Dr David Coomes of the Department of Plant Sciences has been studying plant movements and climate warming in the Botanic Garden, particularly with regard to intraspecific variation in growth responses to non-local soils.
To assess how plants might respond to a change in range causing them to grow in novel soils, the team collected seed of a widespread grass of deciduous forests (Milium effusum) from 22 sites across its distributional range, and planted them into an experimental common garden using combinations of seeds and soil reflecting movement scenarios of up to 1600 km. The plants and soils were also experimentally warmed and shaded to determine temperature and forest-structural effects.
They have found significantly positive effects of the temperature difference between the sites of seed and soil collection on growth and seedling emergence rates. These effects persist under experimental warming. Rising temperatures and light availability generally enhanced plant performance. These results suggest that improved growth in currently ‘colder’ soils can be attributed to the effects of concurrent changes in nitrogen deposition and soil pH on belowground community composition. Soil characteristics can shape climate-change driven plant movements by affecting growth of non-local individuals, which should be integrated into predictions of future range shifts in response to climate change.