Our results demonstrate that in the Amazon, forest height and age regulate photosynthesis interannual variability and are as relevant as mean precipitation. In particular, tall, old and dense forests are more resistant to precipitation variability. Tree size and age directly impact forest structure and thus the carbon cycle in the Amazon. This is especially significant given the importance of the Amazon rainforest, not only for the global carbon cycle, but also for global atmospheric circulation, which is closely connected to the evapotranspiration process of this area. Forest height, age and biomass have a role equivalent to mean precipitation in the regulation of forest photosynthesis response to interannual climate variability [Giardina 2018: 4].
Giardina, Francesco, Alexandra G. Konings, Daniel Kennedy, et al., 2018, Tall Amazonian forests are less sensitive to precipitation variability, Nature Geoscience, https://www.nature.com/articles/s41561-018-0133-5.