Understory Flora Composition Assessment of Jabonga, Agusan del Norte

UNDERSTORY FLORA COMPOSITION ASSESSMENT
OF JABONGA, AGUSAN DEL NORTE

JONI REY H. CAMPILAN

An Undergraduate Thesis
Submitted to the Science Department
College of Natural Science and Mathematics
Mindanao State University
Fatima, General Santos City

In Partial Fulfillment of the Requirements
for the Degree
BACHELOR OF SCIENCE IN BIOLOGY

MARCH 2013

APPROVAL SHEET

This undergraduate thesis entitled ―UNDERSTORY FLORA COMPOSITION

ASSESSMENT OF JABONGA, AGUSAN DEL NORTE‖, prepared and submitted

by JONI REY H. CAMPILAN, in partial fulfillment of the requirements for the

Degree of Bachelor of Science in Biology, has been examined and approved.

THESIS COMMITTEE

______________________________
JAIME NAMOCATCAT, Ph.D.
Adviser

__________________________ _______________________
PROF. CARMEN R. NISPEROS FLORENCE L. ZAPICO, MS
Member Member
________________________________________________________________

This undergraduate thesis is hereby officially accepted in partial fulfillment of the

requirements for the degree Bachelor of Science in Biology.

__________________________ ____________________________
PROF. CARMEN R. NISPEROS MA. LOURDES dM. GALIA, Ph.D
Chairperson Dean

______________________ ______________________
Date Date
ii

PERSONAL DATA

The researcher was born in Tboli Evangelical Clinic and Hospital, Inc. on

January 6, 1993. He is the eldest of the two sons of Ptr. Nicolas P. Campilan and

Mrs. Joan H. Campilan.

When he was four years old, he took his preschool education at TLDFI

(Tribal Leaders Development Foundation, Inc.) Learning Center where he finished

as second honors. His primary education was completed at Lugan Central

Elementary School where he graduated as first honors. He pursued his secondary

education at Edwards National High School and graduated as the class

valedictorian.

With great dedication in the field of science, he took the degree BS Biology

at Mindanao State University-General Santos City. His learning experiences

taught him that life is not perfect but it was very good, time is never lasting, and

relationship must be prioritized than any other things.

Now as he continue to delight himself in the Lord let it be that the desires of

his heart will be fulfilled.


iii

ACKNOWLEDGEMENT

This study will not be accomplished without our Almighty God who brought

all possibilities in the life of the researcher and the completion of this paper. To

God be the glory and honor!

The researcher would like to express his great gratitude to his family for the

love, support and encouragement they had shown; to his mother who teaches him

how to sacrifice, to his father who taught me him how to trust God and to his

brother who taught him how to care for others.

To his adviser, Dr. Jaime Namocatcat, who taught him to excel in all things.

To Dr. Apolinario Remollo, who never ceases to share his knowledge. And to his

team mates, Victoria Mijares, Dwight Invidiado, Angelie Abistano, Joan De Asis,

and to the two guides who strengthen him in his study. To Ms Catherine Aguilar,

who took care of him during the field work, and to the people of Jabonga, Agusan

del Norte who inspire him to pursue this study.

To his friends Vanessa Bidad, Paolo Tagaloguin, Adrian Peñaflorida, Anne

Tarazona, Ressy Mae Ruelan, Ruth Jean Maratas, and Cherry Mae Labrador. To

his ‗Nanays‘, Dory Magabullo and Jane Villarosa. To my SRM family- Tay Dodz,

Steph, Dave, Benj, Bem, Bea, Joy, Love, Jonivee, & Jebee. Thank you for

bringing joy in his life.

Not only that I was knit together in my mother’s womb, I was on the right

place with the right people on the right time.

iv

TABLE OF CONTENTS
APPROVAL SHEET........................................................................................................ ii
PERSONAL DATA..........................................................................................................iii
ABSTRACT…………………………………..……………………………………………….….ix
1. INTRODUCTION........................................................................................................... 1
1.1 Objectives of the Study .................................................................................. 2
1.2 Significance of the Study ............................................................................... 2
1.3 Scope and Limitation ...................................................................................... 3
2. REVIEW OF RELATED LITERATURE ............................................................. 4
2.1 Philippine Biological Diversity ....................................................................... 4
2.1.1 Philippine Biodiversity Conservation and Management Strategies ............ 4
2.2. Understanding Understory Vegetation Diversity .......................................... 6
2.2.1 Effects of Disturbances to Understory Vegetation Diversity ....................... 7
2.3 Belt Transect Sampling Method ..................................................................... 8
2.4 Sampling Parameters ....................................................................................10
3. MATERIALS AND METHODS .........................................................................12
3.1 Description of Study Site...............................................................................12
3.2 Sampling Method ...........................................................................................14
3.2.1 Sampling Materials ........................................................................................15
3.2.2 Species Processing and Identification .........................................................15
3.3 Data Analysis .................................................................................................16
4. RESULTS AND DISCUSSION ........................................................................19
4.1 Species Composition and Richness .............................................................19
4.2 Ecological Measurement ...............................................................................21
4.2.1 Dinarawan, San Pablo, Jabonga ...................................................................21
4.2.1.1 Transect 1 .......................................................................................................21
4.2.1.2 Transect 2 .......................................................................................................23
4.2.1.3 Transect 3 .......................................................................................................26
4.2.1.4 Transect 4 .......................................................................................................27
4.2.2 Kabugaw, San Pablo, Jabonga .....................................................................29
4.2.2.1 Transect 5 .......................................................................................................29
4.2.2.2 Transect 6 .......................................................................................................31
v

4.2.3 Uba, San Pablo, Jabonga ..............................................................................33
4.2.3.1 Transect 7 .......................................................................................................33
4.2.3.2 Transect 8 .......................................................................................................35
4.2.3.3 Transect 9 .......................................................................................................37
4.2.4 Magdagooc, Jabonga ....................................................................................39
4.2.4.1 Transect 10 .....................................................................................................39
4.2.4.2 Transect 11 .....................................................................................................41
4.3 Diversity Index ...............................................................................................43
4.4 Assessment of Conservation Status ............................................................44
5. SUMMARY, CONCLUSION, AND RECOMMENDATIONS .............................51
LITERATURE CITED .....................................................................................................55
APPENDIX 1. Understory Flora Assemblage Transects and Quadrats
in Jabonga, Agusan del Norte ..........................................................66
APPENDIX 2. Transect Coordinates .......................................................................65
APPENDIX 3. Study Sites and Transect Lines .......................................................76
APPENDIX 3. Understory Flora Sampling ..............................................................80
APPENDIX 4. Species List of Understory Flora In Jabonga, Agusan Del Norte ..81
APPENDIX 5. DENR Assessment of Conservation Status
of Threatened Plant Species (DAO 2007-1) .....................................95
APPENDIX 6. Guingab (1994) Assessment of Floral Species
Conservation Status .........................................................................98
APPENDIX 7. Ecological Measurements of Understory Flora Species In Jabonga,
Agusan Del Norte ..............................................................................99
APPENDIX 8. Photographs of Understory Flora in Jabonga…………...…………130

vi

LIST OF TABLES

Table 1. Ecological Measurements for Transect 1 in Dinarawan, Jabonga 21




Table 5. Ecological Measurements for Transect 5 in Kabugaw, Jabonga 29

Table 6. Ecological Measurements for Transect 6 in Kabugaw, Jabonga 31

Table 7. Ecological Measurements for Transect 7 in Uba, Jabonga 32



Table 10. Ecological Measurements for Transect 10 in Magdagooc, Jabonga 39

Table 11. Ecological Measurements for Transect 11 in Magdagooc, Jabonga 41

Table 12. Conservation Status of Understory Flora Based on Guingab (1994) 48

vii

LIST OF FIGURES

11
Figure 1. Map of Jabonga, Agusan del Norte, N 090 07' 14.6" E 1250 31' 50.9"

Figure 2. Schematic flowchart of study, indicators, method, and metrics for 17
assessment of the understory flora composition, and conservation status

