer areas. Buffer wetlands in operational peatland forestry are usually created by simply conducting discharge waters from drained peatlands to pristine mires or, occasionally, also to paludified mineral soils. However, because most peatlands in Finland have been drained for forestry, buffer wetlands are very often created by restoring and rewetting sections of drained peatlands by filling in or blocking the main drainage ditches. Buffer area size may vary considerably but rarely exceeds 1.0-1.5 hectares. If only productive forestry land is available for the construction of the buffer small areas are preferred. The studies have indicated efficient sediment and nutrient removal, especially by large buffer areas (>1% of catchment area) and under low hydrological loading. Thus, the reduction of sediment and nutrient transport is likely governed by how much the water flow is slowed down in the buffer area to allow the sediments to settle down among ground vegetation and surface soil, and also to enable sufficient contact time between nutrient-rich through-flow waters and the vegetative and soil sinks of nutrients. In smaller buffer areas the formation of flow channels especially during the high flow episodes significantly decreases their retention capacity. A study with 32P indicated that the effectiveness of buffer areas in retaining increased P loading may not be satisfactory during spring snow-melt period, when sparse vegetation restricts biological P accumulation and high flows reduce the capacity of deeper soil layers to retain P. Although large peatland buffers are an efficient water protection method, a negative impact may be involved that the restoration and rewetting of drained peatlands for use as buffers initially increases the export of soluble nutrients, especially phosphorus. This is particularly true if a significant proportion of P under drained conditions was adsorped by iron hydroxides or oxides as this P is easily released upon water table rising and consequent redistribution and reduction of iron. Tree harvesting from buffer areas during construction operations and leaving cutting residues on site are also likely to increase P export. However, it should be noted that the buffer areas that initially release phosphorus during and after their restoration later can function as significant and sustainable P sinks. Methane gas fluxes from the buffer areas constructed on undrained, pristine mires may be high, but revitalization of methane emissions after restoration may be a slow process, since the emissions from >10-year-old restored buffer areas were still low. Methanotroph communities between pristine and restored sites were nearly identical, indicating that peatland methanotrophs Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 24 tolerate drainage well and/or recover rapidly after restoration. The low methane fluxes observed on restored peatlands may result from the poor establishment of methanogens. N2O fluxes are low from both natural and restored buffers, but may increase after high N loading. References: Nieminen, M., Ahti, E., Nousiainen, H., Joensuu, S. & Vuollekoski, M. 2005. Capacity of riparian buffer zones to reduce sediment concentrations in discharge from peatlands drained for forestry. Silva Fennica 39(3): 331−339. Nieminen, M., Ahti, E., Nousiainen, H., Joensuu, S. & Vuollekoski, M. 2005. Does the use of riparian buffer zones in forest drainage areas to reduce the transport of solids simultaneously increase the export of solutes? Boreal Environment Research 10: 191−201. Väänänen, R., Nieminen, M., Vuollekoski, M. & Ilvesniemi, H. 2006. Retention of phosphorus in soil and vegetation of a buffer zone area during snowmelt peak flow in southern Finland. Water, Air and Soil Pollution 177: 103−118. Väänänen, R., Nieminen, M., Vuollekoski, M., Nousiainen, H., Sallantaus, T., Tuittila, E.-S. & Ilvesniemi, H. 2008. Retention of phosphorus in peatland buffer zones at six forested catchments in southern Fin-Retention of phosphorus in peatland buffer zones at six forested catchments in southern Fin- land. Silva Fennica 42(2): 211−231. Vikman, A., Sarkkola, S., Koivusalo, H., Sallantaus, S., Laine, J., Silvan, S., Nousiainen, H. & Nieminen, M. 2010. Nitrogen retention by peatland buffer areas at six forested catchments in southern and central Finland. Hydrobiologia 641: 171−183. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 25 Session 2 Water fluxes at different scales Chair: Patrick Schleppi, WSL, Switzerland Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 26 Significance of tree roots to preferential flow in soil horizons with different degrees of hydromorphy Benjamin Lange1, Peter Lüscher1 and Peter F. Germann2 1 Swiss Federal Institute for Forest, Snow and Landscape Research, Switzerland 2 Department of Geography, University of Bern, Switzerland The assumption that forests reduce discharge is in circulation for almost two centuries. Today we think that forest soils contain pores with higher hydrological efficiency when compared with soils carrying other types of vegetation. Tree roots are important factors for the generation and conservation of pores, also in deeper hydromorphic horizons. In this project we explored the influence of the root length distribution