An Examination of Regeneration in the North Selangor Peat Swamp Forest

An Examination of Regeneration in The North Selangor Peat Swamp Forest

- Revised Edition -

Bachelor’s Thesis by Thyge M. Nielsen

Supervisors: Professor Jacob Weiner and Assistant Professor Anders Dahl. Department of Ecology Botany Section

The Royal Veterinary and Agricultural University Copenhagen August 2000

Abstract The purpose of this research was to better understand the regeneration of the timber species in the North Selangor Peat Swamp Forest (NSPSF). The target group include the species Calo- phyllum spp., Cratoxylum arborescens, Gonystylus bancanus, Koompassia malaccensis, Sho- rea uliginosa and Xylopia fusca.

The regeneration of the six target species and of the remaining tree vegetation was registered in three selected parts of the North Selangor Peat Swamp Forest. Data from 1.200 trees has been collected. These are from the sapling and seedling level respectively. The field area has been logged between 10 and 32 years ago at different intensity rates. Additionally an herbarium has been collected in order to illustrate a selection of the present tree vegetation.

The results show an extremely low regeneration rate among the six target species and a high rate of infestation by various palms species, ferns and pioneer species.

A silvicultural treatment could better the situation of the timber species. A treatment should include pest control and artificial seeding or even enrichment planting, but in that case additional research is recommended.

I An examination of regeneration in The North Selangor Peat Swamp Forest.

Sammendrag Projektets formål har været at undersøge regenerationen af Calophyllum spp., Cratoxylum arborescens, Gonystylus bancanus, Koompassia malaccensis, Shorea uliginosa and Xylopia fusca i forhold til den øvrige vegetation. Det er relevant da de til dato har været de mest udnyttede tømmertræarter i Selangors nordlige tørvesump skove (herefter NSPSF). Indtil nu har de udgjort størstedelen af tømmertræarterne i skovene. Men efter intens hugst ser det ud til at regenerationen er hæmmet, som følge af de ændrede økologiske forhold og de manglende moderplanter.

Undersøgelsen inddrager foruden målgruppen et antal meget almindelige tørvemose skovtræar- ter. Analysemetoden tager udgangspunkt i the Point-Centred Quarter Method, hvor densitet, dominans og frekvens er vigtige parametre. Opvæksten er blevet registreret i tre dele af NSPSF, hvor hugst har fundet sted for mellem 10 og 32 år siden. Der er i alt indsamlet data fra 1.200 træer på to forskellige niveauer. Til illustration af områdets vegetation er et herbarium blevet fremstillet.

Resultatet peger på en udpræget lav grad af selvforyngelse blandt de seks udvalgte tømmertræ- arter. Der viser sig at være et højt indslag af ukrudtsarter, som består af palmer, bregner og pionertræ- arter.

Et indgreb bedømmes at ville bedre tømmertræarternes regeneration. Et sådant indgreb kunne bestå i en indsats imod ukrudtet og et indslag af kunstig frøsætning. Plantning bør kun foretages efter yderligere videnskabelige undersøgelser af regeneration i området.

II Preface The work entailed in this report represents my bachelor’s thesis in forestry submitted to the De- partment of Ecology, Botany Section. It was presented on seminar Friday 25. August 2000 at The Royal Veterinary and Agricultural University (KVL).

The report supplements the DANCED project Sustainable Management of the Peat Swamp Forest now in its final stages after more than three years research.

The recipient of this work is DANCED and the Malaysian forestry authorities with jurisdiction over the peat swamps of North Selangor. This report, including all raw data (CD-ROM), has been sent to the Forest Department of Selangor, Shah Alam. Furthermore three copies and a copy on CD-ROM have been sent to the Economic Planning Unit, Kuala Lumpur. It is my hope that the research I have done contribute to the ongoing research on the peat swamp forest of North Selangor.

The inspiration to this thesis was an article by Kanta Kumari in the Royal Swedish Academy of Sciences about the North Selangor Peat Swamps Forest.

All photos supplied by the author.

III An examination of regeneration in The North Selangor Peat Swamp Forest.

