A literature review on carbon stocks in shifting cultivation landscapes in Laos

A literature review on carbon stocks in shifting

cultivation landscapes in Laos

Climate Protection through Avoided Deforestation (CliPAD)

Cornelia Hett1, Juliet Lu2

1 University of Bern, Centre for Development and Environment (CDE) & Institute of Geography, Hallerstrasse 10, 3012 Bern, Switzerland. [email protected]

2 University of California Berkeley, Department of Environmental Science, Policy and Management.

February 2014

mailto:[email protected]

Published by:

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Registered offices Bonn and Eschborn, Germany Climate Protection through Avoided Deforestation (CliPAD) Department of Forestry, That Dam Campus, Chanthabuly District, Vientiane Capital, Lao PDR P.O.Box 1295 T +856 21 254 082 F +856 21 243 083 I www.giz.de

As at

February 2014

Text

Cornelia Hett and Juliet Lu

Acknowledgements:

With inputs from Thilde Bech Bruun, Department of Agriculture and Ecology, Plant and Soil Science

Faculty of Life Sciences University of Copenhagen; Andreas Heinimann, Centre for Development and

Environment, University of Bern.

The work conducted for this report has benefited from collaborations within the I-REDD+ project of

the European Commission Framework Project (FP7-ENV-2010).

The views expressed in this publication are those of the authors and do not necessarily reflect those of

the GIZ, CDE, MAF, MONRE or any other involved institution or organization.

Distributed by:

CliPAD Report completed in February 2014, Printed in 2014.

Contents

Summary ................................................................................................................................................... i

1 Introduction and motivation .......................................................................................................... 1

2 Description of methodology and data used .................................................................................... 3

2.1 Systematic review of literature on carbon values and carbon stocks in shifting cultivation

landscapes of Laos .......................................................................................................................... 3

2.2 Assessment of above-ground biomass carbon stocks in the area under shifting cultivation in

Northern Laos ................................................................................................................................ 4

3 Results and discussion .................................................................................................................... 5

3.1 State of knowledge on measured vegetation based carbon values from case studies in Laos ............ 5

3.2 State of knowledge from Laos case studies in Laos that use existing biomass inventories to

model carbon values in shifting cultivation landscapes .................................................................. 10

3.3 State of knowledge on carbon stocks under current land use and under alternative land use

scenarios in shifting cultivation landscapes of Laos ....................................................................... 12

3.4 A new attempt to assess the regional average carbon value and the total above-ground biomass

carbon stock for shifting cultivation areas in Northern Laos ......................................................... 14

4 Conclusions ................................................................................................................................. 15

References.............................................................................................................................................. 18

Annex .................................................................................................................................................... 19

Annex 1: List of case studies on carbon stock densities in Laos used in this report ................................. 19

List of figures

Figure 1: Shifting cultivation areas of Northern Laos based on Hurni et al. 2013, own representation. Shifting cultivation areas between 2006 and 2010 are shown in green in the large map; the small overview map shows an overview of Laos within mainland Southeast Asia with the ecological zones: dark green: Tropical rainforest; light green: Tropical moist deciduous forest; yellow:

Tropical dry forest; and brown: Tropical mountain zone. ............................................................ 1

Figure 2: Schematic representation of the temporal pattern of forest, crop and fallow fields for one plot in a shifting cultivation landscape (A); and spatial pattern of land covers and their associated carbon values in a shifting cultivation landscape (B) (the values are exemplarily and based on IPCC 2006,

fitted to the Lao PDR context). ................................................................................................... 2

Figure 3: Location of case studies assessing carbon values in Laos; red: Long-O Village, study by Roder et al. 1997; dark blue: Lak Sip Village, study by APN 2012; green: Houaykhot and Phonsavang Villages, study by Kiyono et al. 2007; light blue: study area on the Nakai Plateau, study by

Descloux et al. 2011. ................................................................................................................... 6

Figure 4: Relative areas for different fallow lengths in a regional study in Northern Laos for the period

2003-2004 (Inoue et al. 2010). ................................................................................................... 12

Figure 5: Carbon values of different land cover classes of shifting cultivation landscapes in Laos identified through the systematic review of case studies. Y-axis values are YRF: Young regrowth forest, SWP: swamp; ORF: old regrowth forest; NAF: natural forest (or sometime referred to as dense

or primary forest); GRS: grassland; DGF: degraded forest; AGR: agriculture. Study abbreviations: Kiyono: Kiyono et al. (2007); Roder: Roder et al. (1997); Descloux: Descloux et al. (2011); IPCC Tar, TAWa, TAWb, TM are values from the study of Hett et al. (2011) originating from IPCC (2006) for the different ecological zones; IPCC all is used for carbon values which have the same

value across all ecological zones. ............................................................................................... 15

Figure 6: Summary of above-ground carbon biomass (AGC) values (source: Ziegler et al. (2012)). Open and closed circles are minimum and maximum values of reported ranges, respectively. Crosses refer to reported mean values. The thick line (ending in a cross) is the modified range, defined by the minimum and maximum values reported in Table 3 (also shown in Fig. 2b). Land covers are the following: forest (F); logged over forest (LOF); orchards and tree plantations (OTP); rubber plantations (RP); long-fallow swidden (LFS); non-swidden agroforest (AGF); grassland, pasture, or shrublands (GPS); oil palm plantations (OP); intermediate-fallow swidden (IFS); short-fallow

swidden (SFS); and permanent cropland (PC). ........................................................................... 16

List of tables

Table 1: Definitions of carbon pools based on IPCC's Good Practice Guidance for Land Use, Land Use

Change and Forestry ................................................................................................................... 3

Table 2: Overview of case studies measuring carbon stock densities of vegetation in Laos ....................... 1

Table 3: Carbon values for selected land cover classes in Laos, derived from Hett et al. 2011. In green:

land cover classes belonging to the shifting cultivation land use system. .................................... 10

Table 4: Average carbon stock densities for shifting cultivation systems with different crop-fallow intensities based on Hett et al. 2011, and Kiyono et al. 2007, own representation. TAr: tropical moist zone, TAWa: tropical moist deciduous zone, TAWb: tropical dry zone, TM: tropical

mountain zone .......................................................................................................................... 11

Table 5: Overview of average carbon values of the overall study region, including other types of land use

based on Inoue et al. (2010) ...................................................................................................... 13

Table 6: Carbon stocks densities in the shifting cultivation areas of Laos (national level study) for the current situation, and for two scenarios of alternative crop-fallow cycles and different land

zoning based on Hett et al. (2011). ............................................................................................ 14

Table 7: Overview of the total carbon stored in the vegetation of the landscapes under shifting cultivation in Northern Laos between 2006 and 2010. Values were modelled using carbon stock density

values provided by Hett et al. (2011) and Kiyono et al. (2007) ................................................... 14

i

Summary

Shifting cultivation or slash-and-burn agriculture is the traditional and dominant farming system in the

uplands of Laos. In recent decades this dynamic system consisting of a mosaic of farmed fields and

plots of fallow vegetation of different ages has changed both with regard to extent and the intensity of

farming due to economic, political and demographic factors. These changes cause deforestation and

forest degradation, and consequently lower the carbon stock stored in these landscapes. The

international climate mitigation framework of Reducing Emissions from Deforestation and Forest

Degradation (REDD+) could be a timely instrument for carbon stock management in shifting

cultivation landscapes e.g. through promoting longer crop-fallow cycles or reforestation of degraded

forest areas. In order to quantify the mentioned carbon stock gains and losses, knowledge is needed on

the extent and the intensity of shifting cultivation areas, but also on the carbon stock densities in the

above-ground biomass (referred to as carbon values) of different land covers of this farming system

(cropped fields, fallow fields and different types of forest) in order to calculate landscape level carbon

stocks.

