MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT
VIETNAM NATIONAL UNIVERSITY OF FORESTRY

STUDENT THESIS
Title

APPLICATION OF AUTOMATIC RECORDER AND SOUND ANALYSIS IN
SURVEYING THE PRESENCE AND DISTRIBUTION OF TARGETED BIRD
SPECIES IN NGOC LINH NATURE RESERVE, QUANG NAM PROVINCE.

Major: Natural Resources Management
Code: D850101
Faculty: Forest Resources and Environmental Management

Student: Le Thi Dinh

Student ID:1253091486

Class: K57 Natural Resources Management

Course: 2012 - 2016

Advanced Education Program
Developed in collaboration with Colorado State University, USA

Supervisor: Assoc., Prof., Dr. Vu Tien Thinh

Hanoi, 2016
1

ACKNOWLEDGEMENT
I would like to express my gratitude to Assoc., Prof., Dr.Vu Tien Thinh, my research
supervisor, without his supports, encouragements and patient guidance, I would not have been
able to complete my thesis on time for graduation. I am so grateful to Prof., Lee Macdonald
for his enthusiastic guidance to help us acquire initial knowledge about how to write a thesis
proposal.
I would like to extend my thanks to Ms. Nguyen Thi Hoa and Mr. Tran Van Dung,
members of the Department of Wildlife in Vietnam National University of Forestry for
guiding me to apply RAVEN software on process of analyzing data. There are no words to
show my appreciation to them for assisting and helping me during the period of two months
when I did my research in the office of the Department of Wildlife.
I desire to show how grateful I am to our teacher, Ph.D., Stephen J. Leisz, a teacher
from Colorado State University for helping me to improve my writing skills. Last but not
least, there are no words to show my appreciation to my friends and family for always getting
ready to help me during the entire process of doing research and going field works.

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ABSTRACT
For monitoring and protecting endangered species, it is necessary to figure out
accurate information on their presence and the habitats where they live. While traditional
survey method faces a number of difficulties during surveying, using automatic recorders in
researching offer significant promise for detecting bird species. In this study I examined the
utility of automatic recorders and the associated classification software (RAVEN software) as
a way to survey for wildlife, using 21 targeted bird species, divided into 5 orders and 9
families as examples. The survey was conducted at 11 study sites which belong to three
communes in Ngoc Linh Nature Reserve, Quang Nam province from 4th to 23th of June, 2016.
After data analyzing process, there are 9 bird species, divided into 4 orders and 5 families in
total of 21 targeted bird species in four different habitat types in Ngoc Linh Nature Reserve,

Quang Nam. However, the frequency of presence among them is not the same. While some
birds appear many times in a recording and various recordings, the others only appear a few
times in all recordings. There are differences among the active time during surveying time
(3.00-9.00 AM) of detected bird species. Some species often sing or call in the morning. The
other detected birds usually vocalize at dawn. After surveying, almost detected birds live in
Tra Tap commune and a small number of them live in Tra Linh and Tra Leng commune. In
addition, Medium to High Montane Broadleaf Evergreen Forest contributes the highest
percentage of detected birds in Ngoc Linh Nature Reserve. By contrast, Secondary Vegetation
makes up the smallest proportion of those.

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TABLE OF CONTENTS
ACKNOWLEDGEMENT
ABSTRACT
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
CHAPTER 1. INTRODUCTION ............................................................................................... 1
CHAPTER 2. STUDY GOAL AND OBJECTIVE ................................................................... 4
2.1. Goal ..................................................................................................................................... 4
2.2. Objectives ............................................................................................................................ 4
CHAPTER 3. STUDY SITES AND METHODOLOGY .......................................................... 5
3.1. Selection of study site .......................................................................................................... 5
3.1.1. Ngoc Linh Natural Reserve .............................................................................................. 5
3.1.2. The division of habitat types in Ngoc Linh Nature Reserve to place automatic recorders
in Ngoc Linh Nature Reserve ................................................................................................... 10
3.2. Research methodology ...................................................................................................... 17
3.2.1. Field survey .................................................................................................................... 17

