This is actually true, as improbable and silly as some might think. It appears to be a kind of simplistic notion that a barren land would be barren of joy, barren of love, barren of happiness. But this is often the case and one of the reasons is that the sparse occurrence of life forms reduces the capability of Gaia to provide healing for human inhabitants. Whether they are living in settlements or are a nomadic people, wherever they go, wherever they reside, they will be generating many thoughts, conscious and unconscious, and this energy will create growing thought forms that act as a kind of pollution and will drag down themselves and other people as well, particularly over large spans of time. Ordinarily, living things provide healing because they are geared to seek balance and to process energies that conflict with that circumstance and have innate healing capability as a consequence. By removing discord, they help other life forms indirectly, as well as keeping their own local environment cleaner, and fresher, and more positive energetically.
Trees, in particular, because of their great size, were designed specifically to scrub the environment of human woe, to transmit and ground it into the earth to be transmuted and this cleans up the neighborhood quite literally. When trees are not present and other plant life quite sparse, this leaves a void that will begin to cause problems for people attempting to live in that area, and this will grow over time and worsen. The repeated history of political strife and many difficulties with making progress to find better ways to live, better ways to be, better ways to get along and surmount the problems of life in a harsh environment, are very much restricted by this absence of natural healing. It is a bit like living underwater where there is no oxygen—while not as extreme and immediately causing a huge negative impact, the damage does happen and occurs over time, building steadily, and leading to much unhappiness and then human strife when people reach a breaking point. It would be much wiser to create a greening of the desert before using it for human habitation.