Resumen
Evidence suggests that tree mortality is rising in tropical forests, including the highly diverse Amazonian rainforests, limiting above-ground biomass and carbon storage, and potentially disrupting the composition and structure of ecological communities. These increases could have far-reaching implications for global climate stability. Recent studies have linked rising forest mortality to climate change, particularly due to increased frequency and intensity of drought and heat events. In this study, we assessed tree mortality at both individual and species levels in Yasuní National Park, Ecuador — one of the most biodiverse regions in the world — monitored from 1995 to 2017. Over 170,000 trees (dbh ≥1 cm) and 760 tree species (≥ 20 individuals) in a 25-ha lowland forest plot were evaluated in response to the droughts of 1996 and 2016. Using Bayesian hierarchical phylogenetic models, we examined how these responses varied with tree size, functional traits, and species’ climatic niche properties. At the individual level, annual mortality rates varied with tree size and functional
traits, with significantly higher mortality in 1995–2002 and 2007–2017, both marked by extreme droughts, compared to the drought-free period of 2002–2007. Smaller trees were more vulnerable to drought, showing higher mortality rates. At the species level, however, mortality increased only during the last census period (2007–2017) relative to the previous two periods, with species whose climatic niches were poorly aligned with Yasuní’s climatic conditions —primarily temperature— exhibiting higher mortality rates. This highlights the
critical role of environmental mismatches in species survival. Furthermore, the Yasuní environment transitioned to novel climatic regimes, becoming less suitable for many species’ niche requirements. Our results suggest that
climate change, through extreme droughts and climatic unsuitability, may have contributed to the observed rise in tree mortality at Yasuní, emphasizing the need for predictive models and strategies to mitigate climate change
impacts on Amazon.
traits, with significantly higher mortality in 1995–2002 and 2007–2017, both marked by extreme droughts, compared to the drought-free period of 2002–2007. Smaller trees were more vulnerable to drought, showing higher mortality rates. At the species level, however, mortality increased only during the last census period (2007–2017) relative to the previous two periods, with species whose climatic niches were poorly aligned with Yasuní’s climatic conditions —primarily temperature— exhibiting higher mortality rates. This highlights the
critical role of environmental mismatches in species survival. Furthermore, the Yasuní environment transitioned to novel climatic regimes, becoming less suitable for many species’ niche requirements. Our results suggest that
climate change, through extreme droughts and climatic unsuitability, may have contributed to the observed rise in tree mortality at Yasuní, emphasizing the need for predictive models and strategies to mitigate climate change
impacts on Amazon.
| Idioma original | Español (Ecuador) |
|---|---|
| Título de la publicación alojada | 61st Annual meeting of the Association for Tropical Biology and Conservation |
| Subtítulo de la publicación alojada | Tropical Biology and Conservation for a Sustainable World: Merging Diverse Approaches, Actors, and Local Knowledge |
| Lugar de publicación | México |
| Capítulo | S60 |
| Páginas | 233 |
| Número de páginas | 1 |
| Volumen | 61 |
| Edición | 1 |
| Estado | Publicada - 4 jul. 2025 |