Growth Performance of Three Indigenous Tree Species (Cratoxylum arborescens Vahl. Blume, Alstonia spathulata Blume, and Stemonurus scorpioides Becc.) Planted at Burned Area in Klias Peat Swamp Forest, Beaufort, Sabah, Malaysia

The aim of the study was to evaluate the growth performance of three indigenous tree species planted under open area planting technique of burned area at Klias Peat Swamp Forest, Beaufort, Sabah. Three indigenous tree species was used in this study, namely are Cratoxylum arborescens (Vahl) Blume (Geronggang), Alstonia spathulata Blume (Pulai), and Stemonurus scorpioides Becc. (Katok). A total of 45 seedlings for each species were examined using Randomized Complete Block Design (RCBD) with spacing of 3mx3m. Data collection for height, diameter, and survivality was recorded every two weeks within 10 weeks period from the seedlings was planted. Results from this study showed, the growth performance of Geronggang species was much better than the Pulai species, while all the Katok seedlings were died after week 6 in this experiment. The Geronggang species had the average mean height increment of 24.17 cm and average mean diameter increment of 2.76 mm, while Pulai species had average mean height increment of 9.36 cm and average mean diameter increment with 1.86 mm. For the survivality results, it showed that the Geronggang species had the highest survivality rate at 93.33% and Pulai species with 86.67%. There was a significant difference in term of relative height growth rate between Geronggang and Pulai species. However, there was no significant difference in term of relative diameter growth rate at significant level of P ≤ 0.05. The findings indicates that Geronggang and Pulai are suitable to be planted at burned area in Klias peat swamp forest for the purpose of reforestation using open area planting technique, while the Katok species is not suitable due to environment consideration. The better growth performance of the Geronggang and Pulai species are because they can easily adapted with the open area planting at the study site.


INTRODUCTION
Based on past events in Sabah, there were over 100,000 haof peat swamp forest and almost two-thirds of it was concentrated in the Klias Peninsula, but a large amount has been ruined by repeated fires.
The closest Binsuluk Forest Reserve, in particular, has been rigorously destroyed by fire, leaving only the Klias Forest Reserve somewhat intact. Presently, it is expected that less than 40,000 haof peat swamp forest stay as an effect of habitat loss through fire and land alteration (UNDP, 2006).
Fire poses a significant threat to the conservation of peat swamp forest in Klias Forest Reserve and is expected to remain a serious threat as long as preventive measures are not taken. Forest clearing and burning for cultivation in surrounding areas during extended drought periods is likely to be the major cause of fires in Klias Forest Reserve. The fires of 1998 and 2003, which destroyed parts of the Klias \Forest Reserve, bear testimony to the destructive impact of fire (Sabah Forestry Department, 2005).
For the burned area in Klias peat swamp forest, there is a need to restore to natural forest. However, it is difficult to restore to natural forest without human assistance. It is because the establishment of forest plantations especially in burned areas in peat swamp forest has many problems mainly because of the poor accessibility and low soil 66 ISSN 2354-5844

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Volume 2, Number 1, April 2014 Wetlands Environmental Management production. Thus, plantations may not be successful ventures without intensive management with high capital input (Ismail et al., 2007).
This study was carried out due to the lack of information and more research needed on planting and conserving of indigenous trees species in burned area in Klias Forest Reserve. The results obtained from this study can be used for references in rehabilitation of peat swamp forest in Klias Forest Reserve degraded area especially due to forest fire. Besides, choosing of suitable indigenous species to be planted initially in burned area to regenerated original forest is important, as maintenance cost is high if wrong species is chosen.
Growth performance and survivability of these indigenous species can be used as data base for choosing the right species that can be plant initially in burned area of peat swamp forest in Klias Forest Reserve.
The main objective of this study wasto evaluate the growth performance of three indigenous tree species planted in burned area in peat swamp forest, Klias Forest Reserve. The elements that have been focused on were the growth of diameter, height and the climatic data that influenced on growth of the indigenous trees species at the site planting.

