紅葉はなぜ赤や黄色になるのか?9割が知らない5つの理由|ヨーロッパは黄色ばかりのワケ

黄色は葉にもともとあったカロテノイドが見えてくる色、赤は秋に新しく作られるアントシアニンの色。赤をわざわざ作る理由として有力な「日焼け止め説」(ウィスコンシン大学、2001年)と「虫へのサイン説」(ハミルトンら、2001年)、そしてヨーロッパの紅葉が黄色中心な理由を山脈の向きと氷河期で説明する説(New Phytologist、2009年)を紹介します。気象庁の観測では、カエデの紅葉日は1953年から10年あたり約3日遅くなっています。 【目次】 0:00 オープニング 1:11 その1 黄色は隠れていた色 2:29 その2 赤は秋に作る色 3:41 その3 赤は日焼け止め 5:01 その4 赤は虫への警告 6:14 その5 ヨーロッパは黄色ばかり 7:49 まとめ 【参考にした情報源】 ・https://www.bepal.net/archives/188059 ・https://ddnavi.com/article/d712101/a/ ・https://www.sciencedaily.com/releases... ・https://archive.israel21c.org/why-aut... ・https://www.ncbi.nlm.nih.gov/pmc/arti... ・https://www.newswise.com/articles/res... ・https://pure.psu.edu/en/publications/... ・https://www.data.jma.go.jp/cpdinfo/mo... ・https://www.pref.kagawa.lg.jp/documen... ・https://kotobank.jp/word/%E3%82%AB%E3... 【使用した画像・映像(すべて自由に使えるライセンスのものです)】 ・Acer palmatum 'Inaba Shidare' in autumn sunshine - 2021-10-17 - Andy Mabbett - 01(Wikimedia Commons, CC BY-SA 4.0 / Andy Mabbett) ・Acer palmatum - Red Autumn (236980459)(Wikimedia Commons, CC BY-SA 3.0 / Aquii) ・Acer-palmatum-autumn(Openverse, BY-SA / Sten Porse) ・Autumn foliage in Kyoto with lamp post - 500px photo (188687207)(Wikimedia Commons, CC BY 3.0 / Chi King) ・Tranquil autumn scenery of a Japanese garden pond in Kyoto with colorful foliage.(Pexels, Pexels License / Nizar F) ・Stunning autumn foliage at Tōfuku-ji Temple in Kyoto, Japan, showcasing vibrant red and or(Pexels, Pexels License / Dmitry Romanoff) ・Ginkgo-biloba-autumn(Openverse, BY-SA / Sten Porse) ・Ginkgo biloba autumn leaves(Openverse, BY-SA) ・Beautiful mountain landscape featuring colorful autumn forest foliage.(Pexels, Pexels License / Arn Pau) ・Stunning view of a volcanic mountain surrounded by lush forests in Hokkaido, Japan.(Pexels, Pexels License / Marek Piwnicki) ・Falling autumn leaves(Wikimedia Commons, CC BY-SA 3.0 / The Nature Box; background image: saihanul (Seongho Kwon)) ・Hakkaisan Ropeway and autumn leaves at Muikamachi Hakkaisan Ski Resort, Japan(Wikimedia Commons, CC BY 3.0 / PLAGE-TV) ・Spectacular Autumn Leaves Peak in the Washington Area(Wikimedia Commons, Public domain / VOA News) ・DSG7056-1 Yellow Ginkgo biloba leaves - vivid translucent illumination by autumn sunlight(Wikimedia Commons, CC BY-SA 4.0 / Franz van Duns) ・Golden ginkgo leaves create a stunning canopy under the autumn sky.(Pexels, Pexels License / 开 心) ・Close-up view of vibrant yellow ginkgo leaves in autumn sunlight.(Pexels, Pexels License / Ilo Frey) ・Cloroplasti dentro cellule vegetali - Chloroplasts inside plant cells(Wikimedia Commons, CC BY-SA 3.0 / Marco Vinci) ・Microscopic image showcasing the intricate structure and texture of plant cells.(Pexels, Pexels License / turek) ・Close-up of vibrant green leaves in natural sunlight showcasing botanical growth.(Pexels, Pexels License / Danila Perevoshchikov) ・A detailed close-up of green Zinnia leaves with sunlight casting shadows, showcasing intri(Pexels, Pexels License / Nothing Ahead) ・A picturesque autumn forest scene featuring birch trees and vibrant fall foliage.(Pexels, Pexels License / Skyler Ewing) ・Majestic birch trees with golden leaves during sunset in a serene autumn forest.(Pexels, Pexels License / Stijn Dijkstra) ・A yellow curtain of birch trees leaves in autumn(Wikimedia Commons, CC0 / Роман Рябенко) ・Crowds enjoy a vibrant autumn day under ginkgo trees at Meiji Jingu Gaien, Tokyo.(Pexels, Pexels License / Hakan Nural) ・Meiji Jingu Gaien Ginkgo Festival (53440769967)(Wikimedia Commons, CC BY 2.0 / Dick Thomas Johnson from Tokyo, Japan) ・Oriental Yellow Paper Wasp (Polistes olivaceus) flying around the leaves of a tree(Wikimedia Commons, CC BY-SA 3.0 / Subhashish Panigrahi) ・a tree with yellow leaves against a blue sky(Pexels, Pexels License / Kmeel.com Videos) ・yellow leaves on the grass(Pexels, Pexels License / Evgenij Mikhailov) ・Acer palmatum's red leaves at Niiyama Shrine in Kanzaki(Wikimedia Commons, CC BY-SA 4.0 / Pekachu) ・Acer palmatum-Bonsai(Wikimedia Commons, CC BY 2.0) ・Autumn Rowan Leaf (127802139)(Wikimedia Commons, CC BY 3.0 / Hemmo Vattulainen) ・Detailed view of red rowan berries clustered on branches with autumn leaves.(Pexels, Pexels License / Sergey Okhrymenko) ・Leaf Abscission(Wikimedia Commons, CC BY-SA 4.0 / Frantishak) ・Frosty autumn leaves create a stunning natural pattern with vivid colors and texture.(Pexels, Pexels License / Frank Cone) ・Detailed view of frost-coated autumn leaves on a branch, highlighting nature's beauty in w(Pexels, Pexels License / Susanne Jutzeler, suju-foto) ・Acer rubrum Autumn Flame 0zz(Wikimedia Commons, CC BY-SA 4.0 / Photo by David J. Stang) ・Acer-rubrum-autumn(Openverse, BY-SA / Sten Porse) ・autumn leaves on the tree(Pexels, Pexels Li