IJERD – International Journal of Environmental and Rural Development (2015) 6-2

Research article
erdFloristic Inventory of the Proposed Site for Tarsier Tourism
Center in Villa Aurora, Bilar, Bohol, Philippines
TOMAS D. REYES, JR.*
Bohol Island State University, Bohol, Philippines
Email: tomseyer@yahoo.com, tomseyer@gmail.com

JERALYN B. ABADINGO
Bohol Island State University, Bohol, Philippines

SHIELA G. TABUNO
Bohol Island State University, Bohol, Philippines

EUNICE KENEE L. SERIÑO
Bohol Island State University, Bohol, Philippines

JOECEL B. MABANAG
Bohol Island State University, Bohol, Philippines

RIZALDY C. MERCADAL
Bohol Island State University, Bohol, Philippines
Received 3 March 2015

Accepted 27 August 2015(*Corresponding Author)

Abstract. The study assessed the present vegetation composition of the proposed site for theTarsier Tourism Center (PTTC) at Villa Aurora, Bilar, Bohol and performed comparative
analysis with the existing Tarsier Sanctuary (TS) at Canapnapan, Corella, Bohol. The bases forcomparison were the computed importance values, species richness, species dominance, andpercent distribution of plants according to self-defined diameter at breast height DBH classes.
Results showed that both sites had very high species richness and evenness values. Common
overstorey and understorey plant species found in both areas were katagpo (Psychotria sp.),sagimsim (Syzygium brevistylum [C.B. Rob] Merr.) and bagauak (Clerodendrum minahassae
Teijsm. & Binn.). Apart from sagimsim (S. brevistylum [C.B. Rob.] Merr.), selaginella(Selaginella cuppresina Lin.), and lunas (Lunasia amara Blanco) were also common in the
ground vegetation of both areas. Percent distribution of trees according to self-defined DBH
classes revealed that PTTC had 87.55% of the total recorded plants with DBH measurements of<10 cm. This was found lower by almost 10% from TS. Considerable percentages of trees werealso shared in other DBH classes for PTTC. DBH class range of 10-20 cm had 6.88%, while
5.58% was computed for DBH class of >20 cm. Percent distribution of trees on these DBH
ranges (especially on DBH class >20 cm) indicated the presence of medium and large trees. The
largest DBH measured in PTTC was 70 cm, while in TS was only 22 cm. Based on the findingsof the study, it has been concluded that the proposed 10-ha site in Villa Aurora, Bilar is suited tobe utilized as Tarsier Tourism Center. In case the proposed project is to be pursued, enclosure
similar to what has been constructed in Canapnapan, Corella, Bohol, Philippines should also beestablished to prevent stray animals from predating the captive tarsiers.
Keywords floristic inventory, Philippine tarsier, BoholⒸISERD94

