Tree rings are made of tissue called xylem.

构成年轮的组织被称为木质部。

Carbon and water, more than 1,000 liters of water, in fact, flow freely through the phloem and xylem tubes carry it along.

碳和水，实际上超过 1000 升的水，自由流动于韧皮部和木质部的管道中。

So the xylem cells are transporting nutrients from the roots to the leaf, and the phloem are taking the freshly made sugar from the leaf to the rest of the plant.

所以木质部细将营养物质从根输，韧皮部将新鲜的糖从输植物的其他部分。

Through that space stretches the vascular bundle, with xylem to transport water and phloem which transport sugars after photosynthesis.

通过这个空间，延伸出维管束，木质部负责运输水，韧皮部负责在光合作后运输糖。

Right beside the phloem is the tree's other tissue type: the xylem.

就在韧皮的旁边是树的另外一种组织叫木质。

And if we zoom in, we'll notice its xylem and phloem cells snuggled together, just like they were in the stem.

如果我们放大，我们会注意它的木质部和韧皮部细在一起，就像它们在茎中一样。

This evaporation, called transpiration, creates negative pressure in the xylem, pulling watery xylem sap up the tree.

这种蒸发，叫作蒸腾作，在木质中产生一种负压，把液体的木质树液往树上方拉。

Here at the tree's base, there are more of these particles in one tissue than the other, so the water from the phloem sap is absorbed into the xylem to correct the balance.

在树的根部，这些组织里的微粒分布不均匀，因此，韧皮树液中的水分被吸收木质中，来调节平衡。

And there are two main types of cells that make up that vascular tissue: xylem and phloem.

构成维管组织的细主要有两种：木质部和韧皮部。

The xylem cells, which are moving water and nutrients up through the stem, are clumped toward the inside of the bundle, and the phloem, which is transporting sugars down through the plant, is clustered toward the outside.

木质部细负责将水分和营养物质通过茎部向上输，它们向束的内部聚集，韧皮部负责将糖分向下输，它们向束的外部聚集。

To accomplish this herculean task, the xylem relies on three forces: transpiration, capillary action, and root pressure.

要完成这样艰巨的任务，木质要赖于三种力量：蒸腾作，毛细作和根压。

And where these two forces pull the sap, the osmotic movement at the tree's base creates root pressure, pushing fresh xylem sap up the trunk.

这两种力量推动树液向上，树根部的渗透作也产生树压，把新鲜的木质树液推上树干。

After water flows from the roots to the leaves through the xylem, it can exit the plant through the tiny stomata mouths.

水通过木质部从根流向后，再通过细小的气孔口排出植株。

This process, called osmotic movement, creates nutrient-rich xylem sap, which will then travel up the trunk to spread those nutrients through the tree.

这个过程，叫做渗透运动，会产生营养丰富的木质树液，这些树液会沿着树干向上把营养传整棵树。

Sclerenchyma supports organs that are fully mature, and similar to xylem, it has cells that are dead inside (physically, not emotionally) .

厚壁组织支持完全成熟的器官，与木质部相似，它有从内部死亡的细（我指的是身体上，而不是情感上）。

This capillary motion is in full effect in xylem filaments thinner than human hair.

在木质纤维中毛细作无处不在，这些木质纤维比人的头发还细。

As the plant grows, stem cell clusters called meristems generate new xylem cells, which form bigger pipes to suit the plant's needs.

随着植物的生长，被称为分生组织的干细簇产生新的木质部细，这些细形成更大的管道以适应植物的需要。

There are really tiny tubes called xylem that allow water to move up it.

实际上，存在着称为木质部的微小管道，可以让水向上移动。

The ability to perceive the world through the eyes and ears of other beings, through the phloem and xylem of trees, even reconnects us, humans, to the fantasticand richly diverse network of organisms that make up our shared Earth.

通过其他生物的眼睛和耳朵、树木的韧皮部和木质部来感知世界的能力，甚至将我们人类与构成我们共同地球的奇妙而丰富多样的生物体网络重新连接起来。

But lycopods were also the earliest vascular plants, which means they were the first plants to contain xylem, a special tissue that moves water and nutrients from the roots to the leaves.

但是， 石松类也是最早的维管植物，这意味着它们是第一批含有木质部的植物，木质部是一种特殊的组织， 负责将水分和养分从根部运输子。