In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

441three weeks prior to transplanting them into 10 kg containers of mine soil orforest soil. Growth measurements were made every two weeks.Field ExperimentThe field experiment was located at a six-year-old dumping site in the miningarea of PT. Bukit Sunur, North Bengkulu. The experiment was designed as asplit plot with ripped and non-ripped treatments as main plots andendomycorrhizal inoculation as sub-plots. Four legume timber species weretested, namely Acacia mangium (mangium), Paraserianthes falcataria(sengon), Sesbania grandiflora (turi), and Pneronema canescens (sungkai)(Suhartoyo & Munawar 1998).Results and DiscussionGreen House ExperimentIn general, observations showed that all plants were able to grow relativelywell on both mine and forest soils. Mortality was only found when trees werederived from cuttings, e.g. gliricidea and in the grasses (Suhartoyo & Munawar1998).Four species were determined to be the best for field-testing - Sengon,Turi, Mangium, and Sungkai.Field ExperimentIn general, all legume plants except Sungkai grew relatively well on mine soil.However, data on plant height and stem diameter (Tables 1 to 4) during the firstmonths of the growing period (10 months for mangium) showed that all speciesgrew better on ripped mine soil than on non-ripped soil. As indicated by Munawar(1998) and Suhartoyo and Munawar (1998), soil compaction was identified asthe main constraint to plant growth on coal mined soils in Bengkulu. Verycompacted soils with strengths of more than 4.5 kg/cm2 significantly hinderedroot growth, resulting in poor nutrient and water acquisition.