ON THE FOREST EDGE

After a lifeless little curtain raiser involving a rabbit nibbling on clover and then rushing to hide from a passing weasel, Lerner defines the ""in-between habitat,"" or ecotone, which exists ""where field and woodland meet,"" then goes on to take sequential note of the various small mammals, birds, insects, and plants to be found there on a June morning. But her unimaginative species-by-species treatment doesn't convey the sense of relatedness that an introduction to an ecosystem should be all about, and though she notes in her definition that ecotones are called tension zones because they are places of change, her presentation couldn't be more static. This might find its own small niche on the homework shelf, but a list would do about as well.