proposed changes would open the door to a surge in deforestation.Last May, the House approved a more sweeping amnesty for those who had illegally deforested, outraging environmentalists and scientists. It did not help that the deputies refused to receive a group of respected Brazilian scientists that issued a report condemning the changes. In the House, there was very little consultation with scientists, said Carlos Nobre, a scientist at Brazils National Institute for Space Research who specializes in climate issues. Still, he said, scientists waited too long to realize that the House wanted to radically change the Forest Code, creating a broad and unrestricted license to deforest. Ms. Silva, who was raised in the Amazon, resigned in 2008 after a backlash by rural governors to restrictions on illegal deforestation she had put in place. But she left what environmentalists consider an effective policy to control Amazon deforestation. Among other tactics, Mr. da Silvas government used satellite images to home in on deforesters, organized police raids and blacklisted the worst offenders. The ruralists have pushed so much to change the Forest Code because the government actually started enforcing it under Marina Silva, said Stephan Schwartzman, director for tropical forest policy at the Environmental Defense Fund in Washington. The vote in the House showed how heavily represented the less developed north and northeast are in Brazils Congress, a relic of the military dictatorship The skewed proportional representation in Brazil has shown that the environmentalists have much less power in Congress than they have in public opinion, said Gilberto Camara, director of the National Institute for Space Research, which monitors Amazon deforestation. Days after the House vote last May, a poll by Datafolha showed that 85 percent of Brazilians believed the reformed code should prioritize forests and rivers, even if it came at the expense of agricultural production. After weeks of debate, the bill the Senate approved in December was somewhat more palatable to environmentalists. Rather than outright amnesty for past illegal deforestation, the Senate version lets farmers replant to avoid fines. The legislation now goes back to the House. We have to reconcile the generation of income with sustainability, Izabella Teixeira, the current environment minister, said after the vote. For Marcos Jank, president of the Brazilian Sugarcane Industry Association, a major reason to change the code is to legalize countless Amazon properties lacking land titles that have complicated the tracking of illegal activity. When you have a Forest Code that legalizes land titles, then that has the effect of reducing deforestation, not increasing it, he said. The government claims the code will reforest about 60 million acres, much of it in the Amazon, which the Environment Ministry calls the largest reforestation program in the world. But who will pay for all those new trees? And will the government enforce the replanting requirements? The small producers dont have the money to replant, Mr. Jank said. You need to develop programs to help them. There are also questions about the size of lands being exempted from the legal requirement to preserve 80 percent of the trees in