Against this background a review of existing scientific literature was conducted to assess the current

state of knowledge on carbon stocks and carbon values found in shifting cultivation landscapes of

Laos. The study found only four local case studies conducted over the past twenty years which

measured carbon values and two studies which used existing local and regional values for carbon stock

densities to assess the overall carbon stocks found in shifting cultivation landscapes and to estimate

the total stocks for alternative land use scenarios. The carbon values from the four local case studies

are only comparable to a limited extent as the authors did not use the same land cover categories and

applied different methodologies to assess carbon stock densities. The carbon values found range from

0.6 tons of carbon per hectare (tC/ha) for cropped upland fields to 167 tC/ha in natural, riparian

forests. Fallow fields had values between 5 tC/ha and 52 tC/ha depending on their fallow age. One

case study was found which presented a model to estimate carbon stock densities based on the

number of years since the last cropping. This model can be used by practitioners with carbon related

projects in similar farming environments for calculating carbon stocks in their project area.

Based on the identified carbon values in different land cover types of shifting cultivation landscapes

presented in the Lao case studies, this study assessed the average carbon values for different crop-

fallow cycles. Then, the regional above-ground biomass carbon stock for the area under shifting

cultivation in Northern Laos was assessed assuming an average of one year of cropping and five years

of fallow period. Depending on the carbon values used, this stock amounted to 39, respectively 50

million tons of carbon.

This study contributes to the “Climate Protection through Avoided Deforestation“ (CliPAD) Project

of the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH and KfW

Development Bank. CliPAD supports the Government of Lao PDR to both pilot incentive

mechanisms for climate change mitigation within the framework of REDD+ and establish the Lao

PDR’s legal framework for REDD+ implementation. GIZ and KfW jointly provide institutional

support at national, provincial and district levels for REDD+ concept development, policy advice and

support for capacity development as well as piloting mitigation activities in two districts in Houaphan

province in cooperation with the Ministry of Agriculture and Forestry (MAF) and Ministry of Natural

Resources and Environment (MoNRE).

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1 Introduction and motivation

Shifting cultivation has for centuries been the traditional farming system used in the mountainous regions

of Southeast Asia. But it has undergone dramatic transformations since the mid-1990s with population

pressure, as well as economic and political factors at the root of these transformations. Today, shifting

cultivation remains important for subsistence agriculture. In the uplands of Northern Laos, shifting

cultivation it still the dominant land use system and covers nearly 50% of the area of Oudomxay

Province, nearly 40% of Luang Prabang Province, and nearly 37% of Luang Namtha Province. Figure 1

gives an overview of the extent of shifting cultivation in Northern Laos for the time period between 2003

and 2009 (Hurni et al. 2013).

Figure 1: Shifting cultivation areas of Northern Laos based on Hurni et al. 2013, own representation. Shifting cultivation areas between 2006 and 2010 are shown in green in the large map; the small overview map shows an overview of Laos within mainland Southeast Asia with the ecological zones: dark green: Tropical rainforest; light green: Tropical moist deciduous forest; yellow: Tropical dry forest; and brown: Tropical mountain zone.

The shifting cultivation system is characterized by high spatiotemporal dynamics: A plot is cultivated for a

short period of one to three years and afterwards left fallow for several years so that the vegetation and

soil fertility can regenerate. The same plot is then prepared for another cultivation cycle by slashing and

burning the fallow vegetation. Figure 2 gives a schematic representation of the temporal land cover

pattern present in a shifting cultivation plot. In its spatial dimension the farming system creates a mosaic

landscape with different patches of cropped fields and fallows at different regrowth stages (see Figure 2).

In the global debate on land cover and climate change, shifting cultivation is often blamed as a cause for

deforestation and forest degradation in tropical countries besides industrial agriculture and large-scale

logging. Policy makers across the tropics propose that carbon finance could provide incentives for

shifting cultivation communities to transition away from this land use system and into other systems that

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potentially reduce emissions and/or increase carbon sequestration. The international policy for Reducing

Emissions from Deforestation and Forest Degradation (REDD+) fosters conservation, sustainable

management of forests, and enhancement of forest carbon stocks. It has become an important and much

discussed instrument in the forest and agriculture sector in Laos. The “Climate Protection through

Avoided Deforestation“ (CliPAD) Project, being jointly implemented by the Deutsche Gesellschaft für

Internationale Zusammenarbeit (GIZ), KfW Development Bank, the Ministry of Agriculture and

Forestry (MAF), the Ministry of Natural Resources and Environment (MoNRE) and relevant provincial

and district line agencies in Houaphan province aims to pilot incentive mechanisms for climate change

mitigation within the framework of REDD+ and establish the Lao PDR’s legal framework for REDD+

implementation. The project provides assistance in developing concepts for the reduction of GHG

emissions from deforestation and forest degradation, and its results should carry great relevance to the

national and international debates over the potential role of REDD+, as well as the future of forest and

climate protection. CliPAD is implementing climate change mitigation activities in Houaphan Province,

where shifting cultivation constitutes nearly one fourth (22.1%, see Figure 1) of the area.

In order to implement REDD+ projects in shifting cultivation landscapes of Laos in a meaningful way,

knowledge is needed on the amount of carbon that can be stored in each of the land cover types in the

landscapes under investigation. Only then the net ecosystem carbon changes expected from many land

use transitions, such as moving from shifting cultivation to rubber or teak plantation or different types of

agroforestry systems, could be assessed.

Figure 2: Schematic representation of the temporal pattern of forest, crop and fallow fields for one plot in a shifting cultivation landscape (A); and spatial pattern of land covers and their associated carbon values in a shifting cultivation landscape (B) (the values are exemplarily and based on IPCC 2006, fitted to the Lao PDR context).

Against this background, this study aims to provide an overview of the state of knowledge on carbon

stocks in shifting cultivation landscapes in Laos. Particular emphasis lies in (1) finding evidence of carbon

values measured in case study areas in Laos and (2) providing an overview of existing studies carried out

in Laos on carbon stocks and their changes under different land use scenarios. For this purpose, a

literature review was conducted and carbon stocks were estimated using GIS-based models.

3

This study focused on carbon stocks and carbon values in above-ground biomass. Throughout this

document we use the term “carbon values” as a short form of the term “above-ground biomass carbon

stock density”. Some of the case studies found in the literature review also included carbon values for

other carbon pools, such as cropped fields or dense forest. In delineating different types of carbon pools,

we follow the terminology used in the “Good Practice Guidance for Land Use, Land-Use Change and

Forestry” of the IPCC (2006). Table 1 gives an overview of the terms occurring in this report and their

definitions.

Table 1: Definitions of carbon pools based on IPCC's Good Practice Guidance for Land Use, Land Use Change and Forestry

Pool Description

Living biomass

Above-ground biomass

All living biomass above the soil including stem, stump, branches, bark, seeds, and foliage. Where forest understory is a relatively small component of the above-ground biomass carbon pool, this may be ignored so long as the methodology is used consistently throughout the inventory time series.

Below-ground biomass

All living biomass of live roots. Fine roots under, say, 2 mm diameter may be excluded as they often cannot be distinguished from soil organic matter or litter.

Dead organic matter

Dead wood All non-living woody biomass not contained in the litter, either standing, lying on the ground, or in the soil. This includes wood lying on the surface, dead roots, and stumps (usually defined as having a diameter of at least 10 cm).

Litter All non-living biomass with a smaller diameter than that used for dead wood (say, 10 cm), lying dead, in various states of decomposition above the mineral or organic soil. This includes the litter, fumic, and humic layers. Live fine roots (of less than the diameter limit for below-ground biomass, say 2 mm) may be included here.

Soils Soil organic matter

Includes organic carbon in mineral soils to a specified depth chosen by the country and applied consistently through the time series. Live fine roots (of less than the chosen diameter limit for below-ground biomass) to 30 cm depth may be included here.

2 Description of methodology and data used

2.1 Systematic review of literature on carbon values and carbon stocks in

shifting cultivation landscapes of Laos

In order to assess what knowledge currently exists on carbon values and carbon stocks in shifting

cultivation landscapes in Laos, a systematic review of case studies was conducted. The review focused on

finding articles related to two topics. First, the measurement of carbon values within shifting cultivation

landscapes in Laos; second, the use of existing carbon values to assess the amount of carbon stored under

different land uses and future land use scenarios within areas under shifting cultivation.

