Transkriptio

1 / Mauri Timonen

2 Ring width, mm Sample PIT Year, BC Metla/Erkki Oksanen Lämpömittari on muutaman vuosisadan ikäinen keksintö. Puut ovat hyviä luonnon ilmastoasemia arvioitaessa mennyttä lämpöä ja kosteutta tuhansien vuosien ajalta. Puut kertovat epäsuorasti myös talvikauden ilmastosta kasvukauden alkamisen ajoittumisen välityksellä. Hyvät vuodet merkitsevät leveiden vuosirenkaiden kehittymistä kaikkiin alueen puihin huonot puolestaan vuodet kapeita renkaita. Tässä nykyisen mäntymetsänrajan ulkopuolella sijaitsevassa Lapin lammessa kasvoi tukkirunkoja lähes 3000 vuotta sitten.

3 Climate change Climate forcing Cross-dating Dendrochronology Eemian interglacial Holocene Holocenic climate Interglacial Subfossil Megafossil Petrified wood Quaternary

4 Mauri Timonen These 200 million year log rocks were formed during millions of years as wood cells slowly decayed and were replaced by the minerals of sinking water.

5 Mauri Timonen This cross-section, cut from a 8 m long and 40 cm thick Larix trunk, was found at a 4 m depth in peat, facing to mineral soil. The tree, located in Vuotso, a village in Northern Finland, was growing during the previous interglacial era, called The Eemian interglacial era, about (114000) years ago. Unfortunately the last Ice Age caused the naturally regenarated Larix to disappear from Finland.

6 Matti Eronen Old tree remnants, megafossils, may preserve undecayed for thousands of years in icecold and muddy lakes. Lake Iijärvi, Inari.

7 Land, sea, atmosphere (N:78%, O:21%, CO2: 0,3%) CH4, N2O, H2O +++ Clouds, aerosols --- Winds, sea currents +/- Sun radiation, cosmic radiation +/ Earth axis +/- => Chaotic effects (volcanos, asteroids, nuclear wars, new technologies! etc.) Metla/Erkki Oksanen Climate, indeed, is a very tricky system to be controlled in any Climatic Model. Even the most advanced climatic models of today fail to properly handle even the simpliest things like the effects of cloudiness and water vapour. And much a bigger question is: what actually are the effects of the (too) many cross variances of thousands variables of mesoscale climates interacting the Global Climate? None of us scientists actually knows! Climate, indeed, is a very tricky system to be controlled in any Climatic Model. Even the most advanced climatic models of today in a long run of climate change fail to properly consider even the simpliest things like the effects of cloudiness and water vapour. And much a bigger question: what actually are the effects of the many cross variances of thousands of mesoscale climates interacting the Global Climate? None of Us actually knows! And considering the research of Past Climate: it is also quite a tricky task. But there, luckily, are numerous proxy data sets available helping to resolve the most important climatic parameters Maapallon ilmasto ei riipu pelkästään ilmakehästä, vaan myös maasta, kasvillisuudesta ja meristä. Maa ja meri ovat lämmön vastaanottajia, sen heijastajia sekä hiilidioksidin sitojia ja vapauttajia; ilmakehän aineosat (O, N, CO2). Kasvihuonekaasujen uskotaan lämmittävän ilmastoa estämällä lämmön säteilyä avaruuteen. Pilvet ja aerosolit puolestaan arvioidaan viilentävän ilmastoa (aerosoleja tulee paljon metsistä). Tuulet ja merivirrat siirtävät lämpöä paikasta toiseen maapallolla. Auringon aktiivisuudella ja ilmaston luontaisella vaihtelulla on havaittu olevan yhteyttä; avaruuden kosminen säteily vaikuttaa pilvien muodostumiseen ja viilentää maata (Henrik Svensmark, Tanska). Tulivuorten purkaukset viilentävät maata. Maapallon akselin muutokset kymmenien tuhansien vuosien jaksoissa muuttavat myös ilmastoa. > MONIMUTKAISTA.

8 This schematic figure shows the climate of northern hemisphere during the last years and outlines the next years. An interesting question is: will there really be an extra warming during the next few centuries caused by human activity? Forecasting from the earlier quaternary climatic rhythms, there should a cooling trend towards the next Ice age, which according to some Russian scientists should start even earlier as expected, after 4000 years!

