Effects of monoculture and polyculture farming in oil palm 
smallholdings on terrestrial arthropod diversity
AMAL GHAZALI1, SITI ASMAH1, MUHAMMAD SYAFIQ1, MUHAMMAD S. YAHYA1, NAJJIB AZIZ2, 
TAN LI PENG3, AHMAD R. NORHISHAM1,4, CHONG LEONG PUAN1,5, EDGAR C. TURNER6, BADRUL 
AZHAR1,5
1Department of Forest Management, Faculty of Forestry, Universiti Putra Malaysia, Serdang
2School of Land and Food, University of Tasmania, Tasmania 7001, Australia
3Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, 16100 Pengkalan Chepa, 
Kelantan, Malaysia
4Cardiff School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
5Biodiversity Unit, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, 
Malaysia
6Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2
3EJ, UK
Corresponding author. E-mail address: b_azhar@upm.edu.my (B. Azhar), telephone (Office): 
+60389467206, fax: +60389432514.
Abstract 
Oil palm agriculture has become one of the economic mainstays for biodiversity-rich countries 
in the tropics. The conversion of native forests to oil palm monoculture plantation has caused 
unprecedented biodiversity loss in Southeast Asia. Little is known about the effects of oil palm 
polyculture farming on arthropod diversity.  In this study, arthropods were sampled using pitfall 
traps at 120 sites in Peninsular Malaysia. We examined how arthropod biodiversity responded 
to different oil palm farming practices and local-scale vegetation structure characteristics. We 
found that the number of arthropod orders was significantly greater in polyculture than 
monoculture smallholdings. However, we did not detect a significant difference in arthropod 
order composition nor abundance between monoculture and polyculture practices. In situ 
1
habitat characteristics explained 16% of the variation in arthropod order richness, with key 
predictor variables including farming practice, height of oil palm stands, and number of 
immature palms. The findings of this study suggest that polyculture farming together with 
management for in situ habitat complexity may be a useful strategy in supporting biodiversity 
within in oil palm plantations.
Keywords
 Arthropods; Diversity; Habitat characteristics; Farming practice; Oil palm smallholdings
Introduction
Arthropods including insects, are the most numerous phylum on Earth and represent more than
80% of global species richness (Wilson, 1992). They are also responsible for a wide range of 
important ecosystem functions, including biological control of pests (Letourneau et al., 2009) 
and pollination, both in natural habitats and in agricultural landscapes (Thiele, 2005; Klein et al.,
2007; Ramirez et al., 2010). In agro-ecosystems, these arthropods also aid in decomposition of 
organic matter in soil (Ahmad & Ahmad, 2009)  and at the same time are food source for their 
natural predators (Greenberg et al., 2000). However, intensively managed agriculture (e.g. 
monoculture oil palm plantations) could significantly reduce arthropod biodiversity in 
comparison to the native forests (Bruhl & Eltz, 2010; Luke et al., 2014).
Conversion of natural forests into agricultural lands is currently one of the major threats to 
global biodiversity (Ewers et al., 2009) and represents a major conservation challenge. Over the 
past few decades, oil palm (Elaeis guineensis Jacq.) has become one of the most rapidly 
expanding tropical crops in the world (Clay, 2004; Koh & Wilcove, 2007). Vast areas of natural 
forests have been converted to commercial plantations, and the crop makes a substantial 
contribution to the economy of producing countries (Koh & Wilcove, 2007). This is particularly 
true in Malaysia, with the country currently producing 39% of the world’s palm oil production 
and 44% of world’s export (MPOC, 2014). Within Malaysia, the State of Sabah contains the 
biggest oil palm plantation area, accounting for around 29% of total oil palm plantation area in 
Malaysia (MPOB, 2015). 
2
The large scale expansion of oil palm monoculture plantations has raised concerns about the
impacts of oil palm expansion on biodiversity. Thus, it has reduced species richness and 
abundance in terms of biodiversity (Fitzherbert et al., 2008; Danielsen et al., 2009; Foster et al., 
2011). For example, compared to forest, oil palm plantations have been found to contain a 
lower species richness of butterfly and birds (Koh & Wilcove, 2008) and ground-dwelling ants 
(Fayle et al., 2010). Protecting forest biodiversity from the ecological impact of oil palm 
expansion is a primary concern. However, maintaining farmland biodiversity in existing oil palm 
production landscapes is also important (Koh & Wilcove, 2007; Fayle et al., 2010). Previous 
studies have shown that oil palm can still host common or open-area species (Koh, 2008; Azhar 
et al., 2011, 2015). Oil palm production landscapes can also be habitats for a small number of 
forest species, given that oil palm farms are planted with other crops that provide shelter and 
foraging grounds for other wildlife (Kim et al., 2006; Nair, 2007; Foster et al., 2011). Polyculture 
farming is a common practise and considered to be ecologically more complex than 
monoculture farming (Rice, 2000; Altieri & Nicholls, 2004; Harvey et al., 2006). This has led to a 
focus on multi-cropping systems as a possible means of conserving farmland biodiversity 
(Dietsch et al., 2007; Steffan-Dewenter et al., 2007; Tylianakis et al., 2007). The planting of 
multiple crop species in commercial plantations has been found to have positive effects on 
insect diversity (Chung et al., 2000; Jones et al., 2003). For instance, studies have found that 
polyculture farming systems that integrate two or more crop species contain higher animal 
biodiversity compared to monoculture systems (Perfecto et al., 1996; Siebert, 2002).
Faunal diversity is often associated with plant diversity (Weibull et al., 2003). In 
agroecosystems, increasing plant diversity has been linked to an increase in insect diversity. 
