By: Stephen Talania Keu, MSc I .

Oil Palm Plantations are known in most countries for their wide range of environmental impacts.

Land and water contamination, loss of land and resources to local inhabitant and loss of bio-

diversity is some of the perceived environmental impacts brought about by the oil palm plantation cultivation and management. However, to improve one's understanding of Oil Palm plantation it is appropriate to know about the "oil palm" as a vital commodity product for many countries such as Malaysia, Ghana, Indonesia and Papua New Guinea. I examine a paper on "World Fertilizer Use Manual" on which the latter information on oil palm is based. Oil palm (Elaeis guineensis) is the most productive oil producing plant in the world, with one hectare of oil palm producing between 10 and 35 tonnes of FFB per year (New Britain Palm Oil Limited prospectus, 1999). The palm has a life of over 200 years, but the economic life is 20-25 years, (nursery 11-15 months, first harvest is 32-38 months from planting, and peak yield is 5-10 years from planting.

Normally, Oil Palm grows in the lowlands of the humid tropics, 15° N - 15° S with evenly distributed rainfall of 1800-5000 mm/year. The palm has a wide adaptability range of soils, to low pH, but sensitive to high pH (above 7.5), and to stagnant water. Palms are cultivated on large blocks of land with planting density of 128-148 palms per hectare and are largely dependent on the planting materials, soil and climate. Usually the harvested part is the fruit "fruit bunch" whereby oil is obtained from the fleshy mesocarp of fruit. Oil extraction from flesh amounts to at least 45-56% while kernel account of at least 40-50%.. The palm has a highly varied nutrient demand which depends mainly on the yield potential determined by the genetic make-up of the planting material and on yield limit set by climatic factors such as water, effective sunshine and temperature. In recognition and facilitation of this varied demand, usually large quantities of fertilizer are required. This has a detrimental impact on the environment specifically soil and vegetation..

Pesticides & herbicide are extensively used for weed and pest suppression with the objective to maximize crop yield. Environmental and ecological factors are often negligible. Oil palm has been cultivated in Papua New Guinea for the past 31 years, as compared to countries such as Malaysia and Indonesia where the crop has been suitable for agricultural industry for more than 80 years. This review report is geared towards enhancement of the necessary knowledge to be acquired by the author in relation to the impact of oil palm plantation cultivation. It should be noted that not much emphasis is placed on socio-economic impact as on physical impact, which is the core subject of this report.. A detailed mentioned of soil erosion has been included

Introduction

This review paper is written as part of the preparatory work leading to a Masters Thesis to be compiled by the author as a requirement of a Masters Program offered at the Faculty of Horticulture, Chiba University. It is aimed at the collection of relevant information relating to the various environmental impacts brought about by the cultivation of the oil palm plantation through review of previous similar studies. However, oil palm plantations as perceived by many, are an increasing problem for people and the environment in most countries. For instance, In Indonesia, already 3.2 million hectares of land have been allocated for oil palm plantations, mainly in the Sumatra area . This has resulted in numerous negative environmental impacts, particularly loss of land to indigenous people, their livelihood, the national economy and various other social problems. In Papua New Guinea, particularly in the North/West Parts of New Britain island, oil palm has been promoted as a supplement crop to coconut and cocoa which has resulted in large areas of land being occupied by mono cultured plantations. Due to the PNG government's promotion of oil palm as a crop that can earn foreign exchange, palms are increasingly cultivated in other parts of Papua New Guinea: in New Ireland, Milne Bay, Oro and West Sepik provinces In Malaysia oil palm played an essential role in government policy aimed at reducing poverty as well as income disparities between ethnic groups since 1960. However, by 1975, crude oil palm had become the country's worst source of water pollution, particularly organic waste products and this has been the case at present in New Britain, Papua New Guinea. In Ghana, loss of land was seen to be the major impacts that occurred to the local population. Soil loss has been identified as a major impact derived by the oil palm plantation establishment. However on the world scale oil palm production has since increased which implies more virgin forest area were greatly reduced. Figure 1 shows oil palm production by countries from 1992-1998.

Figure 1.0

Reproduced from data obtained from New Britain Palm Oil Prospectus

In this review report an attempt is made to state possible impacts resulting from oil palm plantation establishment. It covers topics on general biophysical impacts such as soil erosion, pests and insect invasion problems, oil palm waste products, effects of mill effluents and floral diversity. Much emphasis is placed on discussing soil erosion since it is the focus of my research into the impacts of oil palm plantations in Papua New Guinea in order to gain an adequate insight on the subject of soil erosion.