18
Figure 3. Total No. of Species in Understory Flora Assessment in Jabonga

22
Figure 4. Transect 1 Cumulative Species-Area Curve, Dinarawan, Jabonga

29

26

28

30
Figure 8. Transect 5 Cumulative Species-Area Curve, Kabugaw, Jabonga

31

33
Figure 10. Transect 7 Cumulative Species-Area Curve, Uba, Jabonga

35

38

40
Figure 13. Transect 10 Cumulative Species-Area Curve, Magdagooc, Jabonga

Figure 14. Transect 11 Cumulative Species-Area Curve, Magdagooc, Jabonga 42

Figure 15. Simpson's Diversity Index of Understory Flora Vegetation in Jabonga 43

viii

ABSTRACT

CAMPILAN, JONI REY H. ―UNDERSTORY FLORA COMPOSITION
ASSESSMENT OF JABONGA, AGUSAN DEL NORTE‖. Undergraduate Thesis,
Mindanao State University, General Santos City

Thesis Adviser: DR. JAIME NAMOCATCAT

Understory flora of Jabonga, Agusan del Norte were assessed from May
13-18, 2012 using belt transect method in 11 transects measuring 4, 300 m in
length. 276 species of plants were collected resolved into 95 families and two
hundred ten (210) genera where 9 species are Aroids, 1 Bromeliad, 2 Fern Allies,
12 Ferns, 19 Grasses, 42 Herbs, 2 Orchids, 4 Palms, 90 Saplings, 4 Sedges, 32
Shrubs, 50 Vines, 1 Weed, and 4 Zingibers. Euphorbiaceae (18 spp.) and
Moraceae (17spp.) family were highly represented under 4 and 14 genera,
respectively. Simpson‘s Diversity Index Value was calculated highest at 0.963 for
Transect 1 and lowest at 0.871 for Transect 4, suggesting moderate to high
diversity. Based on DAO 2007-01, Pterocarpus indicus Willd. Forma indicus
(Smooth Narra) is listed as Critically Endangered; Afzelia rhomboidea (Blanco)
Vidal (Tindalo) is endangered; Alangium longiflorum Merr. (Malatapay),
Cynometra inaequefolia A. Gray (Dila-dila), Dillenia reifferscheidia Naves
(Katmon Kalabaw), Mangifera merrillii (Pahong Liitan), Securinega flexousa
(Muell,-Arg.) (Anislag), Shorea contorta (White Lawaan), and Vitex parviflora
Juss. (Molave) are vulnerable, and Aglaia luzoniensis (Kuling manok) and Dillenia
philippinensis Rolfe (Katmon Baging) are other wildlife species. The presence of
Nephrolepsis biserrata (Sw.) Schott (Pakong Kalabaw), the most abundant
species, Chromolaena odorata (Hagonoy) and Saccharum spontaneum L.,
(Talahib), invasive species, which considered to have dense population, might
have cause biodiversity loss. With this threats to the biodiversity of the area and
with the observed exploitation activities, the area is considered to be at high risk.
The study reveals the utmost need of Jabonga for biodiversity conservation
strategies.

ix

1. INTRODUCTION

As one of the world‘s eight biodiversity hottest hotspots (Myers et al,

2000), the Philippines is home to some of the most endangered habitats and

species in the world. Due to the extraordinary rate of environmental destruction,

leaving only 3% of the land with primary forest, this biodiversity is at high risk.

Despite that situation, information on Philippine forest vegetation is fragmentary

and focused on trees (Langerberger et al., 2006). Forest management to

diversify tree species is now being promoted to favor biodiversity (Barbier et al.,

2008).

Understory vegetation is influenced by overstory composition and

structure through modifications of resource availability (light, water and soil

nutrients) and other effects, such as physical characteristics of the litter layer

(Barbier et al., 2008). Vegetation has been widely used to describe habitat

characteristics, water quality and make predictions about the presence and

composition of the surrounding communities (Appelgren and Mattila, 2005). The

composition of understory is usually different from that of the canopy, and thus

supports a different fauna than does the canopy (Gentry and Emmons, 1987).

The physical structure of the understory plants provides food resources for many

species of insects, birds, and mammals, and is responsible for a high percentage

of total diversity in the tropical forests (Tchouto et al., 2006).

1

Composition of the vegetative community as well as diversity must be

examined in order to accurately assess differences among communities and the

possible effects of disturbance, including human induced disturbance.

This study investigated the understory flora composition of the remnant

seconcary forests of Jabonga, Agusan del Norte. Conservation status

assessment of plants in the study site was done in order to evaluate the area‘s

biodiversity.

1.1 Objectives of the Study

This study sought to:

1. Collect, classify, and identify understory plants of Jabonga, Agusan del

Norte.

2. Assess the composition and distribution of the identified specimen in

terms of Density, Relative Density, Frequency, Relative Frequency,

Dominance, Relative Dominance, Species Diversity, and evenness.

3. Evaluate the conservation status of plants documented based on DAO

2007-01 and IUCN (International Union for the Conservation of Nature)

Red List on plants.

1.2 Significance of the Study

Results of this study will serve as baseline information on species

richness, composition, distributional range, species‘ population size and

structure, and conservation status of understory plants inJabonga, Agusan del
2

Norte. The given information on the, endemic and endangered plant species will

assist evolving long term habitat conservation, species prioritization, and natural

resources management plan on the area. Furthermore, this will aid the

developing core objectives for the conservation monitoring and decision

makingof the area.

1.3 Scope and Limitation

Composition of understory plant flora was studied in Jabonga, Agusan del

Norte. This study was focused on the inventory and assessment of understory

flora of ≤ 3 m in height of the area. This includes all flora and grass species

including the seedlings, herbs, vines, rattans, saplings and other undergrowths.

Determination of the species composition was confined only on the established

transects along its trails and peripheries. Identification of the different collected

species was based on the directly observable and basic morphological features

of individual species with no extensive anatomical study made. At least, genus

level of documented plant species was identified. Density, relative density,

frequency, relative frequency, dominance, relative dominance, and species

diversity and evenness were the ecological parameters determining the

composition and distribution of understory flora of the area. Conservation status

assessment of understory plants was solely base on the sampled species, and

searched plants.

3

2. REVIEW OF RELATED LITERATURE

2.1 Philippine Biological Diversity

The Philippines has vast natural resources that are source of food,

water, shelter and livelihood for its rapidly growing population. It is one of 17

megabiodiversity countries (containing 2/3 of the earth‘s biodiversity and about

70-80% of the world‘s plant and animal species) due to its geographical isolation,

diverse habitats and high rates of endemism (native, restricted or unique to a

certain country or area). The Philippines is 5th in the number of plant species and

maintains 5% of the world‘s flora (DENR, 2008).

The vegetation of the Philippines is very rich and diverse and a major

proportion of the country is covered with tropical forests. There are varieties of

vines, epiphytes, climbers. Flowering plants including ferns and orchids grow in

large number in the forests of the Philippines (Langenburger, 2004). Philippine

species endemism is very high, covering at least 25 genera of plants. The

Philippines is also one of the world‘s biodiversity hotspots, with a large number of

endangered and threatened species and habitats, making it one of the world‘s

top global conservation priority areas (DENR, 2008).

2.1.1 Philippine Biodiversity Conservation and Management Strategies

Biodiversity maintenance is a key management objective and a requisite

for sustainable forestry (Torras and Saura, 2008). Approaches with a

4

combination of both site-specific biodiversity measures and assessments of

habitat diversity and heterogeneity are not yet established, but in the near future

may lead to a scientifically based evaluation of the potential for increasing

biodiversity by appropriate landscape management (Duelli, 1997).

