THE BURNING SEASON The Murder of Chico Mendes And the Fight for the Amazon Rain Forest By Andrew Revkin Houghton Mifflin. 317 pp. $19.95

THE WORLD IS BURNING By Alex Shoumatoff Little, Brown. 377 pp. $19.95

IN DECEMBER 1988 Chico Mendes, leader of a small trade union of rubber tappers in the western Brazilian state of Acre, was gunned down in his back yard by hired killers. A few years ago, one more shooting in the lawless depths of Amazonia would have gone unnoticed. Yet within weeks of Mendes's murder, movie moguls -- Robert Redford, David Puttnam, Ted Turner and others -- were scrambling for the rights to film the life of this unassuming man.

The reasons for the international media interest in Chico Mendes are very clear. He was the little guy who organized the poorest illiterates to stand up to big business in the form of cattle ranchers backed by financial institutions and, often, by suborned lawmen. He was a rotund, genial and charismatic figure with the charm of the Rev. Martin Luther King Jr. and the nonviolent instincts of Mahatma Ghandi.

But Mendes's tragedy has another powerful dimension. He was also the defender of the Amazon rain forests, the richest ecosystem on earth and the symbol of the environmental movement. The rubber tappers of Acre derive their livelihood from bleeding the sap from wild Hevea brasiliensis, a tree that cannot be grown in plantations in its native Amazonia but must be scattered amid the hundreds of other species that make up the luxuriant forest system. Thus, these backwoodsmen are practitioners of sustainable use. Their forests are being designated as "extractive reserves," an important new concept in the conservationists' armory. If the countries that contain tropical rain forests can be persuaded that there is more money to be made by extracting renewable resources from living forest than by destroying it for timber or cattle pasture, the conservation argument would be almost won.

Chico Mendes was killed by cattle ranchers determined to fell the forests in a usually futile attempt to convert them into ranches. The soils beneath tropical forests are totally different from those under temperate forests -- sandier, acidic and unable to hold nutrients; the evergreen vegetation recaptures almost all the nourishment from decaying litter on the forest floor; voracious insects and weeds demolish crops; scorching sun and torrential rains are too much for most grasses; and the cattle itself is an inappropriate imported animal, often unable to resist heat, ticks and tropical disease.

Long before "The Chico Mendes Story" reaches our big screens, the murder of this environmental champion has produced two excellent books. There are uncanny similarities between Andrew Revkin's The Burning Season and Alex Shoumatoff's The World is Burning. Both authors know Brazil well and are thoroughly steeped in the environmental literature. Both have interviewed all Chico Mendes's family and friends, and both know the colorful cast of activists who are keeping the movement alive (although often bickering in the process), but neither knew Mendes himself. Both Revkin and Shoumatoff are fine writers who tell the drama of the murder with pace and mounting tension: I was reminded of the menace of evil deeds in a quiet, sunny small western town in the movie "Bad Day at Black Rock." The two authors are also skillful interpreters of the scientific issues involved in rainforest destruction, global warming, the greenhouse effect and the potential loss of biological diversity. Reviewing two such admirable books is akin to the task of a music critic: There are only minor differences in the treatments of the same score.

Both books explain the history of the boom and bust of the Amazon rubber era, the political background to the cutting of the Amazon highways in the 1970s, and how a few rubber tappers still continued the old trade, even though most natural rubber is now grown in plantations in Southeast Asia. Chico Mendes drew his inspiration from a follower of Luis Carlos Prestes, an activist who failed to radicalise Brazil in the 1930s. His second mentor was Wilson Pinheiro, who organised the first empate, a nonviolent assembly of rubber tappers to block the path of the chainsaw gangs and bulldozers that came to fell their forests. Pinheiro was shot dead in 1977. But during the 13 years before his own assassination, Chico Mendes mounted 45 empates, 15 of which were successful.

Both Revkin and Shoumatoff credit the British documentary filmmaker Adrian Cowell with spotting Mendes'sbrilliance as a leader and projecting him onto a world stage through his television reports. Before his death, Chico Mendes had received major awards and powerful media recognition. His supporters thought that this would protect him from the ranchers who issued death threats. They failed to appreciate that Darli Alves, the thin, murderous cattleman generally credited with the killing, does not read The Washington Post.

Both these books can be highly recommended, although both are densely packed with information and therefore suffer from having no indexes. Revkin's version gains from its lucid descriptions of the rubber tappers in action and has good pictures of Acre and its characters. Shoumatoff writes vividly about the wrangles between rival movie makers, the squabbling environmentalists, and the sometimes sleazy world of the Brazilian interior. He also has a long and readable section on the annual burning of Amazonia.

The destruction of the rainforests has been described as the most serious of all the issues confronting mankind, and it is no accident that the word "burning" is in the titles of both these books. Chico Mendes is a martyr of the ecological movement, a hero of our times. He has two fitting memorials in these books.

John Hemming is director and secretary of the Royal Geographic Society. His books on Indian history in Brazil include "Red Gold" and "Amazon Frontier."