The three archives searched for literature were Google Scholar (http://scholar.google.ch/), the document

repository for the google group LaoFAB (http://www.laofab.org/ ) and the Forest Carbon Asia

(http://www.forestcarbonasia.org/publications/other-publications/) online library. LaoFAB is a forum

for sharing information about farmers and agribusiness in Laos whose members include government

officials, staff of donor agencies and NGOs, project experts, academics and business people. Forest Carbon

Asia is an online knowledge management platform which provides open, up-to-date, objective and

insightful information and analysis on the resources, policies, players and issues related to climate change

mitigation via forest carbon sequestration and storage across Asia.

These archives were screened for scientific literature (peer-reviewed journal articles). The review was

performed between June and July 2013. The searched keywords included:

http://scholar.google.ch/

http://www.laofab.org/

http://www.forestcarbonasia.org/publications/other-publications/

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One of either of the following terms: “Shifting cultivation” or “swidden farming” or “slash-and-

burn” or “upland farming” AND

“Carbon stock” or “carbon density” or “biomass” AND

“Laos” or “Lao PDR”

Titles and abstracts of articles found through the above search keywords were evaluated with regard to

their content and either included or excluded from the selection of valid cases for the review. Information

was then summarized for the articles categorized as valid cases through factsheets. In a second round of

review, further articles were included based on the works cited in the articles initially selected. In addition

to these systematic online searches, research colleagues working in the field of carbon stock measurement

and modelling were directly contacted and asked to contribute any literature they were aware of.

2.2 Assessment of above-ground biomass carbon stocks in the area under

shifting cultivation in Northern Laos

This study sought not only to create an overview of the existing information on carbon values from

studies conducted within Laos – be it on carbon values in fallow fields with different ages, or average

carbon stock values of shifting cultivation landscapes with varying crop-rotation cycles. It also focussed

on estimating the total amount of carbon stored in the overall area under shifting cultivation in Northern

Laos. Ideally, this figure would be assessed over time, as its change is needed for calculating emissions. In

many areas in Southeast Asia, shifting cultivation is intensified over time (van Vliet et al. 2012). Assessing

the total amount of carbon over time would hence be key for setting historical baselines for REDD+,

provided shifting cultivation areas are considered eligible for participation in the REDD+ framework, e.g.

if considered as forest-agricultural land. On the other hand, knowing the currently existing carbon stock is

important for the evaluation of future land use scenarios for carbon stock management. Alternative land

use schemes could e.g. focus on enhancement of forest carbon stocks by prolonging the crop-fallow

cycle. The net change of carbon stocks directly relates to payments under REDD+ or carbon

sequestration schemes.

The amount of carbon stored in a shifting cultivation landscape depends on three main factors:

1. Knowledge of the overall extent of the shifting cultivation area: The delineation of shifting

cultivation landscapes over vast areas constitutes a significant challenge, despite recent advances

in earth observation systems which allow the identification of different land cover types over

large areas and at high resolution (Hett et al. 2012). In most scientific case studies the area of

interest is given a priori and is of small extent (e.g. a village area). For a Jurisdictional and Nested

REDD+ approach, dealing with large areas, the total share of the area under shifting cultivation

should be known.

Hurni et al. (2013) presented an approach for delineating the area under shifting cultivation in

Northern Laos between 2003 and 2009. The authors used a combination of remote sensing

imagery, namely a time-series of MODIS imagery along with Landsat data.

2. The intensity of farming in the shifting cultivation system: Knowing the crop-fallow cycle length,

the average carbon value can be estimated and the total carbon stock over the entire area of

interest derived. Alternatively, the overall carbon stock can be calculated based on the shares of

the areas of different land cover types, including the different fallow ages. One can combined

these area shares with carbon values for these land cover types (see next point). Inoue et al.

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(2010) presented an approach for determining farming intensity in a shifting cultivation landscape

at a regional (sub-national) scale based on a time-series of Landsat imagery.

3. The carbon values suitable for the area of interest for every occurring land cover type.

As mentioned above, this study involved a spatial analysis carried out in order to estimate the total

amount of carbon stored in the areas under shifting cultivation in Northern Laos. For this report, data

from Hurni et al. (2013) given in Figure 1 was combined with carbon values from two case studies found

in the literature review, namely Hett et al. (2011) and Kiyono et al. (2007). For the former case study, the

shifting cultivation area of Hurni et al. (2013) was stratified into ecological zones using publicly available

spatial data (FAO 2001).

3 Results and discussion

3.1 State of knowledge on measured vegetation based carbon values from case

studies in Laos

Through the literature review, four local case studies were found, which included a total of 15 villages,

and examined vegetation carbon values for shifting cultivation landscapes in Laos. Figure 3 provides an

overview of the locations of these case studies. Three of them – APN (2012), Kiyono et al. (2007), and

Roder et al. (1997) – were carried out in close proximity to Luang Prabang, the capital of Luang Prabang

Province. Luang Prabang is one of the regions in Laos where shifting cultivation is the dominant

traditional farming system. Today, it is practiced at high intensity (short crop-fallow cycles). Thus the

locations of the case studies are not necessarily representative for the whole country.

One study by Descloux et al. (2011), was carried out on the Nakai Plateau in Central Laos in conjunction

with the construction of the hydroelectric dam reservoir for the Nam Theun2 (NT2) project. In the

context of building the reservoir, extensive monitoring and modelling programs, including the

measurement of greenhouse gas emissions, were put in place in order to predict short- and long-term

impacts from the project.

All studies originally measured vegetation biomass. In some studies, these values were already converted

to carbon values; the remaining ones were converted for this report in order to make the values supplied

by different authors comparable. The measurements of vegetation biomass in these four studies were

carried out between 1991 and 2008, and the resulting reports published between 1997 and 2010. At the

time of writing this report, no further recent data exists. Table 1 gives an overview of the carbon values

for different land cover types assessed through the four Lao case studies and are discussed here in detail.

Roder et al. (1997) found average carbon values of 4.9 tC/ha and 7.7 tC/ha for 1-year-old fallow and 2-

year-old fallow fields respectively in their two case study villages. These values are 7 and 11 times higher

respectively than the values assessed in their study for upland rice fields with fully grown rice crop near to

harvest (0.7tC/ha). Roder et al. (1997) neither assessed carbon values for any older fallow fields nor other

land cover classes, such as forest.

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Figure 3: Location of case studies assessing carbon values in Laos; red: Long-O Village, study by Roder et al. 1997; dark blue: Lak Sip Village, study by APN 2012; green: Houaykhot and Phonsavang Villages, study by Kiyono et al. 2007; light blue: study area on the Nakai Plateau, study by Descloux et al. 2011.

Kiyono et al. (2007) focussed on the estimation of chronosequential changes in the carbon stock in

fallow vegetation, largely bamboo vegetation communities. The authors then established the relationship

between the fallow period and fallow-period-average carbon stocks in three carbon pools of these

bamboo-dominated vegetation communities. The pools assessed were above-ground biomass, litter and

deadwood). Based on measurements by destructive sampling, a model and root-to-shoot ratios for

estimating bamboo biomass were devised. This model is valid for any fallow age between 0 and 20 years.

It was used in this report to calculate above -ground biomass carbon values for a sequence of fallow ages

(see Table 1). In order to compare the values for above-ground biomass of Kiyono et al. (2007) to the

carbon stock values of other authors, the values for vegetation biomass from Kiyono et al. (2007) were

converted to carbon values. This was done by using the equation developed by the authors1 for

vegetation biomass, and applying a standard conversion factor from biomass to carbon of 0.5 (IPCC

2006). These values are given in Table 1.

Kiyono et al. (2007) carried out their measurements at the start of the growing season, while Roder et al.

(1997) measured at the end of the growing season, before the rice harvest. Given this fact, measurements

of carbon in a one-year-old fallow field of Kiyono et al. (2007) corresponds to a two-year-old fallow field

in the study of Roder et al. (1997). The carbon values in these two studies are similar – Kiyono et al.

