Article Search
Volume 27.1
January–April 2024
Full table of contents
ISSN: 1094-8074, web version;
1935-3952, print version
Recent Research Articles
See all articles in 27.1 January-April 2024
See all articles in 26.3 September-December 2023
See all articles in 26.2 May-August 2023
See all articles in 26.1 January-April 2023
Samuli Helama. Natural Resources Institute Finland, P.O. Box 16, 96301 Rovaniemi, Finland. samuli.helama@luke.fi
Samuli Helama is a geoscientist with special interest in time-series of annually resolved natural archives and documentary evidence, especially tree-ring chronologies and climatic records. Originally trained as Quaternary geologist, later completing his PhD thesis (University of Helsinki, 2004) on dendrochronology, studying mid and late Holocene tree-ring chronologies as indicators of past climate variability, he is interested in analyzing proxy records of various types in paleoecologic and paleoclimatic contexts. In addition to tree rings, these data include sedimentary records of microfossils, annual shell growth increments, varves, and historical (written) evidence of past environmental changes. He is currently working in a dendroisotope project (QUANOMAL; Quantifying the Past – Environmental anomalies through multi-proxy tree-ring analyses) funded by the Academy of Finland, at the Natural Resources Institute Finland, in Rovaniemi.
Tomi P. Luoto. Division of Aquatic Sciences, Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014, Finland. tomi.p.luoto@jyu.fi
Tomi Luoto is a paleolimnologist with a special interest in reconstructing paleoclimate and past environmental conditions in lakes using modeling approaches. He received his PhD degree in Geology in 2010. His current research focus on biogeochemical cycling and landscape dynamics in the Arctic. He also works in several lake management projects using paleolimnological methods to assess ecological and limnological baseline conditions to set targets for restoration efforts in boreal lakes.
Liisa Nevalainen. Division of Aquatic Sciences, Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, 40014, Finland. liisa.e.nevalainen@jyu.fi
Liisa Nevalainen is a Senior Lecturer of Aquatic Sciences in Department of Biological and Environmental Science, University of Jyväskylä. She is a paleolimnologist and aquatic ecologist with a research focus in understanding lake ecosystem dynamics and lake-catchment coupling processes under natural climate fluctuations and anthropogenic disturbances. She is interested in Holocene-Anthropocene scale changes and boreal, arctic and alpine biomes.
Johannes Edvardsson. Quaternary Sciences, Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden. johannes.edvardsson@geol.lu.se
Johannes Edvardsson is a dendrochronologist and geoscientist with solid history in tree-ring research, climate reconstructions, palaeohydrology, and peatland development. He received his PhD thesis at the Department of Geology, Lund University, Sweden, in March 2013. In his PhD thesis he examined hydroclimatic changes during the Holocene using subfossil peatland trees and stratigraphic records from Swedish peatlands. Johannes Edvardsson continued his hydroclimatic research using subfossil trees from the Baltic region during his three years postdoc employment at the Swiss Tree-Ring Laboratory, Bern University in Switzerland. As a complement to basic tree-ring width data he also has been working with stable isotopes in tree rings and has experience from working with non-invasive analysis of wooden objects, an important aspect when examining art objects. Apart from climatic studies, Johannes Edvardsson has been using tree-ring data to date Flemish 17th Century paintings on oak panels, standing constructions, and archaeological material.
TABLE 1. Characteristics of the eight lake sites (L1-L8) and one peatland site (P9) and their tree-ring data. Abbreviations: LA, Latitude; LO, longitude; NR, the number of rings, NS, the number of tree-ring series; NT, the number of trees; LS, the mean length of the series in years; FY and LA, the first (FY) and last (LY) calendar year (A.D.) of the site chronology; and LC, the total length of the chronology in years.
Site name | Code | LA | LO | NR | NS | NT | LS | FY | LY | LC |
Alakieluu Louhi Kerimäki | L1 | 61.93 | 28.98 | 3424 | 21 | 13 | 163 | 1144 | 1705 | 562 |
Liippilampi Louhi Kerimäki | L2 | 61.92 | 29.03 | 23579 | 158 | 95 | 149 | 595 | 1816 | 1222 |
Kaivanto Louhi Kerimäki | L3 | 61.93 | 28.98 | 28707 | 160 | 94 | 179 | 535 | 1744 | 1210 |
Isokortteikko Kerimäki | L4 | 61.97 | 28.87 | 6464 | 36 | 19 | 180 | 844 | 1693 | 850 |
Valkeajarvi Makkola Kerimäki | L5 | 61.97 | 28.87 | 26703 | 150 | 78 | 178 | 582 | 1742 | 1161 |
Herajärvi Makkola Kerimäki | L6 | 61.97 | 28.83 | 31863 | 214 | 170 | 149 | 559 | 1732 | 1174 |
Hiisjärvi Kerimäki | L7 | 61.90 | 29.02 | 7251 | 57 | 35 | 127 | 885 | 1698 | 814 |
Valkiajärvi Riikola Kerimäki | L8 | 62.03 | 29.17 | 2244 | 12 | 7 | 187 | 1233 | 1831 | 599 |
Purujärvi Suursuo Kesälahti | P9 | 61.80 | 29.75 | 21788 | 131 | 79 | 166 | 845 | 1330 | 486 |
FIGURE 1. Map of North Europe showing the locations of the study site in southern Finland (filled circle) and other late Quaternary palaeoclimate-data producing sites (open circles) mentioned in this study. Lake Iso Lehmälampi is the site of water level reconstructions based on subfossils of the chironomid midge and cladoceran water flea (Luoto, 2009; Nevalainen et al., 2011; Nevalainen and Luoto, 2012). Lit-1 and Lit-2 are tree-ring sites studied by Pukienė (1997) and Edvardsson et al. (2016), respectively.
