ATP - Automated Intra-Annual Tree-Ring Profiling for Dendroecological Research
Final Report Abstract
The structure of wood encodes in high resolution the growths of trees and thus the environmental conditions at the respective time. To reveal the impact of temporary environmental events, like droughts, heat waves or insect attacks, one has to know which part of the tree-ring was formed at that time. This allows to find correlations of environmental signals with wood growths. This project aimed to provide fundamental methods to (i) measure wood growth information at high resolution, (ii) to annotate this data with respective time lines and (iii) to test the potential of such data for subsequent research. The latter focuses not only at relating growth with other measurements but also to enhance time annotation of wood samples, which is called crossdating in dendrochronology. Within the course of the project, we implemented and published a new tool that is central to aggregate high-resolution measurements of wood density. This MICA tool (Multiple Interval-based Curve Alignment), allows to synchronize individual measurements, which is essential to remove individuum-specific variations in growth speed and rhythm from the data. Hence, it contributes to increasing wood growth signal strength. The latter is conducive, for instance, to crossdate wood samples. We could proof that using high-resolution wood density information significantly improves crossdating for short samples. Furthermore, we were able to establish new protocols how such information can be annotated with respective growth times. This is done by relating a tree’s stem growth in girth or diameter measured via sensors on the bark of a living tree with respective wood density measurements after the tree was cut. Since such measurements are laborious, we introduced a MICA-based protocol to extrapolate such temporal annotations to wood density data of other trees. Therefore, the project lays the foundation for subsequent research that can focus on the application of temporally annotated, high-resolution wood growth data given our introduced tools and protocols.
Publications
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Spatiotemporal alignment of radial tracheid diameter profiles of submontane Norway spruce. Dendrochronologia, 37:33–45, 2016
D. Stangler, M. Mann, H.-P. Kahle, E. Rosskopf, S. Fink, and H. Spiecker
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MICA: Multiple interval-based curve alignment. SoftwareX, 7:53–58, 2018
M. Mann, H.-P. Kahle, M. Beck, B. J. Bender, H. Spiecker, and R. Backofen