This study was conducted in Klias Forest
Reserve which is located at West Coast of Sabah, Malaysia, consists of about 3,630 ha of mixed peat swamp forest. It is situated 10 kmfrom Beaufort Town at latitude 115˚ 20-40′ East and 5˚12-15´ North. Most of the site comprises flat or gently undulating terrain. The annual rainfall is approximately 3690 mm. This area is considered as one of the wet area in Sabah. Dry season is from February to March and wet season is from November to December.
Range of temperature is between 25 -31º C. The histories of this area are some of the forest reserve caught fire severely in 1998 and 2003. Experimental design. A Randomized Complete Block Design (RCBD) with Systematic Line Planting was adopted for this study with planting plot size of 15 x 27 m in three replications. In each replicate, a total of 45 seedlings were planted at a spacing of 3 x 3 m. The total numbers of potted-seedlings planted in the burned area were135 seedlings. The open planting method was used for this study. In this study, three indigenous species were chosen for the experiment to evaluate their growth performance. All of the seedlings were supplied by Forestry Department at Klias Station. The average age of the seedlings was sevenmonths. The trees species were Cratoxylum arborescens (Geronggang) Alstonia spathulata (Pulai), and Stemonurus scorpioides Becc. (Katok).
A total of 45 seedlings were planted for each species. The seedlings planted in the three blocks were 135 seedlings. Within each of the block, the number of seedlings planted was 45; 15 seedlings for Geronggang species, 15 seedlings for Pulai species and 15 seedlings for Katok species. The planting started at 7.00 am and completed at 11.30 am on 6 th September 2007. Data collection. For growth performance data, seedling's diameter and height were measured every two weeks in the field for 10 weeks after the seedlings were planted. Diameters of seedlings were measured at 10 cm above the ground using Digital Caliper. To ensure each measurement was taken at the same point, a semi-permanent mark at 10 cm above the ground was installed for each seedling. The height of the seedlings was considered from above the ground to the base of the top bud using a measuring tape. Survival rates (number of seedlings) of the seedlings were recorded.
Climatic and soil data. The data collection of rainfall, temperature and relative

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Volume 2, Number 1, April 2014 Wetlands Environmental Management humidity for this study were based on the data provided by Sabah Meteorological Department based at Kota Kinabalu. While for the light intensity, light meter was used to measure the light intensity at the planting area. The point of the light readings was chosen randomly in the three blocks. The light meter readings were recorded twice a day, in the morning (8.00 to 9.00 am) and in the afternoon (1.00 to 2.00 pm) on the same day during the collecting data of diameter and height parameters. The data of soil nutrient in peat swamp area of KFR had been referred to Sabah Agriculture Department as a secondary data in this study (Deratil et al., 2004).
Data analysis. The growth data measured for diameter and height parameters were compiled using Microsoft Excel program and subjected to the t-test analysis by using SPSS (Statistical Package for The Social Sciences version 12) to evaluate the significant of growth performance between the indigenous trees species. The formula as shownbelow was used to calculate the Relative Growth Rate (RGR) value in term of height and diameter for each species before subjected to the t-test analysis. All the climatic data (light, temperature, relative humidity, and rainfalls) were compiled using Microsoft Excel program and the results have been plotted in a graph. The correlation analysis between growth of both diameter and height for each indigenous species with climatic data had been done by using SPSS (Statistical Package for The Social Sciences version 12).

RESULTS
Number of survived seedlings. The number of the seedlings survived for all indigenous trees species after 10 weeks in the 3 blocks are as shown on Table 2. Geronggang has the highest number of seedlings survived with 42 after 10 weeks out of 45 in the initial planting, followed by Pulai with 39 out of 45 survived and none survived for Katok. All Katok seedlings died at the study site could be probably because of some environment factors that it cannot adapt. Week 2 Week 4 Week 6 Week 8 Week 10    (Table 3).  In this study, eight of the buds seedlings of Pulai had been eaten by the wild animals but the seedlings were alive and grew. Week 0 Week 2 Week 4 Week 6 Week 8 Week 10

Growth performance of indigenous trees species
Diameter growth Table 4 shows the mean increment of diameter growth rate of the seedlings for the period of 10 weeks after planting. Geronggang and Pulai showed an increment in mean diameter growth rate with 2.76 mm and 1.86 mm respectively after 10 weeks. Katok showed a declining mean diameter starting from Week 2 until Week 6 when all seedlings died. Table 3.Mean diameter increment in three blocks

Mean diameter (mm)
Week 0 Week 2 Week 4 Week 6 Week 8 Week 10  Figure 6, shows an increasing mean diameter growth rate of Geronggang and Pulai, while Katok showed decreasing in mean diameter growth rate after Week 2. The initial mean increment diameter growth rate of Pulai was faster tha Geronggang, but after Week 6 the mean increment diameter growth rate of Geronggang was more rapid than Pulai . Table 5 shows the mean increment in height growth rate of the seedlings during the 10 weeks after planting. Geronggang and Pulai showed the increment in mean height growth rate of 24.17 cm and 9.36 cm, respectively after Week 10. While Katok showed no increment in mean height after Week 8.

Growth analysis.
To test the hypothesis of growth performance, the Mean Relative Height Growth Rate (MRHGR) and Mean Relative Diameter Growth Rate (MRDGR) for each species in each block were considered.