IJERD – International Journal of Environmental and Rural Development (2015) 6-2

INTRODUCTION
The Philippine tarsier (Carlitos syrichta (L.) Shykelle) has attracted a lot of attention of scientists andcollectors because of its interesting physical features and habits. It is often fancied as a crossbreed of abat and a rat. The name “tarsier” is derived from the fact that the tarsal region is elongated, a trait ofboth tarsiers and gala goes (Embury, 1994 as cited by Villamor, 1995). Its size is not bigger than two
fists held together. Undeniably, the Philippine tarsier, with three subspecies: syrichta, fraterculus andcarbonarius, is one of the smallest among the different known species (Goodwin, 1991; Embury, 1994
as cited by Villamor, 1995; Neri-Arboleda, et al., 2002). This trait and its rarity status would be thereason why this creature is on the CITES endangered list. It was once then considered as “lower risk
conservation dependent” based on the IUCN 2004, then became “data deficient” in 2006, and now
under the “near-threatened” category since 2008.
The Philippine tarsier habitats are primarily located in secondary lowland rainforest of early- to
mid-succession stage (Neri-Arboleda, et al., 2002; Reyes, 2006). In Bohol, it generally occurs in hilly
areas with patches of second-growth forest (PAWB-DENR, 1992; Lagapa, 1993; Villamor, 1995;
Reyes, 2006), bushes, bamboos, palms and some grasses (Karnain, et al., 1997 as cited by Reyes,2006). The short trees, as well as bamboos, are good for the arboreal adaptation by the tarsiers. The
dense nature of the undergrowth supports a wide variety of insects and small vertebrates which arevital to the survival of tarsiers. The close distance in between small diameter trees, on the other hand,appears to be a necessary condition which favors the locomotive behavior of tarsiers thus enablingthem to have a firm grasp of the small trunks and branches making this type forest a favorable place tolive (Villamor, 1995; Karnain, et al., 1997 as cited by Reyes, 2006). It is also found in abandoned
clearings with signs of new growth of medium-high plants in lands of both low and medium elevations(Hoogstraal, 1947). These types of clearing were believed to be the tarsier’s feeding sites (Rabor, 1977;
Villamor, 1995) until they were disproved by Neri-Arbodela et al., (2002).
Habitat characterization of the Philippine tarsier has been conducted in Bohol by several local
researchers and research institutions (Madulid [undated]; PAWB-DENR, 1992; Lagapa, 1993;
Villamor, 1995; Neri-Arboleda, et al., 2002; Reyes, 2000, 2006; and ERDS, 2009). Among the
researchers, Neri-Arboleda, et al., (2002) and Reyes (2006) provided detailed discussions on several
habitat classifications. Reyes (2006), in particular, described 11 variants of the tarsier’s roosting
territories based on species composition and thicket structure. He also correlated the presence oftarsiers and its scent-markings on abundance of small diameter plants in his study sites. The findings ofthe study of Reyes (2006), on this aspect, were used as the basis in evaluating the suitability of
proposed Tarsier Tourism Area in Villa Aurora, Bilar, apart from the usual species richness anddominance assessment.
The study assessed the present vegetation composition of the proposed tarsier tourism site at Villa
Aurora, Bilar, Bohol, Philippines and compared with the existing tarsier sanctuary at Canapnapan,
Corella, Bohol, Philippines in terms of plant species composition.
METHODOLOGY
Study Site
The Proposed Tarsier Tourism Center (PTTC) is planned to be established at barangay Villa Aurora in
the municipality of Bilar. The total area of the proposed tourism site is 10.194 ha (CENRO-Tagbilaran,2013). It is located along the stretch of the prominent winding road of barangay Villa Aurora, akilometer away from the famous Bilar-Loboc Man-made Mahogany Plantation. This will serve as anextension of the 6-ha Tarsier Tourism Area established at Upper Bonbon, Loboc, Bohol, Philippines.

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The Tarsier Sanctuary and Conservation Site (TS), on the other hand, which is used forcomparison is situated at barangay Canapnapan in the municipality of Corella, Bohol, Philippines. This
134-ha conservation site is managed by the Philippine Tarsier Foundation Incorporated (PTFI) and isopen to public, since 1990s, for recreation and research.
Field Data Collection
Quadrat sampling was used in the collection of data. Twenty quadrats were established preferentiallywithin the 10-hectare PTTC in Villa Aurora, Bilar. The 10 m x 10 m plots were laid selectively on
thickets of small diameter trees and shrubs which could be identified as potential roosting sites of thePhilippine tarsier. All plants with diameter at breast height (DBH) of > 1 cm were recorded. Small
nested subplot with a dimension of 1 m x 1 m was also established at the middle of each plot tofacilitate the identification of the ground vegetation.
For comparative analysis, 10 plots and subplots were also established at TS in Canapnapan,
Corella. The first five plots and subplots were laid in the PTFI tarsier enclosure where visitors areallowed to enter and see the captive tarsiers, and the remaining plots and subplots were laid outside theenclosure, about 30 m away from the PTFI building.
Data Analysis
Analysis of data was mainly concentrated on the determination of species abundance parameters suchas density, frequency, and dominance values of each plant species. These parameters were used in thecalculation of importance value (IV) of all encountered plants in the overstorey, understorey, andground vegetation. IV is a measure of species abundance in an area. It is the summation of the relativevalues of density (number of species per unit area), frequency (number of occurrences of species
relative to the number of plots established), and dominance (basal area of species relative to the total
computed basal areas).
For the purpose of comparison of the two sites, species richness and dominance indices likediversity (Shannon-Wiener diversity index), evenness (Evenness index), and dominance (Simpson’s
index) were computed based on IV. The Shannon-Weiner diversity index assumes that individuals
were randomly sampled from an indefinitely large population and also assumed that all species wererepresented in the sample. Evenness index, on the other hand, is the ratio of observed diversity tomaximum diversity, while Simpson’s index is the probability of any two individuals drawn at random
from an infinitely large community belonging to same species.
Density of plants, in percent (%), on each pre-defined diameter class was also calculated toevaluate the suitability of the proposed site for tarsier conservation as the project proponents (wildlife
permitees from Loboc) claimed its very purpose. This was based on the work of Reyes (2006) who
tested the relationship of DBH to the number of tarsiers seen in the wild. DBH classes used in thisstudy were: <10 cm; 10-20 cm; and >20 cm.
Formulas used in this study and presented below were adopted from Gruezo (1997), Fernando etal., (1998), Reyes (2000, 2006), and ERDS (2009).
For Tree and Shrub Layer:
Density = total number of individuals of a species/unit area
Relative Density = density of a species/total densities X 100
Dominance = basal area of a species/total area sampled
Relative Dominance = dominance of a species/total dominances X 100
Occurrence = number of times a species appeared/total number of established plots X 100
Frequency = number of occurrence of a species/total number of occurrences X 100
Relative Frequency = frequency of a species/total frequencies X 100
Importance Value = Relative Density + Relative Dominance + Relative FrequencyⒸISERD96