9 Returning back to more basic questions of Holocenic climate, several warmer and cooler periods have been detected. The presented temperature ranges changes are only indicative, because climatic conditions vary from one mesoscale climate to another (location, geography etc.). Kuva oikealla: Jonathan T. Overpeckin 1990-luvun alussa tekemien siitepölytutkimusten tulosten mukaan meillä Skandinaviassa on ollut holoseenin ilmasto-optimin aikana kesäisin 2-4 astetta nykyistä lämpimämpää. Eräiden muiden tietojen mukaan kesäisin jopa 2-6 C ja talvisin 3-9 C ( Se on huikean paljon, merkiten kasvukauden lämpösummassa d.d.tä (day degree). Kuva ylhäällä: John L. Dalyn esittelemä kuva kertoo havainnollisesti viimeisen tuhannen vuoden ilmastosta. Oliko keskiajan lämpökausi todella noin paljon nykyistä lämpimämpi, selviää viimeistään vuonna 2009, kun eurooppalainen EY-rahoitettu Millennium-projekti saa mallitustyönsä päätökseen. Lisää pohdintoja koosteissa: Mauri Timonen (2005): Ilmastonmuutos ja Lapin metsät ( Mauri Timonen (2006): Viime aikaiset ilmastonvaihtelut holoseenin aikaperspektiivissä tarkasteltuna ( Mauri Timonen (2006): Muistiinpanoja edelliseen aihepiiriin liittyen ( Aiemmista ilmaston muutoksista saatavissa tietoa historian kirjoista ja kirkonkirjoista. Lämpökaudella Islannissa ja Grönlannissa harjoitettiin maanviljelystä ja Englannissa viinin viljelyä. Ajat olivat ankeat Pikku jääkauden aikana: kylmyys jäädytti meret ja joet (mm. Itämeri, Thames ja Hollannin kanaalit), toistuvat nälkävuodet tappoivat ja musta surma kylvi kuolemaa keskiajan Euroopassa. Emme tunne näiden ilmastokausien syitä sen paremmin kuin luvunkaan lämpenemisen syitä.

10 Scots pine (Pinus sylvestris) spread to Finnish Lapland years ago. Summer climate during the Atlantic period ( BP) was even 4-9 degrees warmer than today. Large pines grew beyond the present pine timberline in those times. The oldest megafossil found so far started its growth 7640 years ago. The hillside behind this small lake halfway the Lake Pöyrisjärvi road once, probably during the Holocene Optimum, was crowded of sawtimer logs. The stumps of these full-sized logs are still attached to their original growing positions about 1 m below the present lake surface level.

11 Depends on season: warmth in spring (beginning) warmth and moisture in summer light in autumn (end) Coldness and snow in winter Metla/Mauri Timonen Pelätään, että ilmaston lämmetessä puut eivät osaisi hyötyä lämpötilan noususta, eivät osaisi lopettaa kasvuaan tai lähtisivät kasvamaan kesken talven. Pelko on aiheeton, sillä puilla on käytössään hienomekanismit kasvun alkamiseen ja päättymiseen sekä sen talviaikaiseen estoon.

12 Kaksi menetelmää puiden paikallistamiseksi mudasta: 1) Jaloilla tapahtuva tunnustelu 2) suorat näköhavainnot. Metla/Mauri Timonen

13 Metla/Mauri Timonen Lake Luolajärvi is one source of subfossil wood. Many of the living pines on the hillside are more than 450 years old.

14 Metla/Mauri Timonen Grassy shores are good indicators in locating submerged logs. Location:, a small lake close to Ahvenjärvi, the Näkkälä road, about 5 km east of Palojärvi.

15 Metla/Mauri Timonen Sub-aqua subfossil forest. An interesting detail in this case is sudden ground water level uprise by about one meter, which is well demonstrated by stump birth point positioning of the trunks. Location: A small roadside lake about 5 km from Näkkälä to Pöyrisjärvi

16 Metla/Mauri Timonen This over 5000 years old pine log was extracted from deep mud. Location: Kalmankaltio roadside.

17 Lake Vallijärvi is located beside Lake Ropijärvi in Finnish Käsivarsi, a region about 30 km beyond the present pine timberline. This sample VAL4973, also called Finland (turn upwards and mirror it), dates at BC. Suomipuu on Vallijärvestä löydetyistä rungon osista erikoisin. Sen vuosilustot ajoittuvat aikaan eaa (näyte VAL4973). Jos kuvan kiekko käännetään 90 astetta vastapäivään, muistuttaa sen sivuprofiili eläinhahmoa (karhu). Edellisen peilikuva puolestaan muistuttaa Suomen karttaa. Siksi nimitys Suomipuu.

