The value of crossdating to retain high‐frequency variability, climate signals, and extreme events in environmental proxies

Abstract

High-resolution biogenic and geologic proxies in which one increment or layer is formed per year are crucial to describing natural ranges of environmental variability in Earth's physical and biological systems. However, dating controls are necessary to ensure temporal precision and accuracy; simple counts cannot ensure that all layers are placed correctly in time. Originally developed for tree-ring data, crossdating is the only such procedure that ensures all increments have been assigned the correct calendar year of formation. Here, we use growth-increment data from two tree species, two marine bivalve species, and a marine fish species to illustrate sensitivity of environmental signals to modest dating error rates. When falsely added or missed increments are induced at one and five percent rates, errors propagate back through time and eliminate high-frequency variability, climate signals, and evidence of extreme events while incorrectly dating and distorting major disturbances or other low-frequency processes. Our consecutive Monte Carlo experiments show that inaccuracies begin to accumulate in as little as two decades and can remove all but decadal-scale processes after as little as two centuries. Real-world scenarios may have even greater consequence in the absence of crossdating. Given this sensitivity to signal loss, the fundamental tenets of crossdating must be applied to fully resolve environmental signals, a point we underscore as the frontiers of growth-increment analysis continue to expand into tropical, freshwater, and marine environments.

Strong evidence for changing fish reproductive phenology under climate warming on the Tibetan Plateau

“…For example, dendrochronological technologies (crossdating) have been widely applied to establish accurate long-term growth chronologies and to explore the effects of climate change on the growth of aquatic animals, such as fish, bivalves, and corals (Black et al, 2016;Morrongiello et al, 2012). All these biological responses to climate change are difficult to examine but potentially become achievable with the application of dendrochronological methods.…”

“…This assumption requires that the periodicity of increments (daily and annually) is validated (Campana & Neilson, 1985), and assumes the environmental influence on annulus formation is relatively consistent among years (Millner, Pilling, McCully, & Høie, 2011;Pilling, Millner, Easey, Maxwell, & Tidd, 2007). Recently, the application of dendrochronology (tree-ring) technologies (crossdating) to fish otoliths has successfully addressed this challenge (Black et al, 2016;Morrongiello, Thresher, & Smith, 2012), thus providing the opportunity to investigate changes in fish reproductive phenology from otoliths. A key challenge of this method is how to accurately assign each fish into the correct calendar year class, particularly for long-lived species and old individuals.…”

“…Thus, by combining the environmental history and the otolith distance information, changes in fish reproductive phenology over time can be examined by a one-time sampling of juveniles and adults within different age classes based on the aforementioned assumptions. Past fish otolith studies using dendrochronological technologies have focused on understanding the changes in growth width chronologies in response to environmental change (Black et al, 2016;Izzo et al, 2016;Morrongiello et al, 2012;Ong et al, 2016), but no one has used these methods to help quantifying changes in fish reproductive phenology. Recently, the application of dendrochronology (tree-ring) technologies (crossdating) to fish otoliths has successfully addressed this challenge (Black et al, 2016;Morrongiello, Thresher, & Smith, 2012), thus providing the opportunity to investigate changes in fish reproductive phenology from otoliths.…”

Climatic history of the northeastern United States during the past 3000 years

“…In addition, growth suppression and tree-ring anatomical variability (Therrell and Bialecki, Sachs et al (2007) 2015) can be used to reconstruct extreme events, such as hurricanes and floods. Specific extreme climatic events or decadal climate fluctuations can be identified using dendroclimatology, which relies on precise and accurate dating of each ring (Black et al, 2016); this is a non-trivial exercise, particularly in closed canopy forests where many factors influence growth. Treering reconstructions also employ direct calibration and verification of the climate-growth model from instrumental data.…”

The effects of environment on <i>Arctica islandica</i> shell formation and architecture

“…The periodicity of such structures ranges from tidal to annual (Gordon and Carriker, 1978;Schöne and Surge, 2012). By crossdating time series with similar growth patterns it is possible to construct century-and millennia-long master chronologies (Marchitto et al, 2000;Black et al, 2008Black et al, , 2016Butler et al, 2013). This basic approach, in combination with geochemical methods, has great potential in reconstructing past climatic conditions (Wanamaker et al, 2011b).…”