3.2.2. Extracting data from recorders ....................................................................................... 20
3.3. Data analysis method ......................................................................................................... 25
3.3.1. Determining the composition of detected bird species. .................................................. 25
3.3.2. Determining the distribution of detected bird species. ................................................... 25
CHAPTER 4. RESULT ............................................................................................................ 27
4.1. Sounds of targeted bird species ......................................................................................... 27
4.2. Presence of targeted bird species in Ngoc Linh Nature Reserve. ...................................... 29
4.3. The distribution of detected bird species ........................................................................... 31
4.3.1. Spatial distribution.......................................................................................................... 31

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4.3.2. Distribution in relation to habitat ................................................................................... 32
CHAPTER 5. DISCUSSION ................................................................................................... 34
5.1. The presence of birds in Ngoc Linh Nature Reserve, Quang Nam province and the
detection from automated recorder. .......................................................................................... 34
5.2. Factors affect the distribution of targeted bird species in Ngoc Linh Nature Reserve,
Quang Nam Province. .............................................................................................................. 35
5.2.1. Factors affect spatial distribution of targeted bird species. ............................................ 35
5.2.2. Factors affect the distribution of targeted bird species in four different habitats. .......... 35
CHAPTER 6. CONCLUSION ................................................................................................. 39
REFERENCES
APENDIX

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LIST OF TABLES
Table 3.1. Meteorological data from weather station in Tra My district.................................... 7

Table 3.2. Plants found in Ngoc Linh Nature Reserve, Quang Nam ......................................... 8
Table 3.3. Vertebrate species recorded in Ngoc Linh Nature Reserve....................................... 9
Table 3.4. Composition of saplings in High Montane Broadleaf Evergreen Forest ................ 11
Table 3.6. List of targeted bird species in Ngoc Linh Nature Reserve..................................... 21
Table 3.7. Data sheet is used to collect information in each study site .................................... 25
Table 3.8. The list of detected bird species by using automatic recorders ............................... 25
Table 3.9. Bird distribution in different habitats in Ngoc Linh Nature Reserve ...................... 26
Table 4.1. The comparison between the sonogram of detected birds and the sonogram of
sample targeted birds. ............................................................................................................... 27
Table 4.2. The active time during surveying time (3.00-9.00 AM) of each detected bird
species....................................................................................................................................... 29
Table 4.3. List of detected bird species in Ngoc Linh Nature Reserve .................................... 30
Table 4.4. Distribution of detected birds in different communes in Ngoc Linh Nature Reserve ... 31
Table 4.4.The distribution of detected bird species in different habitats in Ngoc Linh Nature
Reserve ..................................................................................................................................... 33

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LIST OF FIGURES
Figure 3.1. Map of Ngoc Linh Nature Reserve .......................................................................... 5
Figure 3.2. High Montane Broadleaf Evergreen Forest in Ngoc Linh Nature Reserve ........... 12
Figure 3.3.Canopy Cover at 1,400 m ....................................................................................... 13
Figrure 3.4. Medium to High Montane Broadleaf Evergreen Forest in Ngoc Linh Nature
Reserve ..................................................................................................................................... 14
Figure 3.5. Canopy Cover at 900 m.......................................................................................... 15
Figure 3.6. Low Montane Broadleaf Evergreen Forest in Ngoc Linh Nature Reserve ............ 16
Figure 3.7. Secondary Vegetation in Ngoc Linh Nature Reserve ............................................ 17
Figure 3.8. An automatic recorder was attached to a tree in Ngoc Linh Nature Reserve. ....... 18
Figure 3.9. Map of study sites in Ngoc Linh Nature Reserve .................................................. 20

Figure 3.10. Spectrogram (frequency vs. time) displays of two broad categories of discrete
sound unit shapes ...................................................................................................................... 21
Figure 3.11. RAVEN software ................................................................................................. 23
Figure 3.12. Low quality recording .......................................................................................... 23
Figure 3.13. The process of converting spectrogram’s frequency by Audacity software ........ 24
Figure 3.14. Spectrogram Correlation process ......................................................................... 24
Figure 4.1. Spatial distribution map of detected birds in Ngoc Linh Nature Reserve.............. 32