18 634 eaa. 838 eaa. 5 cm Metla/Mauri Timonen This special sample PAT1-11C, also called Axe Mark Tree, was found just beyond the present pine timberline close to a small village of Pättikkä in Finnish Käsivarsi. This tree, growing between two small lakes, was originally ment to help deer hunters. But failing direction in tree felling turned it to lake mud and saved it to us dendrochronologists! Tässä nykyisen mäntymetsänrajan ulkopuolella sijaitsevassa Käsivarren Pättikän lammessa kasvoi tukkirunkoja lähes 3000 vuotta sitten. Mudasta paljastettu mäntysubfossiili oli 15 m pitkä ja tyveltään 40 cm.

19 There are no pine forests at lake Vallijärvi today. That was not the case during the Atlantic Period years ago when climate was some degrees warmer than today. The last pine megafossils disappeared from the region about 2500 years ago. Karu Vallijärvi sijaitsee Käsivarressa Ropinjärven lähellä noin 420 metrin korkeudella merenpinnasta. Järven ranta-alueet muodostuvat pääasiassa puuttomasta kivirakasta. Järven länsirantaa peittää noin 250 metrin pituinen kapea maa-ainesta sisältävä kaistale. Järvi on matala ja kivipohjainen lukuun ottamatta em. kaistaleen rantaa, jonka pohjaa peittää enimmillään muutaman kymmenen cm:n vahvuinen muta- ja liejukerros. Vallijärveltä ei nykyisin tapaa mäntymetsiä eikä edes yksittäisiä mäntyjäkään. Tunturikoivu on seudun ehdoton valtapuulaji. Mänty on paennut jo kauan sitten Pättikän alueelle noin 20 kilometrin päähän Vallijärveltä. Toisin oli ns. Atlanttisella kaudella vuotta sitten. jolloin ilmasto oli muutaman asteen nykyistä lämpimämpi: silloin mäntymetsät kukoistivat Vallijärvellä. Sen osoittavat lukuisat järven pohjamudasta kaivetut 5000-vuotiset mäntymegafossiilit. Vähittäin tapahtunut ilmaston viileneminen merkitsi männyn elinolosuhteiden ja uudistumisen vaikeutumista. Niinpä männiköt vähitellen harvenivat, kunnes lopulta viimeisetkin mänty-yksilöt kaikkosivat alueelta noin 2500 vuotta sitten.

20 Three methods of locating submerged logs. Left: Physical contact of logs inside mud by foot work. Right up: Direct observing for visible logs in clear waters. Right down: Scuba diving in deep dark waters.

21 A French-made winch, model Tirfor T560, is strong enough to drag most of the Finnish timberline logs out from mud. It weighs 13 kg and uses a strong steel wire (11 mm/20 m/7 kg).

22 Some megafossils ashored at a Kalmankaltio lake. The age of logs over 4000 years.

23 Kuva kiekot on kerätty yli 30 metsänrajaseudun järvestä (kartta). Tästä kiekkokasasta rakennetaan vuosilustokalenteri! Mauri Timonen A set of cross sections waiting for preparation and measuring.

24 Metla (Finnish Forest Research Institute) uses a modernized Eklund-based tree-ring measurement system. Mauri Timonen

25 A method called cross-dating makes it possible to build thousands of years long tree-ring chronologies based on much younger trees, e.g years old Scots pines in Finland.

26 Here is an example of dating two samples. Look at the coincidence of minimums and maximums values to get the idea of cross-dating.

27 1.5 R96A23/Lake Pitkäjärvi Part of the ADVANCE-10K chronology Index Ring width, mm Sample PIT Year Here is another example of dating. The existing year-exact 7640-yr Finnish timberline pine chronology makes it possible to date almost all found archaeological and other type of material in Northern Finland.

28 Program Cofecha is a very powerful - and what is best: a free dating tool. Download it at This example shows a very high degree of coincidence in the dating of the previous Axe Mark Tree. See especially the Add # 1 field and the 0 corrections in the dating (The sample was previously properly dated; that s why the zero year correction.

29

30 The supralong Scots pine chronology is a composite of 1485 samples. The data can be classified into three geographical sections: Upper Lapland, Western and Eastern Lapland.

