Wattle (construction)

Abstract: Acacia mearnsii De Wild (black wattle) is an important plantation species for tannin production and woodchip exports in South Africa and Brazil. This study provides an updated overview of the black wattle industries in both countries, including planted areas and land ownership, silviculture and management, bark extract production, woodchip exports, as well as key research and development issues. The current total planted area to black wattle is 110 000 ha in South Africa and c. 170 000 ha in Brazil. In both countries black wattle is mainly cultivated by farmers (c. 76–78% of the total area). Due to the high prices fetched by the wattle woodchips in the international market, black wattle is a profitable crop. In South Africa, the timber provides 85% of the revenue and the bark the other 15%, and thus the commercial emphasis has shifted from bark to timber. At present the only significant secondary products are charcoal and firewood. Acacia mearnsii bark tannins are used in the leather industry, adhesives f...

Abstract: SYNOPSIS The history of forestry fertiliser research in Southern Africa is described briefly Fertiliser investigations in wattle started in the 1920s and in pines in the 1930s, but investigations with eucalypts started only in the 1950s Nevertheless, it is noted that today more is known about the nutritional requirements of eucalypts than of the other species, mainly owing to the application of foliar analysis in combination with suitable experimental designs The importance of the various nutrients for the different species is discussed with reference to experiments undertaken in Southern Africa The controversial issue whether gains from fertilising are maintained is examined and the conclusion is reached that unsatisfactory design and insufficient replication are the main causes that initial responses have not been shown to be maintained An indication of the commercial use of fertiliser in wattle, eucalypt and pine growing is given and the high profitability of fertilisation for these species indica