Increased diversity can also result in lower insect herbivory damage, perhaps due to an increase
in interspecific competition among pest and non-pest species, and a higher number of natural 
enemies (Cardinale et al., 2006). Oil palm plantations adjacent to forest can serve as a 
complementary habitat for arthropods originating from nearby disturbed forest (Lucey & Hill, 
2012). Although many biodiversity studies have been carried out in oil palm landscapes, these 
have been mostly limited to large-scale monoculture plantations, where management practices 
3
are different from oil palm smallholdings. In addition, smallholdings are characterized by greater
landscape heterogeneity than large-scale plantations (Azhar et al., 2015).
One of the key questions in tropical agricultural research is whether farmlands can provide a
refuge for tropical biodiversity, including arthropods. (Turner & Foster, 2009), reported that 
different arthropod groups experience differing levels of decline between forest and oil palm 
plantation, with some groups having higher abundance in oil palm plantations compared to 
primary forests and logged  forests in Sabah. In addition, although many species decline in oil 
palm plantations, some disturbance-tolerant species may also increase in abundance. For 
instance, a study from Papua New Guinea found that ant abundance and species richness was 
lower in monoculture oil palm compared to forest (Room, 1975), but that nine species of ants 
that had never been recorded in natural forest were found in oil palm plantations. Generally 
there therefore seems to be a community shift of ants towards non-forest taxa in oil palm 
plantations (Bruhl & Etlz, 2010). 
To reconcile palm oil production and biodiversity conservation, it is important to understand
factors that determine biodiversity patterns in oil palm production landscapes. Therefore, this 
study aimed to answer three research questions with respect to the pattern of terrestrial 
arthropod biodiversity associated with agricultural practices in oil palm smallholdings: (1) How 
does terrestrial arthropod abundance and richness differ between polyculture and monoculture
oil palm smallholdings? (2) To what extent do in situ or local-scale habitat characteristics 
influence the arthropod abundance and order richness in oil palm smallholdings? (3) How does 
arthropod composition differ between polyculture and monoculture oil palm smallholdings? 
Methods
Study area
The study was conducted at Banting (centred 02'47.804'N, 101'31.420'E; area = 5,244.82 ha), 
Tanjung Karang (centred 03'21.511'N, 101'13.163'E; area = 3993.88 ha) and Sabak Bernam 
(centred 03'48'09.1'N, 100'53'21.2'E; area = 5,479.49 ha), in the state of Selangor on the west 
coast of Peninsular Malaysia (Fig. 1). All locations were below 10 m above sea level. All sites 
were located on coastal areas that were characterized by peat soil and flat terrain. The size of 
4
smallholdings in the study areas were less than 5 ha each and managed by local farmers or 
independent smallholders. We assigned each smallholding to a category of polyculture or 
monoculture farming system, based on the crop species planted by the smallholders. 
Monoculture smallholdings were those exclusively planted with oil palm, while polyculture 
smallholdings were planted with oil palm, bananas and other crop plants (e.g. coconut and 
cassava). 
Sampling design
We used systematic sampling with random starting points (Morrison, 2008). Sampling points 
were distanced at least 500 m apart. Data were collected from the three locations (i.e. Banting, 
Tanjung Karang and Sabak Bernam) where each had 40 sampling points. These points were 
allocated equally into monoculture (n = 20 sampling points) and polyculture smallholdings (n = 
20 sampling points). Arthropod sampling was conducted from January to August 2014, using 
pitfall traps. Pitfall traps consisted of open plastic containers (473 ml, with diameter of 9 cm) 
sunk into the ground, with the rim of each container level with the ground surface and covered 
with a lid to prevent flooding and disturbance (Southwood, 1994). We poured a water and 
detergent mix into the traps to kill any insects that fell in (Lemieux, 1999), with added salt to act
as preservative for collected specimens. The fluid was filled up to 2 cm from the base of the cup.
A total of 15 pitfall traps were used at each site, with a total of 1,800 pitfall traps used 
throughout the study period. Each pitfall trap was placed randomly within a 5-10 m radius from 
the other traps and at least 5 m from the edge of the smallholdings. Pitfall traps were left for 
three days at each site, which should be sufficient time to provide a reasonably good estimate 
of total arthropod richness and abundance (Olson, 1991). The arthropods were stored in 75% 
alcohol and identified to order in the laboratory (Capinera, 2010; Walters, 2011).
In situ habitat structure measurements 
Thirteen habitat characteristics were assessed in 100 m x 100 m vegetation plots at each 
arthropod sampling point (Table 1). The percentage of understory vegetation cover of grass (i) 
and non-grass (ii) was measured at subpoints to the North, South, East and West (each plot 20 
5
m apart). Mean height of the understory vegetation along the harvesting path was measured at 
subpoints to the North, South, East and West. This included (iii) height of grass cover and (iv) 
height of non-grass cover. Percentage canopy cover along the harvesting path was estimated 
using a canopy densiometer at subpoints to the North, South, East and West (v). The number of 
crop species at each plot was also counted (vi). In addition, (vii) the number of oil palms and 
(viii) the number of banana palms at each plot were counted. The number of crop plants within 
the vegetation plots was also counted. This included (ix) the number of mature oil palms, (x) the
number of immature oil palms of less than five years (Hardter et al., 1997), (xi) the number of 
fallen dead oil palms and (xii) the number of dead standing oil palm at each plot. Finally, (xiii) 
the percentage epiphyte cover on four random oil palm trunks within a rectangular quadrat of 
50 cm x 100 cm was measured. 
Data analysis
To compare the abundance and number of orders between monoculture and polyculture 
smallholdings, we performed one-way Analyses of Variance (ANOVA). Count data were square-
root transformed to meet the assumptions of the test (Ellison & Gotelli, 2004). We included 
different sampling months as blocks in the analysis. 
The relationship between arthropod order richness and in situ habitat characteristics was 
compared using Generalized Linear Models (GLMs) (Schall, 1991). We used log-link function 
assuming a Poisson distribution to fit the models. Correlation tests were conducted to detect 
multi-co-linearity among the predictor variables. Only one of each pair of highly correlated 
explanatory variables were included in the analysis, as co-linearity can distort model estimation 
(|r|>0.7) (Dormann et al., 2013). Height of grass (coefficient of correlation, r = -0.806), was 
therefore excluded, while grass coverage was included in the model. Akaike Information 
Criterion (AIC) tests were conducted to select the most parsimonious models (Burnham & 
Anderson, 2002), with models with the lowest AIC scores were chosen. Under this criterion, the 
chosen model is the one that minimizes the Kullback-Leibler distance between the model and 
the truth (Burnham & Anderson, 2002). Akaike weights were computed to provide a measure of
6
model selection uncertainty. All statistical analyses were computed in GenStat version 15 (VSN 
International).
Analysis of Similarity (ANOSIM) was used to compare arthropod order composition between
monoculture and polyculture smallholdings. We also used SIMPER analysis to determine the 
contribution of each order to differences in the arthropod assemblages. The comparison of 
arthropod order composition between those collected in polyculture and monoculture 
smallholdings was made using non-metric multi-dimensional scaling (NMDS) (Clarke & Warwick,
2001). Bray-Curtis distance was used to calculate the resemblance metric between monoculture
and polyculture smallholdings. ANOSIM, SIMPER and NMDS analysis were conducted in Primer 
version 6 (PRIMER-E Ltd).
Results
Arthropod responses to different farming practices
A total of 15 orders of terrestrial arthropods comprising 15,394 individuals were recorded (Table
2). Arthropods captured were 12 orders of Insecta, but only one order each for Arachnida, 
Diplopoda and Chilopoda. We found that the number of arthropod orders were significantly 
greater (F1,119 = 17.27; p < 0.001) in polyculture smallholdings (mean ± S.E. = 4.717 ± 0.158 
orders) than in monoculture smallholdings (mean ± S.E. = 3.817 ± 0.149 orders) (Fig. 1). No 
significant difference in terms of arthropod abundance (F1,119 = 1.4; p = 0.239) was found 
between monoculture smallholdings (mean ± S.E. = 140.3 ± 16.2 individuals) and polyculture 
smallholdings (mean ± S.E. = 116.3 ± 13.77 individuals) (Fig. 2). 
Arthropod order richness and in situ habitat characteristics
The most parsimonious model was selected according to the lowest AIC value of 120.26 and an 
R2 of 15.98%. The predictive models showed that farming practice (slope = 0.21475), height of 
oil palm stand (slope = 0.01765) and number of immature oil palm (slope = 0.00546) were all 
positively associated with increasing arthropod order richness in oil palm smallholdings (Table 
4).
7
Arthropod community composition
We found that polyculture smallholdings had an average similarity of 64.28%. Three orders, 
Hymenoptera (62.27%), Orthoptera (24.64%) and Araneae (5.11%), contributed more than 90% 
to the arthropod assemblage of polycultures. For monoculture smallholdings, the average 
similarity was 63.69%. Hymenoptera (68.21%) and Orthoptera (25.53%) represented the 
majority of arthropod orders and contributed approximately 94% to the arthropod assemblages
of monocultures. The average dissimilarity between polyculture and monoculture smallholdings
was 36.41%. We did not detect a significant difference in arthropod order composition between
polyculture and monoculture smallholdings (ANOSIM, number of permutations = 999; Global R 
= 0.019; p = 0.072). The NMDS ordination revealed a stress level value of 0.18. Ordination plot 
showed no clear differences in ordinal composition between monoculture and polyculture 
plantations (Fig. 3).
Discussion
Responses of arthropods to different farming practices
We found that arthropod order richess was higher in polyculture smallholdings than in 
monoculture smallholdings. However, arthropod abundance did not differ significantly between 
the two smallholding types. Other studies have already showed that agricultural practice can 
affect animal biodiversity found in farmlands (Kross & Schaefer, 1998; Benton et al., 2003; 
Holzschuh et al., 2007; Rundlof et al., 2008; Azhar et al., 2014). Turner & Foster in 2009, found 
that most arthropods declined in abundance in monoculture oil palm plantations. However, 
some arthropods such as ants, woodlice, cockroaches and beetles favour monoculture oil palm 
plantations. 
This study indicates that polyculture is a better farming practice than monoculture to 
maintain terrestrial arthropod diversity, perhaps because polyculture can increase habitat 
heterogeneity in farmlands. Polyculture farming can increase the floristic diversity and create 
moe variable vegetation structures. Our results are in line with a study by Weibull et al., (2003), 
who suggested that faunal diversity increases with habitat heterogeneity. Kross & Schaefer 
(1998), found that species richness of rove beetles (Coleoptera: Staphylinidae) collected using 
8
pitfall traps was highest in integrated farms with a mixture of crop plants compared to 
monoculture farms. 
Effects of in situ habitat characteristics  on the number of arthropod orders
All habitat characteristics at local scale showed significant effects on arthropod richness except 
for three variables which were removed from the modeling work because of multicollinearity. 