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CHAPTER 1. INTRODUCTION
Bird (Aves) is a group of endothermic vertebrates, characterized by feathers, toothless
beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart,
and a lightweight but strong skeleton. Their bodies are covered with feathers and they have
wings. Feathers have three functions: flight, temperature regulation and display. There are
about 9,000 different species of birds, divided into 24 orders and 146 families, making them
become the most diverse class of endothermic vertebrates which includes mammal and bird.
Vietnam is one of the countries which have the rich bird diversity in the world. They are easy
to observe and identify because most species are active in the daytime. The avifauna of
Vietnam includes a total of 848 species, of which 12 species are endemic : Annam partridge
(Arborophila merlini), Chestnut-eared laughingthrush (Garrulax Konkakinhensis), Collared
laughingthrush (Garrulax yersin), Edwards’ pheasant (Lophura Edwardsi), Golden-winged
laughingthrush (Garrulax ngoclinhensis), Grey-crowned crocias (Crocias Langbianis),
Orange-breasted

laughingthrush

(Garrulax


annamensis),

Pale-throated

wren-babbler

(Spelaeornis Kinneari), White-throated wren-babbler (Rimator pasquieri), Vietnamese
Greenfinch (Carduelis monguilloti), Vietnamese Cutia (Cutia legallen), Black-crowned
Fulvetta (Alcippe klossi) and 9 species are rare or accidental. Of those, there are 43 species are
globally threatened (birdlist.org).
Currently, in Vietnam, there are many national parks and Biosphere Reserves with
diverse bird species. Ngoc Linh (Quang Nam) Nature Reserve is located in Tra Leng, Tra
Don, Tra Tap, Tra Cang and Tra Linh communes, Nam Tra My district, Quang Nam
province. Ngoc Linh (Quang Nam) Nature Reserve is situated on the eastern side of Mount
Ngoc Linh, the western face of which is included within Ngoc Linh (Kon Tum) Nature
Reserve, Kon Tum province (Tordoff et al, 2000). Ngoc Linh (Quang Nam) Nature Reserve
supports high levels of endemism in plants and animals. The Nature Reserve supports
populations of several plant species that are endemic to Vietnam, including Pinus dalatensis

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and Panax vietnamensis. Also, Ngoc Linh (Quang Nam) supports a population of the recently
discovered, endemic mammal species, Annamite Muntjac (Muntiacus truongsonensis).
Furthermore, the nature reserve supports one bird species, Golden-winged Laughingthrush
(Garrulax ngoclinhensis), whose known global range is restricted to the central Annamites.
Due to the presence of Golden-winged Laughingthrush and three other restricted-range bird
species, Ngoc Linh (Quang Nam) Nature Reserve qualifies for inclusion in the Kon Tum
Plateau Endemic Bird Area (EBA), the most recently discovered of Vietnam's four EBAs
(Tordoff et al, 2000). In addition, together with parts of the contiguous Ngoc Linh (Kon Tum)

Nature Reserve, the site qualifies as an important Bird Area (Tordoff et al, 2002). Ngoc Linh
Nature Reserve has recorded 194 bird species belonging to 33 families of 11 sets; including
10 species in Red book Vietnam; 8 species in IUCN; 09 species in Decree 32.
In Ngoc Linh Nature Reserve, Quang Nam province, there are many studies on bird
species which were conducted, such as Tordoff et al, (2000); Tordoff et al, (2002); Le Trong
Trai, (1999) etc. However, most of the surveys were conducted more than a decade ago.
Ngoc Linh Nature Reserve is facing many difficulties in monitoring its diversity. It
covers a large area and contains a variety of high mountains. Besides, surveying on bird
species by the traditional methods may lead to a range of limitations and often do not give
accurate information, resulting in numerous difficulties for conservation. Some methods can
hurt the bird. Besides, the investors could have trouble if they research in bad weather
conditions or in the night.
The management of endangered bird species requires detailed information on the
distribution and abundance of the species that is often hard to obtain. When bird species
communicate by using sounds, one option is to use automatic sound recorders to take
information on the species for long periods of time with low effort. Using automatic recorder
and sound analysis is a new method in surveying presence of birds. Autonomous acoustic
recorders are widely available and can provide a highly efficient method of species

