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

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM NATIONAL UNIVERSITY OF FORESTRY STUDENT THESIS Title APPLICATION OF AUTOMATIC RECORDER AND SOUND ANALYSIS IN SURVEYING THE PRESENC

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

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

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

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

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

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

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

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

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

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”

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

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

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

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

Period of measurements 1978 to 1995

Months of maximum rainfall September, October, November, December

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

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

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

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

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

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

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

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:

- 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

F

ig Mem to Hig Mo Brof Eve Fost in Ngc L Na Reserve

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

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

- 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

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

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

Recorder

ID

Geographical coordinates

Elevation (m)

Habitat types Location

1 SM304785 816286 N

1683013 E 1348

Medium to High Montane Broadleaf Evergreen Forest

Village 4, Tra Leng commune

2 SM305194 816073N

1683098 E 1307 Secondary Vegetation

Village 4, Tra Leng commune

3 SM304785 820908 N

1668061 E 2223

High Montane Broadleaf Evergreen

Village 4, Tra Linh

Forest commune

4 SM304814 822080 N

1668001 E 1753

High Montane Broadleaf Evergreen

Forest

Village 4, Tra Linh commune

5 SM305194 821160 N

1668330 E 2008

High Montane Broadleaf Evergreen

Forest

Village 4, Tra Linh commune

6 SM304785 830045 N

168396 E 871

Low Montane Broadleaf Evergreen

Forest

Tra Tap commune

7 SM304785 825369 N

1680173 E 1342

Medium to High Montane Broadleaf Evergreen Forest

Village 4, Tra Tap commune

8 SM304814 829875 N

1684084 E 922

Low Montane Broadleaf Evergreen

Forest

Village 4, Tra Tap commune

9 SM304814 825696 N

1680947 E 1442

Medium to High Montane Broadleaf Evergreen Forest

Village 2, Tra Tap commune

10 SM305194 830560 N

1684252 E 690

Low Montane Broadleaf Evergreen

Forest

Village 4, Tra Tap commune

11 SM305194 825676 N

1681090 E 1428

Medium to High Montane Broadleaf Evergreen Forest

Village 2, Tra Tap commune

The location of 11 study sites in Ngoc Linh Nature Reserve was described in this map below: