THE SIMPLE ACT OF PLANTING A TREE<i> By The Tree People with Andy and Katie Lipkis (Tarcher: $12.95, illustrated) </i>

This self-congratulatory manual for ecological activism demonstrates the wide gap between good intentions and good writing. Although Andy and Katie Lipkis provide a great deal of information about planting trees for the “urban forest,” the main thrust of the book is how to organize groups to plant trees and persuade corporations and politicians to assist in the endeavor.

The Lipkis’ aims are certainly lofty: American cities do too little to care for the trees that absorb pollution, limit the need for air conditioning and prevent excess runoff of rainwater, and the Tree People organized the successful 1983-84 campaign to plant 1 million trees in Los Angeles.

But their book is marred by a gee-whiz, aren’t-we-terrific tone that will quickly alienate all but the most fervent environmentalists. A more capable presentation of the efforts to reforest the planet undoubtedly would win more converts to this vital cause than the Lipkis’ amateurish prose.