The Editor’s Choice article for Journal of Ecology’s latest issue Volume 108 Issue 5 is “Palms and trees resist extreme drought in Amazon forests with shallow water tables” by Sousa et al.
Here handling Editor, Crystal McMichael highlights the key findings of this research and explores the question “is the Amazon more resilient to drought than previously thought?“
The Amazon is ca. 6 million km2 in size. The forests contain ca. 15,000 tree species, and palms are one of the most common and abundant plant groups (ter Steege et al., 2020). Palms are also disproportionately abundant in Amazonia compared with other tropical forests across the world (Muscarella et al., 2020). Because of their dominance across the Amazonian landscape, palms thus play a large role in ecosystem functioning.
Drought events, which have increased in intensity and frequency over recent decades, have been shown to affect forest dynamics and species composition in Amazonia. These extreme events are associated with changes in forest dynamics, biomass and floristic composition. However, palms are typically not included in these drought response studies, despite their abundance in the forests. The anatomy, physiology, and growth strategies of palms differ from dicotyledonous trees, suggesting their drought response may also vary. Most of the previous work on drought responses by Amazonian plant communities has also been conducted in upland areas with deep water tables, and the results suggest that the forests are particularly susceptible to droughts. Yet one third of Amazonian forests lie in lower areas with shallower water tables, and the drought responses in these forests remain virtually unstudied.
In this Editor’s Choice article entitled “Palms and trees resist extreme drought in Amazon forests with shallow water tables” (Sousa et al., 2020) addresses these knowledge gaps. Sousa et al. conduct drought-response studies in areas with shallow water tables, which also contain a hyper-abundance of palms, and make comparisons to upland areas with deeper water tables. The authors find that both palm and tree communities in areas with shallow water tables were particularly drought-resistant and were shown to increase in recruitment and biomass during drought events. These results contrast previous ideas about Amazonian drought sensitivity. The article also highlights the need to study the various forest types within Amazonia to obtain a more accurate and comprehensive understanding of its ecology.
Crystal N. H. McMichael Associate Editor, Journal of Ecology
Read the full article online: “Palms and trees resist extreme drought in Amazon forests with shallow water tables” by Sousa et al. (2020)