31 Some statistics describing the Finnish 7640-yr Scots pine chronology: - Ring-width on the average: 0.6 mm - Tree-ring index ranges annually from 50 to Peaks in indices (pointer years, event years) indicate warm and cool years. - Number of replications varies from 8 to RBAR (21-yr window correlation level) is EPS-value 0.85 fails in some parts of the chronology. -

32 A non-standardised tree-ring chronology: average annual ring-widths, smoothed 50-yr widths, number of replications and EPS.

33 A standardised tree-ring chronology (indices).

34 Samples by age range and calendar year Lake Kompsiojärvi EPS RBAR 1, ,5 0, N A subdata from Lake Kompsiojärvi. Similar data sets of different time periods available from over 70 sites (lakes).

35 Samples by age range and calendar year Riekkovaara EPS RBAR N Another example, a subdata from Riekkovaara (Saariselkä area).

36

37 Finnish pine timberline reached its highest elevation during the Atlantic period years ago.

38 MAIN RESULTS AND CONCLUSIONS, page 1 Slide 23 The 7640-yr Scots timberline pine chronology in itself is the main key result, because there, for the first time in the history of Dendro-chronology, is a continuous 7640-year tree-ring chronology for Finnish Lapland available. It is the longest year-exact conifer tree-ring chronology in Eurasia and the second longest conifer tree-ring chronology in the world. Not only the length of the chronology but also its exceptional climatic sensitivity (an exceptionally strong connection between ring width and July temperature) provides an great tool for tracking past climate changes. The chronology in itself has proven to be an excellent tool for dating purposes. The chronology, however, is not perfect so far for dendroclimatic analysis, because 1) Data is partly scattered and heterogenous; 2) it is not well enough replicated in all parts of the chronology

39 MAIN RESULTS AND CONCLUSIONS, page 2 Slide 24 Medieval Warm Period, Little Ice Age and Present Warm Period pop up clearly from the basic curve of the chronology. Longer trendlike periods, such as Holocene Optimum ( BP), are a bit more difficult to distinguish in this data. We use advanced standardisation methods, like RCS (Regional Curve Standardization) and Age Banding, but some defects in data make it hard to make reliable conclusions. There seems to be also another way in identifying past climatic ups and downs from tree-rings: cycle amplitudes and level of minimum values that seem to correlate with warm and cool periods of climate (slide 30).

40 MAIN RESULTS AND CONCLUSIONS, page 3 Slide 25 Spectral analysis indicate statistically strong cycles of 30-32, 37, 47-49, and 95 years. The yr cycle gives the strongest signal. We may now have a tool for forecasting the future of natural climate variation for this and possibly the next centuries. Natural climate variation based on the year would roughly mean the following: - latest cool period minimum took place in the 1980s. - warming period reaching its peak some 2030 and a cooling period reaching minimum some (check the smoothed curves of slides 26-30). Spectral analysis shows a cycle of years to be the strongest. Spectral density Period length, years

41 A. Chronology improvement by: Slide 26 Increasing number of replications in some parts of the chronology (better statisical interpretation) Extending the chronology beyond the abrupt Climate Change at 8.2 ky BP (better understanding in today s possible abrupt changes). Tree-ring ring index of Scots pine during the last 500 years in Northern Finland Year

42 B. Advanced analysis by: Slide 27 Investigating more carefully the possible regular cycles in the chronology Finding methods of combining other proxies with tree-ring data Monitoring climate variations and tree-gowth on annual basis Tree-ring ring index of Scots pine during the last 2000 years in Northern Finland Tree-ring index FFT 50y Year

43 C: Expanded the use of the chronology by: Slide 28 Forecasting future climate trends and fluctuations. Tree-ring ring index of Scots pine during the last 7500 years in Northern Finland

44 D: Cycles as a research target: Slide 29 Some notes and triggering comments 1. The four cycles with high amplitudes of variation ( ), not the last one indicate according the hypothesis the cool Little Ice Age. 2. The last cycle with a minimum point close to the average indicates the present warm period. Tree-ring ring index of Scots pine during the last 7500 years in Northern Finland The red-blue curve: average near-surface temperatures of the norhern hemisphere during the past years (red-blue modified from Dansgaard et al., 1969, and Schönwiese nwiese,, 1995). The black curve: 50-yr FFT smoothing on the tree-ring ring index of the Finnish 7638-yr supralong pine chronology. Before Present