(2007) calculated 8.2 tC/ha and Roder et al. (1997) 7.7 tC/ha. The modelled values for above-ground

1 biomass = 16.483*(Y0.6801); where biomass represents the community’s biomass (Mg ha–1) and Y is the number of years since the last slash-and burn cropping (see Kiyono et al. 2007)

7

biomass carbon from Kiyono et al. (2007) for a sequence of fallow ages shows that carbon accumulates

rapidly from one year to the next, reaching around 52 tC/ha after 15 years of fallow.

Kiyono et al. (2007) also derived an equation for assessing total above-ground carbon values, including

the carbon pools of biomass, litter, and deadwood (see Table 2). The study showed that most of the

carbon stock exists in the biomass pool – on average 75% – but this figure varies from 51% to 95%.

Descloux et al. (2011) is the only study in Laos in which an inventory of carbon stock densities for a wide

range of land cover classes was created (see Table 2). The category “Riparian forest“ had the highest

carbon value of 167 tC/ha, while “Dense forest”, reached only 74 tC/ha. The authors ascribe the very

high carbon value of “Riparian forest” to the high density of bamboo found in this forest type. Descloux

et al. (2011) included a forest class called “Degraded Forest” in their study. This class is described as

“Slash-and-burn areas with or without grass”. It has a carbon value of 15 tC/ha. This value can be

considered the average of carbon stock densities found in the shifting cultivation systems in the Nakai

Plateau case study area, according to the authors. Unfortunately, no indication is given by them regarding

the average fallow age of this land cover category. The carbon value, however, corresponds roughly to

that of the 2 to 3-year-old fallow fields in Kiyono et al. (2007).

Finally, the study by APN (2012) assessed carbon stock densities in shifting cultivation areas in Northern

Thailand and Northern Laos, and values were compared to the land cover class, “Dense Forest”, for

which the carbon value was also assessed. The carbon value for this class was 173 tC/ha, which is more

than double the value found for the same land cover type by Descloux et al. (2011). This contrast in

values can, however, be somewhat expected as the APN (2012) value includes both above ground

biomass carbon (stems and branches) as used in the study of Descloux et al. (2011), as well as leaves,

ground cover and litter.

In the APN (2012) study the total carbon value calculated for fallow fields in a shifting cultivation system

of 4–5 year of age was 63.6 tC/ha. Again, this figure is not comparable to the values from the other

studies, as it includes above-ground carbon pools (stems, branches, leaves, ground cover, litter) and

below-ground carbon pools (roots and soil). Unfortunately there is no reference to the carbon values

within the different carbon pools which constitute this total carbon value. The total carbon value for

“Dense Forest” was 236.9 tC/ha. This includes above-ground carbon pools (stems, branches, leaves,

ground cover, and litter) and below-ground carbon pools (roots and soil). Again, this figure is not

comparable to the ones from the other studies but it highlights the importance of the carbon pools of soil

and roots in forests.

Table 2: Overview of case studies measuring carbon stock densities of vegetation in Laos

Citation Location of case study areas

Years of assessment

Method of assessmentt Land use/land cover category

Above-ground biomass (AGB) carbon value

Total above- ground carbon value-

AGB and litter carbon value

Total carbon stock density

Roder et al. (1997) Village Long-O and Phonthong,Luang Prabang Province

1991-1994 Above ground biomass was measured at time of rice harvest Oct/Nov 1991, Dec 1992 and 1993 in the two study villages*

Rice crop at harvest ** ***0.7 tC/ha

1 year fallow field 4.9 tC/ha

2 year fallow field 7.7 tC/ha

Kiyono et al. (2007) Villages Houaykhot and Phonsavang, Luang Prabang Province

2002-2007 Measurements were taken once a year over 2002–2007 periods in six fixed plots. Destructive sampling was carried out and the study devised a model for estimating bamboo biomass (above-ground and below-ground) based on the data obtained by destructive sampling. An equation for carbon values in shifting cultivation landscapes was developed.

1 year fallow field 8.2 tC/ha 11.8 tC/ha




5 year fallow field 24.6 tC/ha 36.6tC/ha


15 year fallow field 52 tC/ha 53.5 tC/ha

Descloux et al (2010) 10 villages on Nakai Plateau, Khammouane Province

2008 Remote Sensing analysis using SPOT 5 imagery was conducted to identify different land cover/use categories in the study area; organic carbon stocks were assessed for different carbon pools, namely living biomass (including above-ground and below-ground biomass, dead organic matter (deadwood and litter) and soils

Dense forest £ 74 tC/ha

Medium forest 42tC/ha

Light forest 49tC/ha

Degraded forest 15tC/ha

Riparian forest 167 tC/ha

Agriculture 0.6tC/ha

Swamps 2.4 tC/ha

APN (2012) Village Lak Sip, Luang Prabang Province

2011

Survey of land-use and carbon stocks in target village: carbon pools in each sampling plot, including above-ground, below-ground biomass through allometric equation or destructive method. $

Dense Forest no value given in the study

172 tC/ha $$ 236.9 tC/ha

Fallow fields in a shifting cultivation system of 4–5 year of age

no value given in the study

no value given in

the study

63.6 tC/ha

- Total above-ground carbon stock density includes the pools AGB, deadwood and litter

* Further details on the methodology: Plant biomass was harvested, plant dry matter estimated by cutting & weighing; dry matter calculated based on moisture content of 12% for air-dried subsamples.

**all values are the average from four monitoring sites

***Roder et al. (1997) measured biomass densities; in order to compare this to the findings in other studies, a conversion factor of 0.5 (IPCC 2006 standard) was applied.

+ The formula for biomass developed by the authors was used for selected years of fallow stages: Biomass = 16.483 *(Y0.6801); a carbon fraction of 0.5 (IPCC 2006 standard) was then used to

8

calculate the carbon fraction.

++ total carbon includes the following carbon pools: biomass, deadwood and litter. The following formula for total carbon developed by the authors of the article was used for selected years of fallow

stage: C(B+D+L) = 15.378[ln(Y)] +11.815; with C(B+D+L) is the carbon stock density in community biomass, deadwood and litter in t/ha; £ Description of the land cover classes: Medium forest: Regenerated forest with regular cover Light forest: Forest (mixed deciduous, broadleaf, and pine forests) with a low tree density (regeneration),

young or sparse on an herbaceous stratum, and bamboo; Degraded forest: Slash-and-burn areas with or without grass; Unstocked forest, tree stratum in poor environmental conditions (frequent

inundation, etc.); Riparian forest: Bamboo forest along the river and around some ponds; Agriculture: Agricultural parcels, pastures, grass zones near water (ponds and river), glades with very low

vegetation, paddy fields; Swamps: Swamp area with the presence of water or very humid; zones with aquatic vegetation. $ Details on the methodology: (1) stratify the project site into strata that form relatively homogenous units through classification and mapping of land use/cover types in the village landscape; (2)

decide size and number of sampling plots for estimating carbon density in each land use/ cover type; (3) estimate the biomass amount in different plots; (4) convert the biomass by multiplying a

conversion factor of 0.5 for carbon content; (5) Sum up different carbon pools in each land use/ land cover as the carbon intensity (tC/ha) for each land use/land cover type. $$ Total carbon stock density is composed of the following carbon pools: Above-ground carbon pools (stems, branches, leaves, ground cover, litter) and below-ground carbon pools (roots and soil)

9

10

3.2 State of knowledge from Laos case studies in Laos that use existing biomass

inventories to model carbon values in shifting cultivation landscapes

In addition to the four studies discussed above, in which biomass densities were measured in Laos and

carbon values derived, the literature review found another two interesting Lao case studies. First, the

study of Hett et al. (2011) is the only available study in Laos which assessed carbon values for all land

cover classes delineated by the official Lao National Forest Inventory, which presents national land cover

and land use, and which gives an overview of vegetation based carbon stocks at the national level. The

authors derived above-ground biomass carbon values for these land cover classes from standard above-

ground biomass data and forest growth rates provided by the International Panel on Climate Change

(IPCC, 2006). In order to match these carbon values to the land cover categories, the study used data

from Google Earth, Landsat and MODIS satellite imagery to refine the official government land cover

data. The authors used carbon values derived from the IPCC global inventory biomass as national level

data or data from the mainland Southeast Asia region did not exist. Hett et al. (2011) distinguished carbon

values for land cover classes across the four ecological zones found in Laos. Table 3 presents an overview

of carbon values for selected land cover categories relevant to shifting cultivation areas.