1.0 The Loss of resources and land for indigenous people

The biophysical impacts that are caused by oil palm cultivation can be significant and damaging. As such I examine a study by Gyasi (1987) which relates to the environmental impact and sustainability of plantations in Sub-Saharan Africa: Ghana's experience with oil-palm plantation. In that study, (Gyasi, 1987) points out the likely significant impacts of the extensive growth of mono-cultured systems such as oil palm would have on the environment and its living conditions, particularly in the wake of increasing population pressure and attendant diminishing supplies of land, the basic source of livelihood in Sub-Saharan Africa.

However, in a paper (unpublished, by author here in) written as an information base on the environmental implication of oil palm influences on people and their resources. For instance, in New Britain of Papua New Guinea the local indigenous people still depend on the forest land and rivers for their daily living. The indigenous population is traditionally oriented in that they perceived regular activities such as fishing, hunting and gathering as an activity that provides subsistence food sources. Most people in oil palm producing provinces live on coastal fringes and depend on the streams and river systems, which originate from inland where oil palm plantations have been established. When plantations are next to a native village, the indigenous population is faced with numerous difficulties. Loss of resources will incur to the indigenous population in various forms such as scarce building material supplies, land shortage, pollution and contamination of land and water bodies, loss of recreational activities and various other social and physical impacts. Obviously, land taken up by oil palm cultivation will not be returned for subsistence farming due to unavailability of sufficient nutrient supplies. Normally the value of land gradually disappears and its revitalization period is long thus making the landholders wait to use land for other agricultural purpose.

In addition, in New Britain of Papua New Guinea (specifically the Talasea area), loss of land and natural resources to the local indigenous population was the primary reason for land disputes. Moreover, there is a great possibility for increase in the future plantation developments on New Britain island. An approximate area of 31,000 hectares is presently under oil palm plantations. The existing and proposed plantation areas in New Britain excluding those that are owned by individual landlords and other major oil palm enterprises are shown in table 1.0, which indicates only those that belong to New Britain Palm Oil Limited.

Table 1.0 Existing Oil Palm Plantation areas managed and owned by New Britain Palm Oil Limited in Papua New Guinea.

Plantation	Mature Palms (ha)	Immature palms (ha)	Future Plantings (ha)	Total palm Area (ha)	Housing & Roads (ha)	Reserves & Nurseries (ha)	Copra & pasture (ha)	Unusable (ha)	Total (ha)
Mosa Leases
Bebere	2,445			2,445	214	20		468	3,147
Kumbango	2,047	262		2,309	118	4		305	2,736
Togulo	1,316			1,316	87			306	1,709
Dami	352	18		370	37	2		22	431
Kapiura Leases
Bilomi	2,035			2,035	97	6		543	2,681
Kaurausu	1,681	173		1,854	116			351	2,321
Kautu	2,712	232	5	2,949	180	10		1,142	4,281
Malilimi	2,363	13		2,376	182			767	3,325
Numondo Leases
Garu	868	1694		2,562	96			1,052	3,710
Haella	1,751	700		2,461	177	20	14	776	3,438
Numondo	478		200	678	44	3	882	641	2,248
Leases Total	18,049	3,092	205	21,345	1,348	65	896	6,373	30,027
Sub Leases
Moroa			800	800				100	900
Tili			600	600					600
Walindi		145		145	12			27	184
Sub Leases total			1,400	1,545	12			127	1,684
Overall Total	18,048	3,237	1,605	22,890	1,360	65	896	6,500	31,711

Source: New Britain Oil palm Limited Prospectus, 1998

It was ascertained that the most adverse impact of Oil Palm Plantation development is the rapid transformation of the forest ecosystem and its resilient diversified ecologically based traditional economy into vulnerable artificial mono-culture system (Gyasi, 1989). The study also indicates that the mono-cultural palms are susceptible to insect pests and diseases, an agro-ecological problem most vividly demonstrated by the unusually massive and destructive insect invasion of the farms. The study did not explore areas relating to the status of the soil physical properties and including that of flora diversity status.

