1. This is a presentation on mangrove carbon stocks assessment.

2. Mangroves – a unique tropical forest type
Topic C3. Slide 2 of 29
Mangroves – a unique tropical forest type
138,000–152,000 km2 (145,000 km2)
Widely distributed – 123 countries
Critical provision of ecosystem services
Values – USD 2000–9000/ha/yr
Spaulding et al. (2010)
Mangroves are a unique tropical forest type. There are about 145,000 km of mangroves located throughout the tropical coastlines of the world. They are widely distributed in about 123 countries. They provide a vast array of ecosystem services that have been valued anywhere between USD 2000 and USD 9000 per hectare every year. A few studies have found that the value of fisheries alone is about USD 32,000 per hectare per year.

3. Mangroves – Tremendous range in structural diversity
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Mangroves – Tremendous range in structural diversity
Mangroves provide a tremendous range of structural diversity. There are huge mangroves in Papua, Indonesia.
In contrast, these are the expansive low mangroves in the Dominican Republic. These are dominated by red mangrove. This same species can grow as high as 20 or 30 meters in other sites
Seneboi River Delta, Papua, Indonesia
Mangle Bajo, Parque Nacional Montecristi, Republica Dominicana

4. Topic C3. Slide 4 of 29
Training objectives: 1. to learn methodologies to efficiently determine carbon stocks and emissions in mangroves. 2. collect the field data necessary to calculate the C stocks, composition and structure of mangroves. 3. Provide policymakers with C stock information of value for climate change mitigation and adaptation activities.
Mangroves – Tremendous range in structural diversity
The objectives of this presentation are to:
(1) learn methodologies to efficiently determine carbon emissions in both tall and low mangroves;
(2) learn how to collect the field data necessary to calculate the carbon stocks, composition, and structure of mangroves;
(3) provide policy makers with carbon stock information for climate change mitigation and adaptation activities.

5. Mangroves – Tremendous range in structural diversity
Topic C3. Slide 5 of 29
Mangroves – Tremendous range in structural diversity
A detailed methods manual for measuring, reporting and verification (MRV) in mangroves exists – Kauffman and Donato 2012.
A detailed methods assessment exists in this manual written by Boone Kauffman and Dan Donato in It is entitled Protocols for the Measurement, Monitoring and Reporting of Structure Biomass and Carbon Stocks in Mangrove Forests.

6. Mangroves – Tremendous range in structural diversity
Topic C3. Slide 6 of 29
Mangroves – Tremendous range in structural diversity
Trees
Non-tree vegetation
Dead wood
When you walk into a mangrove you need to determine how and what to measure in order to quantify the carbon stocks.
Following IPCC recommendations, you would separate the ecosystem into the tree and the non-tree vegetation; other aboveground components include the dead wood and the forest floor. Finally you need to measure the soil carbon pools. This is how you partition the various pools of the ecosystem to determine ecosystem carbon stocks.
Soil
Forest floor

7. Mangroves – Tremendous range in structural diversity
Topic C3. Slide 7 of 29
Mangroves – Tremendous range in structural diversity
Mangrove forest ecosystem
Aboveground pools
Belowground pools
Sediments
Trees >1.3 m ht
palms
Downed wood
Roots
Seedlings
0–10 cm depth
Dead
Live by species
Herbs
0.67 cm diameter
10–30 cm
Blades
Litter
>100 cm dbh
0.67–2.54 cm diameter
Rachis
30–50 cm
50–100 cm dbh
pneumatophores
Bracts
2.54–7.6 cm diameter
50–100 cm
30–50 cm dbh
>7.6 cm diameter
100–200 cm
5–30 cm dbh
sound
rotten
300–500 cm
0–5 cm dbh
>500 cm
In order to measure the carbon stocks of a forest, you need to break it down into
ecologically meaningful components that can be accurately measured. Here is how we partition mangrove forests.
So when you see the forest, you have to also see it like this in order to partition and measure all the various carbon pools of the ecosystem.
When you see this…
You have to also see this

8. PLOT LAYOUT TO DESCRIBE MANGROVES
Topic C3. Slide 8 of 29
PLOT LAYOUT TO DESCRIBE MANGROVES
Trees <5 cm dbh measured in 2 m radius
(A = 12.6 m2) (all plots)
Trees <5 cm dbh measured in 2 m radius
(A = 12.6 m2) (all plots)
Wood debris transects
(4 per plot, all plots)
Trees >5 cm dbh measured in 7 m radius (A=153.9m2)
7 m A B C D
R= 2 m
Marine ecotone
Soil measurements and core extraction (all plots)
This is our plot layout to describe the carbon stocks, composition, and structure of mangrove ecosystems. Basically, in every site we measure the total ecosystem carbon stocks in six plots established along a transect that may be anywhere from 100 to 150 m in length. In this example we established plots every 20 m. In each plot we measure all trees that are greater than 5 cm in diameter at breast height in a 7 m radius circular plot. We measure all trees less than 5 cm in diameter in a 2 m radius nested plot. Downed wood is measured in 4 planar intersect transects in each of the six plots. Finally we measured soils in each of the six plots.
Plot: 1 2 3 4 5 6
20 m
20 m