The three classes, “Old regrowth forest”, “Young regrowth forest”, and “Upland rice field” belong to the

shifting cultivation land use system. “Old regrowth forest” refers to areas of older fallow vegetation and

“Young regrowth forest” to areas of vegetation regrowth between 1 and 3 years of fallow. The values

obtained by Hett et al. (2011) compare well to the ones found in Kiyono et al. (2007) and Descloux et al.

(2011). The former reported 17.4 tC/ha for a 3-year-old fallow field, which is comparable to the “Young

regrowth forest” values for the zones Tar, TAWa and TAWb in Hett et al. (2011). The value of 39.5

tC/ha for a 10-year old fallow field from Kiyono et al. (2007) corresponds to the “Old regrowth forest”

class in Hett et al. (2011) in the tropical moist deciduous zone (TAWb), which is where the case studies in

Luang Prabang Province were located. The study by Descloux et al. (2011) – located in the tropical moist

zone, TAWa – reported 15tC/ha for “Degraded forest”, which corresponds to the value of Hett et al.

(2011) for “Young regrowth forest”.

Table 3: Carbon values for selected land cover classes in Laos, derived from Hett et al. 2011. In green: land cover classes belonging to the shifting cultivation land use system.

Carbon values (tC/ha)

Ecological zone *

Selected land cover categories TAr TAWa TAWb TM

Natural forest 180 105 78 81

Degraded forest 90 52 39 40

Old regrowth forest 90 52 39 40

Young regrowth forest 14 15 13 5

Upland rice field 5 5 5 5

Grassland 8 8 4 6

Rice paddy, agricultural land 5 5 5 5

* TAr: tropical moist zone, TAWa: tropical moist deciduous zone, TAWb: tropical dry zone, TM: tropical mountain zone

Aside from assessing carbon values for Lao land cover classes and specifically for different fallow age

categories, Hett et al. (2011) used the standard IPCC data on biomass, net biomass growth, root/shoot-

ratios, and carbon conversion factors to estimate the regional average carbon values for shifting

11

cultivation systems with different crop-fallow intensities, namely a 1+3 (1 year of cropping and three

years of fallow) system, a 1+5 system and a 1+10 system.

Regional averages for shifting cultivation systems can be calculated by adding together the carbon values

of the cropped field and the chrono-sequence of fallow fields, as shown in Figure 2. This calculation of

area-average carbon values for shifting cultivation systems with a specific crop-fallow cycle can be carried

out for any land use intensity (or rotation speed), if the carbon value for every fallow age within the

system is known. Here, this calculation was done using both the carbon values from Hett et al. (2011) and

the ones provided by Kiyono et al. (2007) for 1+1 rotation systems up to 1+15.Table 4 shows the results

of these calculations.

Table 4: Average carbon stock densities for shifting cultivation systems with different crop-fallow intensities based on Hett et al. 2011, and Kiyono et al. 2007, own representation. TAr: tropical moist zone, TAWa: tropical moist deciduous zone, TAWb: tropical dry zone, TM: tropical mountain zone

Based on Hett et al. (2011) Based on Kiyono et al. (2007)

Shifting cultivation crop-fallow cycle

Average carbon stock density in tC/ha

TAr TAWa TAWb TM

1-year cropping and one year fallow 4.8 5.0 4.7 3.4 4.1

1-year cropping and 2 years of fallow 6.2 6.7 6.1 3.5 7.1








Such regional average carbon values for shifting cultivation systems lend themselves to calculating carbon

gains and losses from adopting new crop-fallow cycle speeds. The speed of crop-fallow cycles is

determined by various factors including government policies and population shifts – which in Laos can

be drastic due to resettlement programs and the merging of villages.

As we have seen above, a shifting cultivation landscape consists of various patches of different land uses

at various stages in a crop-fallow cycle. More accessible areas are usually farmed using short crop-fallow

cycles, while more remote areas are less intensively farmed, resulting in longer crop-fallow cycles. For

study areas of a few hundred km2, a common approach is to conduct a land cover analysis based on

Landsat satellite imagery to determine the shares of the areas of different land cover types, particularly

different fallow ages. Next, carbon values are allocated to each land cover type and the overall carbon

stock is calculated. Inoue et al. (2010) followed this approach and first estimated the share of different

land covers, and then the carbon stocks found in a shifting cultivation landscape in Northern Laos. The

study area of 150 km x 150 km covered large parts of Luang Prabang and Oudomxay Provinces, which

are the provinces with the highest incidence of shifting cultivation (see table in Figure 1). Their Landsat

based analysis relied on the detection of chrono-sequential binary patterns of land use - in other words

the question “field burnt – yes or no” was assessed for every pixel in a long time series of Landsat images.

Based on these temporal patterns for every pixel, the community age of fallow vegetation was calculated

by tracing back to the last slash-and-burn (or “yes-answer”) in the event of each Landsat pixel. The area

distribution in % of each community age in the whole case study area is given in Figure 4.

12

Figure 4: Relative areas for different fallow lengths in a regional study in Northern Laos for the period 2003-2004 (Inoue et al. 2010).

Inoue et al. (2010) then estimated ecosystem carbon stocks by using a semi-empirical carbon stock model

derived from in situ measurements from Kiyono et al. (2007) where the community age was used in order

to calculate the average carbon stock density of the area under shifting cultivation, and the regional

average of ecosystem carbon stock found in their case study area.

3.3 State of knowledge on carbon stocks under current land use and under

alternative land use scenarios in shifting cultivation landscapes of Laos

Besides assessing carbon values and carbon stocks for the current situation in their study area, Inoue et al.

(2010) used a variety of scenarios of for land management alternatives in their shifting cultivation study

area to calculate the potential regional average ecosystem carbon stocks densities. They predicted a series

of future scenarios, where scenario S1 (see Table 5) depicts the actual situation in the case study area in

2003/2004. The area under shifting cultivation in 2003/2004 in the study area was 67.4%, conservation

forest constituted 25.4%, teak plantation 5.0% and the rest of the area included paddy fields, water or

roads – all land use classes with similarly low carbon values. For the future land use scenarios, the authors

changed either the share of total area predicted to be under shifting cultivation, the land use intensity

therein, or both area share and intensity. Table 5 provides an overview of the scenarios that Inoue et al.

(2010) used and the resulting regional average carbon values. For the scenarios S4 and S5, using

alternative cropping systems, high yielding rice cultivars, green manure plants and cash crops were

screened to evaluate their performance under shifting cultivation conditions. It was found that cropping

systems based on the combination of high yielding rice cultivars, green manure plants (e.g. Stylosanthes

guianensis) and cash crops (e.g. paper mulberry) were most promising in terms of carbon sequestration,

and that such a system could be sustainable in a 2+10 crop-fallow pattern.

13

Table 5: Overview of average carbon values of the overall study region, including other types of land use based on Inoue et al. (2010)

Scenario name

Cropping patterns * Alternative cropping system

Regional average of ecosystem carbon values in tC/ha $

S1: Baseline situation 2003/4

Regional cropping pattern as determined in the study in the years 2003 and 2004: A range of patterns exist, 1C + 3F is the most dominant rotation pattern, followed by 1C + 2F; however longer patterns are also present.

48.0

S2 Same as S1 but the longest fallow is limited to 8 years 47.0

S3 Same as S1, but reserved 20% of the area for conservation forest 57.0

S4 2 year cropping + 10 years fallow x 62.1

S5 2 year cropping + 10 years fallow, but reserved 20% of the area for conservation forest

x 68.4

* While the first cropping patterns in the table depicts the real situation in 2003/2004, the other patterns are scenarios; it was

assumed by the authors (Inoue et al. 2010) that the area under shifting cultivation in the study are is 67.4% of the total area. $ The values given here include both above-ground and below ground carbon stocks, including soil carbon.