2.0 Soil erosion impacts and water pollution

Before discussing soil erosion impacts, I consider some basic physical phenomena associated with erosion. Erosion is a three-step process (Daniel Hillel, 1998). It consists of (1) detachment (or entrainment) of particles from the soil surface, (2) down current of down wind movement of the detached particles a stage known as over or along the surface and (3) deposition of the transported particles, a stage known as sedimentation. The process of particles detachment and transport are in reality very complex, complicated by numerous factors-- usually under natural conditions -- including variable sizes, shapes, spatial distributions, bonding of soil particles, variable roughness, slope of surface. This is the main consideration for soil erosion parameters to be determined experimentally (Daniel Hillel, 1998). Thus, the actual amount of erosion depends as much on the erodibility of the soil as it does on the erosivity of the rain (Luk, 1979 in Hillel, 1998). The erodibility of a soil (i.e., its vulnerability to the erosivity of rain or of running water) depends on many factors (Meyer and Harmon, 1984 in Hillel, 1998). Prominent among these factors are the texture (Stern et al., 1991) and structure of the soil (Moore and Singer, 1990).

In his book titled "Environmental Soil Physics" Daniel Hillel notes that the erosion process is an inevitable part of the natural geological cycle by which land areas are alternately lifted by tectonic forces and then gradually worn down by rain and wind. Apparently, this slow rate of geological erosion is greatly accelerated by human activity, especially by the practice of agriculture. In this paper, we discuss oil palm cultivation and management as a cause of erosion and loss of soil. In a broader context, where agriculture is practiced unsustainably and without due regard to soil conservation, it sets into motion a process of soil degradation such as the rapid decomposition of unreplenished organic matter, depletion of nutrient, breakdown of aggregates and of structural stability, crusting, compaction and erosion by water and wind (Morgan, 1986; El Swaify et al., 1985; Lal, 1994 in Hillel, 1998).

The erosion results not only in loss of productivity on sites where it occurs but also in the off-site deposition of sediments that may pollute (eutrophy) surface and underground water resources as well as clog streams, reservoirs, and estuaries. This has been evident in the oil palm plantation areas in New Britain, Papua New Guinea (personal visual observations). Additionally, the erosion process is also a major transport mechanism for agricultural chemicals, significant amounts of which do not remain where they are applied but spread into a larger environment (Hill et al., 1991 in Hillel 1998).

Fundamentally, agriculture consists of removing an area's natural vegetation and introducing in its stead a selection of domesticated and specialized plants, called crops as in the case of oil palm plantations. The very act of eradicating the native vegetation and of baring and pulverizing the soil so as to make it receptive to planted crops renders the soil much more vulnerable to erosion (Freeze, 1980). Most vulnerable is the soil's top layer, which is generally the soil most fertile horizon (being the richest in decomposing, nutrient-releasing plant and animal residues). Moreover the loss of top soil requires farmers to use increasing amounts of fertilizers by way of compensation for the reduced natural fertility, and the increased application of such chemicals itself exacerbates the hazard of groundwater and surface water pollution (Williams, 1991).

Specific to agriculture, a study by Sonneveld et al (1997) reported that the prevailing form of human-induced land degradation in the agriculture areas of developing countries is water erosion. Water erosion occurs when land use does not offer sufficient protection to the soil against the impact of rain and superficial runoff. Soil losses through water erosion are prevalent in the oil palm plantation areas in Papua New Guinea (from my personal visual observation). Similarly, in a study conducted by the Tropical Forest research Institute of India concluded that severely degraded land are topically characterized by eroded or nutrient deficient soils, hydrological instability, reduced primary productivity and low bio-diversity. In addition, persistent physical, chemical and biological barriers-- such as low propagule availability, seed predation, non availability of suitable micro-habitats for plant establishment, low soil nutrients availability, absence of obligate or facultative fungal or bacterial root sybionts, seedling predation seasonal droughts etc. -- often prevent natural succession process from operating within a time scale compatible with short and medium -term human needs.