9. Plot design: Dwarf mangroves and young stands of planted mangroves
Topic C3. Slide 9 of 29
Plot design: Dwarf mangroves and young stands of planted mangroves
Here is an example of a plot layout for young mangroves or low mangrove communities that are less than 2 m in height. It is basically the same design. The only difference is we don’t need to measure the 7 m plot as all trees are less than 5 cm diameter. Also, when you’re measuring small mangroves in addition to stem diameter, you may use a different allometric equation, which also includes measurement of height and sometimes even crown area of each individual tree.

10. Why use a linear transect?
Topic C3. Slide 10 of 29
Why use a linear transect?
Wood debris
transects
(4 per plot, all
plots) A B C D
Trees >5 cm
dbh measured
in 7m radius
(A=153.9m 2 )
Trees <5 cm
in 2m radius
(A=12.6m
) (all
R= 2m
Captures a broad environmental gradient
Avoids species contagion
Less chance of sampler bias
More efficient for field sampling
Fewer steps required for field technicians – less disturbance to the permanent plot; critical in these wet areas with fragile soils
Ease of relocation
There are many ways to establish plots that will adequately quantify carbon stocks. Some designs place the plots in clusters or triangles but we prefer to use a linear transect design for a number of ecological as well as practical sampling reasons. Remember that with dense roots, deep mud, standing water and heat, mangroves can be a really difficult place to work. Also the fragile saturated soils are susceptible to damage by walking, so efficiency is important. A linear transect captures a broad environmental gradient that may be present in mangroves. In tropical forests, there is a great deal of species contagion or clumping. A linear transect avoids species contagion compared to clustered arrangements. It is also impossible to see down the long transect so there’s less chances of sampling bias occurring. A linear transect is more efficient to set up for field sampling so there’s fewer steps to take. This is very important for minimizing worker effort and results in fewer disturbances to fragile soils. Finally, it is easy to relocate or reestablish linear transects. We recommend that the location of the plot center of each plot be plots be recorded with a global positioning system (GPS) for remeasurement and relocation in the future.

11. PLOT DESCRIPTION – METADATA
Topic C3. Slide 11 of 29
PLOT DESCRIPTION – METADATA
General description of the area – trees, soils land use, etc.
Name of plot, date sampled
GPS coordinates of each plot are critical
Compass direction of the transect (degrees)
Salinity – measured at soil sampling plots
pH – measured at soil sampling plots
Photo documentation
Systematic photopoints at center of each plot
Reporting purposes, visualization
Names of field technicians
One important aspect at every site is the collection of metadata. This includes a general description of the area – vegetation, soils, water, land use, etc. It is important to record the name of the plot and the date when the field data were collected. GPS coordinates of every one of the six plots within the site that you are sampling should be recorded. The compass direction of the transect that you’re establishing should also be recorded for future relocation and reestablishment. While collecting soils, it is also a good idea to measure soil salinity. We also measure soil pH soils at each of the soil sampling plots. Finally you should take notes and take several photos. Be sure to record the names of the technicians in the field in case you have questions for them later.

12. Topic C3. Slide 12 of 29
Trees
Now let’s talk about ways that we take measurements to obtain the carbon stock, basal area, density, and composition of the trees.
First, we measure the diameter of each tree rooted in the 7-m plot. This allows us to determine tree density, basal area, composition and aboveground and belowground biomass. We calculate aboveground and belowground biomass via allometric equations.

13. Topic C3. Slide 13 of 29
The tree diameter is usually measured at 1.3 m above the soil surface. This is called the diameter at breast height or DBH. Unfortunately this is not always a straightforward measurement as trees vary in trunk structure. In the tree shaped such as that in number A measurement is straightforward and sampled at 1.3 m in height. But that’s rarely the case. We must measure above the buttresses. For example, trees usually look like the other examples shown in this slide. For species such as the red mangrove – the Rhizophora species, we sample 20–30 cm above the highest prop root (C).

