Early Performance of 23 Dipterocarp Species Planted in Logged-Over Rainforest

Journal of Tropical Forest Science 26(2): 259–266 (2014) Widiyatno et al.

EARLY PERFORMANCE OF 23 DIPTEROCARP SPECIES PLANTED IN LOGGED-OVER RAINFOREST

Widiyatno1, *, Soekotjo1, M Naiem1, S Purnomo2 & PE Setiyanto2

1Faculty of Forestry, Universitas Gadjah Mada, Yogyakarta, Indonesia 2PT Sari Bumi Kusuma, Central Kalimantan, Indonesia

Received December 2012

WIDIYATNO, SOEKOTJO, NAIEM M, PURNOMO S & SETIYANTO PE. 2014. Early performance of 23 dipterocarp species planted in logged-over rainforest. The objective of the present study was to evaluate the growth of selected species of dipterocarps as reforestation potential. The trial was conducted using 23 potential species of dipterocarps and random complete block design, with four blocks used as replication. Diameter at breast height (dbh), height and survival rate were measured at 6.5 years. There was significant difference in dbh. The best two species were Shorea platyclados and S. leprosula where dbh values were 16.6 and 14.3 cm respectively. The species with the lowest dbh was Dipterocarpus caudiferus, 5.7 cm. Height growth was also significantly different. The two tallest species wereS. platyclados and S. leprosula (8.6 and 8.3 m respectively). The species with the lowest height was D. caudiferus (4.4 m). Seven species showed high survival rates (71 to 85%), nine species moderate (50 to 70%) and seven species low (38 to 48%).

Keywords: Species trial, diameter growth, height growth, survival rate, target species

INTRODUCTION

The tropical rainforest in Indonesia is known line replanting (tebang pilih tanam jalur, TPTJ), as one of the centres of biodiversity and the and gap cutting (MOF 2009). For the past few world’s second largest tropical forest in terms of decades, exploitation of tropical rainforest biological diversity (60% of total land area or 10% resulted in decreasing natural forest, forest of the world’s total tropical forest) (Rimbawanto productivity, biodiversity, genetics as well as 2006). One of the families dominating the tropical increasing secondary forest (logged-over forest) rainforest in Indonesia is Dipterocarpaceae, and carbon emission. Exploitation of tropical which plays a vital role in tropical timber market rainforest results in genetic erosion of trees and hence influences the economy of many or unsuited genetic material. This is because South-East Asian countries (Appanah 1998). mature trees have practically disappeared from Dipterocarpaceae consists of 16 genera in 3 local forests and seeds have to be collected from subfamilies, making up about 515 species. In Asia, the remaining resources, i.e. poorly-shaped trees there are 13 genera and 470 species (Bawa 1998). (Langenberger et al. 2005). Dipterocarps are major climax and dominant The residual stand of secondary forests tree species which make up the rainforest in recovering from logging and large natural South-East Asia. They have essentially supported disturbance is considerably different from biodiversity and the carbon sink component in the primary forests with respect to species tropical rainforests. Dipterocarpaceae is not only composition, structure, dynamics and stability harvested as wood but also produces resin and (Ng 1996, Bischoff et al. 2005). Sustainability illepe nut. Bischoff et al. (2005) reported that the of tropical forests is vital especially through the average volume of trees in the primary forest of enrichment of secondary forests. Enrichment tropical rainforest was estimated at 211.75 m3 ha-1 planting programme/large-scale plantation where dipterocarps made up 86.9%. to rehabilitate tropical rainforest rarely uses Tropical rainforest in Indonesian is managed dipterocarps as a source of land rehabilitation by many silviculture systems such as Indonesian or reforestation, although dipterocarps have selective cutting and replanting (tebang pilih predominant role in forest exploitation tanam Indonesia, TPTI), selective cutting and (Langenberger 2006). On the other hand, [email protected]

