The growing need in emerging markets for building materials and fuel has spurred Japanese trading houses to expand their forestry operations.  Sumitomo Corp. plans to spend about 25 billion yen (SGD $319 million) on acquiring more pine forest in New Zealand, one of the Asia-Pacific region's major timber exporters, looking to double its acreage by 2021.  Wood is in increasing demand to build houses in emerging markets as incomes grow. Forest waste is also emerging as a renewable energy source to replace coal.  Sumitomo harvests in 30-year cycles, allowing ...