These were height of non-grass cover, number of mature oil palms and number of banana 
palms. It is therefore clear that habitat quality variables do have a significant effect on the 
number of arthropod orders. Amongst 13 habitat characteristics, the number of crop species, 
height of oil palm crop, and number of immature oil palms most strongly influenced the 
arthropod order richness. Local habitat quality variables explained 15.98% of the variation in 
arthropod order richness. In this study, the arthropod order richness inceased with polyculture 
farming. This may be because the multi-cropping habitat provides a wider range of food and 
hence more resources to support other fauna (Dennis et al., 1998). These results was similar to 
those of Wickramasinghe et al., (2004) and Haddad et al., (2001), who both found that plant 
species richness had a positive influence on arthropod species richness.
In this study, arthropod order richness also increased with height of oil palms. This may due 
to the fact that taller palms provide microhabitats such as epiphytes (Turner & Foster, 2006) 
that can be inhabited by different  arthropod species at different trophic levels. The presence of 
epiphytes on palm stems is unlikely to affect the ground-dwelling arthropods. However, the 
flying or highly mobile insects belonging to some orders such as Lepidoptera, Diptera, and 
Orthoptera may be influenced by the presence of epiphytes. Height of oil palms may affect the 
amount of shading in oil palm plantations. Existing studies suggest that such result is associated 
with microclimate parameters such as air temperature, relative and specific humidity, vapour 
pressure and soil temperature (Turner & Foster, 2006; Luskin & Potts, 2011; Hardwick et al., 
2015), but we did not include these parameters in our study. The results differ from a study on 
weaver ants (Oecophylla smaragdina), which are used to control bagworm infestation in oil 
palm plantations (Pierre & Idris, 2013). This study revealed that this one species of ants favored 
short oil palms to build nest. Although the study only focussed on one species of ant, but it 
9
indicated that height of oil palms can influence the abundance of arthropods in oil palm 
plantations. 
Our results indicated that the arthropod order richness increased with increasing number of
immature oil palms. A similar relationship was observed by Lowman (1985), whereby trees with 
younger leaves had a higher abundance of arthropods in the rainforest of Australia. This was 
mainly due to the fact that some insects prefer younger trees, which may explain the high 
number of arthropod orders in immature oil palms in this study. Luke et al., (2014), showed that
ant abundance was positively influenced by heterogeneity in local-scale habitat characteristics 
in oil palm  plantations. This indicates that habitat  heterogeneity  may increase resources for 
arthropods.
Arthropod order composition in different farming practices
Analysis of order composition of arthropods showed there was no significant difference in 
arthropod order composition between polyculture and monoculture smallholdings (Fig. 1). This 
implies that both farming practices hosted a similar composition of arthropods. However, it 
should be noted that this study was only carried out in smallholdings and results may differ in 
large-scale plantations. This is because the latter are usually characterized by a uniform stand 
age, covering a vast planted area of oil palm monocultures, and therefore show lower levels of 
habitat heterogeneity at these large scales (Azhar et al., 2015). Similar results were discussed in 
Fayle et al., (2010) and Koh  (2008), where none of the in situ habitat characteristics in 
monoculture oil palm plantations had significant effects on butterfly or ant communities. 
Polyculture farming in the context of wildlife-friendly agriculture
Wildlife-friendly agriculture or land sharing can implement agroecological methods including 
polyculture farming that promote on-farm biodiversity, and/or incorporate more small patches 
of natural habitat within the farming landscape (Kremen, 2015). In contrast, the land-sparing 
strategy supports isolating biodiversity conservation from agriculture, using intensive, high-
yielding monocultural production in one portion of the landscape to meet food demands, 
thereby sparing up lands for biodiversity conservation elsewhere (Kremen, 2015; Phalan et al., 
10
2012). The land-sharing strategy supports accomplishing both biodiversity conservation and 
agriculture in the same landscape, but was assumed to endure a yield penalty (Green et al., 
2005; Phalan et al., 2012). We recommend that the focus of future research should be aimed at 
the impacts of polyculture farming on oil palm yield.
Conclusions
Conventional oil palm farming is mainly characterized by large-scale monoculture system and 
uniform stand age that is often hostile to farmland biodiversity. One possibility for developing 
the oil palm industry into a more biodiversity-friendly production system is for stakeholders (e.g.
growers and government agencies) to work together to increase habitat heterogeity at the 
plantation scale. This can be achieved by promoting various conservation measures (e.g. 
maintaining forest patches and riparian vegetation within plantations), thereby maintaining as 
much of the existing farmland biodiversity as possible. It is clear that large-scale monoculture oil
palm plantations have failed to protect biodiversity effectively (Koh & Wilcove, 2008; Edwards et
al., 2010; Azhar et al., 2011), therefore polyculture farming should be considered by plantation 
companies as an alternative production strategy.
Our study indicates that polyculture farming as an alternative approach, may improve 
biodiversity conservation in oil palm smallhodlings and perhaps in large-scale plantations. Even 
though the significance of biodiversity maintenance may be low relative to the diversity of 
primary or secondary forest, these arthropods are likely to provide important ecosystem 
services (e.g. pest control and pollination) that benefit commercial oil palm cultivation (Altieri & 
Nicholls, 2004; Fisher et al., 2006; Scherr & McNeely, 2008; Tscharntke et al., 2012). This may 
provide an economic incentive for oil palm growers to make plantations or smallholdings 
hospitable to farmland biodiversity. Polyculture system therefore has the potential to improve 
farmland biodiversity conservation in oil palm production landscapes.
Acknowledgements
We thank Nurfatin Adila, Norlaili Ibrahim, Sharifah Nuratikah, Chang Phooi Kuan, Yee Siew Ann,
Sohaimi  Samsudin,  Muhammad  S.  Razak  and  Sasidhran  Selvadurai  for  their  valuable
11
contribution  in  this  study.  Amal  Ghazali  was  funded  by  MyBrain  15  scholarship,  Malaysian
Ministry of Higher Education.
