Journal of Wildlife and Parks (2014) 29 : 61-67 61 A MODEL OF GREENED EX-TIN MINE AS A LOWLAND BIODIVERSITY DEPOSITORY IN MALAYSIA Ang, L.H.*, Ho, W.M. & Tang, L.K. Researchers of Ecophysiogy Branch, Forest Plantation Program, Forest Biotechnology Division, Forest Research Institute Malaysia *Corresponding author: [email protected] ABSTRACT Ex-tin mine is a common landscape in Peninsular Malaysia and it covers approximately 113,000 ha spreading mainly in the states of Selangor and Perak. Forest Research Institute Malaysia has successfully greened an ex-tin mine covering 121.5 ha located in Bidor, Perak. Presently, a 17 y-old man-made mixed stand of 60 forest tree species beautifies the once barren-desert like landscape with lush green vegetation surrounding the mining ponds. The man-made mixed forest was established employing findings from two decades of research activities. The forest is also the man-made habitats that house 70 species of birds and many wildlife species from the diminishing nearby lowland forests located about 10-20 km from the greened ex-tin mine. The two fragmented lowland forests are Bikam Forest Reserve and Chikus Forest Reserve which are located in the fast-expanding economic zone of Batang Padang District, Perak. Avian dispersers brought about 20 primary lowland species to the man- made forest since the last 15 years. This paper demonstrates the rehabilitation technology employed to green an ex-tin mine and also reports the regeneration of the tropical rainforest species brought by avian dispersers in the greened ex-tin mine. Keywords: Ex-tin mine, Rehabilitation, Restoration, Biodiversity depository, Man-made forest, Wildlife. INTRODUCTION Malaysia is a developing nation, and degraded lands are part of the landscape, just like elsewhere in the whole wide world. Forestland had been cleared for agriculture in Malaysia, and presently, about 6.48 million ha of oil palms, cocoa, coconuts, and rubber continuously provide the tree cover but without the inhabitation of the once rich biodiversity. Degradation in forests resulted in patches of grassland, secondary forest and compacted sites in logged-over forests. In addition, problematic soils including beaches interspersed with swales (BRIS) and ex-tin mines are also part of the landscape in Peninsular Malaysia. Tree planting trials had been carried out by Forest Research Institute Malaysia (FRIM) or formerly known as Forest Research Institute on these degraded sites since 1929. This paper aims to highlight a successful model of greened ex-tin mine and its sustainable natural succession that is mainly brought by avian dispersers. 62 Ang, L.H., Ho, W.M. & Tang, L.K. OBJECTIVES This paper aims to highlight the success of greening an impoverished ex-tin mine with forest tree species and quantify the natural succession brought mainly by avian dispersers after the establishment of the planting. ADVERSE SITE PROPErtiES AND THEIR IMPROVEMENT Soil degraded through human activities such as logging to mining and the degree of degradation depending on the anthropological activities, normally less disturbance does not involve in the drastic change of existing vegetation and soil properties. The worst form of degradation is tin mining where complete alteration of soil profiles and soil composition was made to extract tin ore. Man-made mixed species forest of Tin Tailings Afforestation Centre (TTAC) of FRIM Field Station Bidor is the model of greened ex-tin mine. Generally, three main site properties include microclimate, soil and water table level, which adversely change during mining activities. Microclimate Microclimate determines ecological patterns in both plant and animal communities and also survival. Its important role is recognized in the ecological research (Shirley, 1945). Adverse microclimate reduces decomposition activity of decomposers and adversely affecting influx of nutrients to the soils. In addition it kills most of the seedlings of tropical rainforest species especially in a barren ex-tin mine. Soil composition Soil composition of degraded lands normally does not change much except in the case of ex-tin mine. Most of the human activities in impoverishing forest lands do not contribute to alteration of soil composition. However, mining activity causes a change in the soil composition. Normally, to extract mineral ores from the concentrate of the processed materials, they are subjected to water separation, and produce two extreme soil formations known as sand and slime tailings. Sand tailings have particle size more than 0.05 mm, viz. sand and gravels. The sand and gravel tailings require additional fine soil particles such as silt and clay to improve their soil physical properties for growing tree species. Mechanical impedance Main physical properties of sand tailings that require further improvement for growing plants