According to Kristof Van Oost et al (1999), soil erosion has been recognized as the major soil degradation process since it adversely affects soil quality by reducing infiltration rates, water holding capacities, nutrients, organic matter, soil biota and depth. As such, soil, erosion causes a reduction of soil productivity and a significant ecological damage by depleting soil bio-diversity and affecting plant composition. He points out that the areas with the steepest slopes have the highest erosion rates, obviously attributed to the slope gradients, which are the major controlling factor. Also in many developing countries soil erosion is considerable, often involving loss of more than 50 or even 100 tons per hectare per year on intensively cultivated land (Jan de Graaff, Soil Conservation and sustainable land use, 1993). In an Oil Palm Plantation, regular contouring during ground preparation that is excavation, road building, and contouring terracing, has resulted in bare soil being exposed to heat, wind and rain droplets. Consequently, losses of topsoil are imminent. In addition a study by Pieter Bleeker, 1983 documents the soil erodibility risk of the major soil groups in PNG are listed table 2.0.

Table 2: Provisional grouping of some major soil groups according to their soil erodibility risk for Papua New Guinea Soils. (After: Peter Bleeker in Soils of Papua New Guinea, 1983)

Great Soil Group	Hydrandepts Humitropepts Dystrandepts Vitrandepts	Rendolls Hapludolls Argiudolls Rhodudalfs Rhodustaffs Psammaquents Tropopsamments Tropohumults Plinthohumults	Tropudalfs Dystropepts Eutropepts Troporthents Fluvaquents Tropfluvents Hydraquents Tropaquepts Tropaqualfs	Pelluderts Pellusterts Plinthaquults Plinthaqualfs Albaquults Plinthudults
Soil Erodibility risk	Very low	Low	Moderate	High
	Soils with very high to high organic matter contents and moderate to rapid permeability's. Granular to fine crumby surface horizons; some lowland Andepts may have moderate very fine sand plus silt contents.	Except for sandy Entisol, these soils have moderate organic matter contents and moderate permeability. Sandy Entisols have generally low organic contents, are rapidly permeable and structure -less (single grain). Entisols often have moderate very fine sand plus silt contents.	Generally slowly permeable soils with moderate organic matter contents are massive and may have moderate very fine sand plus silt contents.	Vertisols; Very slowly permeable, often subject to surface scaling and having prismatic or coarse blocky structures, but moderate organic matter contents. Ultisols and Alfisols; generally relatively low organic matter contents and relatively high very find sand plus silt contents. Poorly structured surface horizons.

Constant destruction of primary forest cover and continuous cropping have significantly impaired the hydrological equillibria and triggered massive topsoil erosion (Samsuzzaman et al, 1999). The objective of the study was to determine the effects of management and hedgerow species on soil properties. Thus, it was ascertained that such destruction leads to the decline in soil fertility and, thereby, crop yields. Moreover, soil bulk density was significantly reduced by the application of Cassia pruning after 12 months (Samsuzzaman et al, 1999). Furthermore, severe erosion of soil has many ecological impacts, including (1) the loss of mineral soil substrate, which in severe cases can expose bedrock; (2) the loss of soil nutrient capital: and (3) secondary effects on aquatic systems, including siltation, flooding hazard, and the destruction of fish habitat (Freedman 1989). In a study by the University of Amsterdam indicated, that soil erosion rate can be quite considerable in relatively small, highly affected watershed areas, which is a classic case of the Seat, Konto, Blue mountains in Jamaica. However in 1983 Food and Agricultural Organization (FAO)/ United Nations Environment Programme (UNEP) study distinguished the following categories, with their immediate causes and determining factors;

· Soil erosion by water, including sheet and rill erosion, which can be amended through cultivation practices, and gully erosion, is too severe to be stopped in this way. Topsoil is particularly affected, and fertility losses are disproportionately high in relation to physical soil losses. Determining factors or control variables are:

-rainfall (erosivity)

-vegetation cover;

-topography;

-soil (erodibility);

-Orientation and aspect (sun/shade).

· Soil erosion by wind, in which finer and more fertile particles are particularly likely to be blown away, creating a high impact on fertility.

· Soil mining, or cultivation without adding chemical or natural fertilizers in quantities sufficient to make up for nutrient losses, hence causing gradual loss of fertility.

· Salinity following long term irrigation, in which case reverse osmosis may occur due to accumulation of salts.

· Leaching, or washing away of nutrients needed by crops, into ground water or with runoff. Fertility declines and/or acidity increases, and in some cases toxic effects appear.

· Tonicities and pollution from industrial or city wastes, brought in via the atmosphere or drainage water.

· Biological degradation through reduction of vegetation and subsequent loss of humus and soil organisms. Other forms of biological degradation include infestations of weeds, such as (Imperata cylindrica) and parasitic plants Striga spp.

