U.S. logging giant Weyerhaeuser yesterday said that if it is successful with its takeover bid for Canadian company MacMillan Bloedel, it will adhere to MacBlo’s promises to use more environmentally sound methods in coastal British Columbia — phasing out clearcutting within four years, cutting fewer trees, and using alternate logging methods in sensitive areas. Enviros were encouraged by the announcement but not entirely convinced, and the Sierra Club of B.C. promised to raise environmental issues at public hearings on the proposed takeover. The deal between the two companies is expected to be closed this fall.