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  • Most of the forest lives in the shadow of the giants

    譯者: Lilian Chiu 審譯者: Carol Wang

  • that make up the highest canopy.

    森林的大部分地區,

  • These are the oldest trees,

    都活在巨人形成的樹冠層陰影底下。

  • with hundreds of children and thousands of grandchildren.

    巨人就是最古老的樹木,

  • They check in with their neighbors, sharing food, supplies,

    有數以百計的孩子, 和數以千計的孫子。

  • and wisdom gained over their long lives.

    它們會關心鄰居近況, 分享食物、補給品,

  • They do all this rooted in place, unable to speak, reach out, or move around.

    以及漫長一生所學到的智慧。

  • The secret to their success lies under the forest floor,

    它們紮根在同一個地方做上述這些,

  • where vast root systems support the towering trunks above.

    無法說話、伸手,或移動。

  • Partnering with these roots are symbiotic fungi called mycorrhizae.

    它們成功的秘密, 藏在森林的地面底下,

  • These fungi have countless branching, thread-like hyphae

    地下廣大的樹根系統 支持著上方擎天的樹幹。

  • that together make up the mycelium.

    和這些樹根合作的, 是共生真菌,叫做菌根。

  • The mycelium spreads across a much larger area than the tree root system

    這些真菌有無數 像線一樣的菌絲分岔出去,

  • and connect the roots of different trees together.

    一起形成了菌絲體。

  • These connections form mycorrhizal networks.

    菌絲體散佈的範圍 比樹根系統還要廣大許多,

  • Through mycorrhizal networks,

    並會將不同樹木的樹根連結在一起。

  • fungi can pass resources and signaling molecules between trees.

    這些連結便形成了菌根網路。

  • We know the oldest trees have the largest mycorrhizal networks

    透過菌根網路,

  • with the most connections to other trees,

    真菌可以在樹與樹之間 傳遞資源和傳訊分子。

  • but these connections are incredibly complicated to trace.

    我們知道,最古老的樹木 有最大的菌根網路,

  • That's because there are about a hundred species of mycorrhizal fungi

    且和其他樹木有最多的連結,

  • and an individual tree might be colonized by dozens of different fungal organisms,

    但這些連結非常複雜,難以追蹤。

  • each of which connects to a unique set of other trees,

    原因是因為菌根真菌就有上百種——

  • which in turn each have their own unique set of fungal associations.

    且一棵樹木就可能有數十種 不同的真菌有機體定殖,

  • To get a sense of how substances flow through this network,

    每一種真菌所連結到的 其他樹木又都不一樣,

  • let's zoom in on sugars,

    連結到的樹木 所關聯的真菌又不同。

  • as they travel from a mature tree to a neighboring seedling.

    若想了解物質 如何在這個網路中流動,

  • Sugar's journey starts high above the ground,

    我們先把糖放大來看,

  • in the leaves of the tallest trees above the canopy.

    看看糖怎麼從成熟的樹木 移動到鄰近的幼苗。

  • The leaves use the ample sunlight up there to create sugars through photosynthesis.

    糖的旅程從離地面 非常高的地方開始,

  • This essential fuel then travels through the tree

    在樹冠層之上, 最高之樹木的樹葉中。

  • to the base of the trunk in the thick sap.

    樹葉運用上面的充足陽光, 透過光合作用來製造糖。

  • From there, sugar flows down to the roots.

    接著,這種基本的 能量來源會透過樹木,

  • Mycorrhizal fungi encounter the tips of the roots

    移動至樹幹的基部, 到濃濃的樹液之中。

  • and either surround or penetrate the outer root cells,

    從那裡,糖便向下流向樹根。

  • depending on the type of fungi.

    菌根真菌碰到樹根的尖端時,

  • Fungi cannot produce sugars, though they need them for fuel just like trees do.

    可能會包圍或是穿透外圍根細胞,

  • They can, however,

    依真菌的類別而異。

  • collect nutrients from the soil much more efficiently than tree roots

    真菌無法產生糖,

  • and pass these nutrients into the tree roots.

