Mangrove Regeneration Survey Protocol Manual_0.pdf · specific conserve protecting damaged 8 9....

Mangrove Regeneration Survey Protocol - a field manual -

CREDITS

This manual has been produced with support from Rufford Foundation as part of a

Rufford small grant.

Project Design : Bhanu Sridharan and Tasneem Khan Protocol : Bhanu Sridharan

Field Work : Bhanu Sridharan and Vishal Kujur Manual Design and Illustrations : Pooja Gupta Images : Tasneem Khan Volunteers: Nayantara Lakshmanan, Camille Mancion, Phillip Samson, Rohan Nongpiur, Nicholas Davies

All content and images used in this document are owned or licensed by

ANET for use in this document only. Unauthorized use is prohibited.

Copyright:

The Andaman and Nicobar Island’s Environmental Team (ANET) Post Bag No.1, Junglighat P.O. Port Blair - 744 103, Andaman and Nicobar Islands. INDIA Phone: +91 - 3192 280081 | www.anetindia.org

http://www.anetindia.org/

CONTENTS

Introduction ............................................................................. 06

Where do I come in? …………….………………………………………………………… 08

How to use this protocol? .......................................................................... 09

Section 1: The Study Area ……………………..…………………….. 11

Selected Sites……………………………………………….. 13

Section 2: Data Collection………………………………………….. 14

Annual Counts: Plant populations and

compositions…………………………………………………..

14

Quarterly Counts: Factors affecting

regeneration……………………………………………………

18

Light Availability……………………………………………… 22

Measuring Soil Characteristics………………………… 24

Monthly Counts: Survival and Herbivory…………. 28

Section 3: Data Entry and Schedule………………………………… 30

Conclusion ………………………………………………………………………. 31

8 9

INTRODUCTION

Mangrove forests in the Andaman Islands have declined from 1000 km² in

1977 to 2003 (FSI 2003). In the recent years, several attempts have been made to

conserve and restore mangrove forests. The 2004 earthquake and tsunami particularly

raised interest in restoration of mangrove forests, primarily to serve as bio-shields

protecting the coastline. Huge amounts of resources have thus been spent to restore

coastal vegetation, but often in an unscientific and arbitrary manner. Restoration

activities mainly include planting exotic trees such as Casuarina spp. or monospecific

mangrove stands comprising a few fast growing species such as Rhizophora spp.

Such practices can lead to further loss of biodiversity and valuable ecosystem services

that these habitats provide.

True ecosystem restoration can be difficult in mangroves, because we know so little

about the natural regeneration process of these dynamic ecosystems. This knowledge

becomes more important in the Andaman context as these processes are very site

specific. Improving our understanding of factors important for natural recovery after

destruction or damage of mangroves can help to improve success in restoration.

These factors comprise both large scale changes brought in by natural disasters like

the tsunami and earthquake and microhabitat characteristics that differ for individual

plant species. The 2004 tsunami and earthquake caused damage to mangrove

forests in the islands. However, the event also provided us with an opportunity to

understand how mangrove forests naturally recover from large disturbances.

Understanding this process is vital to developing effective restoration techniques.

We hope to do this by monitoring natural regeneration in a mangrove forest patch

damaged by the 2004 earthquake and tsunami. The site, located in the Lohabarak

Crocodile Sanctuary, adjacent to the ANET field station, offers us the opportunity to

understand how mangrove forests recover from natural disasters, which plant

species colonize a disturbed patch and what factors affect their survival.

This study also aims to create accurate checklists of flora and fauna of

mangrove forests of the Andamans necessary for future researchers as well as

management authorities planning conservation activities.

WHERE DO I COME IN?

Understanding natural phenomena, such as how plant communities respond

to various events, requires huge amounts of information, collected over long periods

of time. Mangrove plants are affected by multiple events. Natural disturbances like

cyclones, thunderstorms and the rare tsunami; the way tides flood an area; sudden

increase in a particular insect species and of course the presence and activities of

human communities in the surrounding areas. In addition to this, different seasons

leading to an increase in temperature, humidity or rainfall can impact particular

species. This means in order to truly understand how mangrove forests regenerate

after natural disturbances we need to collect lots of different kinds of information.

This takes time and people. This is where you come in.

Scientists are increasingly counting on citizens with any interest in the natural

world to provide them information. Volunteers like you can help us collect data by

following some simple steps laid out in this protocol. Depending on time and

duration of your visit, you will be able to contribute to a particular stage of data

collection. All you have to do is step into the mangrove forest right in our backyard.