The authors calculated the regional average ecosystem carbon stock under the different land use

scenarios, which is an important figure for calculating overall carbon stock gains and losses, as well as the

monetary gains or losses which could result from a REDD+ scheme. The values assessed in the study

and given here include both above-ground and below ground carbon stocks (including soil carbon). The

highest gains in carbon for their study area would be reached under scenario S5: on average, 20tC/ha

would be sequestered by the landscape. Scenario S3, which requires no change in the cultivation system,

no adaption to new cropping technologies, and a reduction of the area under cultivation by 20% would

add 9 tC/ha to the regional average carbon value. It remains to be examined how realistic the changes in

current land use practices to the ones suggested in the future scenarios would be, both from an ecological,

socioeconomic, and demographical perspective.

Hett et al. (2011) also presented scenarios of alternative land use, though their models looked at the

national level. Based on a systematic review of case studies on crop-fallow speed in shifting cultivation

areas in Laos the authors assumed an average 1+5 crop-fallow cycle as the current baseline situation.

They then calculated two scenarios: In the first, they assumed that the same total area would be used

under shifting cultivation, but that the crop-fallow cycle would be 1+10. This is a back-casting model as

this could likely have been the situation 30 years ago. In the second scenario, they assumed a crop-fallow

cycle of 1+3, but limited shifting cultivation to two thirds of the area currently used. At the same time,

they assumed that the remaining one third would revert back to forest land. Table 6 gives an overview of

the calculated regional average carbon values, distinguished in the four different ecological zones. While

the carbon values of Area A in scenario 2 are naturally lower than in the ones from scenario 1 and the

current baseline situation, the total carbon stock gain under scenario 2 is still greatest because of the fact

that one third of the area was left to revert back to natural forest (Area B). The total carbon stock gain

under scenario 1 compared to the baseline is 30 mio tons of carbon, while for scenario 2 the gain was 40

mio tons.

14

Table 6: Carbon stocks densities in the shifting cultivation areas of Laos (national level study) for the current situation, and for two scenarios of alternative crop-fallow cycles and different land zoning based on Hett et al. (2011).

Carbon values in tC/ha

Ecological zone

TAr TAWa TAWb TM

Assumed situation in 2002: C stock density CF-cycle 1 to 5 12.1 13.5 11.8 5.3

Scenario 1: 1 year cropping, 10 years fallow 23.1 25.8 22.5 9.4

Scenario 2: 1 year cropping, 3 years fallow on two thirds of the original area: Area A. Rest of the original shifting cultivation area is left for natural regrowth of vegetation: Area B

Area A 8 8.9 7.8 3.9

Area B 90 52 39 40

3.4 A new attempt to assess the regional average carbon value and the total

above-ground biomass carbon stock for shifting cultivation areas in

Northern Laos

In addition to the two existing models and scenarios mentioned above, an attempt was made during this

study to assess the existing carbon stock in the total area under shifting cultivation in Northern Laos. This

was made possible by recent data generated by Hurni et al. (2013) for delineation of the total area under

shifting cultivation in Northern Laos. For details on the method of assessment, see section 2.2. The

results from this analysis are given in Table 7. Using the carbon values provided by Hett at al. (2011), an

overall regional average carbon value (across all ecological zones) of 11 tC/ha resulted whereas using the

carbon values provided by Kiyono et al. (2007, an average of 14.1 tC/ha resulted. The total carbon stock

was estimated to 38.62 mio tons of carbon and nearly 50 mio tons of carbon based on the carbon values

from the two respective studies.

Table 7: Overview of the total carbon stored in the vegetation of the landscapes under shifting cultivation in Northern Laos between 2006 and 2010. Values were modelled using carbon stock density values provided by Hett et al. (2011) and Kiyono et al. (2007)

FAO (2001)

Hurni et al. (2013) Hett el al. (2001)

Kiyono et al. (2007)

Ecological zone

Area under shifting cultivation in mio ha

Area in %

Carbon values *

Carbon stock in mio tons of carbon

Carbon values

Carbon stock in mio tons of carbon

Tar 0.64 24% 12.1 7.79

14.4 49.52

TAWa 1.24 35% 13.5 16.79

TAWb 0.84 22% 11.8 9.86

TM 0.79 18% 5.3 4.18

Total 3.51 100% 11.0 38.62 14.1 49.52

* it was assumed that the average crop-fallow period is 1+5 (one year cropping and 5 years of fallow); the carbon values given in

the table represent the average value for such a system.

15

The total amount of above-ground biomass carbon resulting from the carbon values from Kiyono et al.

(2007) is much higher than what results from the analysis using the carbon values provided by Hett et al.

(2011). The reason for this is that Kiyono et al. (2007) used only one single value for carbon stock density

(14.1 tC/ha); no distinction is made between ecological zones, and addition, the value used by Kiyono et

al. (2007) is higher than any of the values from Hett et al. (2011).

4 Conclusions

This study showed that case studies measuring carbon values for areas in Laos are rare. During the

literature review conducted, only four Laos-specific case studies were found. The information gained

from these case studies is crucial for the design and implementation of ongoing REDD+ projects

undertaken in Laos. However, a complete picture on carbon stocks found per hectare in Laos is not

available and these limited studies do not allow for generalization. These drawbacks stem from the two

issues. First, the studies did not conduct a full inventory of all land use classes found in their study areas

and assess carbon values for them, but instead focused on a selection of land use classes most relevant to

their specific topic. The study by Descloux et al. (2011) is the only one with a nearly complete inventory

of carbon values for the identified land cover classes. Unfortunately, all fallow fields were combined into

one class and the average fallow age is missing. (2) The carbon values cited in the case studies vary greatly.

Furthermore they are quite different to the values calculated based on the global figures provided in the

IPCC Guidelines for National Greenhouse Gas Inventories (IPCC 2006). Figure 5 shows all the carbon

values of different land cover classes in shifting cultivation landscapes of Laos identified by the literature

review and used in this study. The original land cover categories used by the authors of the case studies

were in some cases renamed to match the other cases.

Figure 5: Carbon values of different land cover classes of shifting cultivation landscapes in Laos identified through the systematic review of case studies. Y-axis values are YRF: Young regrowth forest, SWP: swamp; ORF: old regrowth forest; NAF: natural forest (or sometime referred to as dense or primary forest); GRS: grassland; DGF: degraded forest; AGR: agriculture. Study abbreviations: Kiyono: Kiyono et al. (2007); Roder: Roder et al. (1997); Descloux: Descloux et al. (2011); IPCC Tar, TAWa, TAWb, TM are values from the study of Hett et al. (2011) originating from IPCC (2006) for the different ecological zones; IPCC all is used for carbon values which have the same value across all ecological zones.

These results are no surprise and reiterate what has been found by other authors. In a recent review of

250 scientific papers, Ziegler et al. (2012) created an overview of above- and below-ground carbon

16

estimates for different land-use types in Southeast Asia2.They found that the net total ecosystem carbon

changes expected from many land use transitions were of great uncertainty because the carbon values of

the different land use classes showed great variability (see Figure 6).

Figure 6: Summary of above-ground carbon biomass (AGC) values (source: Ziegler et al. (2012)). Open and closed circles are minimum and maximum values of reported ranges, respectively. Crosses refer to reported mean values. The thick line (ending in a cross) is the modified range, defined by the minimum and maximum values reported in Table 3 (also shown in Fig. 2b). Land covers are the following: forest (F); logged over forest (LOF); orchards and tree plantations (OTP); rubber plantations (RP); long-fallow swidden (LFS); non-swidden agroforest (AGF); grassland, pasture, or shrublands (GPS); oil palm plantations (OP); intermediate-fallow swidden (IFS); short-fallow swidden (SFS); and permanent cropland (PC).

Causes for the variability in carbon values for different land cover types are manifold and include

differences in both the methodologies used and in data quality. Consequently, the comparison of

published values is relatively complex (Descloux et al. 2011). The main possible sources of confusion are:

1. the biomass unit (wet biomass, dry biomass, or carbon)

2. the minimal tree stem diameter

3. whether or not understory biomass is taken into consideration

4. the age of the estimations

Based on the findings from this study, the following recommendations can be given:

Practitioners working at the local level should use the carbon values provided by Kiyono et al.