on preferential flow in soils with stagnic properties. The study site is located in the Flysch region 30 km south of Bern (Switzerland) at an altitude of 1000 m. Soils were characterized by stagnic and gleyic properties. The experimental set up consisted of a 1 m x 1 m sprinkler device and TDR probes that were horizontally mounted from a trench into the centre of each horizon. Each plot was irrigated three times within a 24-hour interval with a volume flux density of 70 mm/h to obtain dates of varying initial soil moisture. After the sprinkling, soil cores (10 cm diameter) were sampled. The roots were extracted from the soil and digitally analysed with the program “winRHIZO”. The application of a rivulet approach to the water content data of the irrigations resulted in the contact length, L (m m-2), per cross-sectional area and the film thickness, F (μm), between mobile water and soil. The volumetric water content, and therefore the amplitude of the infiltration, is given by the product of L and F. Our results indicated that, at high initial soil moisture, the contact length L was significantly positively correlated to the root length per soil volume (R2 = 0.71) and the film thicknesses decreased with increasing root length, but this correlation was less pronounced (R2 = 0.25). To prove the hypotheses that the significance of tree roots to infiltrability is dependent on the degree of the horizon’s hydromorphy, we grouped the investigated horizons according to the frequency of hydromorphic features. At high initial soil water content (third irrigation), the infiltration was positively affected by roots in topsoil layers and hydromorphic horizons. Cambic horizons did not benefit from the pore system created by the roots, since swelling clay particles had possibly decreased porosity which was effectively involved in infiltration. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 27 FOREST stony soil: The contribution of rock fragments to soil water retention Viliam Novák and Peter Šurda Institute of Hydrology, Slovak Academy of Sciences, Slovakia The water retention capacity of coarse rock fragments in forest soils are usually considered negligible. But the presence of rock fragments in a soil can play an important role in both water holding capacity and in hydraulic conductivity as well. Presence od stones in forest soils in hilly areas is frequent. Rock fragments can hold water and act as an accumulation storage (source) during water movement in soil. There is a lot of studies devoted to the hydrophysical parameters of a fine fraction of soil, but a few only, are focused to study the influence of rock fragments on hydrophysical properties of stony soils. The origin of the rock fragments has significant influence on the soil water holding capacity. Flint and Childs, (1984) measured the maximum contribution of rock fragments retention of available soil water for plants from 40 soil locations in southwest Oregon. They found their average contribution to the total available water as 0.15 volumetric water content, ranging from 0.016 to 0.52. This retention range is the result of the differences in quality of the above mentioned rock particles. Rock fragments are changing their water content with changing water potential (as any other porou medium), the relationships between rock water content and rock water potential (retention curve) can be determined. The retention of water in this media can contribute to the available stony soil water capacity. Soils containing rock fragments are strongly influencing even their hydrodynamic characteristics, quantitatively expressed by the soil hydraulic conductivities. The presence of rock fragments usually decrease hydraulic conductivity of soil saturated with water, but in some cases (existence of lacunar pores), it can increase saturated hydraulic conductivity of such soils . This paper presents results of maximum water holding capacity (stone water content saturated with water) measured in coarse rock fragments in the soil classified as cobbly sandy loam sampled at High Tatra mountains. It is shown, that those coarse rock (granite) fragments have the maximum retention capacity up to 0.16 volumetric water content (see Fig.1). Retention curves of the four particular granite fragments have shown water capacity available for plants expressed in units of volumetric water content of 0.005 to 0.072 in the soil water potential range (0, 0.3 MPa). It can be shown, that stones water retention can be significant and available water capacity of stone fragments can contribute to the available water capacity of soil fine earth considerably and help plants to survive during dry spells (Novák, Šurda, 2010). Fig. 1. Probability exceedance curve of saturated stones water content (θs) at site FIRE, High Tatras. References Flint, A.L. & Childs, S. 1984. Physical properties of rock fragments and their effect on available water in skeletal soils. In: J.E.Box,Jr. (ed.) Erosion and productivity of soils containing rock fragments. SSSA Spec. Publ. 13. SSSA Madison,VI. P.91-103. Novák, V.& Šurda,P. 2010. The water retention of a granite rock fragments in High tatras stony soils. J. Hydrol. Hydromech. 