Offline  vegetation model simulations indicate that the extensive tropical and subtropical forests of the Americas could gradually transit towards a savanna-like vegetation, with the most pronounced shifts  from relatively stable forests to savanna-forest transitions occurring in the eastern Amazonian region  depending largely on the yet uncertain strength of the CO2 fertilisation effect and future dry season length, with important feedbacks on the flux of moisture from the forest to the atmosphere . More limited simulations for Central American rainforests under RCP 4.5 and 8.5 also support a transition in some areas to lower biomass tropical dry forest and savanna-like vegetation . Such transitions from one biome type to another will cause major changes in forest structure, species compositions and overall biodiversity. Additionally, the difficulty of species to migrate through highly fragmented tropical forested regions  and 'non-analogue climates', under a climate change scenario, poses extra pressure on tropical biodiversity to adapt and survive . Even in expansive tracts of forests, such as in the Amazon, climate change is expected to become more important than deforestation by 2050 in causing the loss of tree species . Tropical mountain biodiversity hotspots  are particularly vulnerable to species loss due to elevation range shifts . Under a 2ºC increase scenario, a substantial reduction of tropical montane cloud forest in Kenya is estimated .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report