· Physical degradation, in particular as a result of the soil compaction that occurs due to the pounding by rainfall and runoff.

The GLASOD (Global Assessment of Soil Degradation) project, a collaboration project between UNEP and ISRIC (International Soil Reference and Information Center), on the other hand, distinguished 12 types of soil degradation, under four headings; water erosion, wind erosion, chemical deterioration and physical deterioration (Oldeman et al., 1990).

· Energy factors; rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length and slope shortening, and length and shortening of wind fetch

· resistance factors; soil erodibility, infiltration capacity and soil management;

· Protection factors; population density, plant cover, amenity value (pressure for use) and land management

1.1 The "UNIVERSAL SOIL LOSS EQUATION" (USLE).

Ever since its inception in 1976 by the USDA, the Universal Soil Loss Equation devised by (Wischmeier, 1959.; Wischmeier and Smith, 1960; Wischmeier,1976; Wischmeier and Smith, 1978), has been applied widely to agricultural lands in many countries and across the United States. This formula is worth examining as it is vital for the forthcoming research into soil losses in the oil palm plantation areas in Papua New Guinea including that of the natural forests. Incidentally, the equation has been applied by the (CSIRO) to estimate soil losses at least on a broader scale in Papua New Guinea. . However, the equation is considered empirical (Hillel, 1998) which implies simplicity and available for immediate applications. It is used to estimate average annual soil losses in metric tones per hectare. The USLE was originally proposed for estimating sheet and rill erosion losses from cultivated fields in the United States for range lands and forest lands as well as agricultural land. It is equated as;

A = R X K X L X S X C X P

Where A represents the computed soil loss per unit area, R the rainfall and runoff, K the soil erodibility, L the slope length, S the slope steepness, C the cover and management factor and P the support practice factor. The original formulation has been revised (El Swaify et al., 1985; McCool et al., 1989; Renard, 1991; Lal 1995; Post, 1996). The formula has been criticized by Daniel Hillel, 1998 for its simplicity and because it remains largely empirical. He further stated that in general terms erosion is not a steady , orderly, easily predictable process. Much of it takes place episodically, in rare but violent events. Hikaru et al., 2000, in their research into the application of the USLE to mountainous forests in Japan concluded that USLE could be successfully applied to the mountain forests area of Japan. It may be possible to apply this equation to different land use types and oil palm plantation areas including that of natural forest. An application of the USLE for soils in Papua New Guinea are detailed in Pieter Bleeker, 1993 (Soils of Papua New Guinea) with two preliminary initial experiments in two different provinces, Chimbu and Mendi for sweet potato cultivation. Preliminary results of these studies are indicated in the following tables.

Table 3: Soil losses (tonnes/ha/yr) with slope and vegetation cover near Kundiawa, Chimbu Province (after Humphreys unpublished data) in Soils of PNG by Pieter Bleeker.

Plot size (m2)	% Veg. Cover	Number of plots	Average slope (degrees)	Soil losses (tonnes/ha/year)
Bare plots
2	0	4	9.9	9.7
2	0	3	15.7	12.6
2	0	6	20.3	17.3
2	0	2	29	47.7
2	0	2	35	64.7
2	0	3	42	62
Fallow plots
2	>50	3	8	1.8
2	>50	3	13.2	2.2
2	>50	3	17.2	3.6
2	>50	5	20.8	3.2
2	>50	4	34.3	3.1
2	>50	2	44	4.6
Garden Plots
244		1	11	15.3
135		1	11.9	5.4
104		1	12.1	8.8
169		1	12.7	5.5
95		1	14.1	8.7
1375		1	20	28.4

2.2 Soil Chemistry Characteristics in Oil Palm Plantation.

The physical and chemical properties and organic matter content of the soil in an oil palm plantation was assessed 40 years after forest clearing by Kabrah et al., 2000. In that study it was indicated that the clay content of the top soil layer (0-20cm) was 35% less than that of the soil in forested areas, while the exchangeable aluminium content and pH were similar and the aluminium toxicity risk was fourfold higher. Phosphorous, nitrogen and total carbon levels were also markedly lower in the oil palm plantation as compared to the forest. Organic matter was the main factor determining the unfavorable change in soil properties, leading to a marked deficiency in most nutrients

