Edaphic Influences on Tree Species Composition and Community Structure in a Tropical Watershed Forest in Peninsular Malaysia
Total Page：16
File Type：pdf, Size：1020Kb
Journal of Tropical Forest Science 26(2): 284–294 (2014) Khairil M et al. EDAPHIC INFLUENCES ON TREE SPECIES COMPOSITION AND COMMUNITY STRUCTURE IN A TROPICAL WATERSHED FOREST IN PENINSULAR MALAYSIA M Khairil1, WA Wan Juliana2 & MS Nizam2 1Faculty of Agriculture and Biotechnology, Universiti Sultan Zainal, Gong Badak Campus, 21300 Kuala Terengganu, Terengganu, Malaysia; [email protected] 2School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia Received April 2013 KHAIRIL M, WAN JULIANA WA & NIZAM MS. 2014. Edaphic influences on tree species composition and community structure in a tropical watershed forest in Peninsular Malaysia. A study was conducted to determine tree species composition and community structure, and their relationships with edaphic factors at a watershed forest in Tasik Chini, Peninsular Malaysia. Thirty plots of 0.1 ha were established with a total sampling area of 1.4 ha in inland forest, 0.9 ha in seasonal flood forest and 0.7 ha in riverine forest. A total of 3974 trees with diameter at breast height (dbh) ≥ 5.0 cm were recorded. The inland forest recorded 2061 individuals representing 393 species from 164 genera and 57 families; the seasonal flood forest had 1019 individuals representing 268 species from 137 genera and 57 families; and the riverine forest had 894 individuals representing 260 species from 137 genera and 53 families. Endospermum diadenum (Euphorbiaceae) was the most important species in the inland forest with importance value index (SIVi) of 3.36%, Streblus elongatus (Moraceae) in the seasonal flood forest with SIVi of 4.43% and Aporusa arborea (Euphorbiaceae) in the riverine forest with SIVi of 2.96%. The pH values of all three types of forest soils were acidic, with readings between 4.0 and 4.1. The highest average organic matter was in the inland forest (9.30%), followed by the riverine forest (8.49%) and seasonal flood forest (7.84%). The highest available P and K were in the riverine forest with values of 14.27 ± 1.23 and 175.88 ± 27.95 meq/100 g respectively. Ordinations using canonical correspondence analysis showed that the relationships between tree community and soil properties were weakly associated (p > 0.05). However, there were some species that were highly correlated with soil chemical characteristics and organic matter content. Keywords: Vegetation–environment relationship, Chini Lake, tree species diversity, canonical correspondence analysis (CCA) INTRODUCTION Plant associations with environmental factors formation of reserve nutrients for determining have been reported in many studies (Teixiera et the distribution of Dipterocarpaceae in Sarawak al. 2008, Rahayu et al. 2012). The abundance of (Baillie et al. 1987). The dipterocarp community plants is closely related to soil status of an area as in Brunei Darussalam, north-west Borneo soil provides nutrients needed by plants to grow was found to be associated with soil nutrient (Rahayu et al. 2012). Relationships between soil concentrations, soil water availability and properties and plant species abundance have environmental variables (Rahayu et al. 2012). been described in various habitats of grassland Variations in soil nutrient concentrations, (Amorim & Batalha 2007), savanna communities particularly P, Mg, Ca and K, have been credited (Barruch 2005) as well as tropical rainforests (Slik as major drivers of habitat associations displayed et al. 2010, Rahayu et al. 2012). For example, by Bornean Dipterocarp tree species (Paoli et al. physico–chemical characteristics of soil and 2008). A study conducted in the National Park at topography influence the growth of Dryobalanops Merapoh, Pahang in Peninsular Malaysia found aromatica and D. lanceolata in Sarawak (Hirai et that floristic composition patterns were highly al. 1995). The physico–chemical characteristics correlated with edaphic variables as revealed by of soil also influence the rates of seed and fruit canonical correspondence analysis (Nizam et al. production of these species (Hirai et al. 1995). 