Placeholder Image

字幕列表 影片播放

  • Blue whales [Balaenoptera musculus] are the biggest animals ever to exist on earth. They

  • can weigh upwards of 150 tons, which is more than the largest dinosaurs! But the blue whale

  • is not the biggest living thing.

  • That title goes to.... well, it depends on what you mean by "biggest"!

  • The tallest may be a redwood tree [Sequoia sempervirens] nicknamed "Hyperion" in California.

  • At a towering 115M, this giant is taller than the statue of liberty [at 93M...show it's

  • 25% taller].

  • The most extensive organism is a very old "humongous fungus" that covers a whopping

  • 2,385 acres in a national forest in Oregon. At the base of the trees, bunches of "honey

  • mushrooms" [Armillaria solidipes] appear... they are the "fruiting bodies" produced by

  • the fungus, which otherwise lives out of sight - imagine if apple trees [Malus domestica]

  • grew underground and only the apples were visible to us! That's basically what the fungus

  • does, except that it spreads its "mycelia" not just through the soil but also through

  • the roots and bark of trees in the forest, attacking them and stealing their nutrients

  • so it can continue spreading outwards.

  • However, if we're talking about the good old heaviest organism ever found, that prize goes

  • to a giant panda [Ailuropoda melanoleuca] living high on a Utah plateau.

  • Just kidding... It goes to a single quaking aspen [Populus tremuloides] named "Pando"

  • that weighs over 6,000 tonnes - as much as forty blue whales.

  • If you go to Fishlake National Forest, though, you won't see a giant tree trunk - you'll

  • just see a forest of regular-sized trees. But, thanks to genetic testing, we've learned

  • that this stand of aspen covering 106 acres of land is actually a single clonal organism

  • that grew from a lone seed long ago. That single tree was able to spread so much because

  • its roots send up shoots that grow into what look like individual trees.

  • Since all 47,000 "trees" are part of the same organism, the forest behaves somewhat unusually,

  • for example, the entire forest transitions simultaneously from winter to spring and uses

  • its vast network of roots to distribute water and nutrients from trees with plenty to trees

  • in need.

  • Speaking of water... if you include water when weighing these giant organisms, then

  • the humongous fungus might actually weigh more than Pando. But foresters, at least,

  • care only about the mass actually produced during growth: the dry mass. And since fungi

  • are mostly water Pando wins.

  • Either way, it's likely that some of the belowground connections, whether roots or mycelia have

  • become severed over time, meaning these giants are probably made up of smaller, but still

  • ginormous and genetically identical, patches.

  • And finally, because of the extensive testing required to confirm "biggest anything" claims,

  • the fungus and aspen can only profess to be the largest living organisms ever found - there

  • may be even bigger monsters lurking right under our feet, just waiting to be discovered!

Blue whales [Balaenoptera musculus] are the biggest animals ever to exist on earth. They

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B2 中高級

地球上最大的生物體 (The Biggest Organism on Earth)

  • 187 17
    VoiceTube 發佈於 2021 年 01 月 14 日
影片單字