Acknowledgements Without the financial support from the sponsors the work could not have been carried out. My gratitude to the sponsors: SLUSE, DLH-fonden, Studiefonden for studerende ved KVL, Skovri- der C.D. Frederiksen og hustru’s Legat and Forstkandidatforeningens Rejsefond.

I would like to acknowledge the help from Mr. Palle Havmøller, Chief Technical Advisor on the DANCED project Sustainable Management of the Peat Swamp Forest. He offered valuable ad- vice and information during the time of research. Thanks to the Forestry Department (Shah Alam) and FRIM (Kepong) for their friendly support especially concerning hardware and equipment essential for the project. Thanks to the Economic Planning Unit for the necessary permits issued. Thanks to Dr. Ali Hamsa for the friendly support and to Mrs. Munirah Abd. Manan for the brief and concise han- dling. Thanks to Mr. Kamarudin B. Itama Mat Aras and his team of foresters. Thanks also to my assistant Mr. Hamir Shah B. Mohd Saad, whom I got to know quite well during the 2 ½ months fieldwork. Dr. Bernd Hahn-Schilling (FOMISS), Dr. Wong Khoon Meng (UM) and Mr. Ismael Parlan (FRIM). Experts in each their field, who have been very helpful in answering any question. I am very grateful for their time and interest in this project. For proofreading I wish to thank history undergraduate Karen Jane Moore, who spend time in Copenhagen to learn more about Danish welfare and to BA Antonia Fairbanks, who is a trainee at the Danish Environmental Protection Agency. A final grateful thought to professor Niels Ja- cobsen and associate professor Marten Sørensen, who I conferred with after returning to KVL.

IV Contents

1. BACKGROUND...... 1

1.1 Previous surveys in the North Selangor Peat Swamp Forest ...... 1

1.2 DANCED in the NSPSF ...... 1

2. INTRODUCTION AND PROBLEM ANALYSIS ...... 4

2.1 Location and environment...... 4

2.2 The peat swamp forest...... 4

2.3 Introduction to the research area ...... 10

2.4 Logging routine in the NSPSF ...... 12

3. FOREST STRUCTURE...... 14

4. OBJECTIVES...... 15

5. METHOD & MATERIAL...... 16

5.1 The method...... 16

5.2 The field area ...... 18

5.3 The fieldwork ...... 21

5.4 Species and species groups ...... 25

6. LIMITATIONS ...... 30

V An examination of regeneration in The North Selangor Peat Swamp Forest.

7. OUTPUTS...... 32

7.1 Sapling data ...... 32

7.2 Seedling data...... 37

7.3 Light and temperature ...... 41

8. DISCUSSION ...... 42

8.1 Species composition and distribution ...... 42

8.2 Regeneration...... 44

8.3 Infestation ...... 46

9. CONCLUDING REMARKS...... 49

10. REFERENCES...... 52

ACRONYMS OF ORGANISATIONS ...... 56

ABBREVIATIONS ...... 57

APPENDIX A...... 58

APPENDIX B ...... 61

APPENDIX C...... 63

APPENDIX D...... 64

VI 1. Background

1. Background

1.1 Previous surveys in the North Selangor Peat Swamp Forest

In the past, numerous surveys have been carried out on logging and use of the peat swamp forest (PSF), but not many surveys have involved regeneration. Appanah (1997) writes: “No studies have been completed on the growth and yield of these forests”.

Despite the fact that several surveys have been carried out on peat swamps still little is known. Palle Havmøller, the chief technical adviser (CTA) on the project states: “In contrast to the other types of tropical forests in Malaysia very little is known about growth, bio-diversity, hydrology and ecosystem dynamic of the PSF and Forestry Department therefore consider the work that the Pro- ject carries out of great importance for the understanding and future implementation of sustainable management of this valuable natural resource not only for Malaysia, but for the Global Community as well (Havmoller, 1997)”. Also the tropical forests is an ecosystem where there is still much to be learned. Kumari (1996) states: “The precise dynamics of the tropical forests is still not well understood. We know less about the workings of the forest ecosystem than we do about any other biome on earth. The interactive processes in the tropical forests are complex and poorly understood.”

