Earth’s Seasons Are Out of Sync, Scientists Discover From Space

A new study challenges the simple four-season model, revealing that Earth’s seasonal cycles are far more complex and often out of sync between nearby locations. Using a novel analysis of 20 years of satellite imagery, researchers have created an unprecedented global map of plant growth cycles, uncovering this phenomenon of “seasonal asynchrony”.

Key Findings

The research identified global “hotspots” where the timing of seasonal growth varies dramatically over short distances. These hotspots are primarily located in the world’s five Mediterranean climate regions (California, Chile, South Africa, etc.) and in tropical mountains. The study found that these regions of high seasonal asynchrony significantly overlap with many of Earth’s biodiversity hotspots, suggesting a potential link between the two.

Conclusions and Implications

The core conclusion is that seasonal asynchrony may be a key driver of biodiversity. When nearby plant populations have different growth and reproductive cycles, it can lead to reproductive isolation, promoting genetic divergence and potentially the creation of new species over evolutionary time. This has practical implications for understanding animal migration, the ecological impacts of climate change, and even managing agriculture, such as the varied coffee harvest schedules in mountainous regions of Colombia.

Mentoring question

The article suggests that varied seasonal timing in a region can drive biodiversity. How might a changing climate, which is altering seasonal patterns, impact these natural ‘engines’ of evolution in biodiversity hotspots?

Source: https://www.sciencealert.com/earths-seasons-are-out-of-sync-scientists-discover-from-space