In natural ecosystems, the ability of plants to disperse their seeds and maintain seed dormancy are two key strategies for survival, population maintenance, and range expansion. However, it remains poorly understood how these two mechanisms interact across different climatic regions to determine maximum dispersal distance and the species range size.

In a study published in Global Ecology and Biogeography, researchers from Xishuangbanna Tropical Botanical Garden (XTBG)of the Chinese Academy of Sciences and their collaborators show that the interplay between seed dormancy and dispersal syndromes shapes seed dispersal distance and species range size in climate-specific ways.

The researchers compiled data from 631 seed plant species across 118 families worldwide. They systematically tested how the trade-off between maximum seed dispersal distance and seed dormancy varies between animal-dispersed and non-animal-dispersed plants. They also examined the modifying role of climate and how these strategies affect range sizes in tropical and temperate regions.

Among seeds that rely on non-living forces such as wind or water (abiotic dispersal), non-dormant species achieve significantly greater dispersal distances than dormant species, reflecting a trade-off between dispersal capacity and persistence traits (dormancy). In contrast, animal-dispersed seeds travel equally long distances regardless of whether they are dormant or not.

Crucially, the influence of dormancy and dispersal on a species' final geographic range size was not the same everywhere. In the tropics, animal dispersal significantly promotes larger range sizes, while the effect of seed dormancy is comparatively weak. In temperate regions, neither dispersal syndrome nor dormancy alone shows a strong direct effect on range size. However, maximum dispersal distance is positively correlated with range size, highlighting the importance of achieving long-distance dispersal in temperate floras.

The study provides a new framework for predicting plant migration under climate change. As species attempt to track shifting climate envelopes, the ability to disperse long distances and to persist through unfavorable years will be critical.

"We show that you cannot look at dispersal or dormancy in isolation," said YANG Jie of XTBG. “To predict which plants will thrive and which will struggle, we need to know three things: Is the seed dormant? Is it dispersed by animals or the wind? And where in the world is it growing? All three jointly matter."

First published: 19 April 2026