Recently Hahn-Schilling (1994, 1997) has obtained important knowledge about the peat swamp forest, as is evident in his dissertation of 1994 about the selective and sustainable use of the PSF. It includes regeneration as well. This extensive survey of the North Selangor Peat Swamp Forest (NSPSF) is probably the most comprehensive work so far, and will be so until the DANCED- project is finished later this year.

1.2 DANCED in the NSPSF

On September 1st 1996 the Malaysian-DANCED Project on Sustainable Management of Peat swamp forests in Peninsular Malaysia was initiated. The duration of the project was originally three years, but has been extended nine months and will be completed by the end of 2000. The project has been undertaken bilaterally by the governments of Malaysia and Denmark. The implementing agency is the Forestry Department of Peninsular Malaysia in cooperation with DANCED (Danish 1 An examination of regeneration in The North Selangor Peat Swamp Forest.

Cooperation for Environment and Development) who is represented by the Danish consultant com- pany DARUDEC (Havmoller, 1997 and 1999).

The overall developmental objective is to contribute to the management of peat swamp forests in Peninsular Malaysia for sustained social, economic and environmental benefits (Havmoller, 1997 and 1999).

The main objectives are to ensure that enterprises will contribute to develop low impact logging methods and effective methods for rehabilitation of heavily logged over areas. Furthermore to un- dertake growth and yield studies and to conduct field inventories in the PSF with emphasis on forest production, ecology, hydrology, infrastructure, biodiversity and socio-economic values that pro- duce guidelines for long-term and periodic sustainable forest management planning (Havmoller, 1997 and 1999).

The background for this development can be traced in the legal and administrative framework. Be- low is listed the most important laws concerning the NSPSF.

1953 - Malayan Uniform System (MUS) was introduced to manage the rainforests of Malay- sia. From 1960 peat swamps were managed according to the system as well (Wyatt-Smith, 1963). The NSPSF was classified as Stateland Forest and has been subjected to logging since then until it was gazetted in 1990 as Forest Reserve (Kumari, 1996). 1984 - National Forestry Act was introduced to enforce or mobilize the exemplary policy and legislation that existed, but has not been well enforced. The act is potentially the most important tool for practical enforcement of multiple use and management of forests in Malaysia. All states on the Peninsula have endorsed and accepted the act that legislates and officially recognizes forests as having a multi-functional role, in line with sustainability criteria (Kumari, 1996). This is especially true when it comes to water catchments, wildlife and management plans (Havmøller, pers. comm., 1999). 1990 - the NSPSF was made a Permanent Forest Reserve by the federal state of Selangor, ac- cordingtotheNational Forestry Act of 1984, Section 7. The area is now to be used for scien-

2 1. Background

tific research (Hahn-Schilling, 1994 and Ujang & HJ.MD.Som, 1997). The authorities are the Selangor Forestry Department, the Wildlife Department (Selangor) and the Agricultural De- partment, which controls the water level (Havmøller, pers. comm., 1999).

The latest development prior to 1997 was to establish a freeway crossing the NSPSF. It was at an advanced stage when the financial collapse of the Asian economies hit Malaysia in 1997 and abruptly suspended all plans. The original plan had been to cut directly through the forest and divide it in two. Later it was changed to a more reasonable model. It was now planned to run along the western forest fringe, cutting off the edge of the forest area. A freeway is for the moment not scheduled (Havmøller, pers. comm., 1999).

3 An examination of regeneration in The North Selangor Peat Swamp Forest.

2. Introduction and problem analysis

2.1 Location and environment

The tropical country Malaysia is located slightly north of the Equator within the latitudes 1° to 7° North and longitudes 100° to 119° East. Eleven of the thirteen federal states and the Federal Terri- tory of Kuala Lumpur are situated on the Peninsula of Malaysia of approximately 13.2 million ha (FAO, 1997).

The climate is throughout the year humid tropical or wet equatorial with high temperatures and seasonal heavy rain, especially during the Northeast Monsoon, which lasts from Octo- ber/November to February/March (FAO, 1997).