    但它們跟樹木一樣, 需要糖來當作能量來源,

  • In general,

    然而,比起樹根,

  • substances flow from where they are more abundant to where they are less abundant,

    它們從土壤收集營養物的 效率高很多——

  • or from source to sink.

    且會將這些營養物傳送到樹根中。

  • That means that the sugars flow from the tree roots into the fungal hyphae.

    一般來說,

  • Once the sugars enter the fungus,

    物質會從比較多的地方 流向比較少的地方,

  • they travel along the hyphae through pores between cells

    或從供源流向積貯。

  • or through special hollow transporter hyphae.

    這就表示,糖會從樹根 流向真菌菌絲。

  • The fungus absorbs some of the sugars,

    一旦糖進入真菌中,

  • but some travels on and enters the roots of a neighboring tree,

    它們就會延著菌絲, 穿過細胞之間的氣孔,

  • a seedling that grows in the shade and has less opportunity

    或穿過特殊的中空運輸菌絲。

  • to photosynthesize sugars.

    真菌會吸收一些糖,

  • But why does fungus transport resources from tree to tree?

    但有些糖會繼續移動, 進入到鄰近樹木的樹根,

  • This is one of the mysteries of the mycorrhizal networks.

    到在陰影下成長、比較沒有機會

  • It makes sense for fungus to exchange soil nutrients and sugar with a tree

    行光合作用產生糖的幼苗。

  • both parties benefit.

    但,真菌為什麼會把資源 從一棵樹輸送到另一棵樹?

  • The fungus likely benefits in less obvious ways from being part of a network

    這是菌根網路的謎之一。

  • between trees, but the exact ways aren't totally clear.

    真菌和樹木用土壤中的營養物 和糖來做交換是合理的——

  • Maybe the fungus benefits from having connections

    雙方都受益。

  • with as many different trees as possible,

    真菌扮演樹木間之網路的一部分, 受益的方式可能比較不明顯,

  • and maximizes its connections by shuttling molecules between trees.

    但究竟是什麼方式,我們還不清楚。

  • Or maybe plants reduce their contributions to fungi

    也許真菌獲益的方式是盡可能

  • if the fungi don't facilitate exchanges between trees.

    去連結最多樹木,

  • Whatever the reasons,

    並在樹木之間運送分子 來將它的連結最大化。

  • these fungi pass an incredible amount of information between trees.

    或者,也許當真菌不協助 促進樹木之間的交換時,

  • Through the mycorrhizae, trees can tell when nutrients or signaling molecules

    植物就會減少其對真菌的貢獻。

  • are coming from a member of their own species or not.

    不論是什麼理由,

  • They can even tell when information is coming from a close relative

    這些真菌在樹木之間 傳遞的資訊量非常龐大。

  • like a sibling or parent.

    透過菌根,樹木能夠 分辨出營養物或傳訊分子

  • Trees can also share information about events like drought

    是否來自它們自己的同類。

  • or insect attacks through their fungal networks,

    它們甚至能分辨資訊是否來自近親,

  • causing their neighbors to increase production of protective enzymes

    比如手足或父母。

  • in anticipation of threats.

    樹木還能透過它們的 真菌網路來分享資訊,

  • The forest's health relies on these intricate communications and exchanges.

    比如乾旱或昆蟲攻擊,

  • With everything so deeply interconnected,

    讓它們的鄰居能夠 在預知威脅的情況下

  • what impacts one species is bound to impact others.

    增加保護性酵素的產量。

Most of the forest lives in the shadow of the giants

譯者: Lilian Chiu 審譯者: Carol Wang

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B2 中高級 中文 美國腔 TED-Ed 樹木 網路 流向 菌絲體 交換

樹木的祕密語言--Camille Defrenne和Suzanne Simard。 (The secret language of trees - Camille Defrenne and Suzanne Simard)

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    sunny 發佈於 2021 年 01 月 14 日
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