HOW TO USE THIS PROTOCOL

This protocol explains how this study is designed and how each task must be

carried out. The protocol is divided in four sections:

Section 1 describes the study area and location of each permanent plot.

Section 2 covers the data collection process. Changes in plant communities are

slow and have to be covered in a staggered fashion.

This section covers the annual measurements- i.e. the number of plants

regenerating and different species coming up; the quarterly measurements, of

micro-habitat features such as soil characteristics, level of inundation and light

availability; covers monthly measurements - here we follow individual saplings and

seedlings and see if their survival is affected by herbivory.

Section 3 provides a complete time table of activities.

Please read this carefully before collecting data for this project.

11

12

North Andaman

Middle Andaman

South Andaman

Study Area (Wandoor)

Little Andaman

Fig 1 (a)

SECTION 1 | The Study Area

The Andaman and Nicobar archipelago is a group of over 300 islands situated

in the Bay of Bengal (60 - 140 N and 910 – 940 E). The islands comprise a variety

of habitats - coral reefs, mangrove forests and tropical rainforests - and several

endemic flora and fauna with evolutionary links to the Western Ghats, Indo-

Burma region and Sumatra. The study is being conducted in a riverine mangrove

forest patch in the Lohabarak Crocodile Sanctuary, in the South Andaman Island

(Map). Located in a sheltered bay, the study site adjoins coral reefs in the seaward

side and littoral forests on the landward side. As the name suggests, this area is

also an important habitat for saltwater crocodiles (Crocodylus porosus).

Plant composition in the mangrove patch is dominated by true mangrove species such

as Rhizophora mucronata, Avicennia offiicials , Bruguiera gymnorrhiza and

Lumnitzera littorea as well as mangrove associates such as water coconut Nypa

fruticans and the mangrove palm Phoenix paludosa.

Mangrove plants are known to form certain clusters or ‘zones’ based on species.

The study site exhibits some of this species zonation with an Avicennia

dominated zone and a Rhizophora zone. These zones also form the intact patches

of the mangrove. The damaged area lies in between these two zones.

Fig 1(a) shows the Andaman Islands. Circled region is the study area, the Lohabarak

Crocodile Sanctuary in South Andaman Island.

13

14

ANET Intact Avicennia

zone T1 T7

Littoral T5 Beach

Forest T2 T3 T4

Damaged zone

T6

Intact Rhizophora zone

Fig 1 (b)

Selected sites

Based on these species zonation patterns, levels of damage and tidal inundation,

the study site has been divided into seven transects or lines (measuring 50m in

length). Each transect has three circular plots of 10m radius [see Fig 2]. All

features of mangrove forest regeneration are measured within these circular plots.

The seven transects are placed in three distinct zones: Avicennia Intact zone,

Rhizophora Intact Zone and the damaged zone [see Fig 1(b)].

The centre point of each circular plot is permanently marked with a pole. The pole

also has a unique ID number based on the transect and location of the plot.

For example: The fi transect in the study site is called T1. Within T1, the first plot

is called P1. Thus the ID of the plot is T1P1. The second plot within T1 is called

T1P2 and so on (see Fig 2).

Fig 2: Shows the 50m transect line with three circular plots (measuring 10 meters in radius)

15

10m T₁P₁

50m

T₁P₂

T₁P₃

empty clam shell mounds in remarks.

• Seedlings and saplings are plants measuring 200 cm or less in height. • Adult trees are plants measuring more than 200 cm.

16

SECTION 2 : DATA COLLECTION

ANNUAL COUNTS: Plant population and composition

This stage allows for broad understanding of the regeneration patterns in this

mangrove patch. The objectives of this stage are to document the changes in adult

tree composition and regeneration patterns after the 2004 earthquake and tsunami

by measuring:

• The total number of plant species in the damaged and intact portions of the mangroves.

• Ratio of seedlings and saplings to adult trees of different species in damaged and intact portions of the mangrove forest.

• Changes in species zonation patterns.

Methodology

1. Note down time, date, plot ID and observer name in the data sheet.

2. Count all trees, saplings and seedlings* in the plot within a 10m radius from the center pole and note down species name.

- 100 cm

- 80 cm

- 60 cm

Frequency: Once a year

Time: Low tide; day time. Check the tide table for low tide and high tide timings

before heading out. Ideally begin work an hour before low tide time mentioned in

the tide table.

3. Measure the girth (i.e. circumference) of each tree above the roots.

- 40 cm

- 20 cm

- 0 cm

How many: 21 circular plots

Estimated time for each plot: 1.5 hours

Equipment:

4. Measure the height of each seedling and sapling in the plot.

5. Note down features like flowering, fruiting.

6. Record presence of human activity such as lopping, felling,

• Notebooks. • Pens. • Measuring tapes

(up to 10m). • Field guide.

