Exposure of Brazilian conifers to climate change

Abstract In Brazil, apart from anthropogenic pressures linked to agriculture, livestock farming and urban sprawl, conifers are facing habitat loss because of escalating climate change primarily driven by the combustion of fossil fuels. These climatic alterations ultimately disrupt the habitat of this plant group, adversely affecting their distribution and potentially driving them towards extinction. Each species has an optimal range of tolerance to climatic factors established over evolutionary timescales. When tolerance thresholds are exceeded, plants may suffer climatic stress, affecting their growth and inducing morphological and physiological impairments. We aimed to predict the exposure of native Brazilian conifer species to climate change to inform conservation action plans. We coupled occurrence data for species of Podocarpaceae and Araucariaceae, the sole conifer families native to Brazil, with current and future climate data under the optimistic (SSP245) and pessimistic (SSP585) greenhouse gas emission scenarios projected to 2050, outlined by the Intergovernmental Panel on Climate Change. We selected four bioclimatic variables related to temperature and precipitation to identify potential climatic stresses. Our findings indicate that Brazilian conifers will experience varying levels of stress caused by exposure to climate change, with species having narrow distributions and small populations being more vulnerable. Our study underscores the potential risks and challenges for the conservation of these plants in the face of the threat posed by climate change.