3.0 Oil Palm Waste Products

There are many waste products that are generated by the oil palm processing mills. Tthe most common one is the empty fruit bunch. The empty bunch is a solid waste product of the oil palm milling process and has a high moisture content of approximately 55-65% and a high silica content, from 25% of the total palm fruit bunch (Noel Wambeck, 1999). The treated empty bunches are mechanically crushed (de-watered and de-oiled) in the process but are rich in major nutrients and contained reasonable amounts of trace elements. They have a value when returned to the field to be applied as mulch for the enrichment of soil. However, it was noted that over application of the effluent must be avoided as it may result in anaerobic conditions in the soil by formation of an impervious coat of organic matter on the soil surface (Noel Wambeck, 1999).

4.0 Effects of oil palm mill effluent.

Of the numerous negative effects of the mill effluent discharges there are advantages which relate to the yield increase in oil palm production. The application of empty fruit bunch adds nutrient value to the soil especially the (NPK) nitrogen, phosphorus, potassium and magnesium values.

Air emission from the oil palm mills are from the boilers and incinerators, and are mainly gases with particulates such as tar and soot droplets of 20-100 microns and a dust load of about 3000 to 4000 mg/NM. Incomplete combustion of the boiler and incinerator produces dark smoke resulting from burning a mixture of solid waste fuels such as shell, fiber and sometimes empty bunches.

The oil palm mills generate many by-products and liquid wastes that may have a significant impact on the environment if they are not dealt with properly.

Wastewater is discharged from the palm oil extraction, by wet process, normally from the oil room. For instance, pollutant loads in wastewater discharged in four oil mills in Malaysia are as shown in table 2.0.

Table 2.0 Average pollution load in Wastewater discharged from four Oil Palm Mills in Malaysia.

Mills	Working Hours	FFB (tons)	Effluent flow (m3/h)	Effluent/FFB (m3/t FFB)	COD (Kg/t FFB)	BOD (Kg/ton FFB)
Apa	19.56	464.60	10.05	0.44	47.51	25.88
SPb	17.60	437.53	21.53	0.94	62.54	27.59
Upc	24.00	220.00	10.79	1.18	47.81	26.62
UPOc	15.58	414.67	22.37	0.90	51.93	26.24
Mean	19.26	384.20	16.19	0.87	52.54	26.58
Std deviation	3.03	96.43	6.67	0.27	6.08	0.64

After: A.H-Kittikun., et al. Department of Industrial Biotechnology, Faculty of Agro-Industry Prince of Songkla University, Hat Yai, Thailand.

5.0 The influences of anaerobic & aerobic effluent treatment system.

The effluent is not toxic but it has a biochemical oxygen demand of above 25,000 (BOD) which makes it objectionable to aquatic life when introduced in relatively large quantities in waterways and rivers.

6.0 Plantation influences on flora diversity.

One of the obvious impacts appearing during the growth development of the palm is the decrease in the ground cover vegetative growth. This is due to the increase in shade conditions directly resulting from overlapping leaf structure. This situation causes a reduction not only in the number of species of plants but also in the individual species (Ramon G. et al. 1999, ASD Oil Palm Papers No. 19, 1-22). For instance, many bushy melliferous species slowly disappear during weed control process, as they are not able to recover or compete with shade tolerant species. According to the latter report, the author sited an outbreak of pest arthropods that can be an acute or chronic problem. He argues that the reason for the increases in the pest population can be linked with the following factors:

Ø drastic change in the physical environment

Ø genetic or physiological changes in individual organisms in the population

Ø trophic interactions between plants and herbivores or prey and predators.

Ø qualitative or quantitative changes in the host plants, caused by conditions of stress (water de flooding, nutritional imbalances, etc.)

Ø particular strategies in the life history of opportunistic insect species (strategy "r")

Ø escape of pest populations from the influence of their natural enemies

Ø cooperation of various species to undermine the defense system of the host.

Odum (1953), Mac Arthur (1955) and Elton (1958) supported the hypothesis about stability vs. diversity, which indicates that an increase in the diversity of species in ecosystem increases its stability. The authors based their theory on the criteria that a food chain made up of many species is able to withstand more changes in the abundance of individual species than a simple chain. In this sense, the diversity of species is a form of structural complexity that provides stability to the ecosystem. This is the unlikely factor or is absent with the oil palm plantation areas in New Britain of Papua New Guinea...

