The Impact of Logging on Geometroid Moth Populations and Their Diversity in Lowland Forests of Peninsular Malaysia
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Journal of Tropical Forest Science ll(l):61-78 (1999) IMPACE TH LOGGINF TO GEOMETROIN GO D MOTH POPULATIONS AND THEIR DIVERSITY IN LOWLAND FOREST PENINSULAF SO R MALAYSIA J. Intachat, Forest Research Institute Malaysia, Kepong, 52109 Kuala Lumpur, Malaysia J. D. Holloway Department of Entomology, NaturalThe History Museum, Cromwell Road, London 5BD,WS7 United Kingdom & M. SpeighR . t Department of Zoology, Oxford University, South Parks Road, Oxford, 3PS,OX1 United Kingdom Received December 1996 _________________________ ___________________ INTACHAT, J., HOLLOWAY, J. D. & SPEIGHT, M.R. 1999. The impact of logging on geometroid moth populations and their diversity in lowland forests of Peninsular Malaysia. Direct comparisons between geometroid moth samples collected from paired sites in primary forests and logged, secondary forests of the same type around Peninsular Malaysia showed that species diversity (ot) did not differ significantly between logge d unloggedan d forests. However, ther soms wa ee reductioe th n i n number specief so abundancd san individualf eo loggee th n si d forests. Ther alss oewa a shif geometroin i t d moth species composition highee Th . r numbe uniquf ro e species in primary forests indicates that, even after considering tha well-managea t d logged fores abls i t sustai o et majorite n th origina e th f yo l species dangee th , disappearancf ro e of specialist species is still present. Key words: Moths - impact - logging - lowland forests - Peninsular Malaysia INTACHAT,J.,HOLLOWAY,J.D.&SPEIGHT,M.R. 1999. Kesan pembalakan ke atas populasi dan kepelbagaian rama-rama geometroid di hutan tanah pamah Semenanjung Malaysia. Perbandingan secara langsung antara sampe rama-rama du l a geometroid yang dikutip dari pasangan tempat dalam hutan prime hutan rda n yang telah dibalak daripada jenis hutan yang sama di sekitar Semenanjung Malaysia menunjukkan bahawa kepelbagaian spesies (a) tidak berbeza secara bererti antara hutan yang telah dibala n hutakda n yang belum dibalak. Walau bagaimanapun, terdapat pengurangan bilangan spesie n kelimpahada s n individ i hutaud n yang telah dibalak. Terdapat juga peralihan komposisi spesies rama-rama geometroid. Bilangan spesies unik yang tinggi di hutan-hutan primer menandakan bahawa setelah diambil kira bahawa pengurusan pembalakan hutan yang baik mampu untuk menampung sebahagian besar spesies-spesies asli tetapi kehilangan spesies-spesies yang pakar masih wujud. 62 Journal of Tropical Forest Science ll(l):61-78 (1999) Introduction Many foresters view the process of logging as a modification (intensification) of the process of natural tree falls that is a part of the pattern of natural disturbance in forests. The theories of tree falls and gap dynamics have been developed principally throug e studth hf pattern o y d processean s naturan i s l forest disturbances (Attiwill 1994). Such studies have provided the basis for many forest management strategies. There has been extensive research on tree fall and gap dynamics (see Pickett 1983, Canham 1989, Platt & Strong 1989, Whitmore 1989, Denslow & Spies 1990) l seeAl . mo support t Grubb's (1977) conclusions that tree fall createsa wide diversity of gaps. Plant species which might fill in these gaps have varying ecological requirements r instanceFo . , understorey shrub species have different growth requirements compare regeneratino dt g pioneer tree species comped ,an - tition groupbetweeo tw f plano e s nth t species might arise dependin whicn go h one establishes first (Denslow & Spies 1990). Such disturbances change the species composition and community structure and function at a given site and thus increase the heterogeneity and variability of that site. Martinez-Ramos et al. (1988) suggest that it is the temporal and spatial variance of tree fall disturbances which provides for greater diversity in tropical forests compared with temperate ones. However, to date, there have been no detailed analyses comparing species diversity in tropical forests in relation to the frequency and intensity of tree fall, be it natural or enhanced by logging or other drastic types of disturbance. With the concept of selective logging in mind, Attiwill (1994) proposed: Harvesting a forest for all of its benefits, including its timber products, can be controlled so that it creates a disturbance, the effects of which do not differ from those of natural disturbance'. If thi trues si , the diversite nth naturaf yo l primary forest secondard san y forests where logging has been carried out under controlled conditions should not differ significantly at any given locality. Attiwill's proposa s beelha n investigated using various group insectsf so . These include dung beetles (Nummeli Hanskn& i 1989), coccinellid beetles (Nummelin & Fursch 1992) and butterflies (Hill et al. 1995). This paper, however, investigates