The mean temperatures vary between 27.3° C. and 28.4° C. A distinct seasonal change has not been observed. The mean maximum is 32.2°-33.6° C. The minimum temperature ranges from 21.9°-23.9° C. The mean daily sunlight varies from 5.4 hours in September to 7.3 hours in March (Hahn-Schilling, 1994).

For the whole of Malaysia the average annual rainfall is about 2.540 mm (5.080 mm maximum and 1.650 mm minimum) (FAO, 1997). In Peninsular Malaysia the precipitation from June to Septem- ber is determined by the Southwest monsoon and from December to March by the Northeast monsoon. Months with maximum rainfall are October/November and April/May respectively. It is mostly dry in June/July and January/February (Hahn-Schilling, 1994). The mean monthly relative humidity varies between 74,9% and 79,5%, but there is an increase in the months of May and December due to the seasonal precipitation (Hahn-Schilling, 1994).

2.2 The peat swamp forest

The peat swamp forest (Hutan Paya Gambut) is, “A forest on vegetable matter partly decomposed in wet acid conditions where it forms a brown deposit like soil (Thompson, 1995)”.

4 2. Introduction and problem analysis

The ecosystem is distributed worldwide mainly in South-East Asia where it covers 18.1 million ha. Malaysia contains the second largest area of about 1.5 million ha. In 1990 182,724 ha of the total area were located in Peninsular Malaysia. It is a reduction of 22.6% of the original area, which has been utilized mainly for timber since the beginning of the twentieth century (Hahn-Schilling, 1994 and 1997). The intensity of utilization has been increased over time, especially in the late 1980s and early 1990s. Where the peat depth is low, i.e. maximum two metres, forest clearance is imme- diately ready for agriculture and other development (Hahn-Schilling, 1994), e.g. paddy fields, fish farming and the International Airport of Sepang, which is the largest single excision in recent time (Appanah, 1997).

Figure 2.1. Development of the PSF (Hahn-Schilling, 1994 cf. Driessen & Dudal, 1989).

5 An examination of regeneration in The North Selangor Peat Swamp Forest.

The history of the peat swamp begins about 5,000 years ago with the formation of peat deposits, mainly in flat coastal areas and lagoons behind the mangrove belt or depressions along meandering rivers. At a certain stage alluvial river deposits have blocked the admission of saline and nutrient rich waters to the mangroves and up-river-valleys. Thus nutrients came by air transport (Hahn- Schilling, 1994). The anaerobic and saline conditions prevented the decay of plant debris originat- ing from the mangrove vegetation and a shallow peat layer began to build up. Over time the vegetation changed. The area was colonized from mangrove vegetation by various wet tolerant sedges, ferns and grasses. The decomposition of dead organic matter continued over the following thou- sands of years and finally a homogenous peat swamp forest was created (Hahn-Schilling, 1994 and 1997).

Figure 2.2. A typical forest floor in the NSPSF. Figure 2.3. Decay of organic matter.

Mature peat bogs are usually dome or lens shaped, with a flattened centre representing the eldest development and a relative steep slope towards the fringe. This is because of a decreasing decomposition over time from the fringe towards the centre (Hahn-Schilling, 1994).

The drainage of water takes place mostly along the surface. Since the peat bogs are dome shaped the direction of outflow occur from the centres towards the periphery of these centres. Peat in and around the centre releases a high amount of nutrients, which are washed out in the fringes surrounding the centres that are scattered like rings in the water. Thus the highest diversity and the best growing conditions are found in the peat bog fringes (Hahn-Schilling, 1994).

6 2. Introduction and problem analysis

Peat swamps on the west coast are typically found on clay whereas on the more exposed east coast they are developed on sand (Wyatt-Smith, 1963). The depth of the peat usually varies between 1.5 m to more than 20 m (Hahn-Schilling, 1994). Average thickness in the NSPSF is 4 to 4.5 m (Anonymous, 1997). The peat itself is of very different consistency and decomposition varies. There are undecomposed trunks, branches and roots in the wet, doughy peat (Hahn-Schilling, 1994).

Figure 2.4. Peat depth from forest fringe towards centre (Hahn-Schilling, 1994, altered).

