tailieunhanh - Card Project VIE: Sustainable and profitable development of acacia plamtations for sawlog production in Vietnam "

Trees as high as 25 - 30 m, small branches, self-pruning well, easy to grow by seed, long life, nitrogen fixation. Can grow on various soils, including poor soils, poor drainage. Grows fast, high-speed growth in the first few years. Song on a place if planted several consecutive cycles can lead to poor potassium and magnesium in the soil. Pit wood, pulp (wrapping paper), chipboard and wood stem as well due to the high heat of coal. In silvicultural crops used as the supporting soil improvement, shade | CARD Project VIE 032 05 Sustainable and profitable development of acacia plantations for sawlog production in Vietnam Dong Ha Sustainability Trial Site location climate and general characteristics The site is located on the Forest Science Institute of Vietnam s North-Central Research and Production Station near Dong Ha in Quang Tri Province. The geographic location is 17 28 N 106 59 E with an elevation of 50 m above sea level. The mean annual temperature is 25 c and the mean annual rainfall 2300-2400 mm. Soil in the region has suffered erosion due to the impacts of war and poor land use practices over recent decades. The soil type is a brown ferallitic clay loam Chieu Thuan 1996 . It would probably be classified as an Acrisol maybe an Arenic acrisol according to FAO or Kanhaplustults according to the USDA Soil Classification. The Soil contains significant quantities of unconsolidated lateritic gravel with stones ranging in size from 2 to 10 cm. The fine earth fraction which contains the available pool of nutrients is likely to be low. The profile is relatively well drained and the soil strength is high to very high even in the surface soil when dry. Site history The site was covered by natural forest until the 1960s. During the war years and subsequently the forest was progressively degraded by harvesting for fuelwood and charcoal making and gradually replaced by low scrub. In 1997 a 5 ha pilot plantation of a mix of acacia hybrid clones including BV10 BV 32 and BV 33 developed by RCFTI was established on the site. Stand spacing was m between rows and 2 m between trees within rows. There was some informal thinning from below so that by age 9 years the stocking was about 750 stems ha . The plantation was harvested for commercial timber in May 2007. Fifteen harvested trees were harvested in September 2006 and used to measure stem taper and stand volume Table 1 . Table 1. Dong Ha Acacia hybrid plantation at age 9 years after planting September 2006 eight months .