National Geographic Travelさんのインスタグラム写真 - (National Geographic TravelInstagram)「Photo by @daisygilardini | The Greenland tundra's fall colors are simply mesmerizing. The tundra is a zone of treeless ground usually found north of the Arctic Circle or above the timberline. Trees cannot grow on the tundra because of the strong winds and the permafrost that lies below the surface of the black soil. Plants found in this biome include mosses, lichens, herbs, and dwarf shrubs. As with plants in more temperate climes, fall is a time for change. Shorter daylight hours, together with colder temperatures, cause photosynthesis to slow down and eventually stop. Chlorophyll is what causes leaves to appear green. When it breaks down, other chemicals take over: carotene (responsible for yellow) and anthocyanin (red). The yellows and reds shine through, giving us one of the most beautiful shows in nature to admire. Follow me @daisygilardini for more images and stories from behind the scenes.」8月25日 1時30分