(2007) and Descloux et al. (2011) if their case study site is located in a similar environment

(ecological zone, land cover classes and farming history). If their study area is situated in a

different environment, they should first attempt to find other local case studies with similar

conditions conducted in neighboring countries. At the time of writing, such studies are, however,

very limited. For study/project areas located in a different environment, practitioners are advised

to use the carbon values derived from the IPCC Guidelines for National Greenhouse Gas

Inventories (IPCC 2006). The latter should also be used for the time being for REDD+ studies

at the regional (provincial) to national level, as no values valid for the national level have been

established for Laos yet.

2 Most articles used in the study of Ziegler et al. (2012) came from Indonesia and Malaysia, only a few from the mainland of Southeast Asia and none from Laos.

17

In principle, lengthening fallow periods of an existing shifting cultivation system pumps carbon

into the landscape and produces substantial carbon benefits. The same goes for land cover

conversion from intensely cultivated lands to plantations of agroforestry systems. This counts for

any area, regardless of the absolute carbon value.

More research and extensive field campaigns are dearly needed to provide better data on above-

and below-ground carbon values in shifting cultivation landscapes before accurate

recommendations or policy decisions can be made regarding the amount of carbon that is

increased or decreased in the landscape due to land-use changes.

The full and precise quantification of the carbon stock over several hundred square kilometres in tropical

countries is costly, as it is both energy and time consuming. This is even more pronounced in shifting

cultivation landscapes due to their complex spatio-temporal dynamics and as the total number of

different land cover classes is higher than in areas with forestry and permanent agriculture. Full

assessments of carbon values ideally include all land cover types, including the series of different fallow

ages. Furthermore, the amount of carbon stored is dependent on the land use history as long-term

repeated crop-fallow cycles have negative effects on the total amount of carbon stored (Inoue et al.

2010).

18

References

APN (2012). "Forest Carbon Stocks in Shifting Cultivation of Thailand and Lao PDR." Asia Pacific Network for Global Change Research APN Science Bulletin(2): 3.

Descloux, S., V. Chanudet, H. Poilvé and A. Grégoire (2011). "Co-assessment of biomass and soil organic carbon stocks in a future reservoir area located in Southeast Asia." Environmental Monitoring and Assessment 173(1-4): 723-741.

FAO (2001). Global Forest Resources Assessment 2000. Rome, Italy, Food and Agriculture Organisation (FAO).

Hett, C., J.-C. Castella, A. Heinimann, P. Messerli and J.-L. Pfund (2012). "A landscape mosaics approach for characterizing swidden systems from a REDD+ perspective." Applied Geography 32(2): 608-618.

Hett, C., A. Heinimann and P. Messerli (2011). "Spatial assessment of carbon stocks of living vegetation at the national level in Lao PDR." Geografisk Tidsskrift Danish Journal of Geography 111(1): 11-26.

Hurni, K., C. Hett, A. Heinimann, P. Messerli and U. Wiesmann (2013). "Dynamics of shifting cultivation landscapes in northern Lao PDR between 2000 and 2009 based on an analysis of MODIS time series and Landsat images." Human Ecology 41(1): 21-36.

Inoue, Y., Y. Kiyono, H. Asai, Y. Ochiai, J. Qi, A. Olioso, T. Shiraiwa, T. Horie, K. Saito and L. Dounagsavanh (2010). "Assessing land-use and carbon stock in slash-and-burn ecosystems in tropical mountain of Laos based on time-series satellite images." International Journal of Applied Earth Observation and Geoinformation 12(4): 287-297.

IPCC (2006). IPCC Guidelines for National Greenhouse Gas Inventories. IGES, Japan.

Kiyono, Y., Y. Ochiai, Y. Chiba, H. Asai, K. Saito, T. Shiraiwa, T. Horie, V. Songnoukhai, V. Navongxai and Y. Inoue (2007). "Predicting chronosequential changes in carbon stocks of pachymorph bamboo communities in slash-and-burn agricultural fallow, northern Lao People’s Democratic Republic." Journal of Forest Research 12(5): 371-383.

Roder, W., S. Phengchanh and S. Maniphone (1997). "Dynamics of soil and vegetation during crop and fallow period in slash-and-burn fields of northern Laos." Geoderma 1-2(76): 131-144.

van Vliet, N., O. Mertz, A. Heinimann, T. Langanke, U. Pascual, B. Schmook, C. Adams, D. Schmidt-Vogt, P. Messerli, S. Leisz, J.-C. Castella, L. Jørgensen, T. Birch-Thomsen, C. Hett, T. Bech-Bruun, A. Ickowitz, K. C. Vu, K. Yasuyuki, J. Fox, C. Padoch, W. Dressler and A. D. Ziegler (2012). "Trends, drivers and impacts of changes in swidden cultivation in tropical forest-agriculture frontiers: A global assessment." Global Environmental Change 22(2): 418-429.

Ziegler, A. D., J. Phelps, J. Q. I. Yuen, E. L. Webb, D. Lawrence, J. M. Fox, T. B. Bruun, S. J. Leisz, C. M. Ryan, W. Dressler, O. Mertz, U. Pascual, C. Padoch and L. P. Koh (2012). "Carbon outcomes of major land-cover transitions in SE Asia: great uncertainties and REDD+ policy implications." Global Change Biology 18(10): 3087-3099.

19

Annex

Annex 1: List of case studies on carbon stock densities in Laos used in this

report

Forest Carbon Stocks in Shifting Cultivation of Thailand and Lao PDR

(APN) Asia Pacific Network for Global Change Research (2012). APN Science Bulletin Issue 2. 3 pages. ISSN 2185-

761x

The new global initiative for the reduction of deforestation and degradation, including the role of

conservation, sustainable management of forests, and enhancement of forest carbon stocks, or REDD+,

has substantial potential to deliver co-benefits for carbon sequestration, forest and biodiversity

conservation, and local livelihoods. Successful REDD+ strategies require integrating and complementing

the traditional forest management and agro-forestry practices of many local and indigenous communities,

rather than enforcing a barrier between them and their forests, as many forest conservation policies seek

to do.

This project, “Critical Analysis of Effectiveness of REDD+ for Forest Communities and Shifting

Cultivation, based on Lessons Learnt from Conservation Efforts in Lao PDR and Thailand,” was

launched in January 2011 to assess potential and options for shifting cultivators to build on traditional

knowledge and achieve co-benefits from REDD+ in the forested landscape. According to the work plan,

the project focused on surveys of land uses and carbon stocks in two study villages in 2011, one each in

Northern Thailand (Tee Cha, a Pwo Karen village in Sop Moei District of Mae Hong Son Province), and

Northern Lao PDR (Laksip, a Khmu village in Luang Prabang Province). Rotational shifting cultivation

remains the major livelihood in the study village in Northern Thailand, while shifting cultivation is being

converting to timber plantations in the study village in Northern Lao PDR. The two villages offer a good

comparison of traditional land-use systems in transition with consequences on carbon stock, biodiversity

and livelihoods.

Co-assessment of biomass and soil organic carbon stocks in a future reservoir

area located in Southeast Asia

Descloux, S., V. Chanudet, H. Poilvé and A. Grégoire (2011). Environmental Monitoring and Assessment 173(1-4):

723-741.

An assessment of the organic carbon stock present in living or dead vegetation and in the soil on the 450

km2 of the future Nam Theun 2 hydroelectric reservoir in Lao People’s Democratic Republic was made.