Attiwill's proposa relation li geometroio nt d moth (Lepidoptera: Geometroidea) populations and diversity by directly comparing primary and secondary forests. Primar thin yi s case refer pristino t s e unlogged forest, while secondary refero t s forests where logging, usually selective logging, has been carried out. Due to logistic constraint e availabilitth d an s areaf yo sucr sfo h direct comparison, only six different localities were strategically sampled around Peninsular Malaysir afo this pilot study. Journal of Tropical Forest Science. ll(l):61-78 (1999) Material methodd san s The sites For each locality, samples collected from the primary and secondary forests were treated as pairs. Six paired sites (Figure 1) were chosen within the lowland forest categories (Wyatt-Smith 1995). Each pair of sites consisted of primary and secondary (logged-over forest), and the two sites in each were at least 3 km apart except for that at Panti (250 m apart). Samples from the logged areas were obtained from areas wher emodifiea d Malayan Uniform System (MUS) (Wyatt- Smith 1995) logging metho beed dha n applied, mostl1970se th n i y. Wang Kelian South China Sea Figure 1. Sites with sampling pairs 4 6 Journal of Tropical Forest Science ll(l):61-78 (1999) Vegetation description Pair 1: Rompin Endau The natural state of the forest here was characterised by poor drainage with e presencth f Dipterocarpaceao e genue th f seo Dipterocarpus, baudii,. sucD s ha D. cornutus costulatus:. D d an thes oftee ear n associated with Dryobalanops oblongifolia, Hopea mengarawan and Shorea lepidota (Wyatt-Smith 1995). Other common species Koompassiae ar malaccensis Palaquiumd an sppsecondare Th . y forest sit n thiei s are logges earle awa th yn d i 1970s traild r manan , fo s y vehicles accessing other areas pass through it. Pair 2: Tasik Temenggor Gyekis (1967) categorised the forest in this area of Perak near the border with Thailand as Red Meranti-Merbau Lowland Forest. Species of the Red Meranti group of Shorea (Dipterocarpaceae) suc. acuminata,S s ha . leprosula,S . macroptera,S S. ovalis and S. parvifolia are the commonest and, with merbau (Intsia palembanica), majorite mak importanth e p th e u f yo t species. Other important species include Cynometra inaequifolia, Dialium platysepalum, Cedrela serrata and Koompassia excelsa. The virgin forest site was selected 200 m up the ridge trail from the base camp of Malaysiae th n Nature Society Belum Project whil loggee eth dn abou s sitmi ewa 0 1 t boat ride fro e basmth e cam fro m aboud boae m0 th pan t10 tlanding e Th . secondary logge s sitearle eth wa yn d i 1970s. Pair 3: Wang Kelian foresextreme e th Th t a t e northwes Peninsule th f to categorises awa Whits da e Meranti-Gerutu (seasonal) typ Wyatt-Smity eb h (1995), wit hmixtura vegetaf eo - tion limestoneo n . Amon e commoth g n species Whitfoune th f deo Meranti group of the genus Shorea were Shorea hypochra, S. sericeiflora, S. assamica f. globifera and 5. talura. Other common species of Dipterocarpaceae are Parashorea lucida, Hopea ferrea, Dipterocarpus grandiflorus and Anisoptera oblonga . On the limestone, clump f Pandanuso s d smalsppan . l herb d rockfacan s e speciee familth n i ys Gesneriaceae such as .Bora spp., Paraboea spp. and Chirita spp. are common. The secondary logge s sitearle ewa th yn di 1970s. Pair 4: Pasoh A major part of the Pasoh Forest Reserve is under lowland dipterocarp forest f 'Mixeo Merantid dRe ' forest merging into 'Red Meranti' forest (Salleh 1968)t I . was describe (Wyatt-Smity db h 1995 lowlans a ) d dipterocarp centraforese th f o t l and southern 'Red Meranti-Keruing' type. This forest is covered with about 1000 ha of hill dipterocarps toward e northeasterth s n boundary. Approximatels i a h 0 65 y Journal5 6 of Tropical Forest Science. ll(l):61-78 (1999) in pristine condition, while the surrounding buffer zone comprises regenerating lowland forest that was selectively logged between 1955 and 1960. Within an tree6 25 s5 wit 33 a tota , hf o ha steml 0 are5 f sao abovdiametem c 1 e r breast height (dbh) from 814 species, 294 genera and 78 families have been recorded (Manokaran et al. 1992). The most common smaller trees are in the families Euphorbiacea Annonaceaed ean . Dipterocarpaceae, Leguminosa Burseracead ean e species are among the bigger trees. The logged site in this study was situated near the edge of the regenerated forest and was illegally logged in the early 1990s. Pai Pant: r5 i Classified as a primary lowland dipterocarp forest, the primary area has an emergent layer that is even at 30 m in height. Among the common species occurring e areth an i were Koompassia malaccensis, Shorea parvifolia, Hopea nervosa, Scaphium macropodum, Dipterocarpus verucosus and Parkia speciosa. The main canopy was at approximately 22 m with Elateriospermum tapos, Calophyllum pulcherrimum, Artocarpus maingayi, Palaquium maingayi and Lithocarpus wallichianus being the common species. Regeneration was good with the presence of H.