© Forest Research Institute Malaysia 259 Journal of Tropical Forest Science 26(2): 259–266 (2014) Widiyatno et al. little is known about systematic species trial of area of PT SBK is 147,600 ha, managed under Dipterocarpaceae involving a wide range of two silviculture systems, namely, TPTI and TPTJ species tested in different sites (Hardiyanto (MOF 2009). 2006). Future research is needed to support The climate is type A (Scmidt and Ferguson). the rehabilitation of tropical rainforest: species Mean annual temperature in the night is 22– selection, well adapted genetic resources, site 28° C and in the afternoon 30–33 ° C; mean management and productivity, ecology and annual rainfall is 3376 mm/year and the conservation, integrated pest management number of rainy days varies from 89 to 189 days and silviculture (Soekotjo 2006). Species trial (Figure 2). Even though August is the month or species selection is a method that is applied with the least rainfall (96.6 mm), it is still to obtain information on species suitable to be wet. Therefore, the soil under the surface developed at a certain location and on superior always remains moist. The soil is Ordo Ultisol. species prior to subsequent improvement However, this Ordo is the most weathered soil programme on species screening test. The and shows ultimate effects of leaching. Ultisol is objective of the present study was to evaluate the characterised by mineral soils that has B2 horizon, growth of 23 species of dipterocarps and to study 20% more clay compared with the upper B1. the reforestation potential of indigenous species Vegetation of the forest area is dominated by with fast growth. These species of dipterocarps Dipterocarpaceae. which were found suitable on degraded forest would be recommended for rehabilitation Seed collection programme to conserve and increase the productivity of tropical rainforest. The mast fruiting of dipterocarps is infrequent, usually more than 3 years. However, sporadic MATERIALS AND METHODS fruiting occurs almost every year in some parts of the tropical rainforest (Appanah & Weinland Study sites 1993). The seed of dipterocarps is categorised as recalcitrant with less than one month seed This study was conducted in the natural forest viability after collection (Sasaki 1980, Otsamo at Sei Seruan block of PT Sari Bumi Kusuma et al. 1998). The seeds of 23 dipterocarp species (SBK) concession, central Borneo (00° 36'– 01° were collected during a mass flowering event 10' S and 111° 39'–112° 25' E) (Figure 1). PT from January till February 2005 in the whole SBK received the concession in 1978. The total concession area. As fallen fruits were eaten by

Figure 1 Forest research area, PT Sari Bumi Kusuma forest concession, central Kalimantan, Indonesia

5000 Annual rainfall (mm) 200

4500 180

4000 160 140 3500 120 2500 100 2000 80

Annual rainfall (mm) 1500 60 Number of rainy days 1000 40

500 20

0 0 2001 2002 2003 2004 2005 2006 2007 2008 2009

Figure 2 Rainfall pattern in the Sari Bumi Kusuma forest concession animals, fresh fruits were collected everyday S. leavis, S. fallax, S. macroptera, S. atrivervosa, from the same collection sites. The fruits were S. seminis, S. guiso, S. virescens, S. singkawang, taken to a nursery of SBK to be germinated in S. blumutensis, S. lamellate, Hopea mangerawan, 15 cm × 20 cm polybags filled with top soil from Dipterocarpus retusus and D. caudiferus. the forest floor. The topsoil was collected from The total number of seedlings planted was around mother trees of dipterocarps to ensure 2760. Land preparation in the research area was mycorrhizal infection of seedling roots. Seedlings to open the land (land clearing so that sunlight were maintained in the nursery for 12 months. could reach the forest floor). Therefore, each seedling received similar light. Data collected Site preparation and planting were survival rate, diameter at breast height (dbh) and height increment at 6.5 years after An experiment was carried out in a 4.97 ha artificial planting. Survival rate was assessed based on complete count of trees originally planted in gap formed in a logged-over area of the tropical each block. Dbh was taken at 1.3 m from the rainforest. The gap was created between January root collar using diameter callipers. The height and March 2006. Site preparation was done by of plants was measured from the root collar to clear cutting the area to ensure all treatments had the shoot tip using haga meter and the survival the same light and microclimate conditions. Clear rate of each species was counted. Data collected cutting was also effective to control competitive was analysed using one-way analysis of variance vegetation. Planting hole was approximately (ANOVA) to determine the height and dbh 40 cm 40 cm 30 cm and spacing was 6 m × × × increment variations between dipterocarp species 3 m. Site preparation and planting time were and by Duncan’s multiple range test (DMRT) to between February and April 2006. detect significant differences of means between dipterocarp species. Analysis was performed Experiment design using Statistical Analysis System version 9.0 and the significance level was set at 0.05. The design of species trial was randomised complete block design with four blocks used RESULTS AND DISCUSSION as replication. Twenty-three indigenous species (dipterocarps) were used as treatment. Each Survival rate block consisted of 23 dipterocarp species and each species consisted of 3 × 10 tree plots (30 Survival rate of dipterocarps varied between seedlings) with rectangular plot at a spacing of species (Figure 3). At 6.5 years old, 7 species, 6 m × 3 m. They were Shorea leprosula, S. platyclados, had more than 70% survival rate. They were S. johorensis, S. ovalis, S. parvifolia, S. macrophylla, S. leprosula, S. guiso, S. macrophylla, S. fallax, S. S. pinanga, S. scaberima, S. smithiana, S. dasyphylla, johorensis, S. leavis and S. ovalis.