IJERD – International Journal of Environmental and Rural Development (2015) 6-2

For the Understorey Plants and Grasses (weeds and broadleaves):
Species Dominance = Cumulative crown cover (%) of a species
For the Diversity and Evenness Indices:
Shannon Diversity (H’) = -∑ pi * (LNpi) where pi = species proportion
Evenness Index (E) = H’/ LN(s)where s = number of species
RESULTS AND DISCUSSION
Vegetation Composition
Overstorey and understorey plants: A total of 112 species of overstorey and understorey plants wereidentified in the PTTC at Villa Aurora, Bilar. These belonged to 82 genera under 44 families (Fig. 1).
The recorded plant species and genera in PTTC were roughly twice than those in TS. Tables 1 and 2
show the summary lists of common overstorey and understorey plants in both areas. From the list in
Table 1, the first three most common species were katagpo (Psychotria sp.), bayukbok (Elaeocarpus
macranthus Merr.), and langin (Micromelum caudatum Merr.) based on the computed IV of 28.96,
10.94, and 10.62, respectively. The three most common species in Table 2, on the other hand, werealabihig (Arthrophyllum diversifolium Blume), tagoang uak (Croton leiophyllus Muell.-Arg.), andkatagpo (Psychotria sp.) with IVs of 29.70, 19.91, and 19.77, respectively.
As shown in Tables 1 and 2, the species of plants which were found in both areas, apart fromkatagpo, were sagimsim (Syzygium brevistylum (C.B. Rob.) Merr.) and bagauak (Clerodendrum
minahassae Teijsm. & Binn.).
There were also 52 species, 43 genera, and 35 families of ground vegetation in the PTTC. Samewith the overstorey and understorey vegetation, its ground cover was more than twice species rich thatthe recorded ground vegetation in TS. Table 3 presents the summary list of common plants species
identified on the ground based on the number of individuals. The most common species recorded withmore than 30 individuals each, in decreasing order, were sagimsim (S. brevistylum [C. B. Rob.] Merr.),
selaginella (Selaginella cuppresina), and lunas (Lunasia amara Blanco). These species were also listedcommon in TS, as shown in Table 4.

Fig. 1 Bar graph showing the taxonomic information of the Proposed Tarsier Tourism Center,
Villa Aurora, Bilar and Tarsier Sanctuary, Canapnapan, Corella, Bohol, PhilippinesⒸISERD97

IJERD – International Journal of Environmental and Rural Development (2015) 6-2

Table 1 List of common overstorey and understorey plants arranged based on importancevalues (IV) in PTTC, Villa Aurora, Bilar, Bohol, Philippines
Common Name

Scientific Name

Family NameIV

KatagpoPsychotria sp.

Rubiaceae

28.96

Bayukbok

Elaeocarpus macranthus Merr.

Elaeocarpaceae

10.94

LanginMicromelum caudatum Merr.

Rutaceae

10.62

Sagimsim

Syzygium brevistylum (C. B. Rob.) Merr.

Myrtaceae

9.89

Paginga

Discocalyx cybianthoides (A. DC.) Mez.

