Climate dynamics of the last Millennium derived from cell structure measurements of pine and oak trees in the temperate lowlands of NE-Germany and N-Poland

• Applicant: Privatdozent Dr. Ingo Heinrich
• Subject Area: Physical Geography ; Ecology and Biodiversity of Plants and Ecosystems ; Plant Physiology
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 259353585

• Final Report Year: 2018

Final Report Abstract

The project aimed to close a research gap in the temperate lowlands of parts of Europe, where so far long temperature reconstructions based on tree rings were not available. ClimCell was successful in developing two robust multi-centennial multi-parameter cell structure chronologies from European oak and Scots pine. Scots pine contains a larger amount of cells per tree ring than European oak, which is an advantage when deriving time series of different cell size classes. In ClimCell, ten size classes could be derived and correlated with daily climate data. Some of the size classes were shown to be strongly correlated with seasonal climate data. These significant and robust relationships are being used for reconstructions of seasonal temperatures and precipitation in N-Poland. Similarly, excellent correlations with temperature were found for earlywood vessels of European oak in NE-Germany, and based on the findings from the calibration period of the robust vessel chronology an annual mean temperature reconstruction for the last 1000 years is being developed. Apart from the new reconstructions one of the major hypothesis of the proposal could be confirmed, namely that the reconstructions based on cell structures can sustain more low-frequency trends than tree ring-width series from the same sample material. We believe that the discipline of quantitative wood anatomy will receive a boost through upcoming ClimCell publications envisaged to be completed in the near future. The methods initially developed for ClimCell were advanced further during the course of the project. The new set up will facilitate a faster sample throughput. More and longer cell structure chronologies will be achieved in the coming years, with the focus on regions where tree rings alone have so far not been successful, e.g., the tropics and the Mediterranean. ClimCell encountered surprises during the process of sample preparation. For various reasons the cell structure analysis software was changed from WinCELL to ROXAS. During the initial analysis phase with ROXAS it was discovered that this program detects cell structures with less sensitivity than WinCELL. As a result, the sample preparation had to be adjusted. Rather than using wood blocks, long thin section were prepared and stained with safranin. This new procedure resulted in more time invested into the sample preparation, however, it paid out well during the following image analysis because of better contrasts (due to the staining increasing the autofluorescence of the woody material) and generally better image quality (mainly due to the flatness of the thin sections). In ClimCell it was confirmed that the combination of the software programs ROXAS for image analysis, RAPTOR for cell data analysis, and CLIMTREG for high-resolution climate-growth analysis is the cutting-edge methodology for quantitative wood anatomy.

Publications

• (2016): Meteorological Drivers of Extremes in Daily Stem Radius Variations of Beech, Oak, and Pine in Northeastern Germany: An Event Coincidence Analysis. Front. PlantSci. 7, Article 733
  Siegmund J.F., Sanders T.G.M., Heinrich I., van der Maaten E., Simard S., Helle G., Donner R.V.
  
• (2016): Minimum winter temperature reconstruction from average earlywood vessel area of European oak (Quercus robur) in N-Poland. Palaeogeography, Palaeoclimatology, Palaeoecology 449, 520-530
  Pritzkow C., Wazny T., Heussner K.-U., Słowiński M., Bieber A., Dorado Liñán I., Helle G., Heinrich I.
  
• (2017): An 810- year history of cold season temperature variability for northern Poland. Boreas
  Balanzategui D., Knorr A., Heussner K.-U., Wazny T., Beck W., Słowiński M., Helle G., Buras A., Wilmking M., Van Der Maaten E., Scharnweber T., Dorado-Liñán I., Heinrich I.
  
• (2017): Increased water-use efficiency translates into contrasting growth patterns of Scots pine and sessile oak at their southern distribution limits. Glob Change Biol. 00:1-17
  Martínez-Sancho E., Dorado-Liñán I., Gutiérrez Merino E., Michael M., Helle G., Heinrich I., Menzel A.
  
• (2017): Xylem adjustment of sessile oak at its southern distribution limits. Tree Physiol. 37, 903-914
  Martínez-Sancho E., Dorado-Liñán I., Heinrich I., Helle G., Menzel A.
  
• (2018): RAPTOR: Row and position tracheid organizer in R. Dendrochronologia 47, 10-16
  Peters R.L., Balanzategui D., Hurley A.G., von Arx G., Prendin A.L., Cuny H.E., Björklund J., Frank D.C., Fonti P.