Climatic legacy effects on the drought response of the Amazon rainforest. (17th July 2022)

• Record Type: Journal Article
• Authors: Van Passel, Johanna; de Keersmaecker, Wanda; Bernardino, Paulo N.; Jing, Xin; Umlauf, Nikolaus; Van Meerbeek, Koenraad; Somers, Ben
• Is Part Of: Global change biology. Volume 28:Number 19(2022)
• Page Start: 5808
• Page End: 5819
• Publication Date: 2022-07-17
• Subjects: climate change -- EVI -- forest stability -- resilience -- satellite imagery -- tropical forests; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.16336
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Extreme precipitation and drought events are predicted to become more intense and more frequent over the Amazon rainforest. Because changes in forest dynamics could prompt strong feedback loops to the global climate, it is of crucial importance to gain insight into the response of tropical forests to these recurring extreme climatic events. Here, we evaluated the Amazon forest stability (resistance and resilience) to drought in the context of past dry and wet climatic events using MODIS EVI satellite imagery and cumulative water deficit anomalies. We observed large spatial differences in the occurrence of extreme climatic events from 1980 to 2019, with an increase in drought frequency in the central and northern Amazon and drought intensity in the southern Amazon basin. An increasing trend in the occurrence of wet events was found in the western, southern, and eastern Amazon. Furthermore, we found significant legacy effects of previous climatic events on the forest drought response. An extreme drought closely preceding another drought decreased forest resilience, whereas the occurrence of a recent drier‐than‐usual event also decreased the forest resistance to later droughts. Both wetter‐than‐usual and extreme wet events preceding an extreme drought increased the resistance of the forest, and with similar effects sizes as dry events, indicating that wet and dry events have similarly sized legacy effects on the drought response of tropical forests. Our results indicate that the predicted increase in drought frequency and intensity can have negative consequences for the functioning of the Amazon forest. However, more frequent wet periods in combination with these droughts could counteract their negative impact. Finally, we also found that more stable forests according to the alternative stable states theory are also more resistant and resilient to individual droughts, showing a positive relationship between the equilibrium and non‐equilibrium stability dynamics. Abstract : We evaluated the Amazon forest stability (resistance and resilience) to drought in the context of past climatic events. Extreme droughts closely preceding another drought decreased forest resilience, whereas extreme wet events preceding a drought increased the resistance of the forest. This indicates that the predicted increase in drought occurrence can have negative consequences for the functioning of the Amazon forest, whereas more frequent wet periods could counteract their negative impact. Finally, more stable forests according to the alternative‐stable‐states theory were also more resistant and resilient to individual droughts, showing a positive relationship between the equilibrium and non‐equilibrium stability dynamics.