References
Ahmad, A., Ahmad, A.H., 2009. A Preliminary Study on the Decomposition and Dipteran 
Associated with Exposed Carcasses in an Oil Palm Plantation in Bandar Baharu, Kedah, 
Malaysia. Trop. Biomed. 26, 1-10.
Altieri, M.A., Nicholls, C.I., 2004. Effects of Agroforestry Systems on the Ecology and 
Management of Insect Pest Populations. Ecological Engineering for Pest Management: 
Advances in Habitat Manipulation for Arthropods. p. 143-155, CSIRO, Collingwood.
Azhar, B., Lindenmayer, D.B., Wood, J., Fischer, J., Manning, A., McElhinny, C., et al., 2011. The 
Conservation Value of Oil Palm Plantation Estates, Smallholdings and Logged Peat Swamp 
Forest for Birds. Forest. Ecol. Manag. 262, 2306-2315.
Azhar, B., Puan, C.L., Zakaria, M., Hassan, N.,  Arif, M., 2014. Effects of Monoculture and 
Polyculture Practices in Oil Palm Smallholdings on Tropical Farmland Birds. Basic Appl. Ecol. 
15, 336-346.
Azhar, B., Puan, C. L., Aziz, N., Sainuddin, M., Adila, N., Samsuddin, S., ... & Hawa, A. 2015. 
Effects of in situ habitat quality and landscape characteristics in the oil palm agricultural 
matrix on tropical understory birds, fruit bats and butterflies. Biodiversity and Conservation, 
24, 3125-3144.
Azhar, B., Saadun, N., Puan, C.L., Kamarudin, N., Aziz, N., Nurhidayu, S., et al., 2015. Promoting 
Landscape Heterogeneity to Improve the Biodiversity Benefits Of Certified Palm Oil 
Production: Evidence From Peninsular Malaysia. Glob. Ecol. Conserv. 3, 553-561.
Benton, T.G., Vickery, J.A., Wilson, J.D., 2003. Farmland Biodiversity: Is Habitat Heterogeneity 
the Key? Trends Ecol. Evol. 18, 182-188.
Bruhl, C.A., Eltz, T., 2010. Fuelling the Biodiversity Crisis: Species Loss of Ground-Dwelling Forest 
Ants in Oil Palm Plantations in Sabah, Malaysia (Borneo). Biodivers. Conserv. 19, 519-529.
Burnham, K.P., Anderson, D.R., 2002. Model Selection and Multi Model Inference: A Practical 
Information-Theoretic Approach (2nd ed.). USA: Springer.
12
Capinera, J., 2010. Insects and Wildlife: Arthropods and Their Relationships with Wild 
Vertebrate Animals. John Wiley & Sons.
Cardinale, B.J., Weis, J.J., Forbes, A.E., Tilmon, K.J., Ives, A.R., 2006. Biodiversity As Both a Cause 
and Consequence of Resource Availability: A Study of Reciprocal Causality In A Predator-Prey
System. J. Anim. Ecol. 75, 497-505.
Chung, A.Y.C., Eggleton, P., Speight, P., Hammond, M., Chey, V.K., 2000. The Diversity of Beetle 
Assemblages in Different Habitat Types in Sabah, Malaysia. Bull Entomol. Res. 90, 475-496.
Clarke, K.R., Warwick, R.M., 2001. Change in Marine Communities: An Approach to Statistical 
Analysis and Interpretation. Plymouth: PRIMER-E, 2.
Clay, J., 2004. World Agriculture and the Environment: A Commodity-by-Commodity Guide to 
Impacts and Practices. Island Press, Washington, D.C.
Danielsen, F., Beukema, H., Burgess, N.D., Parish, F., Bruehl, C.A., Donald, P.F., et al., 2009. 
Biofuel Plantations on Forested Lands: Double Jeopardy for Biodiversity and Climate. 
Conserv. Biol. 23, 348-358.
Dennis, P., Young, M.R., Gordon, I.J., 1998. Distribution and Abundance of Small Insects and 
Arachnids in Relation to Structural Heterogeneity of Grazed, Indigenous Grasslands. Ecol. 
Entomol. 23, 253-264.
Dietsch, T.V., Perfecto, I., Greenberg, R., 2007. Avian Foraging Behavior in Two Different Types of 
Coffee Agroecosystem in Chiapas, Mexico. Biotropica 39, 232-240.
Dormann, C.F., Elith, J., Bacher, S., Buchmann, C., Carl, G., Carre, G., et al., 2013. Colinearity: A 
Review of Method to Deal With It and a Simulation Study Evaluating Their Performance. 
Ecography 36, 27-46.
Edwards, D.P., Hodgson, J.A., Hamer, K.C., Mitchell, S.L., Ahmad, A.H., Cornell, S.J., et al., 2010. 
Wildlife Friendly Oil Palm Plantations Fail to Protect Biodiversity Effectively.‐  Conserv. Lett. 3, 
236-242.
Ellison, G.N., Gotelli, N.J., 2004. A Primer of Ecological Statistics. Sinauer, Sunderland, 
Massachusetts, USA.
Ewers, R.M., Scharlemann, J.P.W., Balmford, A., Green, R.E., 2009. Do Increases in Agricultural 
Yield Spare Land for Nature? Glob. Chang. Biol. 15, 1716-1726.
13
Fayle, T.M., Turner, E.C., Snaddon, J.L., Chey, V.K., Chung, A.Y., Eggleton, P., et al., 2010. Oil Palm 
Expansion into Rain Forest Greatly Reduces Ant Biodiversity in Canopy, Epiphytes and Leaf-
Litter. Basic Appl. Ecol. 11, 337-345.
