Dendrochronology in Finland Historical milestones and current activities

Dendrochronology in Finland: Historical milestones and current activities World. Dendro 2010 Rovaniemi, June 14, 2010 Kari Mielikäinen Metsäntutkimuslaitos Skogsforskningsinstitutet Finnish Forest Research Institute www. metla. fi

Content of the presentation § § § 1/19/2022 History of Finnish dendrochronology (climatology) Supra-long pine chronology of Finnish Lapland Growth trends in Finnish (European) forests Recent publications based on long chronologies Some future forecasts 2

Total growth and removals in Finnish forests 1923 - 2005 100 Milj. m³ 80 Growth 60 40 Removals 20 0 19231930 1940 1950 1960 1970 1980 1990 2000 1/19/2022 3 © Metla/Erkki Oksanen

Annual ring indices of Norway spruce in Southern Finland (Henttonen 1990) Dashed line => June-July precipitatin included 1/19/2022 4

The impact of N-fertilisation on the radial increment of Scots pine (Kukkola? ? ? ) 1/19/2022 5

Annual ring indices for Scots pine in Lapland (Hustich 1948) 1/19/2022 6

Model for the cyclic variation of the climate 1180 -1960 (Siren 1963) 1/19/2022 7

The forecast for the future temperature of Lapland 1960 - 2060 (Siren 1963) Tmax = year 2020 1/19/2022 8

Collecting data for the longest pine chronology of Eurasia (Eronen 1979. . . ) © Mauri Timonen 1/19/2022 A lake close to Kalmankaltio © Mauri Timonen 9

The Supra-long pine (Pinus silvestris) chronology (5634 BC) for Finnish Lapland 1/19/2022 10

Voi jäädä pois? ? ? Eljaksen julkaisusta jotakin? 1/19/2022 11

The changes of the tree line based on the location of megafossils found in the lakes of Lapland north of the present tree line (Kultti et. al. 2006) 1/19/2022 12

13 Impacts of air pollution on European forests } Situation in the 1980´s n Deposition of sulphur (SO 2) Acid rain n Deposition of nitrogen (traffic and agriculture) n Deposition of heavy metals n Pekka Nöjd / ==> In spite of these facts (next two slides) METSÄNTUTKIMUSLAITOS SKOGSFORSKNINGSINSTITUTET FINNISH FOREST RESEARCH INSTITUTE www. metla. fi

Total growth and removals in Finnish forests 1923 - 2005 100 Milj. m³ 80 Growth 60 40 Removals 20 0 19231930 1940 1950 1960 1970 1980 1990 2000 • 1/19/2022 • 14 © Metla/Erkki Oksanen

Increment and fellings in European forests Gross annual increment Net annual increment Annual fellings In exploitable forests 1950 -1990 (133 mill. ha in 1990), in forests available for wood supply 2000 (149 mill. ha in 2000) Sources: 1/19/2022 years 1950 -1990: Kuusela, K. 1994. Forest Resources in European Forest Institute. Research Report 1. year 2000: UN-ECE/FAO. 2000. Forest Resources of Europe, CIS, North America, Australia, Japan and New Zealand. 15

LAUCHING OF A PROJECT BY METLA AND UNI FREIBURG IN 1992 ”GROWTH TRENDS IN EUROPEAN FORESTS” “HAS FOREST (TREE) GROWTH IN EUROPE CHANGED IN A WAY, THAT CANNOT BE EXPLAINED BY CHANGES IN STAND STRUCTURE OR SILVICULTURE? ” Here: Growth trend = long-lasting deviation from expected growth (Tree age and stand density excluded) ==> 45 forest growth scientist from 12 countries 1/19/2022 16

The residual of growth model against calendar year (experimental data Finland) NO LONG-TERM TREND 1/19/2022 17

Growth Trends in European Forests: Conclusions (Spiecker, Mielikäinen, Köhl & Skovsgaard 1996) 1/19/2022 18

The decadal fluctuations in the timberline pine treering index for the last 7640 years (FFT smoothed) 1/19/2022 19

Recent studies based on long chronologies § Tähän joku kuva Maurilta? 1/19/2022 20

Precipitation anomalies since AD 660 in Lapland (Helama et. al. 2009) = Dark Ages Cold Period = Little Ice Age = Medieval Climate Anomaly 1/19/2022 21

Drought synchrony during Medieval Climate Anomaly in four continents (Helama et. al. 2009) § Drought Area Index: Western USA § Extreme drought without El Nino flooding: Coastal Peru § Water level of Lake Naivasha in Kenya § Low-frequency component of European precipitation record (this study) 1/19/2022 22

Climatic evolution in Lapland since AD 750 (Helama et. al. 2009) § Reconstructed temperature variability in annual, decadal and centennial scale § Medieval Warm Period (warmest 250 years), Little Ice Age (coldest 250 years) and the Twenteth Century Warming (1900 - 1950) 1/19/2022 23

Thermohaline circulation of North Atlantic (solid line) compared with tree-ring based temperatures (Helama et. al. 2009) 1/19/2022 24

Reconstructed temperatures (5500 BC - AD 2004) based on the supra-long pine chronology (Helama et. al. 2010) § Reconstructed temperatures in annual, decadal and multicenturial scale § Multi-centurial component of reconstructed temperature variability and the Denton. Karlen coolings 1/19/2022 25

Sunspot - climate associations for the latest 7500 years (Helama et. al. 2010) Bimillenial scale prevailing until year 0 (lag 0) Millenial scale prevails years 0 -2000 (lag 70) 1/19/2022 26

Forecasts for our future climate § Driver CO 2 § § § Siren 1963: Cooling => 1970 Warming => 2010 Cooling => 2060 § Timonen 2006: Warming => 2010 Cooling => 2050 Driver Millenial activity of the Sun § 1/19/2022 Global warming => 2100 Driver "unknown" cyclicity § § IPCC: Helama et. al. 2010: Lagged warming All Drivers together WHO KNOWS? 27

Lapin "lätkämailoja" 1900 -luvulta 1/19/2022 28