FIGURE 2. Replication curves of the subfossil tree-ring chronologies. 1, lake sites; and 2, the peatland site. Data are given in Table 1.
FIGURE 3. Comparisons of the proxy indications from southern Finland from AD 600 to 1800. 1, the Palmer Drought Severity Index (PDSI) reflecting spring-summer soil moisture conditions (Cook et al., 2015); 2, the water level reconstruction based on subfossil chironomid midge (dashed line) and cladoceran water flea (solid lines; calibrations from intra-site by thick line and multi-site training sets by thin line) communities in Lake Iso Lehmälampi (Luoto, 2009; Nevalainen et al., 2011; Nevalainen and Luoto, 2012); and 3, the replication curves of the subfossil tree-ring chronologies constituting a peatland and eight lake sites (this study).
Rereading a tree-ring database to illustrate depositional histories of subfossil trees
Plain Language Abstract
Tree trunks can preserve over millennia in the peat and in the bottom of small lakes. Long tree-ring chronologies are built using these materials. The counts of pine trees available to such chronologies are used here to interpret the processes responsible for past variations in population density and sedimentary environments. Abundance of peatland pines around one thousand years ago was contrasted by the low number of available trees from lake sites. This interval overlaps with the Medieval Climate Anomaly with long-lasting droughts reported in the study region (southern Finland). Over the following centuries, the availability of pine trunks from lake sites increased but their number from peatland sites decreased. This change overlapped with the climatic change towards wetter Little Ice Age conditions in the study region. These dissimilarities reflect the benefit for pine trees to recruit on peatland when the climate was dry and the water table level was low, during the Medieval Climate Anomaly, whereas the potential for preservation was diminished on riparian environment for lake sites. Likewise, the recruitment of peatland pines was impaired when the water table level rose, during the Little Ice Age, while the accumulation of pine trees into the lake sediment was increased when the raising lake level drowned the riparian trees. Tree-ring data of this study was retrieved from an electronic database and the analysis highlights the potential of similar data to illustrate the depositional histories of succeeding tree generations and, when interpreted with care, to detail the picture of hydroclimate anomalies in deep time.
Resumen en Español
Releyendo una base de datos de anillos de árboles para ilustrar las historias de depósito de árboles subfósiles
Se han construido cronologías de anillos de árboles del Cuaternario tardío utilizando datos recolectados de árboles subfósiles preservados en condiciones favorables en sedimentos lacustres y depósitos de turba. Las anchuras y densidades de los anillos de árboles se usan comúnmente para reconstruir la variabilidad climática pasada. Una forma alternativa de utilizar estos datos es explorar las curvas de replicación de estas cronologías. Utilizamos los datos previamente recolectados que están actualmente disponibles en las bases de datos de los anillos de árboles para demostrar las historias de depósito de pinos una vez acumulados en el sedimento de lagos (i.e., árboles de ribera) y turberas. Se obtuvieron dinámicas divergentes para las historias de depósito respecto a diferentes entornos sedimentarios en el sur de Finlandia. La acumulación de pinos de turbera fue alta, pero la de los árboles ribereños fue baja, alrededor de 1000 años, durante la Anomalía Climática Medieval (ACM, en inglés MCA). Por el contrario, la acumulación de pinos de turbera disminuyó hacia la Pequeña Edad de Hielo (PEH, en inglés LIA), mientras que la de los árboles ribereños aumentó, con un pico máximo alrededor de 700 años. Interpretamos que estas variaciones significan cambios ambientales de transición en los hábitats correspondientes e indican un aumento de la precipitación y una subida de la capa freática desde ACM hacia el PEH. Estos resultados demuestran los papeles relativos de los potenciales de reclutamiento y preservación, y por lo tanto de los procesos paleoecológicos y tafonómicos, en el control de la acumulación de árboles en ambientes de turberas y lacustres, respectivamente. Concluimos que las cronologías de los anillos de los árboles subfósiles, incluso los extraídos de las bases de datos digitales, pueden aportar una visión significativa de la paleoecología, proporcionando nuevas perspectivas sobre el paleoclima, la paleohidrología de los lagos y las turberas, y asimismo pueden ser útiles para estudiar las respuestas de las poblaciones de árboles a los cambios climáticos del pasado.
