A study conducted by Brazilian researchers reveals that climate change will have significant impacts on the Caatinga, a biome of semi-arid shrubs and thorny forests located in the northeastern region of Brazil. The consequences include species loss, the replacement of rare plants with more adaptable vegetation, biotic homogenization, increased aridity, and possible desertification in some areas.
The researchers, affiliated with the State University of Campinas, the Federal University of Paraíba, the Federal University of Pernambuco, the Federal University of Viçosa, and the Federal Institute of Goiás, compiled an extensive database with over 400,000 occurrence records of approximately 3,000 plant species in the biome. They then categorized the species into woody groups (trees, shrubs, palms, and woody vines) and non-woody groups (grasses, herbaceous vines, and succulents).
Using models and simulations, they projected the possible responses of Caatinga’s plant species to future climate variations. The results showed that by the year 2060, 99% of plant assemblages in the Caatinga will experience species loss due to increased aridity and rising temperatures. The hot and dry climate will favor the growth and spread of shrubs and grasses, leading to the replacement of many tree species. This vegetation change will impact essential ecosystem services such as photosynthesis, air renewal, and carbon storage.
Mountainous areas within the Caatinga, such as Chapada Diamantina and Chapada do Araripe, will be particularly affected. Lowland species are expected to migrate to higher grounds as temperatures increase, while highland species are at risk of extinction. Biotic homogenization, where previously distinct plant communities become more similar, will occur in approximately 40% of plant assemblages, resulting in a simplification of their composition.
To mitigate the adverse effects of climate change and human activities such as deforestation and habitat destruction, the researchers emphasize the need for long-term conservation plans at a macro level. These plans could focus on landscape restoration and connectivity to facilitate species dispersal to more suitable areas. However, if biodiversity continues to be compromised, the resources and ecological balance of the Caatinga will be further threatened.
Source: Mario R. Moura et al, Pervasive impacts of climate change on the woodiness and ecological generalism of dry forest plant assemblages, Journal of Ecology (2023).