Tropical explorations: what tree rings can contribute to studying global change effects in the tropics

Tropical forests and woodlands are key components of the global carbon cycle, as illustrated by the strong contribution of tropical vegetation to the inter-annual variation in the global carbon sink. These strong fluctuations in the carbon land sink are associated with precipitation and temperature anomalies, suggesting a strong component of vegetation productivity. Yet, the extent to which such associations also exist for carbon storage in tree stems is poorly understood. Better insights on this are crucial to forecast the long-term carbon storage capacity of tropical vegetation and assess risks of nature-based solutions to climate change. To provide insights into climate sensitivity of tropical tree growth, initiated by Valerie Trouet, Peter Groenendijk, Flurin Babst and I set up a tropical tree-ring network (https://tropicaltreeringnetwork.org/). This now includes close to 500 tropical ring-width chronologies.
In this talk I will share results of a review in which we evaluate the geographic and climatic distribution and representativeness of the network, identify regions with high need for studies and show where potential is largest. Next, I will present results on an analysis of drought effects, showing that effects of precipitation and VPD anomalies on tropical tree growth are overall mild and partially recover during the years following drought.
These results illustrate the potential of tropical dendrochronology to contribute to global change studies in the tropics. Yet, to reach this potential, a major push in this field is needed.