Droughts are becoming more frequent and severe due to human activities and climate change. Scientists have found that the size and shape of seeds play a key role in determining how resilient grasslands are to drought.

The researchers, led by Dr Luo Wentao from the Institute of Applied Ecology of the Chinese Academy of Sciences, studied how different types of plants in a grassland reacted to reduced rainfall over four years.

They found that grasses were more stable than forbs during the drought. They also found that the grassland recovered quickly after normal rainfall resumed. The researchers said that having a variety of plants with different functional traits helped the grassland adapt to dry conditions.

They discovered that seed traits, such as width and thickness, were more important than leaf traits (e.g. specific leaf area and leaf nutrient content) in determining how resilient the grassland was. Plants with larger and thicker seeds were less affected by changes in precipitation over time. The researchers explained that seed traits reflected the evolutionary history and adaptation strategies of plants to different environments. These findings suggest that certain plant traits can provide a new perspective for understanding and predicting how grasslands respond to drought and climate change.

The study, funded by the National Natural Science Foundation of China and the Youth Innovation Promotion Association of the Chinese Academy of Sciences, was published in Functional Ecology.