45 D: Cycles as a research target Slide The last 4 cycles show somewhat identical pattern as about 1000 years ago. Are we possibly facing a warming similar to the 1300s-400s? 4. The four cycles with high amplitudes of variation ( ) indicate the cool period of Little Ice Age. Dansgaard et.al s (969) warming period at this period is conflicting. 5. What is the final message? Tree-ring ring index of Scots pine during the last 2500 years in Northern Finland Before Present

46 D: Cycles as a research target Slide The last 4 cycles show somewhat identical pattern as about 1000 years ago. Are we possibly facing a warming similar to the 1300s-400s? 4. The four cycles with high amplitudes of variation ( ) indicate the cool period of Little Ice Age. Dansgaard et.al s (969) warming period at this period is conflicting. 5. What is the final message? Tree-ring ring index of Scots pine during the last 500 and the next 100 years in Northern Finland 150 Tentative forecast +1 C C

47

48 Similar vegetation and timberline zones make it possible to study climate change throughout the world. One criteria for choosing research areas is using biomes.

49 Scots pine (Pinus sylvestris) is a widely spread tree species. We can create Eurasian wide project based on this feature.

50

51

52 EUROPE: Dendro Sciences Division, Swiss Federal Institute for Forest, Snow and Landscape Research Institute for Forest growth, Albert-Ludwigs-Universität Freiburg, Germany Institute of Plant and Animal Ecology,Laboratory of Dendrochronology, Ekaterinburg, Russia University of Tromsø, Department of Biology, Dendrochronological Laboratory, Norway ASIA: Institute of Botany, Tree-Ring Laboratory, Chinese Academy of Sciences, China V.N. Sukachev Institute of Forest Siberian Branch, Russian Academy of Sciences, Russia AMERICA: Laboratory of Tree-Ring Research, University of Arizona, USA Lamont-Doherty Earth Observatory, Tree-Ring Laboratory, Columbia University, USA Rocky Mountain Tree-Ring research, by Dr. Peter M. Brown, USA AUSTRALIA : Laboratory of Tree-Ring Research, University of Arizona, USA

53

54 Regular meetings with colleagues is important in international cooperation. Here we are negotiating in IPAE (Institute of Plant and Animal Ecology) in Ekateringburg, Southern Urals, Russia. Here historical Finnish- Russian handshakes on the Asian-European border close to Ekaterinburg confirm our joint efforts in climate change research.

55 Academician Eugene A. Vaganov, the head of Siberian Forest Research and Director in the Institute of Forest in Krasnoyarsk.

56 Greening is a new phenomenon in northern hemisphere. Increased CO2 is accumulating in vegetation?

57

58 Pallas-Ylläs region in Western Lapland is one of the research areas used in Metla s Climate Change Studies

59 Mount Kukastunturi is one of our planned WorldWide Network in monitoring Climate Change based of tree-ring and climate data

60 Well, we anyway have to continue our mud baths for further material! Mauri Timonen

61 About 400 participants coming from more than 40 countries Pre-conference fieldweek (June, Sun 6 - Sat 12, 2010) Post-conference excursions: -Scandinavian timberline excursion (June, Sun 20 - Sat 26, 2010) - Komi excursion (June, Sun 20 - Sat 26, 2010) - South Finland excursion (June, Sun 20 - Sat 26, 2010 Climate Change in large geographical areas Human survival in the changing climates Climate modeling Tree-ring ring data and metadata archives Oral poster presentations Other splendid ideas

62 The LUSTIA website, established in 1998, is basically a joint effort of three Finnish organizations: Metla, the University of Helsinki and the University of Joensuu. Our ambitious mission is to provide a platform for the results of the huge study material (samples, data files and related meta material) collected by our Finnish Scientific Group, mainly in the European wide ADVANCE-10K EU-project ( ). But we include also all other dendrochronological information on this site. Drill into the secrets of Finnish TreeTree-Ring Science here! here!

63

64

65 This sampling Plan provides a data of various-aged tree-rings

66 Mount Kukastunturi is one of our planned WorldWide Network in monitoring Climate Change based of tree-ring and climate data

67 Tree-rings of Finnish timberline pine have proven to be an excellent source for local and global climate change analysis. A very interesting and hot question is, how well the observed cyclicity of pine growth can be applied to forecasting future natural climate variations and trends. If applicable, we finally can distinquish antropogenic effects from natural variation. Mauri Timonen