Philippines, a developing country, works with simple monitoring plan to

work out conservation and management of its biodiversity (Danielsen, et.al,

2000). Providing human resource, as major lacking power, is addressed with the

given strategies. Wherein, the monitoring system aims to identify trends in

biodiversity and its uses so as to guide management action; it also promotes the

participation of local people in the management, stimulates discussion among

stakeholders and builds the capacity of park staff and communities in

management skills. In addition, it seeks to provide people with direction regarding

the aims of protected areas, and reinforces the consolidation of existing

livelihoods through strengthening community-based resource management

systems. The system can be sustained using locally available resources. The

countries‘ approach is useful in where it embarks on shared management of park

resources with local communities, where rural people depend on use of natural

ecosystems, and where the economic resources for park management are

limited.

On forestry, the major strategy is the Community Based Forest

Management, CBFM (Lasco & Pulhin, 2006) CBFM focuses on forest and land

management and it includes management of tropical forests (enrichment
5

planting, timber stand improvement or TSI and limited harvesting), rehabilitation

of degraded lands [reforestation, assisted natural regeneration (ANR)] and

agroforestry. The action has positive results that led to conservation of natural

forests and the associated biodiversity. Tree planting in farms and landscapes

has led to soil and water conservation, carbon sequestration and biomass

production.

In small ways, zoos meet their conservation role through captive

breeding, education, research, animal-welfare, environmental enrichment,

reintroduction, and support for in situ conservation of species and their habitats

(Catibog-Sinha, 2008). Another is ecotourism that has been identified as one of

the measures to achieve biodiversity conservation at both in situ (e.g. protected

areas) and ex situ (e.g. zoos) conditions (Catibog-Sinha, 2010).

2.2. Understanding Understory Vegetation Diversity

The understory layer is a critical component of forest ecosystems typically

supporting the vast majority of total ecosystem ﬂoristic diversity (Halpern and

Spies, 1995; Gilliamand Roberts, 2003) and providing habitat elements to

associatedwildlife species (Carey and Johnson, 1995). These communities also

play a central role in the dynamics and functioning of forestecosystems by

inﬂuencing long-term successional patterns (Phillips and Murdy, 1985; Abrams

and Downs, 1990; Oliver andLarson, 1996; McCarthy et al., 2001; Royo and

Carson, 2005;Nyland et al., 2006) and contributing to forest nutrient

6

cycles(Chapin, 1983; Zak et al., 1990; Anderson and Eickmeier, 2000;Chastain

et al., 2006).

Understory vegetation is influenced by overstory composition and

structure through modifications of resource availability (light, water and soil

nutrients) and other effects, such as physical characteristics of the litter layer.

Overstory light transmittance and diverse properties of forest litter are factors that

have been most fully studied to date, but other factors such as throughfall water

quantity and chemistry may also play a role (Barbier et al., 2008). Understory

plant species assemblages may have different patterns of diversity than tree

species because of variable responses to different abiotic factors.

Forests growing on former agricultural land often have reduced

frequencies of many native forest herbs compared with forests that were never

cleared for agriculture. A leading explanation for this pattern is that many forest

herbs are dispersal limited, but environmental conditions may also hinder

colonization. It is suggested that some plants growing in post-agricultural stands

may be N (nitrogen) limited, whereas undisturbed stands in this region appear to

be approaching N saturation (Fraterrigo et al., 2009).

2.2.1 Effects of Disturbances to Understory Vegetation Diversity

An intermediate disturbance hypothesis states that diversity is highest at

intermediate disturbance levels. Stand improvement treatments increased the

7

number of large diameter trees, tree species richness and diversity (cleaning and

thinning), and shrub species richness (pruning) (Torras and Saura, 2008).

In a study, thinning and burning treatments are a common method of

reducing fire risk while simultaneously promoting understory production. These

ecological restoration treatments did promote a more diverse and abundant

understory community. The disturbances generated by these treatments also

promoted an invasion by an undesirable nonnative species (McGlone et

al.,2009).

2.3 Belt Transect Sampling Method

Numerous vegetation sampling techniques are outlinedin sampling

textbooks (Mueller-Dombois & Ellenberg1974; Krebs 1989; Kent & Coker 1994;

and Barbour et al.1999) and in the scientific literature (Stohlgren et al.

1995;Etchberger & Krausman 1997; Stohlgren et al. 1998) for quantifying

different plant community attributes.

Although there is no one correct technique for sampling vegetation, the

sampling design chosen may greatly influence the conclusions researchers can

draw from restoration treatments. Considerations when designing vegetation

sampling protocol include determining what sampling attributes to measure, the

size and shape of the sampling plot, the number of replicates and their location

within the study area, and the frequency of sampling (Korb et al., 2003).

Sampling methods to estimate total species richness of a defined area

8

(conservation unit, national park, field station, "community") will play an important

role in research on theglobal loss of biodiversity. Such methods should be fast,

because time is of the essence. They shouldbe reliable because diverse workers

will need to apply them in diverse areas to generate comparabledata. They

should also be simple and cheap, because the problem of extinction is most

severe indeveloping tropical countries where the scientific and museum

infrastructure is often still rudimentary (Coddington et al, undated).

Sutter (1996) outlined four criteria of monitoringtechniques that must be

met to reliably and precisely detect change: (1) Data need to have a known and

acceptable level of precision; (2) data sampling techniques needto be repeatable;

(3) data need to be collected for a longenough time to capture responses to

treatments; and (4) techniques need to be feasible, realistic, and inexpensive

enough to be maintained long term.

Determining the sampling technique that shouldbe used for a particular

study needs to take into consideration numerous factors such as the restoration

goals, sampling attributes, level of sampling precision, and financialand

personnel constraints (Korb et al., 2003). In this study two 1x1m Belt Transect

was spaced 10m apart across ends of 20m transect line. The primary objective of

the belt transect is to obtain a species list of the area (Kent& Coker 1994). All

herbaceous and shrub species within the belt were recorded including their

foliage cover data.

9

2.4 Sampling Parameters

Species diversity is one of the most frequently sampled attributes in

vegetation studies (Ricklefs & Schluter 1993). Species diversity is often used

interchangeably with species richness.Species richness, however, is one of two

components thatdefine species diversity, the other being species evenness (Kent

& Coker 1994). The well-known concept states that an increase in sampling area

will increase species richness detection (Rapson et al. 1997).

Species abundance is some measure of the amount of a species in a

sample (Chiarucci et al. 1999). Plant community attributes that measure species

abundance include plant foliar cover, plant density, and plant frequency. Plant

foliar cover is one of the most widely used abundance measurements because it

is not biased by the size or distribution of individual species as plant density and

plant frequency measurements can be (Floyd & Anderson 1987). Ecologists have

designed numerous sampling techniques to quantify plant foliar cover. The three

most commonly used techniques include the point-intercept, the line-intercept,

and ocular estimation (Buckner 1985).

Visual estimation of plant cover is oneof the most common measurements

in plant ecology and restoration studies (Kennedy & Addison 1987). Ocular

estimates are normally taken within a 1m 2 area because one of the requirements

for accuracy is that observations must be made from a vertical perspective within

a bounded plot (Buckner 1985). Ocular estimates can either be estimated to the

nearest predetermined percent (e.g., closest 1%) or they can be categorized into
10

published cover classes (e.g., Daubenmire or Braun-Blanquet) (Mueller-Dombois

& Ellenberg 1974).

11

3. MATERIALS AND METHODS

3.1 Description of Study Site

Agusan del Norte Province is located on wide, fertile, coastal plateau in

the northeastern part of Mindanao. This province is bordered on the north and

east by the Province of Surigao del Norte and Surigao del Sur, on the south by

the Province of Agusan del Sur, and on the southwest by the Province of

Misamis Oriental. Fertile, coastal plains and valleys along the Agusan River

characterize the terrain of Agusan del Norte Province. The average elevation is

46 meters above sea level: The climate is classified as tropical wet.

Temperatures of the coolest month are above 18°C, and rainfall in the driest

month is at least 60 mm.

