How could climate and vegetation changes have contributed to Pleistocene megafaunal extinctions?

The hypothesis that abrupt climatic and vegetation changes contributed to Pleistocene megafaunal extinctions focuses on the environmental stress caused by the transition from the last glacial period to the interglacial period.1

During the late Pleistocene, the climate was more equable than today, with reduced seasonal extremes in temperature and moisture. This allowed for "disharmonious" associations, where plants and animals that are currently separated by vast distances or elevations coexisted. As the climate shifted, these stable, unique biotic communities were reorganized.23

Key factors in this environmental disruption include:

• Vegetation Reorganization: Shifts in climate altered plant communities, impacting the availability and nutrient value of food sources for large herbivores.1
• Increased Seasonality: The transition toward modern climate patterns introduced greater seasonal extremes in temperature and moisture, which likely stressed species adapted to the more stable glacial environment.12
• Habitat Loss: Changes in humidity and temperature forced large-scale migrations and caused the loss or fragmentation of specific habitats.43

While the "overkill hypothesis" suggests human hunting played a primary role, many researchers argue that these complex environmental changes and the resulting loss of suitable habitats were significant drivers of extinction.152