7.0 Insects and pests attracted to Oil Palm Plantations.

Most insect pests in the oil palm are defoliating lepidopterans such as, Oiketicus kirbyl Guilding, Opsiphanes cassina F., Sibine megasooides Walkers (=(Acharia hyperoche Dognin), Stenoma cecropia Meyrick, Euprosterna eleasa Dyar and Natada pos. michorta Dyar (Mexzon and Chinchilla, 19992 in ASD Oil Palm Papers No. 19, 1-22, 1999). The report indicated that these species rarely flourish on young plantations due to the abundant entomophagous fauna. In adult palms, however, significant defoliations may occur, which are associated with the scarcity of the natural enemies (Genty 1989; Mexzon 1994b in ASD Oil Palm Papers No. 19, 1-22, 1999). Apparently, monocrop systems limit vegetative density, which reduces sources of food and shelter for phytophagous organisms and natural enemies (De Loach 1970). This, in turn, gives rise to increased damage by insect pests. This latter is an impact that is an ultimate result of removing hosts plants that were available for pests. Pests, insects and diseases have the potential to infest large areas in a short span of time in a monocrop area.

Additionally, Lawton & Schroeder (1977) and Strong & Levin (1979) considered plant size to be an important predictor of diversity. They recognized trees, bushes and grasses as the three main groups that differ in structural complexity and diversity of associated insects. Plants in early stages of development house a lesser number of insect species than those in later stages. Also bushes with dense foliage house a greater number of insect species than plants with sparse foliage or with smaller leaves (Mexzon 1992) in ASD Oil Palm Papers No. 191-22, 1999.

8.0 Conclusion

In this review I have attempt to highlight all the different impacts of the cultivation of oil palm plantations. However, due to the uncertainty of the various impacts, it will be a tedious task to mention and write about them all. It is my view that study of impacts of such large monocultured agro-based plantations can be categorized or narrowed down to (a) Biophysical, (b) Socio-economic and (c) chemical impacts. Ecological impact is the focus of the present study which is related to other studies carried out in countries where oil palm has been grown but soil erosion and vegetation impacts in oil palm plantation are often negligible. Oil palm plantation cultivation generates perceived impacts on almost all the different components of the environment and people. Soil becomes vulnerable to water and other forms of erosions thus rendering its loss. Pollution of the receiving water bodies and including land contamination are the issues which need further scrutiny by any potential developers of a palm plantation. Soil conservation methods need to be applied in areas of high slopes to protect soil losses.

List of reports cited

§ The Environmental impact and sustainability of plantations Sub-Saharan Africa; Ghana's experience with oil-palm plantation A report by Edwin A.G. (1982), University of Ghana, published ASD Oil Palm papers, N14,7-6, 1996.

§ Moisture content/relative humidity equilibrium of oil palm (Elaeis guinensis) kernels produced in Costa Rica, By Ronald Jimenez, Manuel Zeledon, Ramiro Alizaga (1995). Published in ASD Oil Palm Papers No. 10, 16-26, 1995.

§ New Technologies for plantation crop improvement. By Hereward Corley (1999), Silsoe, Bedford.

§ Oil Palms and Sarawak Forests by Paige Fisher and Harlan Thompson (1989), Earth Island Institute , Earth Island Journal -Fall 1999.

§ Measures for integrating Environmental Considerations into Agriculture (Paper by Malaysia's Department of Environment and Conservation, 1998).

§ Plant species attractive to beneficial entomofaunin Oil palm (Elaeis guinenesis Jacq) plantations in Costa Rica. Published in ASD Oil Palm papers No 19, 1-22 1999.

§ Standards form Oil Pam fibre, Malaysia by Sirim Berhad (1998)

§ An introduction to refining process for Palm Oil and other downstream process by Noel Wambeck (1997). A paper downloaded from Internet Web page).

§ Controlling Regrowths of Chromolaena odorata (L) R.M. King and H. Robinson, using Herbicide mixtures in Young Oil Palm Plantation in Nigeria by Utlu, .S.N., (1999), Nigerian Institute for Oil palm (NIFOR) Benin City, Nigeria.

§ Food Uses of Palm Oil in Japan (Paper downloaded from Internet web page) by Hiroyuki Mori and Takashi Kaneda (1999).

