CHARACTERISTICS OF TEN TROPICAL HARDWOODS FROM CERTIFIED FORESTS IN BOLIVIA PART I WEATHERING CHARACTERISTICS AND DIMENSIONAL CHANGE

Ten tropical hardwoods from Bolivia were evaluated for weathering performance (erosion rate, dimensional stability, warping, surface checking, and splitting). The wood species were Amburana cearensis (roble), Anadenanthera macrocarpa (curupau), Aspidosperma cylindrocarpon (jichituriqui), Astronium urundeuva (cuchi), Caesalpinia cf. pluviosa (momoqui), Diplotropis purpurea (sucupira), Guibourtia chodatiana (sirari), Phyllostylon rhamnoides (cuta), Schinopsis cf. quebracho-colorado (soto), and Tabebuia spp. (lapacho group) (tajibo or ipe). Eucalyptus marginata (jarrah) from Australia and Tectona grandis (teak), both naturally grown from Burma and plantation-grown from Central America, were included in the study for comparison. The dimensional change for the species from Bolivia, commensurate with a change in relative humidity (RH) from 30% to 90%, varied from about 1.6% and 2.0% (radial and tangential directions) for Amburana cearensis to 2.2% and 4.1% (radial and tangential) for Anadenanthera macrocarpa . The dimensional change for teak was 1.3% and 2.5% (radial and tangential) for the same change in relative humidity. None of the Bolivian species was completely free of warp or surface checks; however, Anadenanthera macrocarpa, Aspidosperma cylindrocarpon , and Schinopsis cf. quebracho-colorado performed almost as well as teak. The erosion rate of several of the wood species was considerably slower than that of teak, and there was little correlation between wood density and erosion rate. Part 2 of this report will include information on the decay resistance (natural durability) of these species.