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Amazon forests are undergoing rapid transformations driven by deforestation, climate change, fire, and other anthropogenic pressures, leading to the hypothesis that they may be nearing a catastrophic tipping point—beyond which ecosystems could shift to a permanently altered state. This review revisits the concept of an Amazon tipping point and assesses the risk of forest collapse from an ecological perspective. We synthesize evidence showing that environmental stressors can drive critical ecosystem transitions, either gradually through incremental loss of resilience or abruptly via synergistic feedbacks. The interplay between climate and land-use change amplifies risks to biodiversity, ecosystem services, and livelihoods. Yet, there is limited evidence for a single, system-wide tipping point. Instead, the Amazon's resilience—although not unlimited—offers meaningful pathways for recovery. The most immediate and effective strategies to support this resilience include slowing forest loss, mitigating climate change, reducing fire activity, curbing defaunation, and restoring degraded ecosystems. Without decisive action to address direct threats, the Amazon system may be pushed beyond safe ecological-climatological operating limits—even in the absence of sharply defined thresholds—due to the scale and persistence of anthropogenic pressures. Preserving the Amazon's ecological integrity and its vital role in regulating the global climate requires urgent, sustained conservation efforts in collaboration with local and Indigenous communities. 

Abstract What we mean by species and whether they have any biological reality has been debated since the early days of evolutionary biology. Some biologists even suggest that plant species are created by taxonomists as a subjective, artificial division of nature. However, the nature of plant species has been rarely tested critically with data while ignoring taxonomy. We integrate phenomic and genomic data collected across hundreds of individuals at a continental scale to investigate this question inEscallonia(Escalloniaceae), a group of plants which includes 40 taxonomic species (the species proposed by taxonomists). We first show that taxonomic species may be questionable as they match poorly to patterns of phenotypic and genetic variation displayed by individuals collected in nature. We then use explicit statistical methods for species delimitation designed for phenotypic and genomic data, and show that plant species do exist inEscalloniaas an objective, discrete property of nature independent of taxonomy. We show that such species correspond poorly to current taxonomic species ($$< 20\%$$ $<20\%$) and that phenomic and genomic data seldom delimit congruent entities ($$< 20\%$$ $<20\%$). These discrepancies suggest that evolutionary forces additional to gene flow can maintain the cohesion of species. We propose that phenomic and genomic data analyzed on an equal footing build a broader perspective on the nature of plant species by helping delineate different ‘types of species’. Our results caution studies which take the accuracy of taxonomic species for granted and challenge the notion of plant species without empirical evidence. Note: A version of the complete manuscript in Spanish is available in the Supplemental Materials.