Climate change and species distribution

Climate change strongly impacts biodiversity, putting some species at risk of extinction. However, some plant species for example adapt to the new conditions, and go on to thrive and invade areas where they have never grown before.

The black seed grass (Alloteropsis semialata) is the only species known to comprise of individuals that  use both the more common C3 photosynthetic pathway and a pathway called C4, which is a complex combination of leaf anatomical characters and enzymatic reactions that together increase productivity in warm and dry environments. The C4 pathway is present in just three percent of all plant species yet accounts for one quarter of the terrestrial primary production. This impressive productivity is due to C4 grasses, which dominate most open areas of the tropics and subtropics and especially savannahs.

Through genomic analyses a team of international researchers, led by the University of Sheffield were able to understand the ecological changes that happened during the dispersal of Alloteropsis semialata, first in Africa and then in Asia and Australia. The team found that while the non-C4 plants remained confined to a small range of ecological conditions in Central Africa, the evolution of C4 photosynthesis immediately broadened the ecological conditions where the species could grow. C4 plants can disperse broadly across environmental and geographical space, while still surviving in the same habitats occupied by their non-C4 ancestors, showing that this physiological novelty increases the variety of habitats available, which allowed the rapid colonization of three distinct continents.

In a world rapidly affected by climate changes and other anthropogenic alterations of natural systems, understanding how physiological attributes allow some plants to thrive in a variety of conditions might hold the key to the management of more resilient ecosystems. In addition, understanding what allows some plants to be productive in a variety of environments could help direct future crop improvement projects.