Figure 1. Map of Jabonga, Agusan del Norte, N 090 07' 14.6" E 1250 31' 50.9"

12

There is a minimum of seasonal variation in temperature and precipitation, as

both remain high throughout the year. The province is large, 2,590 square

kilometers (Carney et al., 1978).

In Agusan del Norte, Lake Mainit is located where it is covered by

different vegetative groups: grassland, brush land, secondary forest , limestone

forest, marshland, riparian and lowland rice paddies. Municipality of Jabonga is

one of the Municipalities that surrounds Lake Mainit.

There are four study sites in Jabonga that are strategically selected for the

study of the understory flora namely Dinarawan, Kabugaw, Uba, and Magdagooc

(see Appendix 2). Jabonga vegetation is composed of wetlands, grasslands, and

secondary forest.

Dinarawan, Kabugaw, and Uba were primarily composed of secondary

forests with grassland and agricultural areas, located besides Mamanwa‘s

community, along the shore of Lake Mainit. The forest is the main source of

living for the people as it provides food, water, and income. Utilization of Kaong

[Areaga pinnata (Wurmb) Merr.], agricultural area, and the forest timber were the

observed income sources.

Magdagooc is located besides Butuan Bay. The secondary forest in the

area is dominated by Cocos nucifera L.. Coconut and fishing were the main

source of income of the people in the area.

13

3.2 Sampling Method

Belt transect method and transect walk survey was utilized for this study.

All flora and grass species including the seedlings, herbs, vines, rattans, saplings

and other undergrowths of less than or equal to 3-m tall that were physically

intercepted by the transect line or those projection of foliage is intercepted by the

transect lines was identified, counted and recorded. Visual estimation of plant &

soil cover was made by ocular estimation to the nearest 1% percent. Endemic,

threatened and native species were subject for documentation during transect

walk survey. The biological method targeted the determination of the minimal

area and species area curve, density estimation, estimation of plant coverage,

and diversity measurement. A 20m transect tape was used to space successive

sampling stations. Establishment of new stations was made continuously until the

boundary of the study area are reached. Coordinates of sampling stations was

taken using the GPS receiver.

Two (2) perpendicular 1m x 1m belt transect was laid down in to each of

the transect stations established in the line intercept method. This belt transect

was described to be oriented parallel to the axis of the environmental gradient

within an area being sampled. The quadrats were placed five (5) meters apart on

both sides.

Common name, scientific name, family, and genera, abundance and direct

top coverage estimation of each species, as well as the bare ground, were

recorded.
14

3.2.1 Sampling Materials

This study used a 1m X 1m transect belt made of nylon string, and 4

wooden stakes. For preservation of specimens, plastic bags and sacks, wooden

plant pressers, corrugated ventilators, blotters, newspapers, and straps were

used. A digital camera was used to photograph voucher specimens, and

sampling areas, and GPS receiver for determining coordinates of located areas

of belt transects, and track rare species of plants.

3.2.2 Species Processing and Identification

Collected samples were identified with the use of Flora of Manila, USDA

plant database, and Guide to Philippine Flora and Fauna. The identification

scheme covered at least up to the genus level. The conservation status of the

identified plants was assessed with the use of IUCN Red List for threatened

species and DAO 2007-1. Journals and publications for conservation focused in

tropical forest and vegetation in Asia and Philippines were used for further

references. Preparation of the species for herbarium purposes followed the

procedures set by Flora of Manila. Specimens for herbarium were gathered

cumulatively. Field pressing procedure was applied on the actual stations.

15

3.3 Data Analysis

Ecological measurements of species composition and distribution were

evaluated by calculating the species density, frequency, dominance, and their

relative measures. Values were derived using the following formulas:

o Density = Total no. of individuals of species A / Total area sampled

o Relative Density =

o Frequency =

o Relative frequency =

o Dominance =

o Relative dominance =

o Importance Value= Relative Density + Relative Frequency + Relative

Dominance

Diversity per transect was evaluated through the use of Simpson‘s (D)

index as a measure of species richness and evenness of the community using

Microsoft QuickBASIC Application.

16

o Simpson‘s diversity index is calculated by this equation:

∑
D= ( )

Where: n = total no. of organisms of a particular species

N = total no. of organisms of all species

Electronic aid offered by Microsoft Excel was used for faster data

computations and analysis.

17

UNDERSTORY FLORA
STUDY DIVERSITY

TARGET SPECIES FOR
UNDERSTORY DIVERSITY
CONSERVATION

INDICATORS
Rare, Endemic, Endagered Grasses, Ferns, Herbs, Shrubs
Species ≤ 3 m (height)

BELT TRANSECT & AREA
METHOD QUADRAT SAMPLING
SEARCH

METRICS No. of Species Species Status
Relative Abundance,
Frequency, & Density
of Target Species
Species Diversity and
Coverage

RESULT ANALYSIS DATA ANALYSIS & CONSERVATION STATUS ASSESSMENT

Figure 2. Schematic flowchart of study, indicators, method, and metrics for assessment of the understory flora
composition, and conservation status.

18

4. RESULTS AND DISCUSSION

4.1 Species Composition and Richness

Of the 406 qudrats under 11 transects in Jabonga, Agusan del Norte, two

hundred seventy-two (272) species of understory plants were collected resolved

to a total of 95 families and to two hundred ten (210) genera. On record are 9

Aroids, 1 Bromeliad, 2 Fern Allies, 12 Ferns, 19 Grasses, 42 Herbs, 2 Orchids, 4

Palms, 90 tree Saplings, 4 Sedges, 32 Shrubs, 50 Vines, 1 Weed, and 4

Zingibers. Transect 1 captured the highest number of species (83 species)

followed by Transect 9 (63 species). Transect 6 (57 species) and transect 11

captured the least number of species (43 species).

Figure 3. Total No. of Species in Understory Flora Assessment in Jabonga
90 83
80
70 63
55 55 57
60 51 52 52
49 48
50 43
40
30
20
10
0
1 2 3 4 5 6 7 8 9 10 11
TRANSECT LINE

Total no. of Species

19

Nephrolepsis biserrata (Sw.) Schott (Pakong Kalabaw) is the most

abundant species recording 875 individuals in 11 transects. Nephrolepsis

biserrata (Sw.) Schott are ever green perennial herb that form congested

colonies in very wet soils, along the edges of streams or marshes and are

sometimes on surfaces of lake and stagnant waters (Omojola, 1997).

Nephrolepis biserrata distribution is pantropical (Hovenkamp and Miyamoto,

2005), they are indigenous to an immense area, covering most parts of tropical

southern hemisphere and has become naturalized in almost every tropical region

of the globe. They have stems often in the form of rhizome by which they

commonly reproduce vegetatively (Robert et al, 1965). Roots are adventitious

and grow usually in clusters from the rhizome which are pteridophyte (ITIS,

2010). The leaves are commonly pinnately compound and consist of two parts:

the frond (leafy portion) and the stripe (stalk). Young developing leaves are

circinate-coiled in on themselves like a watch spring and the tip unrolls

progressively as the lower plants develop (Chee and Faiz, 1991). Nephrolepsis

biserrata have an exponential growth potential and forms dense population which

displaces native vegetation (Weber, 2003). Its fronds form a thick mat on the

ground, preventing any establishment of native plant (Weber, 2003).

Euphorbiaceae (18spp.) and Moraceae (17spp.) families had the most

number of species under 4 and 14 genera, respectively. The Moraceae (37

genera, 1100 species) is primarily a tropical to subtropical family which displays

an amazing diversity of inflorescence structures, pollination syndromes, breeding
20

systems, floral characters, habit, and contains several economically important

genera (Artocarpus, Brosimum, Brousonettia, Ficus, and Treculia) (Swenson et

al, 2003). Euphorbiaceae is generally distinguished by the milky sap, (When

present) unisexual (evolved) flower, ovary trilocular and superior, placentation

axile (Kothale et al, 2011).