Untouched peat swamp areas have developed a water level independent of the subsoil water. This water lies close to the surface because of the peat’s extraordinary capacity to absorb water. The water level is regulated only by precipitation and drainage from, for example canals, runoff and evaporation (Hahn-Schilling, 1994). The area of the NSPSF receives an average rainfall of 2.300 mm pr. year. Where recharge to ground water makes up 29%, evapotranspiration loss is 65% and runoff is 6%. This is considerably lower than the average for Peninsular Malaysia, which is 2.700 mm pr. year (Yusop et al., 1999). During the monsoon the PSF can be flooded by 50-100 cm of water (Hahn-Schilling, 1994). If drainage leads to a permanent lowering of the water level, water retained in the upper layers of the peat will be lost. The layer will dry out and retain a hydrophobe character and the organic mat-

7 An examination of regeneration in The North Selangor Peat Swamp Forest. ter will begin to shrink and fall apart in a powder-like fashion. Comprehensive drainage, which leads to large-scale aridation of an entire region, poses a risk of erosion (Hahn-Schilling, 1994). Furthermore the aridation of the forest floor leads to an acute fire threat. The peat itself easily burns when dry (Anonymous, 1997). Fire needs three things in order to exist: heat, fuel and oxygen, and all three things are readily available in the PSF (Havmøller, pers. comm., 1999).

The water in a peat swamp usually has low nutrient conditions and a low pH value caused by the humic and fulvic acids that gradually are released by the peat. The tea-like colour of the water has given it the name black water (Hahn-Schilling, 1997). The pH value according to Buch-Andersen & Cold (2000) is pH 3.48-3.99 and pH 3.49-4.09 during the dry and wet season respectively. Min- eral content is low and the Carbon/Nitrogen ratio is high (Hahn-Schilling, 1994).

Hahn-Schilling (1994) summarizes the following characteristics of soil in peat swamp forests: · Depressions contain layers, with water retaining effect · High precipitation (> 2000 mm per year) · Anaerobic conditions due to permanent water logging · Unfavourable decomposition conditions caused by chemical compounds e.g. low pH value, salts, sulfur, polyphenols, fulvic acids and allelopatic secondary compounds.

Some general ecological functions of peat swamp forests: Flood mitigation. Throughout the monsoon the peat swamp absorbs a large amount of water and regulates the flow to the waterways. This minimizes floods in the surrounding Area And it controls the water level in the agricultural areas neighbouring the peat swamp. Paddy fields are especially affected because of the water released during the dry season by the peat swamp (Appanah, 1997). Buffer zone. The PSF prevents saline water intrusion of the freshwater areas. The pressure main- tained by the water of the PSF keeps the separation of the freshwater areas on land and the saline sea intact (Appanah, 1997).

8 2. Introduction and problem analysis

Carbon sink. As much as 100 million tons of CO2 per year are believed to be sequestered from the atmosphere globally by peat swamps (Havmoller, 1997). This is the largest amount of retained organic carbon per ha in the world (Appanah, 1997). In the Peninsular alone the carbon fixation amounts to 940,000 tons of CO2 per year (Anonymous, 1997). Source of wood and non-wood products. Managed according to a multi-use management plan in line with sustainable criteria the forest could become a source of timber and other products (Ku- mari, 1996, Anonymous, 1997). Diversity. The PSF is a rich biodiversity resource with many rare and even endemic species found. This counts for the vegetation as for the fauna (Appanah, 1997). The PSF functions as a gene pool for threatened and endangered species (Hahn-Schilling, 1994).

Figure 2.5. The diversity of flora includes several spe- Figure 2.6. In the forest fringe a proliferation of butter- cies of Nepenthes spp. Commonly distributed in the flies. From the gravel road connecting the test areas. NSPSF, here cf. N. rafflesiana.