48 (3), (in press). r f r r Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 28 Development of a physics-based, dual-permeability model for subsurface stormflow and solute transport in a forested hillslope Hanne Laine-Kaulio and Harri Koivusalo Aalto University, Finland Preferential flowpaths related to the soil structure have a decisive influence on subsurface flow and transport processes in forest soils in the boreal region. The pore space of the soil matrix functions mainly as a storage, whereas the macropore network constitutes preferential flow routes for water, enabling the generation of fast subsurface stormflow. Detailed, physics-based modelling provides a means to investigate the subsurface flow and transport processes in hillslopes that constitute the basic landscape elements of catchments (Troch et al. 2003). Traditional models that consider the soil pore space as one domain cannot, however, capture the non-linear flow pattern of heterogeneous forest soils. A separate, but parallel and coupled simulation of flow in the soil matrix and in the preferential flowpaths is suggested as a solution to the problem (e.g. Gerke and van Genuchten 1993). In the so-called dual-permeability models, the two pore domains are connected by a transfer term that delivers water and solutes between the domains. While several studies advocate the use of the dual-permeability models (e.g. Ray et al. 2004, Jansson 2005), applications of detailed, three- dimensional, Richard’s equation -based, dual-permeability flow and solute transport models are not available for forested hillslopes. The main objective of this study was to produce a dataset that supports the development, parameterisation and testing of a dual-permeability model for simulating fast subsurface flow and conservative solute transport in a forested hillslope in Finland. The collected dataset consists of soil analyses, field measurements and tracer experiments. Combined with inverse modelling, the dataset provide the basis for the model parameterisation. Water levels and tracer concentrations recorded at the tracer experiment provide data for simulating subsurface stormflow and solute transport. In the tracer experiment, intensive irrigation rates were applied to initiate fast lateral, preferential flow along the study slope. Chloride as a conservative tracer produced a direct indication of subsurface stormflow. When simulating the downslope travelling chloride plume first with a traditional, one pore domain model version, a correspondence between the observed and simulated flow velocity was only reached when the transport of water and solute was restricted to an effective fraction of the total pore space in the model. However, as a simplification of the dual domain model, the one pore domain model was not able to reproduce the observed strengthening and dilution of the chloride concentration with any parameterisation, since the exchange of water and solute between the pore domains was not included in the model. The parallel and coupled simulation of the matrix and the preferential flow domains was found to be essential in capturing the observed, dynamic changes in the moisture conditions, flow velocities and chloride concentrations during the initiation, steady-state and recession stages of the studied stormflow event. A dual-permeability model was concluded to be suitable for describing subsurface stormflow and conservative transport in the study slope. Parameterisation of the model was however challenging since the soil matrix and the preferential flow routes need to be parameterised separately. In addition, as many parameters as possible need to be a priori fixed in order to reduce problems with equifinality and model identifiability. Parameterisation of the soil matrix was fixed based on the fact that fast subsurface stormflow is related to the preferential flow routes and is not sensitive to the slow matrix processes. For the same reason, only the water retention properties could be a priori fixed in the preferential flow domain. With respect to capturing the dynamics of the tracer Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 29 plume, the model was sensitive to the remaining parameters, which include the saturated hydraulic conductivity of the preferential flow domain, the fractioning of the total porosity to soil matrix and preferential routes, and the exchange coefficient between the two pore domains. Identification of these parameters was based on the computational estimates of field-scale hydraulic conductivities and the tracer data along the slope. A further development and testing of the dual-permeability model calls for field data in dry conditions and advances in the measurement and parameterisation of the water retention properties. References Gerke, H. H. & van Genuchten, M. T. 1993. A Dual-Porosity Model for Simulating the Preferential Move-A Dual-Porosity Model for Simulating the Preferential Move- ment of Water and Solutes in Structured Porous Media. Water Resources Research 20(2): 305−319. Jansson, C., Espeby, B., Jansson, P. E. 2005. Preferential water flow in a glacial till soil. Nordic Hydrology 36(1): 1−11. Ray, C., Vogel, T., Dusek, J. 2004. Modeling depth-variant and domain-specific sorption and biodegrada- tion in dual-permeability media. Journal of Contaminant Hydrology 70: 63−87. Troch, P. A., Paniconi, C., Emiel van Loon, E. 2003. Hillslope-storage Boussinesq model for subsurface flow and variable source areas along complex hillslopes: 1. Formulation and characteristic response. Water Resources Research 39(11): 1316. