Determining the Dominant Controls of Land Surface Phenology: Implications for Global Modeling

Friday, 19 December 2014: 2:55 PM
Trevor F Keenan1, Andrew D Richardson2 and Koen Hufkens2, (1)Macquarie University, Sydney, Australia, (2)Harvard University, Cambridge, MA, United States
Phenology regulates multiple aspects of ecosystem function, along with associated feedbacks to the climate system. Models predict earlier spring and later fall under future climate change, which would help slow the rate of warming by enabling increased carbon sequestration. That said, current models perform poorly, and there is little consensus as to what are the determining controls of spring and autumn phenology. Here, using global observations of deciduous forest phenology we determine the dominant biotic and abiotic controls, and develop a new suite of predictive models. We examine relationships between spatial and temporal variability, derive a coherent temperature sensitivity of spring phenology, and show that the timing of autumn senescence is dependent on the timing of spring budburst.