Species Mean height (cm)
Week 0 Week 2 Week 4 Week 6 Week 8 Week 10  Figure 7 shows the mean height growth rate of Geronggang was faster than Pulai, while Katok showed decreasing in mean height growth rate after Week 2. Table 6 shows the data for parameters MRHGR and MRDGR for each species. For the analysis of growth performance, Katok was not subjected to this analysis because of insufficient data due to complete mortality atWeek 8, except for Geronggang and Pulai.    Table 8 shows the results of t-test between Geronggang and Pulai in term of MRHGR and MRDGR. There was a significant difference of MRHGR between Geronggang and Pulai at significant difference P ≤ 0.05 but no significant difference between both species for MRDGR (P≥0.05). However, for diameter growth, there was no significant difference between Geronggang species and Pulai.
Correlations analysis between the growth performanc of the indigenous trees species with the climatic data. Table 13 shows correlation analyses between growth performance with climatic data. Each of the species showed no significant correlation between their growth in terms of diameter and height with the climatic data at significant correlations level P≤0.05. This mean that correlations between the growth performances of all the indigenous species with the climatic data were weak.According to Evanset al. (1992), one of the factors that influenced the growth performances of the plant planted was the environment factors that are present at the planting area, this is included the climatic data. However, in this study, the climatic data were showed nosignificant correlation with the growth of all indigenous trees species in terms of height and diameter, probably because during study, the climatic data were stable.

DISCUSSIONS
Growth performance of indigenous trees species from the results this study, Geronggang had performed better growth performance in terms of survival rate (%) and the growth of both diameter and height compared to Pulai. Pulai had also showed a better result of growth performance in term of survival percentage and both diameter and height growth.However, the bud of Pulai seedlings were more susceptible to be eaten by the wild animals. For Katok, all the seedlings were died due to the condition of the some environment factors they cannot adapt at their early growth. The environment factors were light, temperature, relative humidity (%), rainfall distribution, and nutrient peat soil.
Geronggang and Pulai showed better growth because they could tolerate the environment factors that influence the growth performance. The growth performances of the indigenous trees species were influenced by this environmental factors (Evans et al., 1992). These environment factors included light intensity, temperature, relative humidity (%), rainfall distribution, and nutrition in the peat soil as discussed in the following the next topic. Environment factors that affecting the growth performance Light intensity. Janick et al. (1981) stated that light provides the energy for the synthesis of the Ccompounds in plants. It also has great effect on physiological processes. Germination, flowering, dormancy, and plant movement processes also directly affected by light. Light affects the segregation of many Volume 2, Number 1, April 2014 Wetlands Environmental Management plant tissues and organs. It is also a source of heat received by plant from irradiation of long wavelengths outside of the visible range. Plant growth depends on the amount of Cfixed during photosynthesis. Neither photosynthesis nor chloroplast development can take place without light. Even though the process of photosynthesis depends on the availability of light, the more sunlight a plant receives, the better capacity it has to produce plant food through photosynthesis. However, for each plant species, there is a maximum level of light intensity above which photosynthesis does not increase.
On the study site, all the seedlings received sufficient light intensity without interference from any vegetation except the cloud. It means, all the seedlings received light to do their photosynthesis process to growth.

For
Geronggangand Pulai seedlings, the light intensity that they received had assisted them to produce plant food through photosynthesis. This could have influenced the better results in growth performance for these species. For Katok, this is a shade tolerant species which cannot stand direct sun light at their early growth (Sumarto, 2007: personal communication). A high light intensity could lead to death of the plants. So, to get a better growth, this species needs a good shade at the early growth. In this study, Katok was used in the open planting technique due to lack of information whether this species can survive under this technique or not.
Rainfall. Young (1982) reported that when the internal moisture content of a tree decreases, many physiological processes are affected adversely, resulting in growth loss. Among the processes influenced by water shortage are absorption of water stomata aperture, transpiration, photosynthesis, respiration, and mineral uptake.
Based on the rainfall data recorded at the Klias Station, the Klias area received a mean daily rainfall of 10.35 mm from September to November 2007. The rainwater received at the study site diffused directly into the ground and was absorbed by the roots of the seedlings planted. This means that all the seedlings received water as their primary component to do many physiological processes. As Geronggangand Pulai grew well at the study site indicating that the amount of water they need were adequate. On the other hand, Katok, the amount of water received was probably inadequate for their many physiological processes resulting in growth loss.
Temperature. According to Ismail and Yaakob (1994), plants need suitable temperature to be able to grow. This can be seen in the growth of the plant itself. At an optimum temperature, plant growth occurs at an optimum rate. This situation is called plant cardinal temperature. Plant cardinal temperature differs according to different types of plant. If the temperature for certain species drops below its minimum cardinal temperature in certain areas, the metabolic activity of the species will be slower than its normal rate, whereas if the temperature is higher than the cardinal temperature of the species, this situation might damage the growth cells of the plant.
The mean temperature reading recorded in September was 27.2 ˚C, October, 27.4 ˚C and in November, 26.6 ˚C. This showed that the mean temperature reading was between the range where most plants live and grow which is within the temperature range of 0˚C to 50˚C (McMahon et al., 2002).
For Geronggang and Pulai, better growth performance shown by this two species indicated that the mean temperatures that were recorded from September to November were in the range of their cardinal temperature. This means, the highest mean temperature of 27.4 ˚C was tolerable for the growth of Geronggang and Pulai. Meanwhile, for Katok, the mean temperatures from September to November were probably not in the range of their cardinal temperature. This could be higher than its cardinal temperature, hence damaged the growth cells and influenced the death of all Katok seedlings.