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 30 GIS analysis of peatland topo-hydrological features Elve Lode1 and Meelis Leivits2 1 Tallinn University, Institute of Ecology, Estonia & Swedish University of Agricultural Sciences, Department of Soil and Envi- ronment, Sweden 2 Environmental Board, Pärnu-Viljandi Region, Estonia Currently, there are two main Directives which are regulating management of wetlands, including peatlands, in Europe – Natura 2000 and Guidance document no.12 to the Water Framework Directive (WFD), i.e. “The role of wetlands in the Water Framework Directive”. During the last century mires have been declined in all bio-geographic regions of EU; Atlantic, Continental and Alpine regions, Boreal, Mediterranean and Macaronesian regions. From conservation point of view, afforestation is a major problem for mires, in particular for blanket and raised bogs, and aapa mires (Raeymaekers, 1998). In Boreal region (i.e. Estonia, Finland, Latvia, Lithuania and Sweden), which covers 18.8% of EU (Sundseth, 2009), fens were selected for woodland because of their better nutrient conditions and at these sites, forestry was successful. Later, afforestation of ombrotrophic mires took place, but because of the poor and acidic conditions, this didn’t give the expected timber yields because of slow growth rate, poor timber quality and high harvesting costs (Raeymaekers, 1998). However, because of the ditches dug into the mire peat body, diverted or canalized streams and rivers to drain the mires, and “improved” mire surroundings to suit new functions (agriculture, forestry or urbanization) (Ibid), fragmented and often with intensive tree growth (Lode, 2005) mire landscapes were created; fragmented hydrologically, with differently lowered groundwater tables, and fragmented topologically, with artificially and mosaic changed surface heights (Lode et al., 2010). Water is essential for all mire habitats. Therefore providing the mire with enough water with right quality is thus the first and foremost emergency action for conservation and restoration of mire complexes. Since Boreal mires often are integrated landscape complexes of bogs, transitional mires and fens, conservation and restoration can be successful only if the habitats, which share a common hydrological system with the mire biotopes, are included in management objectives (Raeymaekers, 1998). Hereby, the topographic features are important descriptors for water supply conditions of wetland or habitat (Wheeler et al., 2009). The accurate digital nature, visualised usually via DEMs (digital elevation models), is the primary advance of the LiDAR (Laser Imaging Detection And Ranging) data for modelling of important surface and hydrological features of disturbed or managed mire landscapes. Although, according to our study, modelling of mire basins are resolution and algorithm sensitive, the LiDAR based DEMs are powerful tools for creation and visualisation of different (eco)hydrological scenarios for different mire landscape units, e.g. mire ecotopes or mire complexes. Presentation will focus on following items: 1) Statistics of changed mire extensions in EU, and changes caused by forestry, 2) Soil-based re-identification of natural mire extension in its transformed conditions (examples from two Swedish and Estonian mires, statistics of their surface cover), 3) Presentation of LiDAR data based 3D modelling results of two Estonian mires – e.g. surface, water basin and tree coverage features, 4) Important outlets of 3D modelling of mire landscapes. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 31 References Lode, E., Roosaare, J. & Pensa, M. 2010. Typological Up-Scaling of wooded Peatlands. In: Bredemeier, M., Cohen, S., Godbold, D.L., Lode, E., Pichler, V. & Schleppi, P. (ed-s). Forest management and the Water cycle: An Ecosystem Based Approach. Series: Ecological Studies, Springer [printing preparatory stage]. Lode, E. 2005. Integrated wetland and forest management in the transborder area of North Livonia. PIN/ MATRA project 2002/014. Water management and hydrology. Final report. [Online]. Available at: http://www.north-livonia.org/report/report_hydro_final.pdf [Cited 22 June 2010]. Raeymaekers, G. 1998. Conserving Mires in the European Union. Action co-financed by LIFE-Nature. Sundseth, K. & Gazenbeek, A. (ed-s). Ecosystems LTD. Service contract no B4-3200/98/000411/ MAR/D2. [Online]. Available at: http://ec.europa.eu/environment/nature/info/pubs/docs/life/conserv- ing_mires.pdf [Cited 22 June 2010]. Sundseth, K. 2009. Natura 2000 in the Boreal Region. Luxemburg: Office for Official Publications of the European Communities, 2009. Wegefelt, S. (ed.) [Online]. Available at: http://ec.europa.eu/environ- ment/nature/info/pubs/docs/biogeos/Boreal.pdf [Cited 22 June 2010]. Wheeler, B.D., Shaw, S., & Tanner, K. 2009. Using science to create a better place. A wetland frame- work for impact assessment at statutory sites in England and Wales. Environment Agency, Sci- ence report. [Online]. Available at: SC030232/SR1 http://webdoc.sub.gwdg.de/ebook/mon/2009/ ppn%20603890881.pdf [Cited 23 June 2010]. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 32 Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 33 Session 3 Hydrological fluxes in different climatic conditions Chair: Viliam Pichler, Slovak Academy of Sciences, Bratislava, Slovakia Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 34 Forest – Water Interactions: A Reply to the Water Yield Debate David Ellison1, Martyn Futter2 and Kevin Bishop2 1 Institute for World Economics, Budapest, Hungary 2 Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Uppsala, Sweden Five major articles published in the past decade have all concluded that the impact of re- or af- forestation on water yield is negative: planting additional forests will reduce downstream water availability. Likewise, removing forests will result in higher downstream water availability. Even without climate change, such findings have powerful land use implications. In a period of increasing global warming, climate change and changing precipitation patterns, the implications are even more far-reaching—in increasingly water-constrained regions, re-, af-forestation and other land use strategies must be carefully considered. A second group of authors continue to argue that the opposite is true: planting additional forests should ultimately raise downstream water availability and improve the hydrologic cycle. Supporting evidence however has eluded these authors. We provide theoretical and empirical support for both sides of this debate, with the balance of the argument leaning in favor of the second set of authors. Forest cover is intimately and naturally linked to precipitation. Increasing forest cover has the effect of raising the likelihood of precipitation events and ultimately water yield. These two strands of the forest-water interaction literature argue (and measure) past each other because they fail to adequately understand and experimentally operationalize the problem of scale. We resolve this methodological and theoretical dilemma and illustrate the generally positive relationship between forest cover and water yield. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 35 Carbon and nitrogen pathways from boreal headwater catchments downstream to the coast along variable land use cover Tuija Mattsson and Pirkko Kortelainen Finnish Environment Institute, Finland Organic matter transported by streams and rivers from headwater catchments downstream to the coast is affected by processes in the river and by changing land use along the river basin. Hence, the concentrations of total organic nitrogen (TON) and total organic carbon (TOC) show significant variability during the riverine transport from first order catchments to the coast. The TON and TOC concentrations were studied in 42 unmanaged and 21 managed first order catchments covered by forests and peatlands with an area ranging from 0.07 to 56 km2 and in 36 river catchments and their sub-catchments with mixed land use and an area of 73 to 56 500 km2. In small pristine headwater catchments, the proportion of organic nitrogen of the total N load was very high, on average 91% (Mattsson et al 2003, Kortelainen et al. 2006). In headwater catchments where forestry practices have annually affected about 2.4 % of the catchment area, comparable to average values in Finland, the proportion of organic nitrogen was somewhat smaller, on average 77% (Kortelainen et al. 1997). Downstream in the river basins, the proportion of organic nitrogen decreased and in the river mouths the proportion was 53% (Mattsson et al. 2005). Although the proportion of organic nitrogen decreased from headwaters downstream, TON concentrations increased from on average of 340 μg l-1 in first order streams through 400 μg l-1 in river sub-catchments to 550 μg l-1 in river mouths. On the contrary, TOC concentration was on average highest in headwater streams (17 mg l-1), whereas in river mouths, the average TOC concentration was lower (13 mg l-1). These results indicate that land use gradient from headwaters to lowlands affects TON and TOC concentrations and has significant effect on the stoichiometry of our study rivers. References: Kortelainen, P., Mattsson, T., Finér, L., Ahtiainen, M., Saukkonen, S. & Sallantaus, T. 2006. Controls on the export of C, N, P and Fe from undisturbed boreal catchments, Finland. Aquatic Sciences 68(4): 453−468. Kortelainen, P., Saukkonen, S. & Mattsson, T. 1997. Leaching of nitrogen from forested catchments in Finland. Global Biogeochemical Cycles 11(4): 627−638. Mattsson, T., Finér, L., Kortelainen, P. & Sallantaus, T. 2003. Brookwater quality and background leaching from unmanaged forested catchments in Finland. Water Air and Soil Pollution 147(1-4): 275−297. Mattsson, T., Kortelainen, P. & Räike, A. 2005. Export of DOM from Boreal catchments: impacts of land use cover and climate. Biogeochemistry 76: 373−394. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 36 Stable isotopes studies to increase knowledge from the role of peatlands in catchment hydrology Anna-Kaisa Ronkanen1, Hannu Marttila1, Juha Siekkinen2 and Bjørn Kløve1 1 Department of Process and Environmental Engineering, University of Oulu, Finland 2 Metsähallitus, Oulu, Finland After 1960 intensive draining of peatlands, hydrology in the catchment scale has drastically changed and decreased water storage capacity of uplands in Finland. This has inflicted on higher and narrower peaks, and decreased low flow in runoffs, which is followed by poorer ecological conditions for salmonid migrants and river pearl mussel. Nowadays, restoration operations have been initiated at large areas with poor forest growth aim to restore flow and ecological conditions. Runoff detention would also benefit hydroelectric power plants downstream locations. Potential locations for restoration have been studied by the Metsähallitus in the Iijoki catchment area located in the Northern Finland. Two study sites have been chosen to study effects of peatland restoration on hydrology in the catchment scale. One peatland (Marjasuo) has been drained for forestry in around 1960, but the other is still a pristine peatland (Ryövänsuo) locating in the National park of Isosyöte. Both peatlands have their separate local catchment areas but are located at the same bigger catchment area and area part of the Iijoki catchment. Monitoring campaign in both areas includes automatic discharge, groundwater and precipitation measured continuously. Nutrient concentrations (nitrogen, phosphorus, suspended solids) of outflows and groundwater have been analysed once a month. Furthermore, vegetation and tree growth are monitored. The drained peatland are going to restore in the summer 2011. Generally, stable isotopes are used as a tracer in studies of catchment hydrology (Kendall & MacDonnell, 1998). The method is also successfully adapted to peatlands in smaller scale (Ronkanen & Kløve, 2007 and 2008). A properly designed survey of stable isotope composition of water within a given catchment area should yield important information concerning the spatial heterogeneity of isotopic composition of water in this system, which can be linked to the structure of water flow, residence times and preferential flow paths. In order to study, how large peatland areas should be rewetted for sufficient water storage, impacts of restoration are going to study. Objective of the study is to use the stable isotope ratio 18O/16O to find out the effect of peatland restoration on catchment hydrology. Artificial tracer tests and the stable isotope ratio 18O/16O will be used to investigate the changes in flow paths and water balance in the area. References Kendall,C. & McDonnell,J.J. (Eds.) 1998. Isotope Tracers in Catchment Hydrology, Elsevier Science B. V., 803 p. Ronkanen A-K. & Kløve B. 2007. Use of stabile isotopes and tracers to detect preferential flow pattern in a peatland treating municipal wastewater. Journal of Hydrology 347(3−4): 418−429. Ronkanen A-K. & Kløve B. 2008. Hydraulics and flow modelling of water treatment wetlands constructed on peatlands in Northern Finland. Water Research 42(14): 3826−3836. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 37 Runoff generation across spatial and temporal scales following wildfire Jan Jacob Keizer, João Pedro Nunes, Maruxa Malvar, Sergio Prats, Raquel Ferreira, Diana Vieira, María Eufemia Varela, Isabel Fernandes and Silvia Faria CESAM, Dept. Environment, U. Aveiro, Portugal Through their effects on soil properties as well as on vegetation and litter cover, wildfires can lead to considerable changes in geomorphologic and hydrological processes. Previous studies in various parts of the world, including Portugal, have revealed strong and sometimes extreme responses in runoff generation and associated soil losses following wildfire, especially during the earlier stages of the so-called “window-of-disturbance”. Besides wildfire itself, also post-fire forestry practices can strongly influence overland flow and erosion in recently burned areas. Following the catastrophic summer fire season of 2003, in which more than 400.000 ha of Portuguese forests and woodlands were burned, the EROSFIRE projects set out to address the need for a model-based tool for: (i) assessing soil erosion hazard following forest fires in Portugal; (ii) for predicting the effectiveness of selected erosion mitigation measures. To this end, the suitability of various existing erosion models is being compared. Whilst the (semi-)empirical models USLE and MMF are included in this comparison, the physically-based MEFIDIS model has been the focus of data collection efforts. Data gathering for initial parameterization of MEFIDIS and its subsequent calibration and assessment involved as principal methods: (i) field rainfall simulation experiments (RSE’s); (ii) runoff/erosion plots, both bounded micro-plots (< 1m2) and unbounded slope-scale plots; (iii) catchment gauging station; (iv) regular monitoring of soil properties like ground cover, moisture content and water repellency. In the EROSFIRE-I project (POCI/AGR/60354/2004), six slopes covered by eucalypt plantations were intensively studied during the first one or two years following wildfire using a combination of RSE’s, plots and monitoring. In the follow-up project EROSFIRE- II (PTDC/AGR-CFL/70968/2006), continuous recordings of water level and turbidity at the outlet of an entirely burned micro-catchment are being combined with plot measurements at five nearby slopes covered by pine or eucalypt stands and the monitoring of selected soil properties at four pine and eucalypt slopes. Analysis of the collected data is still ongoing and model assessment, in particular of MEFIDIS, has by and large been limited to some preliminary efforts. Therefore, a presentation is proposed that will focus on the following two aspects: (i) changes in overland flow generation with time- since-fire at the micro-plot scale; (ii) differences in overland flow generation at the micro-plot versus slope-scale. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 38 Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 39 Poster presentations Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 40 New methods to control acid sulfate and organic acid leaching from peatland forestry drainage areas Kaisa Heikkinen2, Simo Tammela1, Hannu Marttila1, Tuomas Saarinen1, Kati Martinmäki2, Raimo Ihme2, Mika Visuri2, Jaakko Saukkoriipi2, Jermi Tertsunen3, Timo Yrjänä3, Jukka Tuohino3 and Bjørn Kløve1 1 Department of Process and Environmental Engineering, University of Oulu, Finland 2 Finnish Environment Institute, Finland 3 Centre for Economic Development, Transport and the Environment for North Ostrobothnia, Oulu, Finland Acid sulfate soils are common in the river drainage basins of the Gulf of Bothnia area (e.g. River Sanginjoki). Intensive peatland drainage, among other factors, has increased acid sulfate leaching from these soils under the peat layers. Temporal low pH values (< 4) can appear during flood peaks particularly after dry seasons when soil sulfites have been oxidized. Flooding can also increase leaching of organic acids from forested and peatland dominated areas to the river, causing lowered pH values in the river water. These low pH pulses are harmful to stream biota and may decimate e.g. fish populations. In order to be able to control and decrease the emergence of these low pH values different management methods are tested and studied in the River Sanginjoki basin: Controlled outflow, which slows down the sudden formation of acid peaks in the streams and can also be supposed to prevent their formation by increasing the buffering capacity of the runoff water. Also the effect of limestone weirs at drainage ditches and streams during different hydrological periods is tested in the project with encouraging preliminary results. The project includes also studies on the runoff water acidity decreasing effect of grained ash in a ditched, nitrogen-lacking peatland forest. Localizing of the acidity deposits in the river basin is done with the existing GIS and other geologic soil data and by water quality monitoring. These measures are indicating also whether acidity is sulfate soils or organic acid originated. The project has over 20 continuous and 40 monthly pH-measuring points all over the river channel network. They are completed by bi- weekly water sampling from 16 locations. The project “City and Water – Ecological enhancement and improvement of recreational value of river Sanginjoki” is a cooperation project of University of Oulu, SYKE and Centre for Economic Development, Transport and the Environment for North Ostrobothnia. It is financed by the European Regional Development Fund (ERDF), municipalities of Oulu, Muhos and Utajärvi, Turveruukki Oy, Oulu Golf club and local fishery collectives of the River Sanginjoki area. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 41 Participation of aquatic fungi in litter decomposition in Lithuanian woodland streams Svetlana Markovskaja and Jurga Motiejunaite Laboratory of Mycology, Institute of Botany, Vilnius, Lithuania, About 30 % of the Lithuanian territory is covered by forests of various types and up to 1,5 % is occupied by running and stagnant freshwater basins. Submerged litter of riparian vegetation is an important habitat and food source for many aquatic organisms, including fungi. Aquatic fungi are the major decomposers of such submerged substrates; they produce various enzymes degrading cellulose, hemicellulose, lignin, starch and pectin into usable intermediate compounds. In temperate streams located in forested areas of Lithuania with riparian vegetation characterized by a rich species composition (Alnus, Acer, Betula, Corylus, Quercus, Salix, Tilia, Ulmus and other) the fungal communities reach a maximum peak in overall metabolic activity and species richness in autumn (October-November). After autumn fall, some terrestrial fungi species also may be introduced to streams and lakes from terrestrial litter or phylloplane. The main aim was to study fungal diversity of various taxonomical groups occurring on different submerged substrates (leaves, wood and needles) in the two different woodland streams. Our study indicates that substantial differences exist in species richness and composition of fungal communities established on a particular substrate. We established that aquatic hyphomycetes are the most frequent early decomposers of submerged forest leaf litter in investigated streams. Majority of the fungus species found on wood were aero-aquatic and terrestrial hyphomycetes, which have a slower growth rate and lower density. The results also suggested that diversity and structure of fungal communities depend on diversity of riparian vegetation bordering the streams, seasonal temperature changes and fresh input of litter fall into a stream. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 42 Hydrological and protective services of forests – modelling on watershed level Špela Planinšek, Andreja Ferreira and Anže Japelj Slovenian Forestry Institute, Ljubljana, Slovenia The water and soil regime in this research is dealt at the level of forestry needs and knowledge, from the aspect of both water discharge and erosion, with an emphasis on considering the natural capacity and practical employability of the selected model. Model was developed for the purpose of evaluation and allocation of forest areas with hydrological and protective services. Within the framework of this research, the two effects of the forest have been merged, owing to their close relationship and comparable forest management measures for their consolidation. The model was tested in the alpine watershed and in lowland watershed on alluvial plain. First is characterized by a substantial proportion of forestland (83%) and rather low proportions of other types of land, second has only 42% of forest cover. Both lie on sensible, porous and erodible limestone parent material. The development of the decision support GIS model required first to determine the demands and contemporary the capacity of forest sites for providing hydrological and protective services. We aimed to underline the significance of a suitable stand structure, canopy cover and suitability of tree species for optimal water cycle in the forest ecosystems. Demands are expressed by external-ecological factors (terrain slope and forest soil types, distinguished by their erodibility and water permeability). A forest’s capacity to assure hydrological and protective services is expressed by internal-forest stand factors (stand structure, stand density, degree of stand naturalness). The model was designed to confront the external factors (which in view of their natural features dictate the manner of management) with the stand factors (upon which one can exert certain influence and reach the desired result). Although the basic factors are integrated into several steps, the impacts of separate factors are still visible in the overall results. These characteristics were decisive in the selection of this model, considering that the multicriteria evaluation methods would not have provided for it to such a great extent. In the latter, the impact of a separate factor on the overall result is not clearly visible, owing to the intermediate standardisation and subsequent classification (Ferreira 2000). The joint map of the demands and the needs represented a good basis for determining the most suitable silvicultural actions. We took into account the natural conditions and assist in the process of shaping and directing silvicultural actions in areas where they are most needed. In the prepared model we emphasized critical areas (16% in managed forests, 33% in protection forests). We can maintain, in compliance with needs, existing conditions, or enhance the capacity of a forest to carry out its hydrological and protective service. The idea of multifunctionality in Slovenia’s forestry practice lacks guided measures for the preservation and promotion of the forests’ certain service. This can provide an equivalent management in the entire region, in spite of the different local needs for the functions and services of forests. References de Groot, R. 2006. Function-analysis and valuation as a tool to assess land use conflicts in planning for sustainable, multi-functional landscapes. Landscape and Urban Planning, 75(3-4): 175−186. Ferreira, A. 2000. Methodology for the assessment of the impacts of encroachment upon forest and forest landscape. Zbornik gozdarstva in lesarstva. (62): 171−207. Mohren, G.M.J. 2003. Large-scale scenario analysis in forest ecology and forest management. Forest Policy and Eco- nomics 5(2): 103−110. Store, R. 2009. Sustainable locating of different forest uses. Land Use Policy, 26 (3): 610−618. Twery, M.J. & Hornbeck, J.W. 2001. Incorporating water goals into forest management decisions at a local level. Forest Ecology and Management 143 (1-3): 87−93. Wullschleger, E. 1982. Die Erfassung der Waldfunktionen. Berichte. Eidgenössische Anstalt für forstliche Versuchve- sen, Birmensdorf. 79 p. Working Papers of the Finnish Forest Research Institute 168 http://www.metla.fi/julkaisut/workingpapers/2010/mwp168.htm 43 Stream ecohydrologic surveys to evaluate the impacts of watershed land use Semih Ediş1, Betül Uygur2 and Yusuf Serengil2 1 Cankiri Karatekin University, Faculty of Forestry, Turkey 2 Istanbul University, Faculty of Forestry, Turkey Urban and peri-urban watersheds are affected from human activities and streams draining them are modified in most cases. Therefore, it may be possible to connect stream properties with land use. Streams draining forestlands generally posses functional riparian corridors while the ones passing through settlement areas are less healthy. This study was carried out in Balaban and Kilyos watersheds in Istanbul. The objective was to estimate land use impacts based on the results of stream surveys performed on 2