100 Shorea leprosula S. guiso 90 S. macrophylla S. fallax 80 S. johorensis S. leavis 70 S. ovalis 60 S. Scaberima Dipterocarpus retusus 50 S. parvifolia S. seminis Survival rate (%) 40 S. pinanga Hopea mangerawan 30 S. dasyphylla D. caudiferus 20 S. atrivervosa 10 S. singkawang S. blumutensis 0 S. smithiana S. virescens 0 2 4 6 S. macroptera Age (years) S. platyclados S. lamellata

Figure 3 Survival rate of dipterocarp species

The study indicated that many species of fast-growing species of dipterocarps based on dipterocarps had the potential to enrich a logged- DMRT analysis—S. platyclados, S. leprosula, S. over area of tropical rainforest. However, earlier macrophylla, S. parvifolia and S. dasyphylla showed studies involving enrichment planting of logged- dominant growth and performance where mean over area had varied results. Affendi et al. (2009) annual increment (MAI) of dbh was more than reported that S. leprosula had poor survival rate of 1.90 cm year-1 (Table 2). The best two species 20.7%. Adjers et al. (1996) reported that survival based on MAI of dbh was achieved by S. platyclados rate of 10 dipterocarps varied from 5 to 78% after and S. leprosula, i.e. 2.56 and 2.20 cm year-1 2 years of planting. respectively. Species with moderate growth In this research, S. platyclados appeared to based on MAI of dbh were S. ovalis, S. johorensis, have lower survival rate (42.5 ± 3.2%) compared S. scaberima, S. smithiana, S. virescens and S. with S. platyclados planted by Ang and Maruyama pinanga (1.48–1.71 cm year-1). (1995). The mortality of S. platyclados and The two species that had the lowest growth other dipterocarp seedlings were mainly due of MAI dbh were S. macroptera and D. caudiferus to dehydration. Moreover, this species had not (1.01 and 0.87 cm year-1 respectively). The dbh grown enough to tolerate direct sunlight. Land growth trend of Dipterocarpaceae in the early clearing in tropical rainforest also increases stage was linear with S. platyclados and D. caudiferus water stress of planted seedlings and relative showing y = 2.47x + 0.10 (r² = 0.99) and y = 0.77x light intensity (Kamo et al. 2009). Survival rate + 0.67 (r² = 0.99) respectively (Figure 4). of dipterocarps decreased rapidly during the first 1.5 years and became stable after 3.5 years Height growth (Figure 3). It indicated that they had adapted to the site condition. Height growth showed relative similar pattern to dbh growth where S. platyclados and S. leprosula Dbh growth had the highest growth (Table 2). However, S. johorensis had height growth better than S. ANOVA showed that there were significant parvifolia and S. macrophylla. At 6.5 years old, the differences between species (F = 6.27, p < best two species based on MAI of height growth 0.001) in dbh variable (Table 1). The five were S. platyclados and S. leprosula, i.e. 1.33 and

Table 1 Analysis of variance on 23 dipterocarp species

Source of variation Df Mean square F value Dbh Height Dbh Height Block 3 143.14 25.15 32.78 25.26 Species 22 27.36 5.51 6.27** 5.54**