2


monitoring, especially when coupled with software to automate data processing. Automated
examination of acoustic recordings with a field listening survey, using commercially-available
autonomous recorders and custom call detection and classification software (Andrew et al,
2013). This method was used in many researches on bird in many other different countries.
However, it is not a common method in Vietnam.
Facing this reality, with the desire to have more accurate information in terms of
presence and distribution of some birds in Ngoc Linh Nature Reserve, I decided to conduct
the study:

“Application of automatic recorder and sound analysis in surveying the presence and
distribution of targeted bird species in Ngoc Linh Nature Reserve, Quang Nam province”

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CHAPTER 2. STUDY GOAL AND OBJECTIVE
2.1. Goal
Applying automatic recorder and sound analysis method in surveying birds, providing
information for the study and protection of bird species in Ngoc Linh Nature Reserve, Quang
Nam Province.
2.2. Objectives
1. Determining the presence of targeted bird species in Ngoc Linh Nature Reserve,
Quang Nam Province.
2. Determining the distribution of targeted bird species in Ngoc Linh Nature Reserve,
Quang Nam Province.

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CHAPTER 3. STUDY SITES AND METHODOLOGY
3.1. Selection of study site
3.1.1. Ngoc Linh Natural Reserve
Ngoc Linh Nature Reserve covers an area of 18,430 hectares, with coordinates 15°00'
- 15°15' N, 107°56' - 108°07' E. It is located in Tra Leng, Tra Don, Tra Tap, Tra Cang and Tra
Linh communes, Nam Tra My district, Quang Nam - a province in Central area of Vietnam.
Ngoc Linh Nature Reserve has a high level of overall biodiversity, compared with other
national parks in Vietnam. It provides diverse and suitable natural conditions for a large
number of the world's plant and animal species, especially Endemic and Red-Listed Species.
Ngoc Linh Nature Reserve is also recognized for its unique flora, upper montane forest and a

nationally famous endemic medicinal plant such as Vietnamese Ginseng or Panax
vietnamensis (Tordoff et al, 2000).

Figure 3.1. Map of Ngoc Linh Nature Reserve
a. Geographical condition
Ngoc Linh Nature Reserve is located in Kon Tum Plateau which is a dominant
mountain range including a series of sharp peaks compared with other areas in the Central
5


Highlands. Each block mountain in this plateau is relatively far from other mountains. The
terrain in Ngoc Linh Nature Reserve is relatively steep, the slope usually ranges from 40° to
45° but sometimes, even reach 60°-65° in the northern part. Meanwhile, the highest mountain
is Ngoc Linh Mountain with 2,598 meter ASL. Other high mountains include Ngoc Lepho
(2,070 m) and Ngoc Pa (2,251 m) in east-south of this reserve. But the averaged slope seems
to be ranging from 900 to 1200 m due to the erosion in the north-west of Ngoc Linh Nature
Reserve (Tordoff et al, 2000).
b. Hydrology
In this area, there are two main river systems consisting of Tranh River and Leng
River. The upstream of Tranh River is located in the south of this reserve, which flows to the
north into the Thu Bon River that is an important river in Quang Nam province. Leng River
originates from the northwest of Ngoc Linh Nature Reserve that is a sub-river of Tranh River.
River and stream system of the area is short, narrow, steep and have fast flow. Therefore, it is
easy to wash away soil, resulting in soil erosion in some areas that has low forest cover. In the
rainy season, floods usually happen suddenly and regularly leading to riverbank erosion and
destroying the irrigation infrastructure. During the dry season, most of river systems are
drying up, except for some big streams and rivers. This leads to problems for agricultural
production and domestic water for local people in this area (Tordoff et al, 2000).
c. Soil
Available data shows that there are four major types of soil in Ngoc Linh Nature