Fischer, J., Lindenmayer, D.B., Manning, A.D., 2006. Biodiversity, Ecosystem Function and 
Resilience: Ten Guiding Principles for Commodity Production Landscapes. Front. Ecol. 
Environ. 4, 80-86.
Fitzherbert, E.B., Struebig, M.J., Morel, A., Danielsen, F., Brühl, C.A., Donald, P.F., Phalan, B., 
2008. How Will Oil Palm Expansion Affect Biodiversity? Trends Ecol. Evol. 23, 538-545.
Foster, W.A., Snaddon, J.L., Turner, E.C., Fayle, T.M., Cockerill, T.D., Ellwood, M.F., et al., 2011. 
Establishing the Evidence Base for Maintaining Biodiversity and Ecosystem Function in the 
Oil Palm Landscapes of South East Asia. Philos. T. Roy. Soc. B. 366, 3277-3291.
Green, R.E., Cornell, S.J., Scharlemann, J.P., Balmford, A. 2005. Farming and the fate of wild 
nature. science 307, 550-555.Greenberg, R., Bichier, P., Angon, A.C., MacVean, C., Perez, R., 
Cano, E., 2000. The Impact of Avian Insectivory on Arthropods and Leaf Damage in Some 
Guatemalan Coffee Plantations. Ecology 81, 1750-1755.
Haddad, N.M., Tilman, D., Haarstad, J., Ritchie, M.J., Knops, M.H., 2001. Contrasting Effects of 
Plant Richness and Composition on Insect Communities: A Field Experiment. Amer. Nat. 158,
17–35.
Hardwick, S.R., Toumi, R., Pfeifer, M., Turner, E.C., Nilus, R., Ewers, R.M., 2015. The Relationship 
Between Leaf Area Index and Microclimate in Tropical Forest and Oil Palm Plantation: Forest 
Disturbance Drives Changes in Microclimate. Agric. For. Meteorol. 201, 187-195.
Harvey, C.A., Gonzalez, J., Somarriba, E., 2006. Dung Beetle and Terrestrial Mammal Diversity in 
Forests, Indigenous Agroforestry Systems and Plantain Monocultures in Talamanca, Costa 
Rica. Biodivers. Conserv. 15, 555-585.
Holzschuh, A., Steffan Dewenter, I., Kleijn, D.,  Tscharntke, T., 2007. Diversity of Flower Visiting ‐ ‐
Bees in Cereal Fields: Effects of Farming System, Landscape Composition and Regional 
Context. J. Appl. Ecol. 44, 41-49.
14
Jones, D.T., Susilo, F.X., Bignell, D.E., Hardiwinoto, S., Gillison, A.N., Eggleton, P., 2003. Termite 
Assemblage Collapse Along a Land-Use Intensification Gradient in Lowland Central Sumatra, 
Indonesia.? J. Appl. Ecol. 40, 380–391.
Kim, J., Williams, N., Kremen, C., 2006. Effects of Cultivation and Proximity to Natural Habitat on 
Ground-Nesting Native Bees in California Sunflower Fields. J. Kans. Entomol. Soc. 79, 309-
320.
Klein, A.M., Vaissiere, B.E., Cane, J.H., Steffan-Dewenter, I., Cunningham, S.A., Kremen, C., et al., 
2007. Importance of Pollinators in Changing Landscapes for World Crops. Proc. R. Soc. Lond. 
[Biol.] 274, 303–313.
Koh, L.P., 2008. Can Oil Palm Plantations be Made More Hospitable for Forest Butterflies and 
Birds? J. Appl. Ecol. 45, 1002-1009.
Koh, L.P., Wilcove, D.S., 2007. Cashing in Palm Oil for Conservation. Nature 448, 993–994.
Koh, L.P., Wilcove, D.S., 2008. Is Oil Palm Agriculture Really Destroying Tropical Biodiversity? 
Conserv. Lett. 1, 60-64.
Kremen, C. 2015. Reframing the land sparing/land sharing debate for biodiversity conservation.‐ ‐
Annals of the New York Academy of Sciences, 1355, 52-76.
Krooss, S., Schaefer, M., 1998. The Effect of Different Farming Systems on Epigeic Arthropods: A 
Five-Year Study on The Rove Beetle Fauna (Coleoptera: Staphylinidae) of Winter Wheat. 
Agric. Ecosyst. Environ. 69, 121-133.
Lemieux, J.P., Lindgren, B.S., 1999. A Pitfall Trap for Large-Scale Trapping of Carabidae: 
Comparison Against Conventional Design, Using Two Different 
Preservatives. Pedobiologia 43, 245-253.
Letourneau, D., Jedlicka, J., Bothwell, S., Moreno, C., 2009. Effects of Natural Enemy Biodiversity 
on the Suppression of Arthropod Herbivores in Terrestrial Ecosystems. Annu. Rev. Ecol. Syst. 
40, 573-592.
Lowman, M.D., 1985. Temporal and Spatial Variability in Insect Grazing of The Canopies of Five 
Australian Rainforest Tree Species. Aust J Ecol. 10, 7–24.
Lucey, J.M., Hill, J.K., 2012. Spillover of Insects From Rain Forest Into Adjacent Oil Palm 
Plantations. Biotropica 44, 368-377.
15
Luke, S.H., Fayle, T.M., Eggleton, P., Turner, E.C., Davies, R.G., 2014. Functional Structure of Ant 
and Termite Assemblages in Old Growth Forest, Logged Forest and Oil Palm Plantation in 
Malaysian Borneo. Biodivers. Conserv. 23, 2817-2832.