4.2 Ecological Measurement

4.2.1 Dinarawan, San Pablo, Jabonga

4.2.1.1Transect 1

There are forty (40) quadrats positioned in Transect 1 covering a total of

five hundred eighty-six (586) individuals resolved to eighty-three (83) species.

Soleria scribiculata Nees (Arat) was the most abundant species recorded (53

individuals). Also, it is the densest species scoring 1.196 and has a relative

density of 9.39% and the most frequent species (16) with a relative frequency of

6.48%. Donax cannaeformis (G. Forst.) K. Schum (Bamban) was the most

dominant species (9.022) with a relative dominance of 11.66%.

Table 1 shows the top ten important species in the transect where Soleria

scribiculata Nees had the highest importance value of 25.554 followed by Donax

cannaeformis (G. Forst.) K. Schum and Chromoloena odorata (Hagonoy) scoring

20.397 and 14.095, respectively.

21

Table 1. Ecological Measurements for Transect 1 in Dinarawan, Jabonga

RELATIVE RELATIVE RELATIVE IMPORTANCE
SPECIES
DENSITY FREQUENCY DOMINANCE VALUE
Chromoloena odorata 8.874 2.834 2.388 14.095

Dioscorea hispida 2.048 3.644 2.949 8.641
Donax cannaeformis (G. Forst.)
3.072 5.668 11.657 20.397
K. Schum
Ficus pseudopalma Blanco 2.560 2.834 2.528 7.922
Leucosyke capitellata (Poir.)
3.242 2.834 1.404 7.481
Wedd.
Nephrolepsis biserrata (Sw.)
4.437 2.834 4.635 11.906
Schott
Saccharum spontaneum L. 7.850 2.024 1.264 11.138

Selaginella plana Hieron 3.584 4.049 4.073 11.705

Semecarpus philippinesis Engl. 1.706 2.834 3.652 8.192

Soleria scribiculata Nees 9.386 6.478 9.691 25.554

Simpson‘s Diversity Index value of 0.963 suggest that Trasect 1

understory vegetation has high diversity and there is no species that clearly

dominates area. The Species-Area Curve for Transect 1 (Figure 4) indicates that

there could be uncovered species in the area sampled. Local guides prohibited

the researcher to survey the rest of the trek in accordance to their belief that the

foregoing area is sacred.

Soleria scribiculata Nees is a sedge under Cyperaceae family, considered

to be an abundant species. The stems of Bamban (Donax) is economically

manufactured to laundry basket (FPRDI, 2012). Chromolaena odorata is

considered as one of the world‘s most invasive weeds. It produces huge

22

numbers of windborne seeds within 8–10 weeks after flowering (more than 80

000 seeds per plant per season). Each seed has a tuft of white hairs that allow it

to be transported by wind and water. Seeds will also attach to vehicles,


90
80
70
60
Species No.

50
40
30
20
10
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45
No. of Belt Transect

machinery, clothing, footwear and animals. Most seeds germinate immediately

after rain, though some appear to remain dormant for several years (EDI, 2012).

4.2.1.2 Transect 2


three hundred thirty-one (331) individuals resolved to fifty-five (55) species.

Nephrolepsis biserrata (Sw.) Schott (Pakong Kalabaw) was the most abundant

species on record (101 individuals). Also, it is the densest species scoring 2.53

and has a relative density of 30.50% and the most frequent species, appeared 27

23

times, with a relative frequency of 30.17%. Donax cannaeformis (G. Forst.) K.

Schum (Bamban) was the most dominant species (1.94) with a relative

dominance of 19.9%.

Table 2 shows the top ten important species in the transect where

Nephrolepsis biserrata (Sw.) Schott had the highest importance value of 68.02

followed by Saccharum spontaneum L. (Talahib) and Soleria scribiculata Nees

(Arat) scoring 23.46 and 15.76, respectively.


SPECIES

Blumea balsamifera L. DC 1.511 2.439 4.239 8.188

Caryota mitis 2.115 3.415 3.768 9.297
Donax cannaeformis (G. Forst.) K.
Schum
2.719 4.390 5.024 12.133


Ganophyllum falcatum Blume 1.813 2.927 2.512 7.094

Hypyis capitata Jacq. 6.647 4.878 4.239 15.763
Leucosyke capitellata (Poir.)
Wedd.
4.532 4.878 3.297 12.706
Schott
30.514 13.171 24.333 68.017




understory vegetation has moderate diversity and 25% of the area is nearly

dominated (24%) by Nephrolepsis biserrata (Sw.) Schott. The Cumulative

24

Species-Area Curve for Transect 2 (Figure 5) showed that the transect survey

covered the total species in the area sampled.


60

50

40
Species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Saccharum spontaneum L., an invasive Asian grass species (Graminae),

one of two wild species of sugarcane (Hammond 1999). S. spontaneum forms

dense, continuous thickets that inhibit the establishment of woody species

(Hooper et al., unpublished data) and are resistant to weed control measures due

to the species‘ deep and extensive root system. S. spontaneum resprouts

vigorously after fire (Peet, Watkinson et al. 1999; Peet, Watkinson et al. 1999).

25

4.2.1.3 Transect 3


three hundred thirty-one (331) individuals resolved to fifty-five (55) species.

Nephrolepsis biserrata (Sw.) Schott (Pakong Kalabaw) was the most abundant

species on record (101 individuals). Also, it is the densest species scoring 2.523

and has a relative density of 30.50% and the most frequent species, appeared 27

times, with a relative frequency of 30.17%. Donax cannaeformis (G. Forst.) K.

Schum (Bamban) was the most dominant species (1.94) with a relative

dominance of 19.9%.


SPECIES
Acrostiqhum aureum L. 3.474 3.286 4.881 11.642
Cylea merrillii Diels. 2.417 5.634 2.232 10.282
Donax cannaeformis (G.
8.459 11.268 14.505 34.232
Forst.) K. Schum
Lygodium flexuosum (L) Sw 5.287 7.512 4.184 16.983
27.341 8.451 11.158 46.950
Schott
Thespesia populnea (L.)
2.568 4.225 3.626 10.420
Soland ex Corr.
Zoysia matrella Linn. 5.891 3.756 3.068 12.715

26



followed by Saccharum spontaneum L. (Talahib) and Soleria scribiculata Nees

(Arat) scoring 21.77 and 17.74 respectively.


understory vegetation has moderate diversity and there is no species that clearly

dominates area. The Cumulative Species-Area Curve for Transect 3 (Figure 6)


60

50

40
Species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

showed that the transect survey might covered more species in the area

sampled.

4.2.1.4 Transect 4

27


six hundred sixty (660) individuals resolved to fifty-five (55) species.

Nephrolepsis biserrata (Sw.) Schott was the most abundant species on record

(203 individuals). Also, it is the densest species scoring 5.08 and has a relative

density of 30.76% and the most frequent species, appeared 32 times, with a

relative frequency of 15.76%. It is also the most dominant species (19.87) with a

relative dominance of 22.85%.



followed by Hypyis capitata Jacq. (Dilang Baka) and Donax cannaeformis (G.

Forst.) K. Schum scoring 34.30 and 18.98 respectively.

SPECIES
Alpinia zerumbet (Pers.)
2.424 4.433 1.580 8.438
Burtl. & Smith
Cylea merrillii Diels. 1.818 3.448 1.437 6.703
Dinochloa luconiae (Munro)
2.727 3.941 3.161 9.829
Merr. Babuai
7.727 4.926 6.322 18.975
Forst.) K. Schum
30.758 15.764 22.845 69.366
Schott
Nephrolepsis hirsutula 1.818 2.463 2.586 6.867

Paspalum conjugatum Berg. 3.788 3.448 4.023 11.259

Piper aduncum 1.364 3.448 1.724 6.536


28



(23%) dominated by Nephrolepsis biserrata (Sw.) Schott. The Cumulative

Species-Area Curve for Transect 4 (Figure 7) showed that the transect survey

had uncovered species in the area sampled.


