From "Periodical Observations” to "Anthochronology” and "Phenology” - the scientific debate between Adolphe Quetelet and Charles Morren on the origin of the word "Phenology”

Mankind has observed and documented life cycle stages of plants and animals for a long time. However, it was comparatively recently that the newly emerging science was given its name. The name of Charles Morren and the year 1853 are being cited, although not frequently. Exact information is hardly known among present-day phenologists, yet new evidence shows that the term "phenology” was already in use in 1849. In the early 1840s, physicist and astronomer Adolphe Quetelet set up an observational network named "Observations of periodical Phenomena of the Animal and Vegetable Kingdom” and issued instructions for it. Even though biologist Charles Morren welcomed Quetelet's initiative, differences between Morren and Quentlet regarding the instructions for the observations and the potential results soon arose and a debate started, which lasted for nearly 10years. In the wake of these disagreements, Morren was compelled to create a new term to denote his ideas on "periodical phenomena”. At first, he temporally used the word anthochronology, but in the end he coined the word phenology. The term was first used in a public lecture at the Académie royale des Sciences, des Lettres et des Beaux-Arts de Belgique' in Brussels on 16 December 1849, and simultaneously in the December 1849 issue of volume V of the Annales de la Société royale d'Agriculture et de Botanique de Gand. One had to wait until 1853 before the new name appeared in the title of one of Morren's publications. Based on evidence from archives and original publications, we trace the 10-year-long scientific debate between Morren and Quetelet. Morren states his biologist's view on the subject and extends the more climate-related definition of Quetelet of "periodical phenomena

A decade of cold Eurasian winters reconstructed for the early 19th century

Annual-to-decadal variability in northern midlatitude temperature is dominated by the cold season. However, climate field reconstructions are often based on tree rings that represent the growing season. Here we present cold-season (October-to-May average) temperature field reconstructions for the northern midlatitudes, 1701-1905, based on extensive phenological data (freezing and thawing dates of rivers, plant observations). Northern midlatitude land temperatures exceeded the variability range of the 18th and 19th centuries by the 1940s, to which recent warming has added another 1.5 °C. A sequences of cold winters 1808/9-1815/6 can be explained by two volcanic eruptions and unusual atmospheric flow. Weak southwesterlies over Western Europe in early winter caused low Eurasian temperatures, which persisted into spring even though the flow pattern did not. Twentieth century data and model simulations confirm this persistence and point to increased snow cover as a cause, consistent with sparse information on Eurasian snow in the early 19th century

Origins of the word "phenology"

Observing and documenting life cycle stages of plants and animals have been tradition and necessity for humans throughout history. Phenological observations—as called by their modern scientific name—were key to successful hunting and farming because the precise knowledge of animal behavior and plant growth, as well as their timing with changing seasons, was critical for survival. In today's context of environmental awareness and climate change research, phenological observations have become prime indicators of documenting altered life cycles due to environmental change in disciplines from biology to climatology, geography, and environmental history. Observations on the ground, from space, and from models of different complexity describe intra-annual and interannual changes of life cycles at individual, pixel, or grid box scale