Wildlife habitat. Migrant birds winter here on their annual north-south migration. The PSF also functions as a refuge for species who have lost their natural habitat as an effect of development (Hahn-Schilling, 1994). Recreation. The opening and construction of canals that have been established during the last 40 years have led to a new popular activity which is “recreational fishing”. A community of fish has adapted to the extreme black water habitat of the NSPSF. It comprises of 35 species of which 29 species can be found in the forest area (Buch-Andersen & Cold, 2000). An evaluation by Sonder- gaard (1999) points out that almost 60 species occur in the NSPSF. The research of Buch- Andersen & Cold (2000) has shown that the fish biomass in the NSPSF is 125.5 kg/ha and 32.7

9 An examination of regeneration in The North Selangor Peat Swamp Forest. kg/ha during dry and wet seasons respectively. This attracts anglers with fishing rods and nets every weekend along the rivers and canals of the NSPSF.

2.3 Introduction to the research area

The North Selangor Peat Swamp Forest (NSPSF) is today the largest coherent PSF area on the West coast of the Peninsular. It is comprised of the Raja Musa Forest Reserve (36.161 ha) and the Sungai Karang Forest Reserve (36.655 ha) - a total of 72,816 ha. The location is in the northern part of Selangor State about 30 km north of Kuala Selangor, along the southern border of Perak at latitude 3Ε 25'-42' North and longitude 101Ε 05'-27' East bounded by the rivers Sungai Selangor in the south and Sungai Bernam in the north. These rivers were connected in 1957 with an 8-10 m wide canal to provide the paddy fields with a better water supply. In 1966 timber was, for the first time transported along the Tengi River (Hahn-Schilling, 1994) (Figure 2.9).

Figure 2.7. Main canal at noon, N/W direction. Figure 2.8. Main canal in the morning, S/E direction.

Along a Northwest/Southeast direction the PSF covers a distance of circa 45 km. South- west/northeast the distance is circa 25 km (Hahn-Schilling, 1994).

The altitude lies at sea level, but rises along a west-east direction with a slight gradient (1:2000). In the East the peat swamp meets the cape of the Malay mountain range. There altitudes of 200-400 metres exist (Hahn-Schilling, 1994).

10 2. Introduction and problem analysis

Adjacent to the NSPSF lies in the east, the biggest single agricultural investment in the state, i.e. the Integrated Agricultural Development Project (IADP), which is a paddy producing scheme con- solidated in 1978 (Kumari, 1996). To the Northeast lies the Sungai Dusun Wild life Reserve.

The only river that runs through the forest area is the Sungai Tengi. It is connected with the Ber- nam River by an artificial canal referred to as the Feeder canal (Kumari, 1996). The Tengi River emerges in the East and floats in a Southeast direction towards the Melacca Straits through the neighbouring paddy fields.

Figure 2.9. The NSPSF and neighbouring Integrated Agricultural Development Project (IADP) (Based on Hahn- Schilling, 1994 cf. Scott, 1989 and Kumari, 1996).

The situation concerning the continuous preservation of the NSPSF seems for the moment stable. Almost no logging or other exploitation has occurred recently (Hahn-Schilling, 1994).

11 An examination of regeneration in The North Selangor Peat Swamp Forest.

2.4 Logging routine in the NSPSF

Logging in the NSPSF can be traced back as far as 1951, but it is certain that a light form of selective logging has occurred prior to this date (Hahn-Schilling, 1997). The classical “kuda-kuda” extraction method was used in combination with rail transportation when logging operations in the Area Commenced (Hahn-Schilling, 1997). One team of men pulled out the logs while another team placed rafts underneath them to ease the friction (Havmøller, pers. comm., 1999). This excessive labour demanding method has been phased out in the Malay Penin- sular for the last 15-20 years and more efficient methods have found their wayintotheloggingrou- tine (Hahn-Schilling, 1994 and 1997).

Logging in peat swamp forests is different from the procedures followed in dry land forests. The waterlogged nature of the soil cannot withstand the high pressure exerted by logging equipment typically used elsewhere. Therefore special methods are being used in the PSF (Kumari, 1996).