60

50

40
Species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Hypyis capitata Jacq. is an introduced species originally from tropical

America but now pantropic, it could grow from near sea level to 750 m and is

usually found on degraded farmland and along roads and clearings in lowland

rain forest (Jacquin, 1787).

4.2.2 Kabugaw, San Pablo, Jabonga

4.2.2.1 Transect 5

29


five hundred eighteen (518) individuals resolved to fifty-one (51) species.








followed by Hypyis capitata Jacq. and Chromoloena odorata scoring 21.46 and

19.06 respectively.

Table 5. Ecological Measurements for Transect 5 in Kabugaw, Jabonga
SPECIES
Ipomoea obscura (L.) K.G 3.282 6.195 3.448 12.925
Nephrolepsis biserrata
11.776 9.735 12.787 34.298
(Sw.) Schott

30




showed that the transect survey covered the total species in the area sampled.

60

50

40

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

4.2.2.2 Transect 6

There are forty-four (44) quadrats positioned in Transect 6 covering a total

of five hundred sixty-five (565) individuals resolved to fifty-seven (57) species.





31



followed by Hypyis capitata Jacq. and Chromoloena odorata scoring 23.26 and

25.68 respectively.

Table 6. Ecological Measurements for Transect 6 in Kabugaw, Jabonga
SPECIES
2.655 3.879 3.766 10.300
Forst.) K. Schum
Lygodium flexuosum (L)
3.717 5.172 3.117 12.006
Sw
17.522 11.207 16.494 45.223
(Sw.) Schott
Spathoglottis plicata
9.558 6.897 9.221 25.675
Blurne
Thespesia populnea (L.)
2.478 4.310 2.987 9.775
Soland ex Corr.





60

50

40
Species No.

30 32
20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

4.2.3 Uba, San Pablo, Jabonga

4.2.3.1 Transect 7


four hundred eighty-nine (489) individuals resolved to forty-eight (48) species.

Hypyis capitata Jacq. was the most abundant species on record (94 individuals).

Also, it is the densest species scoring 2.35 and has a relative density of 19.29%

and the most frequent species, appeared 17 times, with a relative frequency of

9.44%. It is also the most dominant species (9.38) with a relative dominance of

10.85%.

Table 7. Ecological Measurements for Transect 7 in Uba, Jabonga

SPECIES
2.258 2.222 2.894 7.374
Burtl. & Smith
Centrosema pubescens
9.647 9.444 10.999 30.090
Benth.
2.668 2.778 3.618 9.064
Forst.) K. Schum

18.678 16.667 19.392 54.737
Schott
Paspalum conjugatum Berg. 8.621 3.889 5.933 18.443

Piper aduncum 2.258 3.333 2.460 8.051

33


Table 7 shows the top ten important species in the transect where Hypyis

capitata Jacq. had the highest importance value of 39.59 followed by

Nephrolepsis biserrata (Sw.) Schott and Centrosema pubescens Benth.

(Sentrosema) scoring 54.74 and 30.09 respectively.






60

50

40
Species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43

Centrosema pubescens is a vigorous, trailing, twining and climbing

perennial herb with trifoliate leaves and is fairly drought tolerant (Skermann,

1988).
34

It is native to Central America (extending to 22° N in Mexico) and South America

(Colombia) and is introduced as forage plant near sea level to 100 m. It is widely

distributed throuout the world but it is mostly found in the New World (Ren and

Gilbert, 2010).

4.2.3.2 Transect 8


five hundred fifty-nine (559) individuals resolved to fifty-two (52) species.







SPECIES
14.848 6.704 7.747 29.299
Burtl. & Smith
Centrosema pubescens
9.660 9.497 11.478 30.635
Benth.

Cyperus rotundus L. 5.188 1.117 1.435 7.740


Lygodium japonicum 1.431 3.352 2.152 6.935
Neotrewia cumingii
2.326 2.793 1.865 6.984
(Muell.-Arg) Pax & K.
16.279 12.849 17.073 46.201
(Sw.) Schott
Paspalum conjugatum
2.504 2.235 3.587 8.326
Berg.
35




followed by Alpinia zerumbet (Pers.) Burtl. & Smith (Barik) and Zoysia matrella

Linn. (Barit) scoring 29.30 and 23.63 respectively.





60

50

40
Species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Alpinia zerumbet (Family Zingiberaceae) is a perennial ginger growing

widely in the subtropics and tropics. It is used in folk medicine for its anti-
36

inflammatory, bacteriostatic, and fungistatic properties (Zoghbi, 1999). Zoysia

matrella (L.) Merr.), commonly known as Manila Grass, is one of the the most

commonly used lawn grass species and it typically grows more slowly and is less

cold-hardy, but is more tolerant to salinity and insect pests among other Zoysia

species (Patton, 2010).

4.2.3.3 Transect 9

There are forty-four (44) quadrats positioned in Transect 9 covering a total

of five hundred three (503) individuals resolved to sixty-three (63) species.

Alpinia zerumbet (Pers.) Burtl. & Smith was the most abundant species on record





Table 9 shows the top ten important species in the transect where Alpinia

zerumbet (Pers.) Burtl. & Smith had the highest importance value of 30.89

followed by Paspalum conjugatum Berg. (Carabao Grass) and Selaginella plana

Hieron (Kamariang Gubat) scoring 14.31 and 24.41 respectively.





37


SPECIES
Acrostiqhum aureum L. 3.380 4.813 4.559 12.751
16.302 8.556 6.029 30.888
Burtl. & Smith
Arachis pentoi 4.970 1.070 2.500 8.540
Caryota cumingii Lodd. 1.789 4.278 4.412 10.479
Caryota mitis 1.789 2.674 3.971 8.434
2.783 3.209 2.500 8.492
(Sw.) Schott
Paspalum conjugatum
11.531 1.604 1.176 14.312
Berg.

Paspalum conjugatum Berg. is a species under the genus Paspalum, one

of the most complex genera containing over 400 species that are largely endemic

to the tropics and subtropics of the world (Clayton and Renvoize, 1986). In

Nigeria, P. conjugatum is one of the species which are mostly straggling plants

grown in damp open places in the genus (Lowe,1989).

Selaginella plana Hieron is a naturally spreading species of Seleinella

through human introduction (Setyawan, 2011). Aging and drought causes the

color of S. plana to become darker reddish brown than young and humid ones

(Lu and Jernstedt 1996). In Sabah, Dayaks use S. plana to treat high fever and
38

headache (Ahmad and Raji 1992). S. plana leaves is drunk in decoction as tonic

for treatment postpartum (Harada et al. 2002).


70

60

50
Species No.

40

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
No. of Belt Transects

4.2.4 Magdagooc, Jabonga

4.2.4.1 Transect 10

There are forty-four (44) quadrats positioned in Transect 10 covering a

total of eight hundred forty-three (843) individuals resolved to fifty-two (52)

species. Hypyis capitata Jacq. was the most abundant species on record (135




39

Table 10 shows the top ten important species in the transect where Hypyis

capitata Jacq. had the highest importance value of 37.28 followed by .

Nephrolepsis biserrata (Sw.) Schott and Dimeria ornithopoda Trin., Fund. Agrost.

(T Plant) scoring 33.34 and 20.08 respectively.

SPECIES
8.660 5.654 4.853 19.166
Burtl. & Smith

Derris elliptica Benth. 4.745 6.360 5.109 16.214
Dimeria ornithopoda Trin.,
8.778 5.300 6.003 20.081
Fund. Agrost.
Dinochloa luconiae
6.406 1.767 2.043 10.216
(Munro) Merr. Babui

10.676 9.894 12.771 33.342
(Sw.) Schott


Table 10. Ecological Measurements for Transect 10 in Magdagooc, Jabonga





40

D. ornithopoda is a widespread, polymorphic species, in which a number

of infraspecific taxa has been recognized. It is often found in streams, moist

places, and is often gregarious (Shouliang and Phillips, 2006).