Luskin, M.S., Potts, M.D., 2011. Microclimate and Habitat Heterogeneity Through the Oil Palm 
Lifecycle. Basic Appl. Ecol. 12,  540-551.
Morrison, M.L., Block, W.M., Strickland, M.D., Collier, B.A., Peterson, M.J., 2008. Wildlife Study 
Design (p. 386). New York, USA: Springer.
MPOB. 2015; Version 2015. Malaysian Oil Palm Statistic 2009.  
http://econ.mpob.gov.my/economy/annual/stat2009/EID_statistics09.htm.   Retrived on 
26th May 2015.  
MPOC. 2014; Version 2014. Malaysia Palm Oil Industry. 
http://www.mpoc.org.my/Malaysian_Palm_Oil_Industry.aspx#sthash.axbEwtUO.dpuf. 
Retrived on May 7th 2014.
Nair, P.K.R., 2007. The Coming of Age of Agroforestry. J. Sci. Food Agric. 87, 1613-1619.
Olson, D.M., 1991. A Comparison of the Efficacy of the Litter Sifting and Pitfall Traps for 
Sampling Leaf Litter Ants (Hymenoptera: Formicidae) in a Tropical Wet Forest, Costa Rica. 
Biotropica 23, 166-172.
Perfecto, I., Rice, R.A., Greenberg, R., Vander-Voort, M.E., 1996. Shade Coffee: A Disappearing 
Refuge for Biodiversity. BioScience 46, 598-608.
Phalan, B., Onial, M., Balmford, A., Green, R.E. 2011. Reconciling food production and 
biodiversity conservation: land sharing and land sparing compared. Science 333, 1289-1291.
Pierre, E.M., Idris, A., 2013. Studies on the Predatory Activities of Oecophylla Smaragdina 
(Hymenoptera: Formicidae) on Pteromapendula (Lepidoptera: Psychidae) in Oil Palm 
Plantations in Teluk Intan, Perak (Malaysia). Asian Myrmecol. 5, 163-176.
Ramirez, S.R., Roubik, D.W., Skov, C., Pierce, N.E., 2010. Phylogeny, Diversification Patterns and 
Historical Biogeography of Euglossine Orchid Bees (Hymenoptera: Apidae). Biol. J. Linn. Soc. 
100, 552–572.
Rice, R.A., Greenberg, R., 2000. Cacao Cultivation and the Conservation of Biological Diversity. 
Ambio. 29, 167-173.
16
Room, P.M., 1975. Diversity and Organization of the Ground Foraging Ant Faunas of Forest, 
Grassland and Tree Crops in Papua New Guinea. Aust. J Ecol. 23, 71-89.
Rundlöf, M., Bengtsson, J., Smith, H.G., 2008. Local and Landscape Effects of Organic Farming on
Butterfly Species Richness and Abundance. J. Appl. Ecol. 45, 813-820.
Schall, R., 1991. Estimation in Generalized Linear-Models With Random Effects. Biometrika 78, 
719–727.
Scherr, S.J., McNeely, J.A., 2008. Biodiversity Conservation and Agricultural Sustainability: 
Towards a New Paradigm of ‘Ecoagriculture’landscapes. Philos. Trans. R. Soc. B. 363, 477-
494.
Siebert, S.F., 2002. From Shade to Sun-Grown Perennial Crops in Sulawesi, Indonesia: 
Implications for Biodiversity Conservation and Soil Fertility. Biodivers. Conserv. 11, 1889-
1902.
Southwood, T.R.E., 1994. Ecological Methods: With Particular Reference to The Study of Insect 
Populations. Chapman & Hall, London.
Steffan-Dewenter, I., Kessler, M., Barkmann, J., Bos, M., Buchori, D., Erasmi, S., et al., 2007. 
Tradeoffs Between Income, Biodiversity and Ecosystem Functioning During Tropical 
Rainforest Conversion and Agroforestry Intensification. Proc. Natl. Acad. Sci. U.S.A. 104, 
4973-4978.
Thiele, R., 2005. Phenology and Nest Site Preferences of Wood-Nesting Bees in a Neotropical 
Lowland Rain Forest. Stud. Neotrop. Fauna Environ. 40, 39–48.
Tscharntke, T., Clough, Y., Wanger, T.C., Jackson, L., Motzke, I., Perfecto, I., et al., 2012. Global 
Food Security, Biodiversity Conservation and the Future of Agricultural Intensification. Biol. 
Conserv. 151, 53-59.Turner, E., Foster, W.A., 2006. Assessing the Influence of Bird's Nest 
Ferns (Asplenium Spp.) on the Local Microclimate Across a Range of Habitat Disturbances in 
Sabah, Malaysia. Selbyana 27, 195-200.
Turner, E.C., Foster, W.A., 2009. The Impact of Forest Conversion to Oil Palm on Arthropod 
Abundance and Biomass in Sabah, Malaysia. J. Trop. Ecol. 25, 23-30.
Tylianakis, J.M., Tscharntke, T., Lewis, O.T., 2007. Habitat Modification Alters the Structure of 
Tropical Host-Parasitoid Food Webs. Nature 445, 202-205.
17
Walters, M., 2011. The Illustrated World Encyclopedia of Insects. Ann. Pub. Ltd., Leicestershire.
Weibull, A.C., Ostman, O., Granqvist, A., 2003. Species Richness in Agroecosystems: The Effect of
Landscape, Habitat and Farm Management. Biodivers. Conserv. 12, 1335-1355.
Wickramasinghe, L.P., Harris, S., Jones, G., Vaughan, J.N., 2004. Abundance and Species Richness
of Nocturnal Insects on Organic and Conventional Farms: Effects of Agricultural 
Intensification on Bat Foraging. Conserv. Biol. 18, 1283-1292.
