LANZHOU, April 24 (Xinhua) -- When spring arrives, plants face a critical challenge in their life cycle via a "wisdom of balance," starting to grow leaves early enough to capture sunlight, while avoiding the risk of deadly frost damage. Chinese scientists have recently cracked the code behind how plants solve this ancient survival puzzle.
This study is the first to measure the relationship between "greening up" and "frost avoidance" on a global scale, according to Lanzhou University in northwest China's Gansu Province.
The study was led by researchers of Lanzhou University, in collaboration with researchers from East China Normal University, the Institute of Applied Ecology of the Chinese Academy of Sciences (CAS) and the Institute of Tibetan Plateau Research of the CAS. Their findings were published in the journal Nature Communications.
"This evolutionary mechanism offers a new way to predict plant behavior under climate change," said He Jinsheng, professor at Lanzhou University and leader of the study.
He explained that early spring green-up is usually beneficial for individual plants. The earlier plants start growing, the longer their growing season becomes, giving them less competition and greater access to resources, all boosting their survival and reproduction chances. However, earlier green-up also means plants face higher frost risks.
"Plant spring timing must balance starting the growing season as early as possible with avoiding deadly frost risk. Understanding this trade-off helps reveal the evolutionary logic behind spring plant timing and provides a foundation for understanding how plants adapt their survival strategies to global warming," He added.
The team studied this trade-off using "safety margin" measurements, which refer to the difference between the minimum environmental temperature during spring plant activity and the lowest temperature plants can survive. A higher safety margin means lower risk of deadly frost.
Researchers combined spring freezing resistance data from 193 plant species across 126 global research sites and recorded daily minimum temperatures when spring growth occurred. They then calculated safety margins for plant exposure to deadly frost risk.
The study results showed that plants maintain strong freezing resistance during spring, consistently surviving temperatures as low as minus 12 degrees Celsius with a remarkable safety margin of about 17 degrees Celsius during spring emergence.
Plants have evolved a stable balance between "greening up" and "frost resistance" that doesn't change with short-term climate variations. Plants generally have strong cold tolerance in spring, enough to handle current environmental minimum temperatures, and so they face low risk of deadly frost, the study revealed.
Advanced model predictions also demonstrate that while future climate warming will continue pushing spring growth earlier, plants will still start spring activity while maintaining this trade-off mechanism, maximizing their survival and reproductive success.
"This study provides a new theoretical foundation for building and testing next-generation plant timing models. Future climate warming will likely cause continued advancement of plant spring timing, reshaping the safety margin against deadly frost," He said.
He added that: "Our research team has used multiple models to predict future spring timing and safety margins. Moving forward, we will continue conducting detailed research and validation." ■
