The mechanisms of phenology: the patterns and processes of phenological shifts

Helen E. Chmura, Heather M. Kharouba, Jaime Ashander, Sean M. Ehlman, Emily B. Rivest and Louie H. Yang


Species across a wide‐range of taxa and habitats are shifting phenological events in response to climate change. While advances are common, shifts vary in magnitude and direction within and among species, and the basis for this variation is relatively unknown. We examine previously suggested patterns of variation in phenological shifts in order to understand the cue‐response mechanisms that underlie phenological change. Here, we review what is known about the mechanistic basis for nine factors proposed to predict phenological change (latitude, elevation, habitat type, trophic level, migratory strategy, ecological specialization, species’ seasonality, thermoregulatory mode, and generation time). We find that many studies either do not identify a specific underlying mechanism or do not evaluate alternative mechanistic hypotheses, limiting the ability of scientists to predict future responses to global change with accuracy. We present a conceptual framework that emphasizes a critical distinction between environmental (cue‐driven) and organismal (response‐driven) mechanisms causing variation in phenological shifts and discuss how this distinction can reduce confusion in the field and improve predictions of future phenological change.

Ecological Monographs

2019 Experimental Ecology and Evolution in the Field (EVE/ENT 180 A/B)

Winter and Spring 2019

What is it? A 2-quarter field course focused on a single research project.

Why should I take it? Past students have said:

“There is no other course on campus that promotes such a high level of independent thinking as well as cooperative work. By far, one of the best and most unique courses available at UC Davis.”

“Let me be clear. I have learned more, developed more as an ecologist, and experienced more valuable lessons in the past 6 months than in the entirety of the past 3 years. This class is how college is meant to be taught!”

“Probably the best course I have taken at Davis. I learned so much; even though it is a lot of work, truly the best way to learn is through hands on experience, which this class definitely provided!”

“EVE 180 is such a great class. It has really influenced the way I view experiments and the scientific method. The stuff I learned in this class will help me in grad school and beyond. Favorite class I’ve ever taken for sure.”

“The hands on approach of this course has been vital to understanding the process of science. After this course, I feel I really know what I am in for in my future career.”

What else do I need to know? The prerequisites are incorrect on Schedule Builder. The correct prerequisites are: EVE 100 + (ENT 105 or ESP 100 or EVE 101). Due to the unusual nature of this course, all prospective students are strongly encouraged to contact the instructor (Louie H. Yang,