0000000000614811

AUTHOR

Elisabeth Düthorn

On the hidden significance of differing micro-sites on tree-ring based climate reconstructions

Tree-ring chronologies are commonly extended back in time by combining samples from living trees with relict material preserved in man-made structures or natural archives (e.g. lakes). Although spatially close, these natural archives and living-tree-sites often comprise different micro-climates. Inhomogeneous growth conditions among these habitats, which may yield offsets in growth-rates, require caution in data processing. Here we assess species-specific growth dynamics in two micro-habitats and their potential effects on long chronologies by combining tree-ring data from different living-tree-sites with an “artificial” subfossil dataset. Well replicated (n > 80) Norway spruce (…

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Ecological and climatological signals in tree-ring width and density chronologies along a latitudinal boreal transect

ABSTRACTShifts in the climate sensitivity of trees throughout the twentieth century might indicate climate change effects in the boreal forest ecosystem. We here evaluated such potential changes by analyzing six tree-ring width (TRW) and maximum latewood density (MXD) chronologies from northern, central and southern boreal forests in Finland (60°N–69°N). Besides latitudinal effects, differing micro-sites (lakeshore and inland) were considered to evaluate the influence of ground water access on twentieth-century tree-ring formation and climate sensitivity. Overall, the boreal MXD chronologies appeared less affected by micro-site conditions compared to the TRW chronologies. Along the boreal t…

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Regional coherency of boreal forest growth defines Arctic driftwood provenancing

Arctic driftwood represents a unique proxy archive at the interface of marine and terrestrial environments. Combined wood anatomical and dendrochronological analyses have been used to detect the origin of driftwood and may allow past timber floating activities, as well as past sea ice and ocean current dynamics to be reconstructed. However, the success of driftwood provenancing studies depends on the length, number, and quality of circumpolar boreal reference chronologies. Here, we introduce a Eurasian-wide high-latitude network of 286 ring width chronologies from the International Tree Ring Data Bank (ITRDB) and 160 additional sites comprising the three main boreal conifers Pinus, Larix, a…

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Diverse growth trends and climate responses across Eurasia’s boreal forest

The area covered by boreal forests accounts for similar to 16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not o ...

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Micro-site conditions affect Fennoscandian forest growth

Abstract The long tradition of dendroclimatological studies in Fennoscandia is fostered by the exceptional longevity and temperature sensitivity of tree growth, as well as the existence of well-preserved subfossil wood in shallow lakes and extent peat bogs. Although some of the world’s longest ring width and density-based climate reconstructions have been developed in northern Fennoscandia, it is still unclear if differences in micro-site ecology matter, and if so, whether they have been considered sufficiently in previous studies. We developed a Fennoscandia-wide network of 44 Scots pine ring width chronologies from 22 locations between 59°–70 °N and 16°–31 °E, to assess the effects of moi…

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