By Cazzy Medley
For the past several years, ESSIC Scientist Andrew Feldman has dedicated his research to discovering how this new rainfall pattern affects plant growth around the world using satellites. In a 2025 paper published in New Phytologist, Feldman argues that short rainfall events, known as “rainfall pulses”, likely play a much bigger role in controlling plant photosynthesis and carbon uptake than is currently recognized.
The pulse of plants
Throughout his research, Feldman found that these pulses can directly stimulate photosynthesis and growth across many global ecosystems, and that these effects can continue for several days afterwards as plants slowly take up water. This could influence how plants store carbon dioxide and release water to the atmosphere over time.
“We tend to think that plants are slowly responding to week-to-week variations in light, temperature, and moisture. However, if a brief addition of water to the soil causes plant photosynthetic processes to have a prolonged response, then plants don’t always quickly forget that a rain event occurred,” said Feldman, “This means that if plants are substantially responding to each pulse, then rainfall pulses are collectively having a surprising amount of influence on plant behavior over a season or year.
“You can think of it this way: if you have a house plant and only a jug of water for the week, should you drench your plant with the full jug on Sunday? Or should you space it out in smaller additions on Monday, Wednesday, and Friday? One could argue that since it is the same amount of water, there isn’t much of a difference.”
Source : umd.edu