February 2021

Is understanding the past enough to predict the future? Global tree-ring data show complex impacts of climate change.

A deep-rooted concept in the dendrosciences is to infer climate or ecosystem variability from statistical relationships established between tree-ring and instrumental data. By extent, these relationships can then be extrapolated into past or future time frames, for example, to anticipate the impacts of anthropogenic climate change on forest ecosystems. Problematically, evidence is mounting that matters are not so simple and that the uncertainties associated with temporal and spatial scaling of tree-ring data are substantial.

Stable isotopes of tree rings reveal seasonal-to-decadal patterns during the emergence of a megadrought in the Southwestern US

Recent evidence has revealed the emergence of a megadrought in southwestern North America since 2000. In this occasion I will talk about how we examined tree-ring growth and stable isotope ratios in Pinus ponderosa at its driest niche edge to investigate whether trees growing near their aridity limit were sensitive to the megadrought climatic conditions during or before the establishment of the current megadrought.

Multicentennial perspectives on extreme climate and natural disasters in the northeastern Pacific

Over the past decade, the northeastern Pacific has witnessed repeated and severe heatwaves that have profoundly impacted the functioning and productivity of marine and adjacent terrestrial ecosystems. However, there remains considerable and long-standing uncertainly regarding NE Pacific climate variability prior to 1900 CE and the extent to which recent extremes are atypical in a longer-term context.

RingdateR: A statistical and graphical tool for crossdating

Crossdating is the defining technique of dendrochronology, ensuring that all measurements in a dataset are annually resolved and absolutely dated. This level of accuracy allows for the development of high-resolution environmental reconstructions of climate, disturbance, and productivity not only in trees, but also in other ring-forming organisms including fish, corals, and bivalves. However, crossdating is a laborious process and can be a significant bottleneck in the development of new chronologies, especially when attempting to find matches among undated, dead-collected material.