The fundamental trade-off between current and future reproduction has long been seen as a factor influencing the tendency of species that can reach large sizes to begin reproduction at larger sizes. However, estimates of the size at which trees mature remain scarce due to the extended time required to reach maturity. Because of that long term maturity stage, and limited data, we are lacking of a comprehensive view of the trade-off between tree at maturity and maximum size.
In our last study, we used more than 10 million of observation of seed production data with tree size from five continents. We were able to estimate the maturation size of 486 tree species, covering climates ranging from tropical to boreal.
Our results showed that the size at maturity of tree species increases with their maximum size, but not proportionally as we would initially expect based on evolutionary theory. We found that the largest species begin to reproduce at smaller sizes than would be expected if maturation were simply proportional to maximum size (see the illustration just bellow).
Figure for illustrative purpose: Trees do not wait too long before being able to reproduce (blue dotted line). Instead, large trees species can be already reproductive at smaller size (plateau, brown plain line).
This phenomenon is particularly marked in cold climates, where the reduction in relative maturation size is most abrupt. These results provide new insights into forest dynamics and species responses to disturbance and climate change. We now know a little more about when trees start to reproduce! Read the full story:
https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.14500