Reserve including Highland Alittic Humus Soil, Feralit Humus Soil, Feralit Soil and River
and Stream Alluvial Soil.
Highland Alittic Humus Soil is usually found in elevations above 2,000m ASL and
temperature below 15°C. In spite of the thin aeolian and soil layer, soil is in humid state. It
can be explained by the thick upper humus layer (about 50 cm), especially in Ngoc Linh peak,
the humus layer may reach over 1 m thick. The total area of this soil type is roughly 7,600 ha,
accounting for 15.4% of the total area in this Nature Reserve.
6


Feralite Humus soil is usually found in the altitude ranging from 1000 to 2000m ASL.
The weather in this elevation is always humid and cool. The annual temperature is about 15°C
to 20°C. In this type soil, there is a large amount of humus that has been accumulated.
Besides, acidic and impermeable features are represented for Feralite Humus soil in this area.
Feralit Soil is distributed from 500 to 1,000m ASL, accounting for 21.2% of total land
area in Ngoc Linh Nature Reserve. This soil type is divided into Yellow and Red Feralite Soil
on Magmatic Acidic Rock in Lowlands; Brown and Red Feralite Soil on Magmatic Alkaline
and Neutral Rock in Lowlands; Yellow and Red Feralite Soil on Metamorphic Rock and Clay
Slate in Lowlands.
River and stream alluvial soil is created by the alluvium in riverbank and streams.
This type of soil which is also found at the foot of mountains or hills is grey, brown and
porous. Therefore it is usually used for agriculture cultivation because of its fertility.
d. Meteorology
The study site is in a remote mountainous area without any weather stations. The
following table shows some characteristics of representative data of the Nature Reserve’s
climatic conditions in Tra My district where Ngoc Linh Nature Reserve is located in.
Table 3.1. Meteorological data from weather station in Tra My district
Meteorological data

Weather station in Tra My district


Latitude

15°21’ N

Longitude

108°13’ E

Altitude (m)

200

Period of measurements

1978 to 1995

Total annual rainfall (mm)

3840

Maximum daily rainfall (mm)

403

Months of maximum rainfall

September, October, November, December

Rainy season


April to January

Dry season

February to March

Annual rainy days

173 days

Annual mean temperature (°C)

25.3

Annual humidity (% RH)

86

Evaporation (mm)

728 mm
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Ngoc Linh Nature Reserve is represented by humid tropical climate. But the difference
at the altitude from 500 to 2598 m ASL leads to various climate conditions. The average
annual temperature ranges from 22°C to 25°C in different regions. Rainfall rates also vary
with altitude (4000 mm in Ngoc Linh peak) which can cause storms and floods during the
rainy season. The dry season causes severe water shortages in the west of the Nature Reserve.

e. Flora overview
Several researches in Ngoc Linh Nature Reserve showed that there are 385 plant
species in 260 genera and 120 families (conducted in April-May 1996 and March-May 1998).
The number of threatened species is 45, of which 16 species are in IUCN Red List of threatened
species (IUCN 1997) and 34 species are listed in the Red Book of Vietnam. In this reserve,
there are totally 238 timber species, 169 medicinal species and 78 ornamental species.
Table 3.2. Plants found in Ngoc Linh Nature Reserve, Quang Nam
Order

Family

Genera

Species

Lycopodiophyta

2

2

2

Polypodiophyta

14

28

43


Pinophyta

3

5

7

Magnoliophyta

103

255

333

Total

122

260

385

In Ngoc Linh Nature Reserve, there are 9 endemic plant species of Vietnam. They are
Panax vietnamensis, Pinus dalatensis, Amentotaxus poilanei, Cinnamomum balansae,
Alchornea annamensis, Baccaurea silvestris, Bulbophyllum evrardii, Otochilus fuscus and
Calamus poilanei. (CITE)
Flora in Ngoc Linh belong to 26 families: Asteraceae, Orchidaceae, Rutaceae,

