When God causes water to flow in the desert, a variety of trees will grow there. The trees mentioned in this verse cannot all be identified with certainty, but it seems they are primarily large ones, not bushes or shrubs. There has to be an abundance of water for such trees to grow.
I will put in the wilderness the cedar, the acacia, the myrtle, and the olive: Instead of the verb put, Good News Translation has “make … grow,” which is a helpful model. For the cedar tree, see the comments on 2.13 and 9.10. The acacia tree is a short evergreen tree with sharp spines, fern-like leaves, and yellow flowers. It produces bean pods. Its wood is useful for building purposes. The myrtle tree grows mostly in moist soil in valleys. It is a small evergreen tree with dark green leaves, white flowers, and blue berries. Its leaves give off a fragrant scent. For the olive tree, see 17.6.
I will set in the desert the cypress, the plane and the pine together: This line is parallel to the previous one, mentioning three more trees. For the use of desert as a parallel with wilderness, see the comments on 40.3. For the cypress tree, see 14.8. The plane tree is a large tree that is wide at the top. It has dark green leaves and small green flowers. The pine tree is another type of evergreen tree. It is similar to the cypress tree since it also grows tall and has small fern-like leaves and round cones.
All the Hebrew words for the trees in this verse are singular, but they have a collective sense, so translators may use the plural. If a language does not have names for all of these trees, a general term may be used for some of them (see the second example below).
Translation examples for this verse are:
• I will plant cedar, acacia, myrtle and olive trees in the wilderness;
I will fill the desert with cypress, plane and pine trees.
• I will cause the wilderness to produce cedar trees and olive trees;
I will make the desert flourish with cypress trees and many other trees.
Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .

There are 7 trees mentioned here on my Bible(The Holy Bible): Cedar, Shittah, myrtle, oil tree, which will be planted in the wilderness and the fir tree, pine tree and box tree will be set in the desert.
I realized that there are 7 of them. God had to mention 7 and 7 is a significant number. Plus these trees are of similar kind: strong, tall ,large , ever-green trees and are useful for building as well as useful as herbs.
I am asking about their main reasons of use in this verse. There should be a message about (my own life) a person’s life too.
Just my thoughts. Thanks 😊