60

50

40
species No.

30

20

10

0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43

4.2.4.2 Transect 11

There are thirty (30) quadrats positioned in Transect 11 covering a total of

three hundred fifteen (315) individuals resolved to forty-three (43) species.

Selaginella plana Hieron was the most abundant species on record (14



41




Selaginella plana Hieron had the highest importance value of 64.35 followed by

Alpinia zerumbet (Pers.) Burtl. & Smith and Begonia nigritarum Steud. scoring

25.38 and 20.11 respectively.

Table 11. Ecological Measurements for Transect 11 in Magdagooc, Jabonga
SPECIES
11.111 9.009 5.263 25.383
Burtl. & Smith
Begonia nigritarum Steud.
11.429 3.604 5.075 20.107
Spp.
Costus malorticanus 1.905 2.703 3.947 8.555
Derris elliptica Benth. 2.857 3.604 1.504 7.965
Homolomena rubescens
3.175 2.703 6.767 12.644
(Roxb.) Kunth
5.079 5.405 5.827 16.312
(Sw.) Schott
Schimatoglottis spp. 5.397 5.405 7.707 18.509



(22%) dominated by Selaginella plana Hieron. The Cumulative Species-Area

Curve for Transect 11 (Figure 14) showed that the transect survey covered the

total species in the area sampled.

42

Begonia nigritarum is widely distributed in the Philippines and presents

considerable variation (Merrill, 1912). According to Hughes (2010), Begonia

nigritarum is considered doubtful, giving a total of 10 species, nine of which are

endemic in the Philippines.

50
45
40
35
Species No.

30
25
20
15
10
5
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

4.3 Diversity Index

Among the eleven (11) transect lines that were assessed, Transect 1

located at Dinarawan, Jabonga, Agusan del Norte scored the highest in

Simpson‘s Diversity Index. This value was described the understory vegetation

diversity as high. Transect 5 and 6 in Kabugaw and 7, 8, 9 10 in Uba, Jabonga

were considered also as highly diversified areas. Transect 4 followed by Transect

2, Transect 11, and Transect 3 were considered as moderately diversified.
43

The Simpson‘s Diversity Index ranged from 0.871 to 0.963 which indicates

that Jabonga, Agusan del Norte exhibits moderate to high diversity understory

flora composition. This also indicates that no species clearly dominates each

transect.

Figure 15. Simpson's Diversity Index of Understory Flora Vegetation in Jabonga

SIMPSON'S DIVERSITY INDEX
0.980 0.963
0.960
0.941 0.938
0.929 0.932
0.940
0.921
0.920
0.897 0.900
0.893
0.900 0.887
0.880 0.871

0.860
0.840
0.820
T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11

4.4 Assessment of Conservation Status

IUCN ver. 2012.2 database on threatened species showed that among

the 276 species recorded, Shorea contorta (White Lawaan) is a critically

endangered species and Pterocarpus indicus Willd. Forma indicus (Smooth

Narra), Vitex parviflora Juss. (Molave), Afzelia rhomboidea (Blanco) Vid.

44

(Tindalo), Dillenia philippinensis Rolfe (Katmon Baging), and Alangium

longiflorum Merr. (Malatapay) are vulnerable species, while Aglaia luzoniensis

(Kuling manok) is a near threatened species.

In the list of DAO 2007-1, there is one critically endangered species,

coded as CR A1cd, in the area, the Pterocarpus indicus Willd. Forma indicus

(Smooth Narra); one endangered: and Afzelia rhomboidea (Blanco) Vidal (coded

as EN A1cd); seven are vulnerable: Vitex parviflora Juss. (Molave) (VU A1c) ,

Cynometra inaequefolia A. Gray (Dila-dila) (VU A1c) , Dillenia reifferscheidia

Naves (Katmon Kalabaw) (VU A1c), Alangium longiflorum Merr. (Malatapay) (VU

A1c), Mangifera merrillii (Pahong Liitan) (VU A1c), Shorea contorta (White

Lawaan) (VU A1cd), Securinega flexousa (Muell,-Arg.) (Anislag) (VU A1c); and

two other wildlife species: Aglaia luzoniensis (Kuling manok) and Dillenia

philippinensis Rolfe (Katmon Baging)

Pterocarpus indicus is one of the commercial tree legume species that

dominate South-East Asia and some Pacific regions (Soerianegara & Lemmens

1993). It is one of the most valuable and commonly used reforestation species in

the Philippines. It is propagated by seeds and cuttings but seedling stocks are

mainly used for reforestation and rehabilitation of denuded land areas (Rise,

1995). Pterocarpus indicus grows on a variety of soil types from fertile

agricultural soil to rocky soil, along inundated river banks, swamps and lagoons

(Allen & Allen 1981, Corner 1988). It has the status of national tree in the

Philippines and has been identified by the Forest Research Institute Malaysia
45

(FRIM) as one of the potential ‗millennium tree‘ species for forest plantation

establishment in Peninsular Malaysia because of its fast growth and other

desirable characteristics (Appanah & Wienland 1993, Lok 1996). The timber of P.

indicus is classified as light hardwood and is used for light to heavy construction,

joists, beams and interior finishes. The wood, which is commonly traded as

rosewood, has beautiful distinct growth rings and is ranked among the finest for

furniture making, high grade cabinet work, carvings, decorative flooring and

musical instruments (Appanah & Weinland 1993, Soerianegara & Lemmens

1993).

Pterocarpus indicus was characterized as critically endangered and coded

as CEN A1cd which indicates that the species is critically endangered as its

population is reduced in the form of an observed, estimated, inferred or

suspected reduction of at least 80% over the last 10 years or 3 generations,

whichever is the longer, based on a decline area of occupancy, extent of

occurrence and/or quality of habitat and actual or potential levels of exploitation.

According to Orwa et al (2009), Vitex parviflora Juss. occurs most

commonly in comparatively dry regions in lowland forest, often in deciduous

forest on rocky ground, on grassy slopes and on dry limestone soils, but

sometimes also in littoral rain forest or hill forest. It is usually found in regions

with distinct wet and dry seasons. The species often occur gregariously in

secondary forest and primary forest, in association with Intsia, Pahudia, Sindora,

Toona and Wrightia species. V. parviflora tolerates a wide range of soils but
46

occurs mostly on dry limestone soils. Vitex timber is used for high-grade

construction, interior finishing, flooring, house building, shipbuilding, railway

sleepers and carving. The wood often takes on a yellowish- green or greenish-

brown tint when boiled in water.

Vitex parviflora Juss. is coded as EN A1cd, B2bc which indicates that the

species is endangered where its population is reduced in the form of an

observerved, estimated, inferred or suspected reduction of at least 50% over the

last 10 years or 3 generations whichever is longer, based on a decline area of

occupancy, extent of occurrence and/or quality of habitat and actual or potential

levels of exploitation; and the extent of occurrence of the species is estimated to

be less than 20,000 km2 or area of occupancy is estimated to be less than 2,000

km2, and estimates indicates continuing decline, inferred, observed or projected

in area of occupancy and area, extent and/or quality of habitat (Fernando et al,

2012).

Tindalo [Afzelia rhomboidea (Blanco) Vid.] of the family Caesalpiniaceae

is an endemic tree in the country that plays an important role in ecosystem

processes such as in biochemical and hydrological cycles. It also provides

habitat for wildlife and offers protection against soil erosion (Pandey, 2002).

Tindalo is a leguminous tree species and it is considered as one of the finest

wood in the country (Florido, 2001). It belongs to the Molave type forest which is

valued for its natural beauty and durability (DENR, 2001). At present, the global

conservation status of Tindalo is endangered both on 2001 by the Genetic
47

Resource Conservation for Timber of the Philippines (Fernando, 2001) and in

July 2002 by the Rainforest Action Network (2002).