14. How to determine whether trees are ‘inside’ or ‘outside’ the plot.
Topic C3. Slide 14 of 29
How to determine whether trees are ‘inside’ or ‘outside’ the plot.
Where do we sample the trees? Typically we sample all trees within the 7-m radius circular plot. At least half of the main trunk has to be within that plot.
We might also ask why we use a circular plot instead of a rectangular or square plot. There are three good reasons for using a circular plot.
(1) It is very easy to establish a circular plot – you only have to have a midpoint.
(2) They’re quite easy to measure. All that you need is a rope or tape from the plot center.
(3) There’s less edge to area ratio so there are less errors in determining whether each tree is inside or outside the plot.
Why use a circular plot?
Ease of setup and relocation
Ease of measurement
Less edge to area ratio

15. Dead trees Live (with leaves) – measure dbh
Topic C3. Slide 15 of 29
Dead trees
We separate live trees from dead trees in our estimates of carbon stocks. We break down dead trees into three classes. Class I trees are those that have been recently killed. Class 2 dead trees are with only small branches missing, and Class 3 trees are those that have been dead for quite some time, with only the trunk or maybe a few main stems present.
Live (with leaves) – measure dbh
Class 1 dead – recent death, only leaves missing – measure dbh
Class 2 dead – dead with all small branches missing – measure dbh
Class 3 dead – only trunk/mainstems present – measure dbh and height

16. W1 W1 W1 W2 Elliptical crown area = (W1 x W2/2)2*π;
Topic C3. Slide 16 of 29 W1 W1 W1 W2
Crown
depth
Height
Elliptical crown area = (W1 x W2/2)2*π;
Where W1 is the widest length of the plant canopy through its center, and W2 is the canopy width perpendicular to W1.
Crown volume = elliptical crown area * crown depth.
Height is measured from the sediment surface to the highest point of the canopy.
D30 is the main stem diameter at 30cm.
D30
In low mangrove stands, we may use a different allometric equation that requires measurement of crown area or plant height. It depends on which allometric equation that you use.
Most often we use models
that use diameter and plant height to determine biomass

17. Topic C3. Slide 17 of 29
Examples of specific tree equations – for species encountered in the Neotropics and West Africa
Avicennia germinans
B = 0.14D2.4
R2=0.97; N=25
Fromard et al. 1998
French Guiana 42
B=.403D1.934
R2=0.95;
N=8
Smith and Whelan 2006
Florida, USA
21.5
Rhizophora spp (mangle and racemosa)
B= D2.6
R2=0.92; N=9 32
Rhizophora mangle
B=0.722D1.731
R2=0.94;
N=14
20.0
Laguncularia racemosa
B=103.3D2.5
R2=0.97; N=70 10
B=0.362D1.930
R2= 0.98;
N=10 18
See Kauffman et al 2012 and Kauffman et al (2014) for a review of mangrove allometric equations throughout the world
Here are some examples of specific tree allometric equations for species encountered in the Caribbean, Latin America, and West Africa. You would use a wholly different set of equations in Asian mangroves. Usually, it is possible to use species-specific allometric equations in mangroves. More equations can be found in Kauffman and Donato (2012).

18. Topic C3. Slide 18 of 29
Dead wood
Pieces cm
measured here 0m 9m
14 m 2m
Pieces >7.6 cm measured here
Let’s move to the next important component of aboveground carbon pools – i.e. dead wood. Dead wood is an important ecological component in all forests and therefore should be measured.
Here is an example of the wood debris transect for sampling downed wood. At each of the six plots establish four12-meter-long transects. These are actually 14 m long but the first 2 m are not measured to avoid bias in oversampling in the center. We measure all wood greater than 7.6 cm in diameter for the entire length of the 12-meter transect. Small wood pieces 2.5 to 7.6 cm in diameter are only measured in the last 5 meters.

19. Soil depth and sampling
Topic C3. Slide 19 of 29
Soil depth and sampling
Intervals: 0–15 cm, 15–30 cm, 30–50 cm, 50–100 cm, 100–300 cm
Finally let’s examine how we measure the belowground carbon stocks, particularly the soils. Here is a series of photos that give you a step-by-step approach of how we collect the soils in the field for determination of carbon concentration and soil bulk density in the laboratory.
We collect soils at various layers or deaths – in this case five samples are collected at depths of 0 to 15 cm, 1530 cm, 30 to 50 cm, 50 to 100 cm, and 100 to 300 cm – that’s assuming that depth is at least 300 cm or greater. It is really important to get the depth of the soils and for this we might use something such as a 3 meter avalanche: or even a very long piece of bamboo.

20. Extract the soil core and cut it off flush with the smooth edge
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We use a modified auger specifically for saturated soils for sampling in mangroves Here is an example of cleaning the auger prior to extraction and collection of the soil sample for lab analysis.
Extract the soil core and cut it off flush with the smooth edge

21. Measure the depth ranges to collect sample
Topic C3. Slide 21 of 29
After you clean the soils you must measure the depth range where you will collect the samples.
Measure the depth ranges to collect sample

22. Topic C3. Slide 22 of 29
Then you carefully extract a 5 cm sample and place it in the soil can for safekeeping. The samples are then brought back to the lab where they are dried and weighed to determine the soil bulk density and analyzed for carbon concentration.

