A new study provided key insights into how and why tree populations migrate in response to climate change at the continental scale.
Suitable habitats for forest trees are shifting fast with recent climate change. Most tree species in North America have shown evidence for northward migrations due to warming temperatures. But how trees move into new areas depends on whether the trees are found in the West or the East.
Duke University scientists separated effects of seed production. They also separated the establishment of juvenile trees to identify larger patterns. The study has been published in Proceedings of the National Academy of Sciences. The study provides the first continental-scale evidence for migration. It also provides geographic shifts in the processes that control migration.
Scientists discovered that in the interior mountain West, there are high seed production and the recruitment of juvenile trees. They found out how well baby trees do when they are just getting started. In the Northeast, migration is limited by seed production.
The study collected data from MASTIF network. This features a massive synthesis of seed-production data from over 130 research sites across North America. It has seven years of data from the Forest Global Earth Observatory. The south-eastern United States emerges as a fecundity hotspot.
It is situated south of tree population centers. There high seed production could contribute to poleward population spread. But seedling success is highest in the West and North. It serves offset limited seed production near poleward frontiers.