§ Impact of plantations in degraded land on diversity of ground flora, soil microflora and fauna and chemical properties of soil. By Verma R.K et al (1999). Tropical Forest research Institute, P.O. - RFRC, Mandla road, Jabalpur 482 021, India., Tropical Ecology Jnl 40 (2): 101-197, 1999.

§ Food uses of palm oil in China, (Paper downloaded from Internet web page) by Fan Weuxun and Chen Xiaoshu (1999).

§ Evaluating the impact of the changes in the landscape structure on soil erosion by water and tillage, by Kristof Van Oast etal ( 1999)., Laboratory for Experimental Geomorphology, K.U. Leuven, B-300 Leuven, Belgium. (Published in the Journals of Landscape Ecology 15:577-589, 2000, Kluwer Academic Publishers, Printed in Netherlands).

§ Soil property changes in contour hedgerow systems on sloping land in the Philippines by Samsuzzaman. S., et al (1999). (Published in the Journals of Agroforestry Systems 46: 251 - 272, 1999, Kluwer Academic Publishers, Printed in Netherlands).

§ Application of the Universal Soil Loss Equation (USLE) to mountainous Forests in Japan by Hikaru Kitahara et al., (2000). Faculty of Agriculture, Shinshu University, Nagano 399-4598, Japan (Published in the Journals of Forest Research Vol. 5 No. 4 of 2000, The Japanese Forestry Society.

References (Books)

Agriculture, Pesticides and the Environment Policy Options OECD (1997), Published by the Centre Francais d' exploitation du droit de copie (CFC), 20 rue des Grands-Augustins, 75006 Paris, France.

Bein,. R.F.L, (1999) The Bio-diversity Inventory; A case study of the Kamilai Wildlife Management Area. Paper published in "Environment Papua New Guinea" by Environmental Research and Management Center PNG University of Technology, LAE.

Bill, F., (1989). ENVIRONMENTAL ECOLOGY, The impacts of pollution and other stresses on ecosystem structure and function, Department of Biology and School of Resource and Environmental Studies, Dalhousie University, Halifax, Nova Scotia, Canada.

Collin., P.,H., (1988). Dictionary of Ecology and the Environment. Published by Richard Clay Ltd, Bungay, Suffolk, Great Britain.

Filer with Sekhran (1998) Loggers, Donors and resource owners ( policy that works for forests and people, Papua New Guinea, National Research Institute, Port Moresby and International Institute for Environment and Development, London.

Stephen R. Gliessman (1989) Ecological Studies 78, Agro-ecology, Researching the Ecological Basis for Sustainable Agriculture: University of California, Santa Cruz, California.

Hereward Corley (2000) New technologies for plantation crop improvement., Cranfield University, Silsoe, Bedford.

Jan de Graaff., (1993) Soil conservation and sustainable land use: an economic approach. (Development oriented research in Agriculture;4) Royal Tropical Institute - Amsterdam.

Pieter Bleeker (1983) Soils of Papua New Guinea., The Commonwealth Scientific and Industrial research Organization in association the Australian National University, Canberra.

Daniel Hillel., (1998) Environmental Soil Physics, University of Massachusetts, Amberst, Massachusetts., Academic press, a division of Harcourt Brace & Company, San Diego.

Eyre S.R. (1962) Vegetation and Soils 2nd Edition., University of Leeds., The Camelot Press Ltd., London and Southampton.

FitzPatrick E.A. (1980) SOILS, Their formation, classification and distribution., University of Aberdeen. (Published in the United States of America by Longman Inc. New York).

Bellamy J.A. and McAlphine J.R (1995) Papua New Guinea Inventory of the Natural Resources, Population Distribution and Land Use handbook 2nd Edition, (PNGRIS Publication No.6)., Commonwealth Scientific and Industrial Research Organization for the Australian Agency for International Development.

Soil Taxonomy. Review and Use in the Asian Pacific Region (1985) ., Food and Fertilizer Technology Centre for the Asian and Pacific Region., Agriculture building, 14 We Chow Street, Taipei Taiwan, Republic of China.

New Britain Palm Oil Limited Prospectus, distributed in 1999 for the offer of 96,000,000 Shares by Macquarie Equity capital markets limited.

Acronyms:

PNG. Papua New Guinea

WNBP West New Britain Province

NBPOL New Britain Palm Oil Limited

FFB Fresh Fruit Bunch

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