If something is to be planned and built it needs a basis or a foundation. Decisions on any aspect of planning have a relative importance which relates to the permanence of the effect of that decision. It is unlikely that he buys the suit of clothes to match the tie, but logical to buy the tie to match the suit. Every decision made on any aspect of land planning must be based on or fit in with all others that are more permanent, or more permanent in their effect than it is. They should not be planted along an old fence that will need to be replaced in ten years, particularly if the farmer can now see that the fence was erected originally in the wrong place.
Many recommendations suggest the planting of trees to protect valleys.
It would be surely a shame, when a few years later it became necessary to remove them to make way for a dam. Farm roads are sometimes an endless source of trouble. A subdivision fence is required to divide arable land from a grazing area. Certain gateways wash badly. A new building is to replace an old one.