** = significant at 0.01 level of probability; Df = degree of freedom; Dbh = diameter at breast height

Table 2 The average of dbh and height of 23 dipterocarp species at 6.5 years old

No. Species Dbh Standard deviation No. Species Height Standard deviation (cm) (m) 1 Shorea platyclados 16.66 3.34 1 S. platyclados 8.64 2.19 2 S. leprosula 14.32 3.15 2 S. leprosula 8.30 1.28 3 S. macrophylla 13.74 3.57 3 S. johorensis 7.27 2.79 4 S. parvifolia 13.03 3.70 4 S. ovalis 7.22 1.50 5 S. dasyphylla 12.77 3.10 5 S. parvifolia 7.13 1.37 6 S. guiso 11.90 2.37 6 S. macrophylla 7.08 1.14 7 S. ovalis 11.11 2.40 7 S. dasyphylla 6.83 1.42 8 S. johorensis 10.92 4.91 8 S. scaberima 6.67 1.35 9 S. scaberima 10.85 4.56 9 S. smithiana 6.63 1.06 10 S. smithiana 10.25 2.56 10 S. guiso 6.25 1.33 11 S. virescens 10.01 2.99 11 S. pinanga 6.23 1.21 12 S. pinanga 9.59 2.96 12 S. blumutensis 5.93 1.92 13 S. fallax 8.89 5.05 13 S. leavis 5.86 0.81 14 S. blumutensis 8.62 4.33 14 H. mangerawan 5.58 2.40 15 S. cryso 8.27 3.64 15 S. lamellata 5.46 1.21 16 S. leavis 7.83 1.77 16 S. virescens 5.43 1.24 17 S. seminis 7.65 2.59 17 S. atrivervosa 5.35 1.91 18 Dipterocarpus retusus 7.60 4.23 18 S. singkawang 5.03 1.79 19 S. singkawang 7.32 4.16 19 S. fallax 5.02 1.70 20 S. lamellata 7.27 1.32 20 S. seminis 4.71 1.34 21 Hopea mangerawan 6.64 3.45 21 D. caudiferus 4.64 1.86 22 S. macroptera 6.59 4.19 22 D. retusus 4.47 1.35 23 D. caudiferus 5.68 3.42 23 S. macroptera 4.37 2.06

1.28 m year-1 respectively. ANOVA showed Species evaluation significant difference in height (F = 5.54) (Table 1). Some species classified as moderate Dipterocarp species have different requirements growth were S. parvifolia, S. macrophylla, S. during their early survival and growth. When they dasyphylla, S. scaberima and S. smithiana (1.02– were established on degraded tropical rainforest 1.10 m year-1) (Table 2). initially their growth was under shade. Some The species with lowest height was S. macroptera species of dipterocarps prefer to grow in shade where the MAI of height was 0.67 m year-1. Some condition while others can grow well in gaps of saplings of dipterocarps were sensitive to light different widths (Appanah & Weinland 1996). during the initial establishment stage but later The main constraint for some dipterocarps to responded to light to support their growth. The survive is high air temperature. The average height growth trend in the early stage was linear air temperature in the morning, afternoon for S. platyclados and D. caudiferus (y = 1.22x + and evening were 23.98, 33.16 and 30.29 °C 0.89 (r² = 0.99) and y = 0.57x + 1.07 (r² = 0.92) respectively. On the other hand, the average respectively) (Figure 5). relative humidity in the morning, afternoon and

18 Shorea platyclados S. leprosula 16 S. macrophylla S. parvifolia 14 S. dasyphylla S. guiso 12 S. ovalis S. johorensis 10 S. scaberima S. smithiana 8 S. virescens S. pinanga Diameter (cm) 6 S. fallax S. blumutensis 4 S. atrivervosa S. leavis 2 S. seminis Dipterocarpus retusus S. singkawang 0 S. lamellata 0 2 4 6 Hopea mangerawan Age (years) S. macroptera D. caudiferus

Figure 4 Diameter at breast height growth of 23 dipterocarp species

Shorea platyclados 10 S. leprosula S. johorensis 9 S. ovalis 8 S. parvifolia S. macrophylla 7 S. dasyphylla S. scaberima 6 S. smithiana S. guiso 5 S. pinanga

Height (m) S. blumutensis 4 S. leavis Hopea mangerawan 3 S. lamellata 2 S. virescens S. atrivervosa 1 S. singkawang S. fallax 0 S. seminis 0 2 4 6 Dipterocarpus caudiferus D. retusus Age (years) S. macroptera

Figure 5 Height growth of 23 dipterocarp species evening were 99.9, 78.6 and 87.6% respectively. growth and height as well as high survival rate. The high air temperature and low relative Besides they are known as less tolerant to shade temperature will increase water loss from the leaf in their initial growth and benefit from open area and cause stomata closure. On the other hand, condition (Appanah & Weinland 1993). The four the rate of net photosynthesis will be reduced species have potential to rehabilitate logged-over and the tree will have low survival (Ang 2005). area of tropical rainforest that has low volume or Based on survival rate, dbh and height growth, species composition compared with fast-growing dipterocarp species that could be selected for exotic tree species (Adjers et al 1996). rehabilitation of degraded tropical rainforest Shore leprosula showed higher dbh growth in were S. leprosula, S. parvifolia, S. macrophylla and S. the present study compared with those of Affendi johorensis. These species showed the highest dbh et al. (2009) and Symington (1974) who reported