Poaceae,

Fagaceae, Moraceae, Euphorbiaceae, Araliaceae, Myrsinaceae, Cyperaceae,

Lauraceae , Rosaceae, Fabaceae, Apocynaceae, Theaceae, Ericaceae, Araceae, Meliaceae,
Anacardiaceae, Rutaceae, Lamiaceae, Polypodiaceae,Verbenaceae, Annonaceae, Mimosaceae
and Melastomaceae. A large percentage of the tree flora is dominated by species from the less
species-rich families such as Fagaceae, Lauraceae, Hamamelidaceae etc.
8


Pinus kesiya is known as a widespread species, both in monospecific stands and in
mixed forest. Several other coniferous species such as Pinus dalatensis, Dacrycarpus
imbricatus and Keteleeria evelyniana. They are not diverse; however they have particularly
large specimens.
There are a wide range of plant species which have the high values, especially for
traditional medicine. The Araliaceae consists of a large numbers of medicinal plant species,
such as the endemic Ngoc Linh Ginseng, which has been increasingly over-exploited day by
day and is endangered recently (Tordoff et al, 2000).
f. Fauna overview
In Ngoc Linh Nature Reserve, there are some surveys revealing a total number of 306
vertebrate species, including 52 mammal species, 190 bird species, 41 reptile species and 23
amphibian species.
Table 3.3. Vertebrate species recorded in Ngoc Linh Nature Reserve
Class

Orders

Families


Species

Mammals

7

21

52

Birds

11

33

190

Reptiles

2

14

41

Amphibians

2


6

23

Total

20

67

306

g. Forest types
According to available classification of Thai Van Trung (1978), there are four main
types of forest in Ngoc Linh Nature Reserve. They are High montane broadleaf evergreen
forest, medium to high montane broadleaf evergreen forest, low montane broadleaf evergreen
forest and secondary forest.
h. Forest and vegetation cover
Ngoc Linh Nature Reserve has a considerable forest cover area that makes up 88% of
the total area of this reserve. The primary forest has significant proportion with approximately
9


60% of the total area. There is available data show that the extent of rich and medium forest is
relatively high. These types of forest are distributed in medium and high altitudes in this area,
extending south into Gia Lai and Dak Lak provinces, north into Quang Nam province and
west into Laos (Tordoff et al, 2000).
g. Social features
In general, population densities are low. The average population density in the buffer
zone is about 18 people/km2. Meanwhile, the average population density of Vietnam is 232

people/ km2. Agricultural production in relatively stable in this area. The rate of conversion
from forest to agriculture for over 10 years was very low, compared with other parts of the
Highlands. However, deforestation for cultivation remains an obstacle for conservation in the
future. The reasons may be resulted from the population growth in this area and immigration
from other regions to live. Therefore, the conservation measures should concentrate on
handling the problem of population growth and migration to the southern part of the Tra My
district, especially paying special attention to the new economic zone of the buffer zone in
this reserve Tac Po (Tordoff et al, 2000).
3.1.2. The division of habitat types in Ngoc Linh Nature Reserve to place automatic
recorders in Ngoc Linh Nature Reserve
Based on topographic map, the classification of forest of Thai Van Trung (1978) in
Ngoc Linh Nature Reserve, combining with practical investigation, I divided the study sites
into four major different types of forest:
1. High montane broadleaf evergreen forest
2. Medium to high montane broadleaf evergreen forest
3. Low montane broadleaf evergreen forest
4. Secondary forest
In each habitat, we conducted to investigate the characteristics of topography, soil,
fauna, flora and the influences of local people on each habitat.