Nine land cover types were defined on the studied area: dense, medium, light, degraded, and riparian

forests; agricultural soil; swamps; water; and others (roads, construction sites, and so on). Their

geographical distribution was assessed by remote sensing using two 2008 SPOT 5 images. The area is

mainly covered by dense and light forests (59%), while agricultural soil and swamps account for 11% and

2%, respectively. For each of these cover types, except water, organic carbon density was measured in the

five pools defined by the Intergovernmental Panel on Climate Change: aboveground biomass, litter,

deadwood, belowground biomass, and soil organic carbon. The area-weighted mean carbon densities for

these pools were estimated at 45.4, 2.0, 2.2, 3.4, and 62.2 tC/ha, respectively, i.e., a total of about 115 ±

15 tC/ha for a soil thickness of 30 cm, corresponding to a total flooded organic carbon stock of 5.1 ± 0.7

MtC. This value is much lower than the carbon density for some South American reservoirs for example

20

where total organic carbon stocks range from 251 to 326 tC/ha. It can be mainly explained by (1) the

higher biomass density of South American tropical primary rainforest than of forests in this study and (2)

the high proportion of areas with low carbon density, such as agricultural or slash-and-burn zones, in the

studied area.

Spatial assessment of carbon stocks of living vegetation at the national level in

Lao PDR

Hett, C., A. Heinimann and P. Messerli (2011). "." Geografisk Tidsskrift Danish Journal of Geography 111(1): 11-

26.

The international mechanism for Reducing Greenhouse Gas Emissions from Deforestation and Forest

Degradation (REDD) supposedly offers new opportunities for combining climate mitigation,

conservation of the environment, and socio-economic development for developing countries. In Laos,

REDD is abundantly promoted by the government and development agencies as a potential option for

rural development. Yet, basic information for carbon management is missing: to date no knowledge is

available at the national level on the quantities of carbon stored in the Lao landscapes. In this study we

present an approach for spatial assessment of vegetation-based carbon stocks. We used Google Earth,

Landsat and MODIS satellite imagery and refined the official national land cover data to assess carbon

stocks. Our study showed that more than half (52%) of the carbon stock of Laos is stored in natural

forests, but that 70% of this stock is located outside of national protected areas. On the basis of two

carbon-centered land use scenarios we calculated that between 30 and 40 million tons of carbon could be

accumulated in shifting cultivation areas; this is less than 3% of the existing total stock. Our study

suggests that the main focus of REDD in Laos should be on the conservation of existing carbon stocks,

giving highest priority to the prevention of deforestation outside of national protected areas.

Assessing land-use and carbon stock in slash-and-burn ecosystems in tropical

mountain of Laos based on time-series satellite images

Inoue, Y., Y. Kiyono, H. Asai, Y. Ochiai, J. Qi, A. Olioso, T. Shiraiwa, T. Horie, K. Saito and L. Dounagsavanh

(2010). International Journal of Applied Earth Observation and Geoinformation 12(4): 287-297.

In the tropical mountains of Southeast Asia, slash-and-burn (S/B) agriculture is a widely practiced and

important food production system. The ecosystem carbon stock in this land-use is linked not only to the

carbon exchange with the atmosphere but also with food and resource security. The objective of this

study was to provide quantitative information on the land-use and ecosystem carbon stock in the region

as well as to infer the impacts of alternative land-use and ecosystem management scenarios on the carbon

sequestration potential at a regional scale. The study area was selected in a typical slash-and-burn region in

the northern part of Laos. The chrono-sequential changes of land-use such as the relative areas of

community age and cropping (C) + fallow (F) patterns were derived from the analysis of time-series

satellite images. The chrono-sequential analysis showed that a consistent increase of S/B area during the

past three decades and a rapid increase after 1990. Approximately 37% of the whole area was with the

community age of 1–5 years, whereas 10% for 6–10 years in 2004. The ecosystem carbon stock at a

regional scale was estimated by synthesizing the land-use patterns and semi-empirical carbon stock model

derived from in situ measurements where the community age was used as a clue to the linkage. The

ecosystem carbon stock in the region was strongly affected by the land-use patterns; the temporal average

of carbon stock in 1C + 10F cycles, for example, was greater by 33MgCha−1 compared to that in 1C +

2F land-use pattern. The amount of carbon lost from the regional ecosystems during 1990–2004 periods

was estimated to be 42MgCha−1. The study approach proved to be useful especially in such regions with

low data-availability and accessibility. This study revealed the dynamic change of land-use and ecosystem

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carbon stock in the tropical mountain of Laos as affected by land-use. Results suggest the significant

potential of carbon sequestration through changing land-use and ecosystem management scenarios. These

quantitative estimates would be useful to better understand and manage the land-use and ecosystem

carbon stock towards higher sustainability and food security in similar ecosystems

Predicting chronosequential changes in carbon stocks of pachymorph bamboo

communities in slash-and-burn agricultural fallow, northern Lao People’s

Democratic Republic

Kiyono, Y., Y. Ochiai, Y. Chiba, H. Asai, K. Saito, T. Shiraiwa, T. Horie, V. Songnoukhai, V. Navongxai and Y.

Inoue (2007). Journal of Forest Research 12(5): 371-383.

In northern Lao People’s Democratic Republic, rising human population has drastically reduced the

fallow period of slash-and-burn agriculture which has led to a considerable decrease in the carbon stock

in these communities. We estimated chronosequential changes in the communities’ carbon stocks, and

established the relationship between the fallow period and fallow-period-average carbon stocks in three

carbon pools of bamboo-dominated communities in hilly areas of the Luang Prabang Province, northern

Lao People’s Democratic Republic. Based on measurements by destructive sampling, we devised a model

and root-to-shoot ratios for estimating bamboo biomass. In six secondary plant communities established

after slash-and-burn cropping, we estimated community biomass using the above model and others, and

measured deadwood and litter stocks. The communities’ biomass and deadwood significantly increased

with time after the last cropping and the former reached about 100 Mg ha–1 after 15 years, whereas litter

stocks did not show significant trends over time. Extending the fallow period from 2 to 5 years would

increase fallow-period-average carbon stock from 14.2 to 25.1 Mg C ha–1. The overstory height was

significantly correlated with biomass, deadwood, and litter carbon stocks of these communities. Based on

our findings, changes in a community’s carbon stocks can be estimated using the changes in overstory

height, which should be taken into account in future studies to reduce uncertainty in estimating carbon

stocks in tropical ecosystems.

Dynamics of soil and vegetation during crop and fallow period in slash-and-burn

fields of northern Laos

Roder, W., S. Phengchanh and S. Maniphone (1997). Geoderma 1-2(76): 131-144.

Slash-and-bum rice production systems in northern Laos are undergoing dramatic changes. Increased

population pressure and regulations limiting access to land have resulted in shorter fallow periods.

Limited information is available on nutrient dynamics in slash-and-burn systems of Southeast Asia in

general and particularly on effects of reduced fallow length. Crop and fallow effects on soil parameters

and fallow vegetation were quantified in slash-and-bum fields in Luang Prabang, northern Laos from

1991 to 1994. Over the cropping season from May to October declines of 8, 7, and 3% organic C and 33,

40, and 53% extractable P, were observed for the depth intervals of 0-3, 3-10 and 10-25 cm, respectively,

Over the same period extractable K declined by 34% in the 0-3 cm interval and increased by 15 and 17%

in the 3-10 and 10-25 cm intervals. The declining trend continued over the 3 year crop-fallow cycle with

losses (depth 0-100 cm) of 29 + 7.6 t organic C ha- ~, 2.0 _+ 1.1 t total N ha- ~, and 0.7 ___ 0.8 t

extractable K ha- ~. At the end of the fallow period the above ground biomass contained 100 kg N ha-~,

5 kg P ha ~, and 140 kg K ha i. The fallow vegetation was dominated by Chromolaena odorata with a

gradual succession towards tree and bamboo species. The nutrients in the above ground fallow vegetation

represent only a small fraction of the N and C lost due to mineralization and leaching. With the present

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no-till system, mineralization losses are far more serious than losses due to soil erosion. Short fallows will

result in a fast decline and low equilibrium of soil organic C levels, reducing the potential for rice yields

and limiting farmer’s choice for other land use options which may become available with better market

access.

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Registered offices Bonn and Eschborn, Germany Climate Protection through Avoided Deforestation (CliPAD) Department of Forestry, That Dam Campus, Chanthabuly District, Vientiane Capital, Lao PDR P.O.Box 1295 T +856 21 254 082 F +856 21 243 083 I www.giz.de

A literature review on carbon stocks in shifting cultivation landscapes in Laos

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