Non-food | Food
Productive use value is the one most visible for mangroves. In Singapore, because mangroves have shrunk in area so considerably, productive use value is practically zero, but in the rest of the world, this is still very significant. The products that can be extracted for sale in local and international markets are myriad.
Sawn timber: Heritiera and Xylocarpus species produce high-quality timber but are often scarce and difficult to access.
Tannins and dyes: Bark of mangrove trees are harvested as a source of tannin for the tanning industry. High tannin content is found especially in members of the Rhizophoraceae, to increase their resistance to herbivores. With development of cheap synthetic tannic acids after World War II, the commercial exploitation of mangrove bark has dropped to practically zero. Mangrove sap is, however, still used by East Africans or Polynesians to make the black dye for tapa cloth.
Raw materials for industries: Mangrove trees are exploited for the lignocellulose for the manufacture of chipboard, pulpwood (newspaper and cardboard) or synthetic materials (e.g., rayon).
From "A Guide to Mangroves of Singapore", Peter K. L. Ng and N. Sivasothi (editors)
Volume 1: The Ecosystem and Plant Diversity and Volume 2: Animal Diversity
Authors: Kelvin K. P. Lim, Dennis H. Murphy, T. Morgany, N. Sivasothi, Peter K. L. Ng,
B. C. Soong, Hugh T. W. Tan, K. S. Tan & T. K. Tan
BP Guide to Nature Series published by the Singapore Science Centre, sponsored by British Petroleum
© 2001 Raffles Museum of Biodiversity Research, The National University of Singapore & The Singapore Science Centre