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3.1.2.1. High montane broadleaf evergreen forest
It is located in elevations above 1,700 m ASL on Ngoc Linh Nature Reserve. The
main soil type in this forest type is humus soils with a base of granite combined with rionite
and daxite rocks. This forest type consists of a range of mixture forest. The major plants are
broadleaf trees and conifers. Some flora families can be examples such as Lauraceae,
Fagaceae, Theaceae. Some conifers are found in this elevation such as Dacrycarpus
imbricatus, Podocarpus neriifolius, Pinus dalatensis and Dacrydium elatum. In which, Pinus

dalatensis makes up a large proportion in terms of number of trees. Epiphytic load is high in
this forest type: orchids and ferns are common. Trees in this forest type exhibit stunted and
xerophytic morphology due to strong winds, low nutrient availability and periods of drought.
This type of forest is divided into three layers:
- Emerergent layer: It can be considered a dominant tree layer in this forest type. With
from 80 to 150 cm in diameters and from 25 to 30 m height, Quercus spp., Dacrycarpus
imbricatus and Pinus dalatensis become the most remarkable emergent.
- Closed canopy: This type of forest is extremely diverse in species and forest cover
such as trees of the Araliaceae and Euphorbiaceae, small timber trees. Noticeably, the density
of these trees is about 6,000 trees/ha.
- Open Understorey, Shade-Tolerant Forest: This layer consists of types of trees in both
two aforementioned layers. It forms a continuum to the forest floor, including monocotyledons
and several dicotyledons leading to some other layers such as shrub and herb.
Table 3.4. Composition of saplings in High Montane Broadleaf Evergreen Forest
Taxon

Density

Eurya sinensis var. glabra

30%

Pentaphylax spp.

20%

Symplocos cochinchinensis

15%


Quercus chevalieri

10%

Neolitsea cambodiana

2%

Randia spp.

2%

Other species

21%
11


Figure 3.2. High Montane Broadleaf Evergreen Forest in Ngoc Linh Nature Reserve
3.1.2.2. Medium to High Montane Broadleaf Evergreen Forest
This forest type distributed from 1,000 to 1,700 m ASL, accounting for the largest
forest area in Ngoc Linh Nature Reserve. Its main types of soil consist of red, yellow and
brown feralite humus soil, with a base of bioclastic granite rock, basaltic extrusive rock and
altered slate. The soil layer is relatively thick, about 0.8m, soil erosion happens rarely.
Generally, this forest type seems to dominate. The characteristics of this undisturbed forest
are bushy canopy cover and a complicated forest structure with the richness in the
composition of flora species. In which, there are small areas that have been converted to
cultivation. Dacrydium elatum, Dacrycarpus imbricatus, Podocarpus kesiya and P.
neriifolius which are found in mountain sides and lower peaks, are some major kinds of
coniferous trees. Generally, this forest type is distributed far from habitation. Consequently,

areas visited during the field survey exhibited low levels of disturbance, with human impact

12


limited to hunting and non-timber forest product collection. The forest canopy is closed and
even, and most gaps are the result of natural tree fall. Canopy cover is approximately 80%.

Figure 3.3.Canopy Cover at 1,400 m
(Source: Tordoff et al, 2000).
Broadleaf trees make up a considerable percentage at these altitudes, especially species
of two families including the Fagaceae and Lauraceae. Some species of Michelia, Manglietia
and Magnolia are examples of the Magnoliaceae. The Sapotaceae is represented by a
significant proportion of Madhuca pasquieri, with a mean diameter of 40 to 50 cm.
At an altitude of 1,400m ASL, vegetation in the medium montane broadleaf evergreen
forest is divided into three layers:
13


- Canopy layer: The height of tree in this layer is from 11.6 m. The members of families
including Fagaceae (Lithocarpus spp., Quercus spp. and Castanopsis spp.), Lauraceae (Litsea
sp. and Cinnamomum spp.), Podocarpaceae (Podocarpus imbricatus and Dacrydium elatum)
and Araliaceae (Macropanax simplicifolius and Schefflera sp.) are dominated in canopy layer.
- Emergent Layer: Trees in this layer are distributed from 19 to 22 m height, 20.2 m
height in average. Plant species in emergent layer are relatively similar to canopy layer.
- Ground layer : This layer is dominated by shrubs, such as Melastoma sp. and
Lasianthus sp., lianas, such as Smilax sp., and herbs, such as Hedyotis sp. and Alpinia sp.
Ground layer also is home of saplings and seedlings of some canopy species. This shows that
natural regeneration is occurring.