Wilson, E.O., 1992. The diversity of life. Cambridge, Massachusetts, Belknap Press.
Table 1
Summary statistics of habitat variables measured for monoculture and polyculture 
smallholdings.
Variable Site Mean SD Minimum Median Maximum
Canopy cover (%) Polyculture 58.25 35.60 70 0 100
Monoculture 73.67 22.28 25 75 100
Epiphyte cover (%) Polyculture 22.73 19.33 0 20.47 64.69
Monoculture 39.74 16.86 0 40.31 83.75
Number of banana plants Polyculture 32.03 17.85 6 27 90
Monoculture 0 0 0 0 0
Number of dead oil palms 
(fallen)
Polyculture 0.817 1.455 0 0 5
Monoculture 1.4 2.035 0 0 8
Number of dead oil palms 
(standing)
Polyculture 0.4 1.061 0 0 5
Monoculure 0.8 1.885 0 0 13
Grass cover (%) Polyculture 31.21 27.32 0 21.25 86.88
Monoculture 30.39 23.53 0 24.53 72.19
Mean height of grass (cm) Polyculture 15.82 12.02 0 14.06 52.50
18
Monoculture 15.91 12.22 0 15 56.88
Mean height of non-grass 
(cm)
Polyculture 23.63 15.30 0 22.44 77.50
Monoculture 22.59 12.42 0 25.06 50.31
Mean height of oil palm 
canopy (m)
Polyculture 6.681 2.211 3.375 6.5 11.5
Monoculture 9.069 2.894 3.75 8.5 14.75
Number of crop species Polyculture 2 0 2 2 2
Monoculture 1 0 1 1 1
Non-grass cover (%) Polyculture 31.30 20.98 0 25.78 76.56
Monoculture 26.70 21.84 0 21.25 75.31
Number of immature oil 
palm 
Polyculture 10.67 9.906 0 7 28
Monoculture 5.35 7.611 0 3 28
Number of mature oil palm Polyculture 13.13 9.842 0 18 28
Monoculture 20.68 5.350 0 21.5 30
Table 2
Summary statistics of arthropod count for monoculture and polyculture smallholdings.
Order Monoculture Polyculture
Total count Mean ± S.E. Total count Mean ± S.E.
Aracnidae 54 0.900 ± 0.173 86 0.173 ± 0.185
Chilopoda 1 0.017 ± 0.017 0 0
Diplopoda 1 0.017 ± 0.017 31 0.517 ± 0.239
Blattodea 41 0.683 ± 0.232 31 0.517 ± 0.129
Coleoptera 41 0.683 ± 0.202 51 0.850 ± 0.138
Dermaptera 4 0.067 ± 0.033 11 0.183 ± 0.115
Diptera 135 2.250 ± 0.700 70 1.167 ± 0.262
Hemiptera 28 0.467 ± 0.140 53 0.883 ± 0.178
Homoptera 2 0.033 ±  0.023 0 0
Hymenoptera 7020 117.00 ± 14.55 5902 98.37 ± 13.58
Isoptera 3 0.050 ± 0.0284 8 0.133 ± 0.0769
Lepidoptera 20 0.333 ± 0.094 25 0.417 ± 0.093
Neuroptera 0 0 1 0.017 ± 0.017
Orthoptera 1066 17.77 ± 2.750 708 11.80 ± 1.136
Plasmatodea 0 0 1 0.017 ± 0.017
19
Table 3
All models were fitted to a dataset and the best models were selected by using R² and AIC 
values. The twelve predictor variables are coded as follows: CC, percentage canopy cover; E, 
percentage epiphyte cover; DOPS, number of dead oil palm (standing); HG, Height of grass; 
HNG, height of non-grass; HOPC, height of oil palm; TYP, type of farming practice; GC, 
percentage of grass cover; NGC, percentage of non-grass cover; OPI, number of immature oil 
palm.
Model K: Terms R2 AIC AICc Delta Relative
Likelihood
Akaike’s
Weight
1 1: TYP 11.13 122.73 123.80 2.3 0.3166 0.1018
2 2: As model 1 + OPI 13.91 121.02 122.21 0.71 0.7012 0.2254
3 3: As model 2 + HOPC 15.98 120.26 121.50 0 1 0.3214
4 4: As model 3 + HG 16.61 121.41 122.83 1.33 0.5143 0.1653
5 5: As model 4 + NGC 17.25 122.56 124.16 2.66 0.2645 0.0850 
6 6: As model 5 + HNG 18.23 123.26 125.09 3.59 0.1661 0.0534
7 7: As model 6 + E 18.33 125.11 127.23 5.73 0.0570 0.0183
8 8: As model 7 + DOPS 18.40 127.03 129.47 7.97 0.0186 0.0060
9 9: As model 8 +  OPM 18.41 129.01 131.82 10.32 0.0057 0.0018
10 10: As model 9 + CC 18.45 129.04 132.26 10.76 0.0046 0.0015
20
Fig. 1. Map of study area showing 120 sampling sites within oil palm smallholdings in Peninsular
Malaysia.
21
Fig. 2. Box plots showing number of arthropod orders and abundance of arthropods per sample 
in monoculture and polyculture smallholdings. Polyculture smallholdings maintained greater 
number of arthropod order than monoculture smallholdings. Both farming practices maintained
similar arthropod abundance.
22
Transform: Square root
Resemblance: S17 Bray Curtis similarity
Practice
Polyculture
Monoculture
2D Stress: 0.18
Fig. 3. Non-metric multidimensional scaling (NMDS) ordination comparing the arthropod 
community between polyculture smallholdings and monoculture smallholdings. 
23