The logging operation consists of two processes: extraction and transportation. The extraction includes the felling and the transfer to a hauling point. Felling is done by chain saw before the log is winched by a so-called traxcavator, which is a modified bulldozer suitable for the work in the PSF (Kumari, 1996 and Anonymous, 1997). Selection and selective felling are considered the only op- tions in the PSF since uniform and clear cutting systems destroy the ecological system completely (Sørensen, 1998). However selective logging also damages the soil conditions and forest regeneration is hampered due to the compression and toppling of vegetation occurring when traxcavators move along the forest floor (Kumari, 1996). From the hauling point the logs are transported to the nearest road system where they are being picked up by trucks for further transport (Kumari, 1996). A network of extraction routes have been established in order to get the logs to the hauling points. It includes extraction trails, railways, canals and roads (Anonymous, 1997). Canals and tramlines are the most preferred mode of transport (Kumari, 1996).

Canals extend from the logsite tothe edge of the forest or tothe nearest river. The loggingteam itself has constructed these canals. A line demarcates where the canal will be, and along that line the

12 2. Introduction and problem analysis peat is dug out and piled along the sides. (Kumari, 1996). The depth is usually 4 m (Anonymous, 1997) where the width varies from 2.4-4.5 m. 4.5-7.6 m when the disturbance includes the peat spill (Kumari, 1996). Tramlines also extend from log site to the forest edge. The logs are being transported along the tramlines on locomotives operated by mini generators. The width of the tracks varies from 0.9-1.2 m. When the spillage on either side is included the width of disturbance is up to 3.5 m. Wood for the tramline is taken from the forest. After use the tracks are normally lifted and used elsewhere (Kumari, 1996).

Compared with canals, the tramlines are less damaging to the forest and drainage patterns are not significantly affected. The tramlines cause local damages where the canals damage the forest and forest floor much more extensively, of- ten irreversible. Regeneration is hence made impossible where canals have been introduced because of the hard treatment. In general tramlines represent lesser problems with regeneration (Kumari, 1996). Constructing canals is about twelve times cheaper than constructing Figure 2.10. Deserted tramline S/E of Area C. tramlines (Cedergren & Ibrahim, 1999). This affects the choice, since the most commonly combination of logging methods is traxcavator and canal. The most sustainable method however is a combination of winch and tramline. In this method the logs are being pulled out to the tramline by a winch and the soil not damaged. The latter method represents the most costly combination, but on the other hand gives the highest total economic value (TEV) in relation to the natural environment (Kumari, 1996).

13 An examination of regeneration in The North Selangor Peat Swamp Forest.

3. Forest structure

Most of the peat swamps of Peninsular Malaysia are found near the sea. The richest forest type, the Mixed Swamp Forest, dominates the community. This is one of six Phasic Communities differen- tiating distinctly in their vegetation composition, physiognomy and structure (Hahn-Schilling, 1994). The mixed Swamp Forest is characterized by Gonystylus bancanus, Dactylocladus stenostachys and Neoscortechinia kingii. This forest type, situated close to the sea, is more distinct than the types found inland. Structure and species diversity in this community is in the most complex form. The average height of trees in the upper storey amounts to 40-45 m. The canopy is relatively open and exposed to wind. Besides the characteristic species others occur frequently. These are Copaif- era palustris, Dryobalanops rappa and five species of the genus Shorea (Hahn-Schilling, 1994).

The PSF is made up by three layers or zones unlike the four layers found in the Lowland Diptero- carp Forest (Appanah, 1997). In the top is the upper storey with the largest trees of up to 45 m (Hahn-Schilling, 1997). This includes the main canopy, which is more open and less dense than the dryland forest. The second layer is the main layer. It is situated below the main canopy. The trees are smaller and reach 30-35 metres (Anonymous, 1997). The third layer, which forms the under storey is of considerable depth. This vegetation reaches a height of 10-20 metres (Anonymous, 1997). The majority of the trees in the NSPSF seem to be found in this layer i.e. beneath a height of 15 m (Sørensen, 1998). The shrub layer is usually quite sparse. The ground flora (i.e., herbs and creepers) is also poor in both species and coverage (Anonymous, 1997; Appanah, 1997 and Wong, pers. comm., 1999).

Since the trees are growing on porous and periodically wet peat, trees are developing a proliferation of buttresses, spreading roots, still roots, knee roots, etc. Pneumatophores (breathing roots) are common (Appanah, 1997). Roots never exceed 90 cm in depth, including roots from emergents. This means there is no contact between vegetation and the nutrient rich mineral soil underlying the peat layer (Hahn-Schilling, 1994).