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3.1.2.3. Low Montane Broadleaf Evergreen Forest
This type of forest is located from an altitude of 150m (in the North-East of Ngoc Linh
Nature Reserve) to 1000m ASL. Plant species in this forest type are relatively diverse,
consisting of a variety of different families.

14


Local people usually live near to low montane broadleaf evergreen forest. Therefore, a
large proportion of this forest type have been cut and cleared for cultivation, especially in the
south of this reserve in Tra Linh commune. Meanwhile, in other communes such as Tra Leng
and Tra Tap communes, rich forest which close to numerous villages still remains.
At an elevation of 900 m ASL, canopy cover is approximately 85%. The vegetation is
relatively sparse.

Figure 3.5. Canopy Cover at 900 m
(Source: Tordoff et al, 2000).
Low montane broadleaf evergreen forest is divided into 4 layers:
- Emergent layer: It includes a small number of large trees which consist of Canarium
album and Madhuca sp.

15


- Canopy layer: This layer in low montane broadleaf evergreen forest is considerably

greater than that of medium montane broadleaf forest. Plant species are diverse. Noticeably,
several specimens of Canarium album have DBHs more than 100 cm.
- Middle layer: Smaller trees restricted to this layer include members of the
Euphorbiaceae, Rubiaceae and Annonaceae.
- Ground Layer: The ground layer vegetation is less abundant than that of high montane
broadleaf evergreen forest, and dominated by shade-tolerant species including ferns
(Adiantaceae, etc) and palms (Pinanga duperreana and Calamus spp.)

Figure 3.6. Low Montane Broadleaf Evergreen Forest in Ngoc Linh Nature Reserve
3.1.2.4. Secondary Vegetation
Since local people cultivated rotational swidden, a considerable area of secondary
vegetation are created in Ngoc Linh Nature Reserve, about 5,008 ha in total, accounting for
27% of the total area. Almost this area contains scrub and scattered broadleaf trees. But in
some sites where soil fertility has been relatively depleted due to over-exploitation or repeated
16


burning, areas of grassland become smaller. Moreover, the vegetation has been recovered for
a long time after cultivation, secondary forest has regenerated.
Secondary vegetation is located at elevations up to 1,800 m ASL, from villages to the
edge of the primary forest. In Ngoc Linh Nature Reserve, Quang Nam, it mainly distributed in
Tra Leng commune. This vegetation is combined with cultivated hill fields and remnant
patches of primary forest.

Figure 3.7. Secondary Vegetation in Ngoc Linh Nature Reserve
3.2. Research methodology
3.2.1. Field survey
Firstly, I put the automatic recorders in the habitats that are divided into four types
(Table 3.5) in Ngoc Linh Nature Reserve, Quang Nam Province. These locations were
determined based on topographic conditions and consulting with staffs in Ngoc Linh Nature

Reserve, Quang Nam Province. In total, 11 sites were surveyed. The coordinates of these sites
were marked and saved by GPS.
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Each recorder has a microphone on both the left and right side and was attached to a
tree. The recorders were set to record the bird songs. The recording was saved to the disk at
30-minute intervals to prevent the loss of the entire recordings in the event when the batteries
ran out. The batteries were replaced every week. The process of recording took place 19 days
from 4 to 23 June, 2016.

Figure 3.8. An automatic recorder was attached to a tree in Ngoc Linh Nature Reserve.
Table 3.5. Characteristics of study site in Ngoc Linh Nature Reserve
Study
sites

1

2

3

Recorder

Geographical

Elevation

ID


coordinates

(m)

SM304785

SM305194

SM304785

816286 N
1683013 E

816073N
1683098 E
820908 N
1668061 E

1348

Habitat types

Location

Medium to High

Village 4,

Montane Broadleaf


Tra Leng

Evergreen Forest

commune
Village 4,

1307

Secondary Vegetation

Tra Leng
commune

2223

18

High Montane

Village 4,

Broadleaf Evergreen

Tra Linh