MAI of dbh 1.03 and 1.2 cm year-1 respectively. site matching of dipterocarp species is needed Shorea leprosula has been known as a dipterocarp in large-scale plantation because each species species tolerant to water stress and a light requires different site conditions. For example, demander in the early stage of growth (Appanah S. leprosula needs sites with sufficient soil water, & Weinland 1993). This species is also adapted only occasional water stress and no perched to a wide range of site distribution (Newman et water tables (Ashton 1982); S. macrophylla can al. 1996). be planted in impeded drainage or riparian site Shorea parvifolia is one of the light demanders (Appanah & Weinland 1996). of dipterocarps. It grows in clay soil on lowland High variation in growth rates (dbh and and hill forest up to 800 m above sea level height) between species provides us opportunity (Appanah & Weinland 1993, Newman et al. to select fast-growing and valuable wood 1996). The MAI of dbh and height of S. parvifolia of dipterocarps in large-scale dipterocarp in Sampadi and Balai Ringin, Malaysia were plantation. This will conserve dipterocarp species 0.48–1.06 and 0.24–0.85 m year-1 respectively from extinction and improve productivity of (Vincent & Davies 2003). tropical rainforest. Collection of seeds from Shorea johorensis has natural distribution plus trees of selected dipterocarp species in Peninsular Malaysia, Sumatra and Borneo. should be conducted to establish progeny test It needs sites with well-drained alluvium and so that suitable plus tree can be propagated by undulating soil that can be found up to 600 m generative or vegetative technique to support above sea level (Newman et al. 1996). Shorea future large-scale dipterocarp plantation (Zaki johorensis reported slow growth in line planting et al. 2002). (3 m in line width) system where the survival rate and MAI of dbh at 2 years old were less CONCLUSIONS than 70% and 0.6 cm year-1 (Adjers et al. 1995). Shorea platyclados had the highest MAI both in dbh Their results contradicted our results where and height, i.e. 2.56 cm year-1 and 1.33 m year-1 MAI of dbh and height of S. johorensis were respectively but had low survival rate (42.5%). 1.91 cm year-1 and 1.45 m year-1 The species recommended for rehabilitation Shorea macrophylla can produce wood and of degraded area of tropical rainforest were illepe nut. It is naturally distributed in Borneo S. leprosula, S. parvifolia, S. macrophylla and S. especially in West Kalimantan, East Kalimantan, johorensis. These species had high survival rate Brunei as well as central and western Sarawak as well as growth of dbh and height. These (Appanah & Weinland 1993, Newman et al. species not only can produce valuable wood in 1996). It can be found below 600 m above sea 20–30 years time but they are also considered level and uncommon on hillsides (Newman et to protect and conserve indigenous species in al. 1996). Our study showed that MAI of dbh tropical rainforests. and height of S. macrophylla were 2.11 cm year-1 and 1.09 m year-1. Azani et al. (2001) reported ACKNOWLEDGEMENTS that S. macrophylla had MAI of dbh and height of 0.44–0.80 cm year-1 and 0.4–0.71 m year-1 This study was made possible by PT Sari Bumi respectively. Shorea macrophylla is mainly found in Kusuma (PT SBK) and the Ministry of Forestry riparian site but does not occur on flat or slightly of Indonesia that funded this research. We would undulating land that is well watered with small like thank the Dean of the Faculty of Forestry stream (Appanah & Weinlad 1993). This species for allowing us to conduct this research. In will be recommended for planting in sites prone particular, thanks are due to the staff of PT SBK to flooding (Appanah & Weinland 1996). for their help in carrying out this experiment. The evaluation of dipterocarp species to rehabilitate degraded tropical rainforest is not REFERENCES only based on their growth but also their survival rate to achieve successful rehabilitation. Thus, the Adjers G, Hadengganan, Kuusipalo J, Nuryanto J & Vesa L. 1995. Enrichment planting of dipterocarps in choice of tree species to be planted in degraded logged-over secondary forests—effect of width, tropical rainforest is not only from their tolerance direction and maintenance method of planting to available light but also the ability to adapt to line on selected Shorea species. Forest Ecology and their microclimate. On the other hand, species– Management 73: 259–270.

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