Annual plant

[1] The annual life cycle has independently emerged in over 120 different plant families throughout the entire angiosperm phylogeny.

This hypothesis finds support in observations of increased prevalence of annuals in regions with hot-dry summers,[1][4][6] with elevated adult mortality and high seed persistence.

[7] Disturbances linked to activities like grazing and agriculture, particularly following European settlement, have facilitated the invasion of annual species from Europe and Asia into the New World.

[8] However, in certain Mediterranean systems, a unique scenario unfolds: when annuals establish dominance, perennials do not necessarily supplant them.

For instance, annuals, by allocating less resources belowground, play a more minor role in reducing erosion, storing organic carbon, and achieving lower nutrient- and water-use efficiencies than perennials.