2006). The soil pH, inorganic-N and P appeared Edaphic factors seem to have a role in the to be the principal environmental determinants © Forest Research Institute Malaysia 284 Journal of Tropical Forest Science 26(2): 284–294 (2014) Khairil M et al. of tree communities. Different soil types in the MATERIALS AND METHODS 50 ha plot in Pasoh Forest Reserve, Peninsular Malaysia was reported to supply different amounts Study plots and tree sampling of nutrients for plant growth and P was the main limiting nutrient (Wan Juliana et al. 2009). In The Tasik Chini basin includes a lush their study at Tekam Forest Reserve and Pasoh tropical logged-over forest covering 4975 ha. Forest Reserve in Peninsular Malaysia, Amir and Tasik Chini is connected to the longest Mona (1990) reported that the distribution and watercourse in Peninsular Malaysia, Pahang abundance of legumes such as Koompassia sp. River via Chini River which meanders for about were highly correlated with chemical properties 4.8 km (Mushrifah et al. 2005, 2009). There are of soil where they absorbed more N, K, Mg three types of forests at the Chini watershed, and Zn. namely, inland forest, seasonal flood forest and Many comparative studies on floristic patterns riverine forest. of riparian and inland forests in a tropical The lake system comprises 12 open water watershed forest of Peninsular Malaysia were bodies. Most of the area is at low altitude; almost conducted by Fajariah (2004), Foo (2005), Siti 80% of the area is lower than 250 m above sea Najmi (2005), Norwahidah and Wan Juliana level (asl) except for Bukit Chini which has the (2009) as well as Khairil et al. (2011). Most highest peak of 641 m asl (Wetlands International of these studies found that the diversity of Asia Pacific 1998). inland forest was slightly higher than riparian Thirty plots of 50 m × 20 m each with a total forest. However, there have been no studies to area of 3 ha were established stratifically based determine patterns of tree species abundance on the coverage areas of each of the forest type and their relationship with physico–chemical within the Chini watershed (Figure 1). Fourteen characteristics of soils in a watershed area in plots were established in the inland forest, nine Peninsular Malaysia. Thus, this study was aimed plots in the seasonal flood forest and seven plots at determining the associations between tree in the riverine forest. The number of study species abundance and edaphic factors especially plots differed between the forest types because soil acidity in a watershed forest surrounding a there were some inaccessible areas especially natural freshwater lake at Chini, Pekan, Pahang in the seasonal flood and riverine forests. All in Peninsular Malaysia. plots were at the same altitude and the ranges Based on Khairil et al. (2011), three types of were between 100 m and more than 200 m. forests, namely, inland, seasonal and riverine The plots in the seasonal flood and riverine forests showed differences in terms of species forests were approximately 5–10 m from the composition and abundance. Most tropical water bodies. All trees with diameter at breast areas have high soil acidity (Jansen et al. 2000, height (dbh) of 5 cm and above were measured, Metali et al. 2011). We expect soil acidity to be identified, and leaf samples were collected and an important factor that determines tree species pressed. The specimens were identified using abundance in the Chini watershed, Pahang. keys by Whitmore (1972, 1973) and Ng (1978, Thus, parameters that contributed to soil acidity 1989) and by referring to voucher specimens at such as pH, cation exchange capacity (CEC), H+, Universiti Kebangsaan Malaysia. Al3+, acidic and base cation exchange were taken into account besides available P (Wan Juliana Soil analysis et al. 2009), K (Baille et al. 1987) and organic matter (OM) (Nizam et al. 2006), which were Three soil samples were taken from each plot well known factors influencing the distribution using an auger at depths between 0 and 15 cm. of plants. Data and information on tree species Each sample was about 500 g. The samples were community, physico–chemical characteristics then air dried. Roots, small stones and leaves were of soil as well as the relationship between tree separated from the soil. Samples were then sieved species distribution and edaphic factors from through a 2 mm sieve, while lumpy soils were this study are important and may be used as broken up using agate tools. The samples were a guideline to future ecological research in analysed for physico–chemical characteristics, wetland forest areas. which include soil particle size distribution, © Forest Research Institute Malaysia 285 Journal of Tropical Forest Science 26(2): 284–294 (2014) Khairil M et al. N W E S Meters Water catchment 0 1,250 2,500 6,000 Inland forest (Plots 1–14) Riverine forest (Plots 24–30) Seasonal flood forest (Plots 15–23) Figure 1 Thirty sampling plots at Chini watershed forest in Pahang; the location of Chini watershed is indicated by the red circle on the map of Peninsular Malaysia OM content, exchangeable acid cation (Al+ atomic absorption spectrophotometry. Cation and H+), exchangeable basic cation, CEC and exchange capacity was obtained by summation electrical conductivity. Available nutrients that of acid and basic cations. Electrical conductivity were determined include P, K and Mg. Organic was determined using saturated