include mechanical impedance. High mechanical impedance > 1.5 MPa is commonly encountered in ex-tin mine and logged-over forests or any form of degradation involving heavy machinery. The mechanical impedance of sand is reckoned to be high and caused impedance to root growth (Ang & Ho, 2004). The compaction introduced to the sand tailings was due to the movement of heavy machines during levelling. High mechanical impedance of sand tailings can be overcome by deep-hole planting technique, followed by an application of peat or organic waste such as empty fruit bunch of oil palm. The average size of the planting hole is 1.5 m length x 1 m width x 1 m depth, and was prepared using an excavator. About 2/3 depth of the hole was filled back with sand particles. A Model of Greened Ex-Tin Mine as a Lowland Biodiversity Depository in Malaysia 63 Unfavorable water table level Sand tailing is often dry during drought period. Drought period of two weeks will dry up all the available water to 15 cm depth from the surface (Ang et al., 1999). The cause of such evaporative demand effects is mainly due to the particle size distribution of sand tailings which comprises > 90% coarse sand. The high porosity of sand has inverse relationship with its water retention capacity. The main approach adopted in the site preparation of the project site where the sand dunes are situated at > 4 m above surface water level (aswl) was to reduce water loss from the root zone during dry period. The level of sand tailings determines its suitability for rehabilitation and restoration with plant species. If sand dunes are situated more than 4 m above standing water table level (aswl), a drought of two weeks (rainfall < 4 mm day-1) would dry up the available water of the 0-15 cm depth of sand dune (Ang et al., 1999). The dehydrating of sand dune in dry season is mainly due to its high composition of sand and gravel. The high permeability of sand results in low water retention capacity and it is costly to irrigate the timber planting compared to high value production of agriculture produce. Hence, another approach was developed by planting tree seedlings in a pit of lower than 45 cm surface of sand dune situated at 4 m aswl, using a big-hole planting technique; the planting hole of 1 m to 1.5 m deep and 0.5 m to 1 m width and enriched with empty-fruit-bunch of oil palm at the bottom and refilled to 0.45 cm below the surface of the sand dune. This method of planting proves to be a success in establishing dipterocarp and leguminous climax rainforest species on 6 to 10 m sand dunes in Bidor (Ang & Ho, 2004). Soil chemical properties Sand tailings have lower concentration of macronutrients and some of the important trace elements compared to the mineral soils as shown in Table 7. The pH ranges from 4.0 to 6.5 for both types of tin tailings (Ang & Ho, 2004). Soil properties of sand tailing have been the main obstacle for enhancing growth and survival of timber tree species. Sand is low in fertility. Many studies showed that introduction of organic fertilizer either from plant materials or animal wastes to sand tailings would improve its fertility and also improve its physical properties. This approach has been used to improve the nutrient status of sand tailings in the project site. Low pH is the main concern for growing timber tree species on slime tailings. Application of ground magnesium limestone (GML) is absolutely necessary, if the ex-mining land is originally a peat swamp forest. The soil pH of the project site is from 4.0 to 6.5, and with the application of about 200 g GML per planting point, the growth of the seedlings was observed to be healthier at one year after planting. Thick weed cover Shifting cultivation site and grassland normally have the same problem, the ferocity of weeds especially Imperata cylindrica and Melastoma malabathricum. These weeds render the planting for rehabilitation and restoration purpose meaningless as the roots of the weed and their fast-growth rate suppresses the growth of the seedlings either from harvesting the photosynthetically active radiation or competing for soil moisture and nutrients in the root region. Removing of the weed cover is the main task before planting. Three methods of weeding were practiced in TTAC: manual, mechanical and chemical methods. 64 Ang, L.H., Ho, W.M. & Tang, L.K. A MIXED-SPECIES FOREST StaND ON AN EX-TIN MINE at TTAC Forest Research Institute Malaysia (FRIM) has established a Research Substation at Bidor, Perak with the aims to develop the ex-tin mine into a model of rehabilitated mixed forest stands. The research station is established on tin tailings left by Malaysia Mines Cooperation in 1940s. It is located about 138 km north of Kuala Lumpur and is easily accessible. The extent of the station is about 125 ha and comprising sand tailings, ponds and slime tailings.