Myrsinaceae

7.80

Katong matsin

Chisocheton pentandrus (Blanco) Merr.

Meliaceae

7.18

Bagauak

Clerodendrum minahassae Teijsm. & Binn.

Lamiaceae

6.98

BatinoAlstonia macrophylla Wall. ex DC.

Apocynaceae

6.72

Malak-malak

Palaquium philippense (Perr.) C. B. Rob.

Sapotaceae

6.52

Big-leaf mahogany

Swietenia macrophylla King.

Meliaceae

6.44

Aniam-gubat

Antidesma subolivaceum Elm.

Euphorbiaceae

6.35

Malaikmo

Celtis philippensis Blanco

Ulmaceae

6.05

Talang gubat

Diospyros copelandii Merr.

Ebenaceae

5.79

AlahanGuioa koelreuteria (Blanco) Merr.

Sapindaceae

5.74

Lunas

Lunasia amara Blanco

Rutaceae

5.62

DuguanMyristica philippensis Lam.

Myristicaceae

5.51

Palosapis

Anisoptera thurifera (Blanco) Blume

Dipterocarpaceae

5.23

Table 2 List of common overstorey and understorey plants arranged based on importancevalues (IV) in TS, Canapnapan, Corella, Bohol, Philippines
Common Name

Scientific Name

Family NameIV

Alabihig

Arthrophyllum diversifolium Blume

Araliaceae

29.70

Tagoang uak

Croton leiophyllus Muell.-Arg.

Euphorbiaceae

19.91

KatagpoPsychotria sp.

Rubiaceae

19.77

Sagimsim

Syzygium brevistylum (C. B. Rob) Merr.

Myrtaceae

19.50

Balinghasai

Buchanania arborescens Blume

Anacardiaceae

18.30

Bagauak

Clerodendrum minahassae Teijsm. & Binn.

Lamiaceae

14.04

Matang arau

Melicope triphylla (Lam.) Merr

Rutaceae

13.74

Takip asin

Macaranga grandifolia (Blanco) Merr.

Euphorbiaceae

10.08

Sudiang

Ctenolophon philippinense Hallier F.

Linaceae

8.19

Mussaenda sp.

Rubiaceae

8.01

Niog-niogan

Ficus pseudopalma Blanco

Moraceae

7.93

Pandan gubat

Freycinetia sp.

Pandanaceae

7.83

Kubi

Artocarpus nitida Trec. subsp. nitida

Moraceae

6.77

MolaveTambo

Vitex parviflora Juss.
Thysonolaena latifolia (Roxb. ex Hornem.)
Honda

Lamiaceae

5.66

Poaceae

5.23

Ficus sp.

Moraceae

5.14

Ficus

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Table 3 List of common plants species comprising the ground vegetation arranged based on
the number of individuals in PTTC, Villa Aurora, Bilar, Bohol, Philippines
Common Name

Scientific Name

Family Name

Individuals

Sagimsim

Syzygium brevistylum (C. B. Rob.) Merr.

Myrtaceae

53

Selaginella

Selaginella cuppresina

Selaginellaceae

40

Lunas

Lunasia amara Blanco

Rutaceae

38

Flacourtia sp.

Flacourtiaceae

27

LanginMicromelum caudatum Merr.

Rutaceae

22

Tubli

Derris sp.

Fabaceae

20

Paginga

Discocalyx cybianthoides (A. DC.) Mez.

Myrsinaceae

17

Takipan

Caryota rumphiana Mart. var. philippinensis Becc

Arecaceae

11

White nato

Pouteria macrantha (Merr.) Baehni

Sapotaceae

11

Table 4 List of common plants species composing the ground vegetation arranged based on thenumber of individuals in TS, Canapnapan, Corella, Bohol, Philippines
Common Name

Scientific Name

Family Name

Individuals

Sagimsim

Syzygium brevistylum (C. B. Rob) Merr.

Myrtaceae

49

Selaginella

Selaginella cuppresina

Selaginellaceae

40

LanginMicromelum caudatum Merr.

Rutaceae

27

Tagpo

Ardisia squamulosa Presl.

Myrsinaceae

15

Nino

Morinda bracteata Roxb.

