The research maps variations in flowering times and harvest readiness, underscoring how changes in seasonal timing affect agriculture, ecology, and biodiversity.

Asynchronies in seasonal cycles can influence ecological processes and evolution, potentially driving reproductive isolation and speciation in some regions.

These asynchronies are common in biodiversity hotspots and can alter resource availability and reproductive timing, potentially guiding interbreeding patterns over generations.

A new global study shows that Earth's seasonal rhythms are diverse and often out of sync across regions, with practical implications for agriculture, crop timing, food production, and disease dynamics as climate change shifts seasonal patterns.

Understanding place-specific seasonal rhythms is essential for modeling climate impacts, biodiversity dynamics, and agricultural planning, with broader implications for ecology, evolution, and even disease dynamics.

For example, in Arizona’s Phoenix and Tucson, differing rainfall patterns—monsoonal summer rain in Tucson versus January rainfall in Phoenix—illustrate how regional timing shifts affect local ecosystems.

Led by biogeographer Drew Terasaki Hart at UC Berkeley, the research shows neighboring habitats can experience different seasonal events, challenging the idea of a single global seasonal rhythm.

Five Mediterranean climate regions—California, Chile, South Africa, southern Australia, and the Mediterranean Basin—show forest growth peaks about two months later than other ecosystems, reflecting cross-ecosystem timing shifts.

Regions with high biodiversity, such as tropical rainforests and Mediterranean climates, exhibit more irregular seasonal rhythms, affecting forest growth timing and peak productivity.

Seasonal timing divergence can occur even among nearby regions with similar climates, leading to dramatic differences in local seasonal cycles that shape ecology and evolution.

The Nature-published study analyzes two decades of satellite data to map Earth's seasonal timing, revealing substantial regional asynchronies across landscapes.

This study represents the most comprehensive global map to date of terrestrial seasonal cycles and underscores the significance of regional diversity in seasonality from space.