23. Topic C3. Slide 23 of 29
This is a picture of field drying the soils samples collected in the field. This is commonly done before transporting the samples to the laboratory. In the lab the samples are thorough dried to determine bulk density and in preparation for carbon analysis
When you are out in the field for many days it’s important to field dry the soils samples. This makes it easier for the samples to be transferred back to the laboratory and processed once they are in the laboratory.

24. Topic C3. Slide 24 of 29
Here is an example of total ecosystem carbon stocks by three vegetation types from the Dominican Republic. The data were collected in the same manner as described here. You can see that the majority of carbon is stored in the soil layers. The green bars at the top represent the aboveground tree biomass. In these sites, it is only about 5 or 10% of the total ecosystem carbon stock. Also note how little carbon is in the shrimp ponds. Comparing the carbon stocks in the mangrove forests to the shrimp ponds allows us to calculate the emissions from land use. In this case, it may be as high as 3000 tonnes of carbon dioxide equivalents per hectare.

25. Topic C3. Slide 25 of 29
EXAMPLE 2: Examples of total ecosystem carbon stocks for selected mangroves of the west Pacific and Asia
Here are four more examples of total ecosystem stocks of selected mangroves from the West Pacific and Asia. Again, the majority of the carbon stock is in the belowground soil pools. Note the range of ecosystem carbon stocks is from 566 megagrams per hectare in the Sundarbans to 1259 megagrams per hectare in Kalimantan. Globally, carbon stocks of mangroves range from a low of about 200 megagrams per hectare to over 2000 megagrams per hectare.

26. SUMMARY Why is this work important?
Topic C3. Slide 26 of 29
SUMMARY Why is this work important?
Mangroves provide a number of critical ecosystem services
The carbon stocks in mangroves are among the highest of any ecosystem on earth
Rates of land-use/land-cover change in mangrove conversion are high
Greenhouse gas emissions from mangrove conversion are high
MRV is possible in mangroves
So finally, why is it important for us to measure the carbon stocks and other ecosystem characteristics of mangrove ecosystems?
First -mangroves provide a number of critical ecosystem services. Most people in the world live near coastal ecosystems and millions are dependent upon them.
They have among the highest carbon stocks of any tropical forest type.
Rates of land-use/land-cover change or deforestation are very high in mangrove ecosystems.
The greenhouse gas emissions that arise from land use in mangroves is also very high.
And finally, monitoring and reporting and verification is possible in mangroves for participation in climate change mitigation and adaptation activities

27. Topic C3. Slide 27 of 29
References
Donato DC, Kauffman JB, Murdiyarso D, Kurnianto S, Stidham M, and Kanninen M Mangroves among the most carbon-rich forests in the tropics. Nature Geosciences 4:293–297. doi: /NGEO1123.
Howard J, Hoyt, S, Isensee K, Telszewski M, Pidgeon E (eds.) Coastal Blue Carbon: Methods for assessing carbon stocks and emissions factors in mangroves, tidal salt marshes,and seagrasses. Arlington, Virginia, USA: Conservation International, Intergovernmental Oceanographic Commission of UNESCO, International Union for Conservation of Nature.
[IPCC] Intergovernmental Panel on Climate Change Good practice guidance for land use, land-use change, and forestry. Penman J, Gytarsky M, Hiraishi T, Krug Thelma, Kruger D, Pipatti R, Buendia L, Miwa K, Ngara T, Tanabe K, et al, eds. Japan: Institute for Global Environmental Strategies.
Kauffman JB and Donato DC Protocols for the Measurement, Monitoring, & Reporting of Structure, Biomass and Carbon Stocks in Mangrove Forests. Working Paper 86. Bogor: Center for International Forest Research.
Kauffman JB, Donato D, Adame MF Protocolo para la medición, monitoreo y reporte de la estructura, biomasa y reservas de carbono de los manglares de México. CIFOR Working Paper/Documento de Trabajo 117. Bogor: Center for International Forest Research.

28. Topic C3. Slide 28 of 29
References
Kauffman JB, Heider C, Norfolk J, Payton F Carbon Stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic. Ecological Applications 24:518–527.
Spalding MD, Kainuma M, Collins L World atlas of mangroves. London: Earthscan.
[UNEP] United Nations Environment Programme The Importance of Mangroves to People: A Call to Action. van Bochove J, Sullivan E, Nakamura T, eds. Cambridge: United Nations Environment Programme World Conservation Monitoring Centre, Cambridge.