Palabras clave: Paleobotánica; paleoclimatología; paleoecología; paleohidrología; ganancia tafonómica; anillo de árbol
Traducción: Enrique Peñalver (Sociedad Española de Paleontología)
Résumé en Français
Une seconde lecture d'une base de données de cernes de croissance d'arbres pour illustrer les histoires dépositionnelles des arbres subfossiles
Les chronologies des cernes de croissance d'arbres du Quaternaire récent ont été construites en utilisant des données collectées sur des arbres subfossiles préservés dans des conditions favorables dans des sédiments lacustres ou des dépôts de tourbières. Les épaisseurs et densités des cernes de croissance d'arbres sont généralement utilisées pour reconstituer la variabilité des climats passés. Une autre manière d'utiliser ces données est d'explorer les courbes de réplication de ces chronologies. Dans cet article, nous utilisons des données précédemment collectées et disponibles dans les bases de données de cernes de croissance d'arbres pour reconstituer l'histoire dépositionnelle des pins accumulés dans le sédiment dans des sites de lacs (i. e., des arbres proches des berges) et de tourbières. Des histoires dépositionnelles différentes ont été obtenues pour différents contextes sédimentaires du sud de la Finlande. L'accumulation des pins de tourbière était importante, mais celle des arbres de berges de lacs était faible autour de 1,0 ka pendant l'Optimum Climatique Médiéval (MCA). Au contraire, l'accumulation des pins de tourbière a diminué autour du Petit Âge Glaciaire (LIA), alors que celle des arbres de berges de lacs a augmenté, avec une culmination vers 0,7 ka. Nous interprétons ces variations en termes de changements environnementaux transitionnels dans les habitats correspondants, indiquant des précipitations plus importantes et une nappe phréatique plus haute du MCA au LIA. Ces résultats illustrent les rôles relatifs des potentiels de recrutement et préservation, et donc des processus paléoécologiques et taphonomiques, contrôlant l'accumulation d'arbres dans des environnements de lacs et de tourbières, respectivement. Nous concluons que les chronologies de cernes de croissance d'arbres subfossiles, même celles extraites des bases de données électroniques, peuvent fournir des connaissances approfondies de la paléoécologie, fournissant de nouvelles perspectives sur les paléoclimats, la paléohydrologie des lacs et des tourbières, et sur l'étude des réponses des populations d'arbres aux changements climatiques passés.
Mots-clés : paléobotanique ; paléoclimatologie ; paléoécologie ; paléohydrologie ; gain taphonomique ; cernes de croissance d'arbres
Translator: Antoine Souron
Deutsche Zusammenfassung
Neue Leseart einer Jahresringe-Datenbank zur Darstellung der Ablagerungshistorie subfossiler Bäume
Mit Daten subfossiler Bäume, erhalten unter günstigen Bedingungen in Seesedimenten und Moorablagerungen, wurde eine spätquartäre Jahresring-Chronologie aufgebaut. Üblicherweise werden die Abstände und Dichte der Jahresringe zur Rekonstruktion der vergangenen Klimavariabilität genutzt. Die Replikationskurven dieser Chronologie zu untersuchen, ist eine alternative Möglichkeit diese Daten zu verwenden. Hier bedienen wir uns zuvor gesammelter Daten die aktuell aus Jahresring-Datenbänken verfügbar sind, um die Ablagerungsgeschichte von Kiefern zu demonstrieren, sobald sie in einem Seesediment (Uferbäume) oder Moorgebiet abgelagert sind. Es wurden verschiedene Ablagerungsmöglichkeiten für verschiedene Ablagerungsbedingungen in Südfinnland ermittelt. Die Anhäufung von Kiefern aus Moorgebieten war hoch, jedoch die von Uferbäumen war mit 1.0 ka während der mittelalterlichen Klimaanomalie (MCA) niedrig. Dagegen nahm die Anhäufung von Kiefern aus Moorgebieten gegen die Kleine Eiszeit hin ab, während die der Uferbäume zunahm, mit einem Höhepunkt bei um die 0.7 ka. Wir interpretieren diese Variationen als vorübergehende Umweltveränderungen in den dementsprechenden Habitaten, die erhöhten Niederschlag und einen steigenden Grundwasserspiegel von der MCA hin zur Kleinen Eiszeit anzeigen. Diese Ergebnisse zeigen die jeweiligen Rollen von Rekrutierung und Erhaltungspotential und daher von paläontologischen und taphonomischen Prozessen bei der Kontrolle von Baumakkumulation in Moor – bzw. Seegebieten. Wir folgern, dass subfossile Baum-Chronologien, auch diese aus elektronischen Datenbänken, wichtige Erkenntnisse über die Paläoökologie und darüber wie Baumpopulationen auf Klimaveränderungen reagieren, liefern und neue Perspektiven über das Paläoklima und die Paläohydrologie von Seen und Moorgebieten geben.
Schlüsselwörter: Paläobotanik; Paläoklimatologie; Paläoökologie; Paläohydrologie; taphonomischer Gewinn; Jahresring
Translator: Eva Gebauer
Arabic
Translator: Ashraf M.T. Elewa
-
Review: The Princeton Field Guide to Mesozoic Sea Reptiles
The Princeton Field Guide to Mesozoic Sea Reptiles
Article number: 26.1.1R
April 2023 -