Afzelia rhomboidea is coded as EN A1cd, B2c which indicates that the

species is endangered where its population is reduced in the form of an

observerved, estimated, inferred or suspected reduction of at least 50% over the

last 10 years or 3 generations whichever is longer, based on a decline area of

occupancy, extent of occurrence and/or quality of habitat and actual or potential

levels of exploitation; and the extent of occurrence of the species is estimated to

be less than 20,000 km2 or area of occupancy is estimated to be less than 2,000

km2, and estimates indicates continuing decline, inferred, observed or projected

in area, extent and/or quality of habitat.

The six vulnerable species coded as VU A1c were characterized to be

plants undergone population reduction in the form of a decline in area of

occupancy, extent of occurrence and/or quality of habitat while Shorea contorta

characterized coded as VU A1cd was said to be vulnerable as it undergone

population reduction in the form of a decline in area of occupancy, extent of

occurrence and/or quality of habitat, and actual or potential levels of exploitation.

Two other wildlife species Aglaia luzoniensis and Dillenia philippinensis

Rolfe are evaluated species but does not satisfy any of the categories Critically

Endangered, Endangered, or Vulnerable but have the tendency to become

threatened due to predation and destruction of habitat. This is equivalent to the

Lower Risk, least concern category of IUCN.
48

Based on the conservation assessment of Guingab (1994), there are three

endemic species, and fifteen economically important species in the area (as

shown in Table 12). Endemic species is described as- the taxon is confined to a

certain geographical region or its parts thus; it is unique and found nowhere else

in the world. The Economically important species are under this criteria on the

basis of known uses, these taxon that command high economic value are prone

to extinction because they tend to be over-exploited.

Table 12. Conservation Status of Understory Flora based on (Guingab, 1994)

Scientific Name Common Name Status
Canarium asperum Benth. Pagsahingin EIS
Ficus nota (Blanco) Merr. Tibig EIS
Ficus septica Burma f. var. septica Hawili EIS
Ficus ulmifolia Lam. Isis EC/VU
Lantana camara L. Coronitas EIS
Leca guineensis G. Don Mali-Mali EIS
Leucosyke capitellata (Poir.) Wedd. Alagasi EIS
Litsea glutinosa Sablot EIS
Macaranga tanarius (Linn.) Muell.-Arg Binunga EIS
Mallotus philippinensis (Lam) Banato EIS
Melanolepis multiglandulosa (Reinw ex Blume) Alim EC/EIS
Melastoma malabathricum Linn. Malatungaw EIS
Mussaenda philippica A.Rich Kahoy Dalaga EC
Polyscias nodosa (Blume) Seem. Malapapaya EIS
Premna odorata Blanco Alagao EIS
Semecarpus philippinesis Engl. Kamiring EIS
Vitex parviflora Juss. Molave VU/EIS

The threatened species described are mainly shrubs and saplings of

trees. These species could be vulnerable to habitat fragmentation caused by

logging and kaingin, to anthropogenic pressures brought by development plans,
49

housing projects, encroachment of agriculture in the uplands, frequent burning,

domestic animal grazing, temperature build-up at the forest fringe, and pollution,

and to introduction of invasive alien species that dramatically alter many

ecosystems in the world.

50

5. SUMMARY, CONCLUSION, AND RECOMMENDATIONS

The taxonomic understanding is critical to convene the challenges of

biodiversity conservation in the 21st century (Bhaskaran and Rajan, 2010). It is of

fundamental importance for understanding biodiversity and ecosystem

functioning, as it provides us with the data to explore and describe biodiversity

through scientific analysis. The study provides the basic information about the

understory flora species, which are currently found in Jabonga, Agusan del

Norte. Such a list could play an important role for the local and national

authorities interested in future to conserve and sustainable use the phyto-

diversity for the sustainable development of the area.

There are two hundred seventy-six (272) species of understory flora that

were recorded in Jabonga, Agusan del Norte resolved to a total of 95 families

and two hundred ten (210) genera. Of these species, thirty-three percent (33%)

were saplings, eighteen percent (18%) were vines and sixteen percent (15%)

were herbs. Euphorbiaceae (18 spp.) and Moraceae (17 spp.) family had the

most number of species that were under 4 and 14 genera, respectively. The

PAWB (1997) study recorded 219 floral species distributed in 84 genera and 78

families in the area surrounding Lake Mainit. Thus, this study extensively improve

the data recorded in the area.

Simpson‘s Diversity Index Value was calculated highest at 0.963 for

Transect 1 and lowest value of 0.871 for Transect 4 both transects are located in
51

Dinarawan, Jabonga. This shows that the area is moderately to highly diversified

and there is no one species that clearly dominates each transect. Such diversity

is of high priority in biodiversity conservation.

Under the National List on Threatened Philippine Plants, there is one

critically endangered species found in the area, the seedlings of Pterocarpus

indicus Willd. Forma indicus, one is endangered species, Afzelia rhomboidea

(Blanco) Vidal; seven are vulnerable: Cynometra inaequefolia A. Gray, Dillenia

reifferscheidia Naves, Alangium longiflorum Merr., Mangifera merrillii, Shorea

contorta, Securinega flexousa (Muell,-Arg.), Vitex parviflora Juss., and two are

considered as other wildlife species: Aglaia luzoniensis and Dillenia

philippinensis Rolfe. Under IUCN 2012 database Shorea contorta is a critically

endangered species and Pterocarpus indicus Willd. Forma indicus, Vitex

parviflora Juss., Afzelia rhomboidea (Blanco) Vid., Dillenia philippinensis Rolfe,

and Alangium longiflorum Merr. are vulnerable species, while Aglaia luzoniensis

is a near threatened species. These threatened species are at high risk in

possible forest exploition activities indicated by the presence of illegal logging

and kaingin. This further shows that Jabonga, Agusan del Norte deserve

consideration for urgent conservation support.

There are threatening species recorded in the area. The most abundant

species, Nephrolepsis biserrata (Sw.) Schott (Pakong Kalabaw) that dominates

73% or eight out of eleven of transects, have an exponential growth potential and

52

forms dense population which displaces native vegetation (Weber, 2003). Also

the presence of invasive species Chromolaena odorata (Hagonoy) and

Saccharum spontaneum L., (Talahib) with the abilities to form dense population.

Invasive species can have devastating ecological impacts and may be the

primary cause of biodiversity loss (Mack et al., 2000).

Selaganilla planna Hieron (Kamariang Gubat), a highly distributed

through human introduction, also dominates one of the transect (Transect 11).

Selaginella grow at various climatic and soil types, but generally require humidity

for better growing and need water for fertilization; its presence in an area

becomes indicator of habitat condition, including global warming and global

cooling (Setyawan, 2011).

These study compared with the dendrological assessment of the same

area of Mijares (2013), shows that there is a higher number of understorty flora

species (272) recorded than of the tree species (222). The understory flora

composition is thereby more diversed than of the tree species in the area. Thus,

the understory flora must be prioritized, in terms of biodiversity conservation,

more than the overstory flora community.

This floristic inventory is far from complete. The discovery of additional

native species is very likely and new exotic plant species could invade and

become established. It is recommended that a further exploration of the area

should be made to support preliminary results and to expand knowledge of plant

53

diversity and conservation. Also a continuous monitoring should be made

especially for plant species being threatened by utilization.

There is a need to increase awareness level of researchers, local

government, and communities nearby on critical flora resources and plant

diversity of the area through production and distribution of information materials,

like flyers, leaflet and the like preferably written in local dialects. Or in other

means, information dissemination regarding with the conservation and

biodiversity of the area must be done through symposiums.

Billboards to warn gatherers as a preliminary measure against illegal

cutting of plant species must be displayed around the area. A pictorial guide to

the identification of the floral species is envisioned in the near future. This should

be published to facilitate identification by students and researchers.

54

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