14 4. Objectives

4. Objectives

The aim of this study is to conduct research in order to examine the regeneration of Calophyllum spp., Cratoxylum arborescens, Gonystylus bancanus, Koompassia malaccensis, Shorea uliginosa and Xylopia fusca. It is relevant because they are among the most utilised and logged timber species that frequentlyoccurred in the PSF. After intensive logging it seems that regeneration is hampered due to changes in the ecological conditions and the lack of seed trees (G. bancanus) (Hahn- Schilling, pers. comm., 1999).

The six target species will form the first category. They are the only timber species to be identified to species level in this study. The second category will be "Other species" which shall include all other species in sight, many of these being very common PSF species. The occurrence of weeds in homogeneous stands is to be examined as well. Weeds in this work are made up of the palm species Cyrtostachys renda, Eleiodoxa conferta and Licuala spp. and by Pandanus spp., which probably are the major threat to regeneration.

15 An examination of regeneration in The North Selangor Peat Swamp Forest.

5. Method & material

Measuring the woody plants at the shrub layer (i.e., seedlings and saplings) give an idea of the overall regeneration of the present plant environment (Hahn-Schilling, 1994). Seedlings are described as woody plants of heights between 0.40 m and 1.30 m whereas saplings have heights above 1.30 m but do not exceed 5 cm dbh. (Hahn-Schilling, 1994 and Anonymous, 1997).

In order to get a picture of the distribution of the two size classes a method using random sampling and statistical formulas was found to be practicable (Weiner, pers. comm., 1999). This method, The Point-Centered Quarter Method (PCQM) uses four parameters: species, distance to centre, diameter at base, and frequency (Mueller-Dombois & Ellenberg, 1974). In order to calculate reliable values of density, dominance and frequency it is necessary to investi- gate 50 plots in each area (Weiner, pers. comm., 1999). Since a plot consists of four quarters each area is attached by a data set of 400, which needs to be collected. The method, its strength and weaknesses are explained below.

5.1 The method

The Point-Centered Quarter Method (PCQM) is a plot less method for vegetation analysis in the field, which builds on a plot less sampling technique (Mueller-Dombois & Ellenberg, 1974).

Four quarters are formed at the sampling point through a cross, made up by two lines. One line points in the transect direction. The other lies perpendicular to the transect direction through the sampling point. The distance to the midpoint of the nearest tree from the sampling point is measured in each quarter (Figure 5.1) (Mueller-Dombois & Ellenberg, 1974).

16 5. Method & material

Figure 5.1. The Point-Centred Quarter Method (Mueller-Dombois & Ellenberg, 1974).

The four distances of the sampling points are averaged and squared. This equals the mean area oc- cupied by each tree (Mueller-Dombois & Ellenberg, 1974).

The accuracy increases with the number of sampling points where 20 is the minimum recommended per stand (Mueller-Dombois & Ellenberg, 1974).

The method has two limitations. An individual must be located within each quarter, and an individual must not be measured twice. Hence stands with wide spacing of individual’s presents a problem, because the method underestimates density in contagiously distributed populations and gives strong overestimates, where distribution seems to be uniform. Expressing data as relative values solves this problem. However this is of course at the expense of information. The unreliabil- ity does not apply to diameter and frequency measurements (Mueller-Dombois & Ellenberg, 1974). To deal with the first limitation only homogeneous stands is measured in practice. Because the 50 sampling points - in all three compartments - were laid along a transect with plenty of space in between, the latter limitation does not seem important in this case.

17 An examination of regeneration in The North Selangor Peat Swamp Forest.

The most important advantage is the time saving aspect, which is considerable compared to plot methods. Furthermore personal errors from judging whether boundary individuals are inside or outside a quadrate is eliminated to a certain extend. And then it is less complicated to applicate the method in the field, where it extracts greater information value per sampling point (Mueller- Dombois & Ellenberg, 1974). The PCQM-method obtains the same four parameters as plot methods: a. Species, b. De