• A 1m calibrated

pole (ideal for measuring sapling and seedling height).

17

**If a species is not familiar, take photographs note down the number in the data

sheet. While entering data give each unidentified species a code according to the

plot ID and a unique letter (e.g. T1P1_A) Finally name all the photographs

accordingly and save it in the mangrove database, in the folder titled Unidentified

Check field guides in the ANET library to try and ID them.

18

PLANT REGENERATION MOCK DATA SHEET

PLANT REGENERATION MOCK DATA SHEET

Researcher: Nayantara, Bishal Date: 20/09/2014

Location: Lohabarak Time: 9:40am

Grid

Plot

Species*

GBH (cm)

Height (cm)

Flowers

(y/n)

Fruits (y/n)

Coppicing

(y/n)

UID*_Photo No

Remarks

1 1 AO 30 800 n n y Branches lopped

1 1 RA - 20 n n n

1 1 T1P1_A** 24 n n n T1P1_A**

1 1 RA 20 400 n n n

1 2 BG 40 1000 n y n

1 2 T1P2_A** 45 1200 n y n T1P2_A** Two BG trees nearby felled

1 2 T1P2_B** 23 n y n T1P2_B**

*SPECIES CODES

1. Avicennia officials AO

2. Bruguiera gymnorrhiza BG

3. Rhizophora apiculata RA

4. Rhizophora mucronata RM

5. Lumnitzera littoralis LL

6. Ceriops decandra CD

7. Ceriops tagal CT

8. Nypa fruticans NF

9. Phoenix paludosa PP

10. Pandanus Pan

11. Exoceria alogacha EA

12. Heritiera fomes HF

13. Heritiera littoralis HL

14. Casuarina equestifolia CE

19

- 100 cm

- 80 cm

- 60 cm

- 40 cm

- 20 cm

20

QUARTERLY COUNT: Factors affecting regeneration

To understand mangrove regeneration, it is important to track, environmental factors

such as tidal inundation, light availability and soil characteristics.

Tidal Inundation

Tidal inundation is an important feature of mangrove forests. The amount of salt

water entering mangrove forests and duration of flooding can determine the type of

plant species growing in an area. For instance, Rhizophora species are believed to

require regular tidal flooding while Brugueira species are considered to prefer drier

areas with less frequent tidal water input. Tracking tidal cycles and comparing it with

species composition will help us verify this.

Frequency: One tidal cycle in 3 months (Ideally January, May, September)

Time: High tide, day time (ideally 1 hour before the high tide time on tide tables)


Equipment: • A 1m calibrated pole

Methodology

1. Check the tide chart and mark a 15 day period between Spring tide (full moon or new moon) and Neap tide (First or last quarter).

2. Within this 15 day period measure one transect a day (i.e. three plots a day). Each transect should be measured twice in the tidal cycle, once at the beginning of spring tide and once at the beginning of neap tide (See Mock Schedule according to Tide Table).

3. To measure water level, take the calibrated pole during high tide, and place it at the centre of each plot. Note down the length of the stick immersed in water (in cm) (See Mock Data Sheet).

21

22

This is a time table for September 2014. The tidal cycle for collecting inundation data

occurs between September 2, 2014 and September 15, 2014. The times marked in

red, are the high tide times when you have to collect data. Please remember to go one

hour before the time mentioned in the tide table. The column ‘Transect’ refers to the

transect (i.e. the three plots) that should be covered while collecting this data.

