[In "The Changeling" Snyder] writes about a pair of children who play in a grove of trees and invent a planet called the Land of Green Sky, where the Tree People could "glide like blowing leaves." At the end of the book, Green Sky is forgotten by the children because they grow up, but not by the author herself, who fortunately doesn't. For Zilpha Snyder the notion obviously developed on its own … until it became this book, "Below the Root," in which the once-playful Land of Green Sky is a world presented whole.
Of course the children's invention had to be broadened and surrounded with an ethical framework, until it resembled other alternate societies that exist in books, systems running back and forth in time, settings in which the physical or moral bravery of the characters reflects or is pitted against some good or evil imbedded in the nature of things…. One is reminded of Ursula Le Guin's "Wizard of Earthsea."… (p. 32)
Zilpha Snyder's sober style does not quite achieve the sinewy grandeur of Le Guin's, nor does her leafy landscape have the scope of that island-dotted main. But the fact that her structure is reminiscent of other made-up countries is not to be held against her. (pp. 32, 34)
After all, the Green-sky arrangement was first recommended by Plato, who dreamed of a republic in which philosophers would be the guiding kings….
The moral is not surprising: that knowledge must be free, that there must be no secrets in lofty places (mild overtones of Watergate).
But it is not the moral or the events that make "Below the Root" such a pleasing book. It is the fact that it is a full realization of the game of Let's Pretend….
The sense of this light-dappled green world encloses the reader throughout, and the author has worked out in detail its charming possibilities…. (p. 34)
Jane Langton, "Childrens Books: 'Below the Root'," in The New York Times Book Review (© 1975 by The New York Times Company; reprinted by permission), May 4, 1975, pp. 32, 34.