Plitvice Lakes' Ever-Changing Travertine

In Utah's Fishlake National Forest, a clonal grove of quaking aspen trees named 'Pando' (Latin: 'I spread') consists of about 47,000 individual stems that are genetically identical, sharing a single root system. Weighing approximately 6,000 metric tons and covering 43 hectares, it is estimated to be 80,000 years old.

In the Malheur National Forest, Oregon, a single Armillaria ostoyae (honey fungus) spreads across 965 hectares (2,385 acres) — roughly 1,350 football fields. Estimated to be about 8,000 years old, it grows mostly underground as mycelium. Discovered in 1998, it broke the previous record held by a similar fungus in Michigan.

In 1964, Australian scientists Isabel Joy Bear and Richard Thomas named the distinctive smell of rain on dry earth 'petrichor', from the Greek 'petra' (stone) and 'ichor' (the fluid of the gods). The scent comes primarily from geosmin, produced by Streptomyces bacteria, and plant oils released by rainfall.

A typical cumulus cloud contains about 500 million grams of water distributed as microscopic droplets — equivalent to 500 metric tons (500,000 kg). Clouds don't fall because those ultra-fine droplets (10–20 micrometers wide) are supported by warm upward air currents that balance the force of gravity.