INUNDATION DATA MOCK SCHEDULE

September 2014 Day High Low Moon Sunrise Sunset Transect

Mon 1 12:22 PM IST / 1.84 m

6:36 PM IST / 0.65 m

5:08 AM IST 5:29 PM IST

Tue 2 1:13 PM IST / 1.69 m

7:29 PM IST / 0.78 m First Quarter 5:08 AM IST 5:28 PM IST T1

Wed 3 2:30 PM IST / 1.56 m

8:55 PM IST / 0.88 m

Data

Collection

Period

5:08 AM IST 5:27 PM IST T2

Thu 4 4:24 PM IST / 1.54 m

10:46 PM IST / 0.87 m 5:08 AM IST 5:27 PM IST T3

Fri 5 6:00 PM IST / 1.67 m

5:08 AM IST 5:26 PM IST

Sat 6 6:28 AM IST / 1.99 m


Sun 7 7:22 AM IST / 2.16 m


Mon 8 8:09 AM IST / 2.31 m


Tue 9 8:51 AM IST / 2.40 m

3:11 PM IST / 0.16 m Full Moon 5:08 AM IST 5:24 PM IST T7

Wed 10 9:32 AM IST / 2.42 m

3:48 PM IST / 0.13 m

Data

Collection

Period

5:08 AM IST 5:23 PM IST T1

Thu 11 10:11 AM IST / 2.37 m


Fri 12 10:49 AM IST / 2.26 m


Sat 13 11:26 AM IST / 2.09 m


Sun 14 12:04 PM IST / 1.90 m


Mon 15 12:45 PM IST / 1.69 m


Tue 16 1:39 PM IST / 1.51 m

7:38 PM IST / 0.92 m Last Quarter 5:08 AM IST 5:19 PM IST T7

23

INUNDATION MOCK DATA SHEET

Researcher: Philip, Cami, Bishal Date: 20/09/2014

Location: Lohabarak Time: 9:40 am

Tide: Spring

Transect Plot Depth (cm) 1 1 25 1 2 30 1 3 40 2 1 10 2 2 15 2 3 20 3 1 60

24

LIGHT AVAILABILITY

Plant species vary in the amount of sunlight they require. Some species thrive in

open areas with maximum sunlight while others will wither and die. For managers

planning restoration by planting mangrove species, understanding which species are

light tolerant and which are not is vital information.

Frequency: Once in 3 months (Ideally January, May, September)

Time: Day time, noon (Time should be constant throughout the monitoring period)


Equipment: • A digital camera

Methodology

1. In order to measure light, simply put a digital camera on shutter priority mode and fix the shutter speed to100 and ISO to 200.

2. From the centre of the plot, walk approximately 5m and point the camera towards the sky and take a picture.

3. Repeat this from all cardinal directions.

4. Note down the photo id numbers from the camera for each plot.

5. To store the photos: Label the images according to the Quarter (e.g. Q 1), plot ID (e.g. T1 P1), and image code (xxx). So the image name will look something like this: Q1_T1P1_xxx.

6. In the mangrove database, find the folder labelled > Quarterly canopy images. Within this find the folder corresponding to the months when you took the pictures, e.g. October-December 2014. Save the images within this folder. Ensure that the image numbers from the camera (noted in the data sheet) match the images codes given in database.

25

LIGHT AVAILABILITY MOCK DATA SHEET

Researcher: Philip, Vishal Date: 20/09/2014

Location: Lohabarak Time: 12 noon

Tide: Spring

Transect Plot Photo Id 1 1

1 2

1 3 2 1 2 2

2 3

3 1

26

MEASURING SOIL CHARACTERISTICS

The type of soil can tell us which plant species may survive and thrive in a particular

site. With changes brought in by the tsunami and earthquake of 2004, the soil

characteristics in a mangrove forest may have changed drastically. To document these

changes we measure two things on fi soil pH and soil salinity.

SOIL pH

Time: Low tide, ideally 1-2 hours after high tide recedes.

How many: 21 circular plots.

Equipment: pH meter

A metal pipe for digging

Methodology

1. To measure amount of phosphorous in the soil dig a hole, approximately 15-25 cm into the soil using a metal pipe in each plot.

2. Dip the electrode of the pH meter in the 15-25 cm hole and press hold.

3. When the reading on the screen stabilizes note it down.

4. Wash the pH meter with distilled water before reusing.

Hold / Ent

Cal

On / Off

pH Meter.

27

QUATERLY MEASUREMENT: SOIL CHARACTERISTICS

Researcher: Philip, Vishal Date: 20/09/2014

Location: Lohabarak Time: 12 noon

Tide: Spring

Plot ID PH Salinity (%) Temperature (Celsius) T1P1 7 30 20 T1P2 8 33 21 T1P3 7 30 18 T2P1 7.5 32 23 T2P2 7.3 31 24 T2P3 8.2 30 20

SOIL SALINITY

Daylight Plate

Eyepiece Prism

• After a salinity and temperature reading for a plot has been has been completed, wipe the label off the vial to reuse it.

• Clean the lens of the refractometer with distilled water after each reading. • Wash the syringe and vials with distilled water

28

The amount (percentage) of salt in the soil of a particular plot can help us understand

the level of salt tolerance of the plant species found there.

Frequency: Once in 3 months (Ideally January, May, September).

Time: Low tide, ideally 1-2 hours after high tide recedes.

How many: 35 circular plots.

