Nitrogen deposition and leaching in the boreal forest environment

Transcription

1 Nitrogen deposition and leaching in the boreal forest environment Eero Kubin, Jarmo Poikolainen, Juha Piispanen, Lindroos, A-J. & Jouni Karhu Finnish Forest Research Institute Oulu Unit 26th Task Force Meeting of the UNECE ICP Vegetation 28th 31st January, 2013, Halmstad, Sweden Metsäntutkimuslaitos Skogsforskningsinstitutet Finnish Forest Research Institute

2 Content 1. Background 2. Monitoring nitrogen deposition by bioindicatiors compared with bulk deposition 3. Nitrogen leaching in a changing boreal forest environment 4. Conclusions 5. Acknowledgement

3 Background Finnish Forest Research Institute Long term studies on the environmental effects of forestry Permanent National Forest Inventory plots monitoring network since 1985

4 The Finnish Forest Research Institute Established 1917 New organization in 2010 Permanent staff 600 Kolari 1964 Muhos Research Unit (staff 42) moved to Oulu University campus to the Environmental Sciences Building in 2012 Rovaniemi 1973 Muhos/Oulu 1969/2012 Kannus 1985 Parkano 1961 Suonenjoki 1981 Joensuu 1981 Punkaharju 1988 Haapastensyrjä 1960 Vantaa 1995

5 University of Oulu, Linnanmaa campus Environmental Sciences Building - Metla - Finnish Forest Research Institute - MTT - Agrifood Research Finland - RKTL - Finnish Game and Fisheries Research Institute - SYKE - Finnish Environment Institute - THULE-istitute (University of Oulu)

6 Long term studies on the environmental effects of forestry started in 1973 In Finland we at first started to study the effects of forestry to runoff water quality at the Kivesvaara experimental site in F C F C S P T P T P S C F S 20 T C P Kivesvaara experimental site P Spruce forest Pine stand (young) Boundary of forest sector Ditch and direction of flow Contour line Road Field laboratory Sampling point F C S P T Forested strip No treatment after clear cutting Scalped strip Heavy reforestation plough Complete turning of the soil T C F P P T S 200 S 16 C m

7 Later in 1985 the work contnied by monitor inggroundwater quality after cutting and waste wood harvesting Hautala Pahalouhi 7

8 Permanent monitoring network was established in 1985 as a part of National Forest Inventory A total of secret sites The main aims were: - forest inventory - estimate the condition of the forests - collect biological samples - map the forest vegetation The network is used especially for heavy metal deposition surveys in 1985, 1990, 1995, 2000, 2005 and 2010

9 Bark, mosses and lichen were sampled for the deposition surveys Hylocomium splendens Pleurozium schreberi Pine bark Hypogymnia physodes

10 Content 1. Background 2. Monitoring nitrogen deposition by bioindicators compared with bulk deposition 3. Nitrogen leaching in a changing boreal forest environment 4. Conclusions 5. Acknowledgement

11 Modification of nitrogen analyse method Modification of the old and well known Kjeldahl method was the first step which made nationwide nitrogen surveys possible in Finland To analyse nitrogen in nation-wide surveys was started in 1985 (lichens), in 1990 (mosses)

12 The self made asbestos-lined aluminium vessel was the start of modification micro Kjeldahl method as early as 1978 on the basis of the earlier reports Photo: Helvi Kangas

13 The suitability of this modification to different plant species was also tested Published in 1980

14 Good results made possible also to write a guide The determination of the organic nitrogen in plant material This manual has been in use up to present time!

15 Analyzing nitrogen in practice In this modification the ammonium nitrogen is determined after digestion by phenyl hypochlorite procedure

16 The first nitrogen survey was made by epiphytic lichen Hypogymnia physodes Altogether samples all over Finland were analyzed The results were published in 1990: Kubin, E A survey of element concentrations in the epiphytic lichen Hypogymnia physodes in Finland in In: Acidification in Finland. N (%) Above Below 1.0 Undefined area n = 2 385

17 National N-surveys were then continued by mosses since 1990 connected to heavy metal surveys

18 Nitrogen concentrations are smaller in northern latitudes; interesting is increasing between , < 64 N N % 1,4 1, ,0 0,8 0,6 0,4 0,2 0,0 < < < < 68 > 68 Latitudes

19 Deposition of nitrogen is highest in southern Finland and fits well nitrogen in mosses Nitrogen deposition 2003 Caused by: - domestic emissions - long-range transboundary air pollution Source: Researcher Jussi Vuorenmaa, NO 3 -N mg/m 2 NH 4 -N mg/m 2

20 The same can well be seen in the bulk deposition of the ICP forest monitoring sites Map on the right: An example, mean annual NO 3 -N deposition (mg m -2 yr -1 ) in bulk deposition for the period Total nitrogen deposition varies between 1-6 kg/ha/year Lindroos A-J., Derome, K., Neminen T.M Forest Condition in Finland. National Report 2012

