The University of Arizona

College of Agriculture and Life Sciences

Climate Change Means Spring Is Coming Earlier

Wednesday, December 11, 2019

Arizona radio KJZZ recently interviewed Theresa Crimmins of the National Phenology Network (NPN) about how climate change has caused shifts in seasonal biological events, such as when plants leaf out and flower. NPN uses biological data collected by professional and volunteer scientists to develop predictive models and maps that are freely accessible to the public (https://www.usanpn.org/data/maps).
 
A recent analysis of this data found that Spring is arriving earlier in Arizona and throughout much of the country, shifting up to three weeks earlier in the past 70 years. This is concerning for ecologists because organisms respond differently to shifts in cues that initiate spring activity. In some cases, a pair of species that have traditionally relied on each other (such as a flower and its pollinator) experience reduced overlap in the timing of their spring emergence because the environmental cues (i.e. temperature, preciptation, day length) synchronizing the relationship between the two species no longer sync up. For example, an insect may no longer emerge at the same time that a plant is flowering because the plant, but not the insect, has delayed flowering in response to temperature. Such asynchronies could hinder survival and reproduction for plants and animals alike, ultimately changing how an ecosystem functions and which species are most common in the area.
 
For more details, listen to the full story here. More information about the NPN can be found on their website.