Equipment:

Methodology

1. Salinity can be measured from water that collects in the holes dug for soil pH sampling.

2. Wait for a few minutes to allow water to percolate in the hole.

3. Collect the water with a syringe and deposit into a vial.

4. If no water collects, collect the wet soil in the hole and put it in the syringe and squeeze water out into the vial.

5. Label the vial with Plot ID for analysis back at the base.

6. Measure the temperature of the water before collecting it and note it down in the data sheet below.

7. Put one drop of water on the lens of the refractometer. Now point towards the sun and look through the eye-piece while adjusting the dial at the end of the refractometer to focus.

• A hollow metal pipe • A 3-5ml syringe • Distilled water

• Filter paper • Refractometer • Thermometer

Note: A refractometer measures the change in the movement of light as it passes from atmosphere to water. Light moves slower in water and the salt in water further reduces the speed.

Eyepiece

8. You will notice scale measurements with percentage readings one side and ppt readings on the other’, shaded in blue and white.

9. There is a line that separates the blue portion from the white on the scale. This is the reading. Note down the percentage reading from the right hand side at this point.

10. All readings from a refractometer must be taken at 12 noon each

time, and from the same place (the area outside the ANET hall is ideal).

29

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MONTHLY COUNTS : Survival and Herbivory

Insects, fungi and small marine invertebrates such as snails feed extensively on

mangrove leaves, a process called herbivory. While adult trees can tolerate a certain

amount of herbivory, young plants that have very few leaves often cannot deal with

the onslaught. Herbivory is an important process that determines how many young

plants will survive to adulthood. With this project we hope to understand:

• How many young plants are susceptible to herbivory • Which mangrove plant species are more prone to herbivory

We do this by following seedlings and saplings that have been marked using cable

ties and plastic labels, within the permanent plots. Each plant that has been tagged

Methodology

1. Find each tagged plant within or around a permanent plot.

2. Note down unique ID on the tag.

3. Measure height and girth of the plant.

4. Count the total number of leaves on the plant.

Equipment: • Calibrated pole • Measuring tape

has a unique ID. For instance a Rhizophora apiculata seedling may be called RA 1, the

second will be called RA 2. An Avicennia official’s seedling is called AO 1, the second

AO 2 and so on. Each tagged plant will be observed until its death or until it turns

into an adult (i.e. attains 200 cm in height).

Frequency: Once in a month

Time: Low tide, ideally 1-2 hours after high tide recedes

How many: Approx. 200 tagged plants in and around 21 plots

5. Count the number of leaves with signs of herbivory (bite marks

or holes).

6. If plant is dead, note down in data sheet and remove tag.

7. If plant is above 200 cm in height, note down and remove tag.

Signs of Herbivory.

31

HERBIVORY AND SURVIVAL MOCK DATA SHEET Researcher:

Nayantara, Vishal Date:

20/09/2014 Location:

Lohabarak Time:

12 noon Tide: Spring

Transect

ID* Plot

ID* Plant

ID** GBH

(cm) Height

(cm) Total

Leaves Leaves

eaten Fauna

Type

Remarks

1 1 RA 1 4 20 10 5 Periwinkle 20 1 1 RA 2 5 30 12 10 Periwinkle 21 1 2 AO 1 2 40 14 6 Insect 18 2 3 BG 2 2 100 16 8 Not visible 23 2 3 AO 3 - - - - - 24

32

SECTION 3: DATA ENTRY AND SCHEDULE

DATA ENTRY

The final step of this process is to enter all the data you have collected in some clear

useful format. After each day’s sampling, you need to come back to the base, and enter

all this data on Microsoft Excel. The formats are in the mangrove database, in the ANET

library.

TIME TABLE

All this information can be pretty confusing. So here is a simple schedule for you to

follow. The annual measurements are once in a year, the quarterly measurements are

once every four months and the monthly collections are well of course monthly.

What are we going to do with all this data? As mentioned before, our short

term goal is get out an accurate checklist of what mangrove plants are surviving,

growing and reproducing. But with data about inundation, light, soil type and

herbivory we can understand the reasons behind this. For instance, it is interesting

to find out that Rhizophora species are regenerating very well in Lohabarak. But

with herbivory measurements we can also assess if they are surviving to adulthood.

And doing this over a long period of time, with help from volunteers like you,

we can predict what the future of this mangrove patch will be -which species will

dominate and which will disappear.

Finally, thank you for reading this long (hopefully interesting) manual. We hope

to see you out in the mangroves. There is a lot of work, but it is also going to be a

lot of fun.

33

Data Collection Stage J F M A M J J A S O N D

Annual Counts Plant Regeneration

x

Quarterly Inundation

x

x

x

Quarterly Light

x

x

x

Quarterly Soil

x

x x

Monthly Herbivory and Sapling Survival

x

x

x

x

x

x

x

x

x

x

x

x

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