21 Nitrogen content (Hylocomium splendens) is decreasing towards the north also in the ICP Forest Norway spruce sites with one exception 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 Poikolainen et. al. Map Lindroos A-J., Derome, K., Neminen T.M Forest Condition in Finland. National Report Columns Pallasjärvi Uusikaarlepyy Juupajoki Tammela Kivalo Punkaharju 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 1,8 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0,

22 Content 1. Background 2. Monitoring nitrogen deposition by bioindicatiors compared with bulk deposition 3. Nitrogen leaching in a changing boreal forest environment 4. Conclusions 5. Acknowledgement

23 Changing boreal forest environment - many responses

24 Coverage of Hylocomium splendens is decreasing one example Coverage, % Mäkipää, R. et al Kasvit muuttuvassa metsäluonnossa.

25 NO 3 -N cycle in boreal forests. What are the effects of climate change and whole tree harvest with lifting stumps? Natural state Conventional cutting Whole tree harvesting N-cycle N-cycle N-cycle Deposition: Interception + + Leaching: Depends on site + + (?) Decomposition: Slow + + (?)

26 Leaching in surface waters Nitrate contents in the runoff water after cutting and site preparation ( in 1974) µg/l NO 3 -N Clear cutting and site preparation Only clear cutting Kubin, E Site preparation and leaching of nutrients. Metsäntutkimuslaitoksen tiedonantoja 567

27 Example of groundwater quality monitoring - 26 years nitrate leaching after cutting and waste wood harvesting NO - N µg/l 3 Clearcutting: Avohakkuu: Hakkuutähteet Clearcutting, jää waste not collected Uncut Kontrolli control NO - N µg/l 3 Hakkuutähteet Clearcutting, kerätty waste collected year Vuosi Uncut Kontrolli control Clearcutting Avohakkuu: year Vuosi

28 Studying the effects of stump harvesting on groundwater quality was the next step New research in Metla (Finnish Forest Research Institute) Financed also by the Ministry of Agriculture and Forestry New information for science, forestry practice and policy makers

29 Data collecting from catchment areas

30 Groundwater research areas Uncut control Clear-cut, no restocking Clear-cut, no waste wood harvesting, spruce planting Block III Clear-cut, 70 % logging residue removal, spruce planting Clear-cut, 70 % logging residue removal, stump removal, retaining 25 stumps/ha, spruce planting Block I Clear-cut, all stumps and waste wood harvested, spruce planting

31 Uncut control 747 groundwater samples collected annually from all site So far (since year 2006) approximately samples collected and analyzed

32 Actions in stump harvesting study sites Uncut forest Clear cutting Harvesting of logging residues Stump harvesting

33 After the first year leaching of nitrate nitrogen is increasing from year to year in all treatments Examples of Middle-Finland NO 3 -N µg/l 3,500 3,000 2,500 2,000 1,500 1, Uncut control No waste wood harvesting Clear-cut, 70% logging residue removal, patch mounding, spruce planting Clear-cut, 70 % logging residue removal, stump removal, retaining 25 stumps/ha, patch mounding, spruce planting All stumps and waste wood harvested

34 New forms to utilize raw wood material need better understanding how to maintain site fertility and biodiversity how to sustain carbon balance how to protect water resources systems the role of nitrogen

35 Content 1. Background 2. Monitoring nitrogen deposition by bioindicatiors compared with bulk deposition 3. Nitrogen leaching in a changing boreal forest environment 4. Conclusions 5. Acknowledgement

36 Conclusions 1. Nitrogen deposition decrease in Finland from south to north - can be found by bioindicators 2. Local sources like fur farming can be recognised 3. Forestry has strong environmental effects to the nitrogen cycle 4. Return needs a long time: plant and tree succession is important 5. Results of heavy metal moss surveys are widely used in Finland, e.g. in the Finnish Official Statistics and metal industry

37 Finnish Statistical Yearbook of Forestry 2012 Lead mg/kg < > Nickel mg/kg < > Lead and nickel concentration in mosses in 1985, 1995 and 2010

38 Bioindicator samples are stored to the Paljakka ESB Exhibition hall Sample storage

39 Content 1. Background 2. Monitoring nitrogen deposition by bioindicatiors compared with bulk deposition 3. Nitrogen leaching in a changing boreal forest environment 4. Conclusions 5. Acknowledgement

40 Great thanks to all who involved these works Researchers with deposition and monitoring Eero Kubin; professor Jarmo Poikolainen; Ph.D., Researcher Juha Piispanen; Ph.D., Researcher, Head of laboratory Antti-Jussi Lindroos; Ph.D., Researcher, Metla Vantaa (ICP Forests) Other staff in sampling, analyzing and data processing Reijo Seppänen; Jouni Karhu; Research Assistant M.Sc. Senior Systems Analyst Pekka Honkanen; Timo Mikkonen; Tuula Aspegren; Laboratory Official B.Sc., Research Official Research Official

41 Thank you for your attention!