Why are there plants and flowers growing on the trunks of these trees?

为什么这些树的树干上长着花草呢?

youdao

These baits can be placed either on the ground or on the trunks of trees or large shrubs.

这些鱼饵可以放在地面上，也可以放在树干或大的灌木上。

youdao

On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow, as seen in the rings visible in the cross sections of their trunks.

在地球上，人们认为，表明太阳黑子周期最可靠的迹象之一是树木的生长速度，就像树干横截面上可见的年轮一样。

youdao

In between the villages, the slopes are covered in rhododendrons and the peeling, papery trunks of silver birch trees.

BBC: Nepal��s other Everest

Ahead of them a horse whinnied in the timber and then, through the brown trunks of the pine trees, only a little sunlight coming down through their thick, almost-touching tops, he saw the corral made by roping around the tree trunks.

NPR: Robert Jordan, Hemingway's Bipartisan Hero

Even at the bottom, the trunks of the spindly, shag-topped trees are thin enough to wrap a good hug around, yet hard as concrete.

BBC: Colombia��s valley of the palms