Rubiaceae

10Species Richness and Dominance
The results of species richness and dominance computations (Fig. 2) revealed that both sites were
species rich given by Shannon-Weiner diversity index values of 4.26 for PTTC and 3.56 for TS.
According to Fernando et al., (1998), diversity index values above 3.5 are considered very high. Valuesof the dominance indices such as evenness and Simpson’s dominance index also supported this finding.
Evenness value of almost 1.0 (0.9031 for PTTC and 0.9012 for TS) means that the observed (orcomputed) diversity value is almost equal to the expected maximum diversity value (Gruezo, 1997;
Fernando et al., 1998; Reyes, 2000).

Fig. 2 Species richness and dominance index values for the Proposed Tarsier Tourism Center,
Villa Aurora, Bilar and Tarsier Sanctuary, Canapnapan, Corella, Bohol, PhilippinesⒸISERD99

IJERD – International Journal of Environmental and Rural Development (2015) 6-2

Very high evenness index is always accompanied by very low dominance index. For both sites,
Simpson’s dominance index values were computed less than 0.04. This only means that there is only
less than 4% chance that two individual plants to be selected in both sites would belong to the same
species.
Reyes (2000) reported that the species diversity in the identified six roosting territories of thePhilippine tarsier in barangay Cabacnitan, Bilar ranged from 2.01 (low) to 3.125 (high).
Self-defined DBH Classes
The computation on percent distribution of plants in three different self-defined DBH classes showedthat PTTC had 87.55% of the total recorded plants with DBH measurements of <10 cm. This wasfound lower by almost 10% from TS. Considerable percentages of trees were also shared in other DBH
classes for PTTC. DBH class ranged of 10-20 cm had 6.88%, while 5.58% was computed for DBH
class of >20 cm. Percent distribution of trees on these DBH ranges (especially on DBH class >20 cm)
indicated the presence of medium and large trees. The largest DBH measured in PTTC was 70 cm.
For TS, only less than 3% combined was computed for DBH classes of >10 cm. The largest DBH
measured was 22 cm (Table 5).
Table 5 Percent distribution of plants in self-defined DBH classes
DBH Class (cm)Study Site

<10

10-20

>20

Proposed Tarsier Tourism Center

87.55

6.88

5.58

Tarsier Sanctuary and Conservation Site

97.13

2.01

0.86

CONCLUSION AND RECOMMENDATION
Based on the findings of the study, it is concluded that the proposed 10-ha site in Villa Aurora, Bilar issuited to be utilized as Tarsier Tourism Center. Apart from the site’s inherent diversity in plant species,
the current vegetation composition and the presence of medium and large size trees in PTTC suggests
its similarity to one of the variants described by Reyes (2006) as advance thickets of many small
diameter trees, few medium- and large-sized trees and dense undergrowth. However, in case theproposed project will be pursued, enclosure similar with what has been constructed in Canapnapan,
Corella should also be established to prevent stray cats and other animals from predating the captive
tarsiers.
REFERENCES
Community Environment and Natural Resources Office-Tagbilaran. 2013. Map of the proposed tarsier tourism
site at Villa Aurora, Bilar. CENRO Tagbilaran, DENR.
Ecosystems Research and Development Services. 2009. Floral and faunal assessment of the proposed tarsier
sanctuary in Corella, Bohol. Unpublished Technical Report. Ecosystems Research and Development Services(ERDS) Region 7, DENR.
Fernando, E., Jumawid, R.J. and Peras, J. 1998. Resource inventory and assessment of biodiversity in the Subic
Bay metropolitan authority area. Unpublished Terminal Report. UPLB-SBMA-PCARRD-DOST.
Gruezo, W.S.M. 1997. Floral diversity profile of Mount Makiling Forest Reserve, Luzon, Philippines, In: The
Conditions of Biodiversity Maintenance in Asia. Michael R. Dore and Percy E. Sajise (eds.). East-WestCenter, Honolulu, Hawaii.

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Hoogstraal, H. 1947. The inside story of the tarsier. Chicago Natural History Museum Bulletin, 18, 7-8 (Nov.), 45 (Dec.).
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Madulid, D.A. (undated). Vegetation analysis of the forest in Corella, Bohol. Unpublished Report. National
Museum, Manila.
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tarsier (Tarsius syrichta Linne.) territories in Cabacnitan, Bilar, Bohol. Tropical Technology Journal, 3 (4),ISSN 1656-0264.
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