greenhouse gas emissions (IPCC 2007). Developing countries in South and East
Asia and the Middle East contributed, according to Achard et al. (2004), an annual
loss of 1.7 Gt year
À1 of CO 2 to the atmosphere during the 1990s. Despite mitigation
attempts taking place and decreases in global deforestation rates, the losses are still
largest in South America, Africa and Southeast Asia.
The mountainous regions of northern Vietnam have witnessed drastic changes in
land use during the last few decades. Vien et al. (2006) indicated that government
development policies often seek to modernize the rural sector through the introduction of new agricultural technologies and improved marketing, without taking
existing, local capacities into account. With land use intensification, these mountainous landscapes become dominated by less diverse rain-fed upland fields, wetland rice terraces, small areas of fallow vegetation and patches of secondary forest
(Turkelboom et al. 2008). According to Kirschbaum et al. (2012), soil C stock
changes usually occur after deforestation and lead to subsequent soil loss by
erosion; however, the scale of these changes depends largely on the cropping
system involved. For example, Vang Rasmussen et al. (2012) found a reduction
in above-ground (ABG) C stocks in the range 4–13 Mg C ha
À1 to be associated with
a shift from fallow vegetation to cassava cropping. Further C loss pathways from
watersheds include burning and biomass mineralization, as well as export due to
harvest and the removal of plants for use as livestock fodder.
This study focuses on the C stocks (see also Chap. 2) of perennial vegetation and
upland crops, and provides data on the C stocks of ten representative perennial
LUTs, plus maize and cassava – the two most important uplands crops in the
Chieng Khoi catchment area. It also addresses the potential for Clean Development
Mechanism (CDM) measures to be used to generate income for smallholders.
3.5.1 Carbon Stocks of Perennial Vegetation
In Chieng Khoi commune (for further details of the study area, refer to Fig. 1.1 in
Chap. 1), the Rapid Carbon Stock Appraisal (RaCSA) approach, one of several
tools provided by the World Agroforestry Centre’s ‘Trees in multi-Use Landscapes
in Southeast Asia’ (TUL-SEA) project (TUL-SEA 2010), was used to generate data
on perennial biomass and related C stocks, as well as C stock changes. Figure 3.14
shows the land use pattern to be found in Chieng Khoi commune in 2007 (Zemek
et al. 2009).
Ten representative perennial land-use systems were defined and surveyed using
a nested sampling plot design (Fig. 3.15). Overall, 20 Â 100 m
2 nested sample plots
were established, representing two plots per LUT. The LUTs were:(1) protected
natural tropical semi-deciduous forest, (2) grazed secondary forest, and (3) bamboo
forest, as well as plantations of (4) Tectona grandis, (5) Mangifera spp.,
(6) Dimocarpus longan, (7) Musa spp. (basjoo and paradisiaca), (8) Chukrasia
tabularis, (9) Pinus massoniana, and (10) a mixed fruit tree plantation (including
Artocarpus heterophyllus, Tamarindus spp., Dimocarpus longan and Mangifera
134
H.L. Fro ¨hlich et al.
Asia and the Middle East contributed, according to Achard et al. (2004), an annual
loss of 1.7 Gt year
À1 of CO 2 to the atmosphere during the 1990s. Despite mitigation
attempts taking place and decreases in global deforestation rates, the losses are still
largest in South America, Africa and Southeast Asia.
The mountainous regions of northern Vietnam have witnessed drastic changes in
land use during the last few decades. Vien et al. (2006) indicated that government
development policies often seek to modernize the rural sector through the introduction of new agricultural technologies and improved marketing, without taking
existing, local capacities into account. With land use intensification, these mountainous landscapes become dominated by less diverse rain-fed upland fields, wetland rice terraces, small areas of fallow vegetation and patches of secondary forest
(Turkelboom et al. 2008). According to Kirschbaum et al. (2012), soil C stock
changes usually occur after deforestation and lead to subsequent soil loss by
erosion; however, the scale of these changes depends largely on the cropping
system involved. For example, Vang Rasmussen et al. (2012) found a reduction
in above-ground (ABG) C stocks in the range 4–13 Mg C ha
À1 to be associated with
a shift from fallow vegetation to cassava cropping. Further C loss pathways from
watersheds include burning and biomass mineralization, as well as export due to
harvest and the removal of plants for use as livestock fodder.
This study focuses on the C stocks (see also Chap. 2) of perennial vegetation and
upland crops, and provides data on the C stocks of ten representative perennial
LUTs, plus maize and cassava – the two most important uplands crops in the
Chieng Khoi catchment area. It also addresses the potential for Clean Development
Mechanism (CDM) measures to be used to generate income for smallholders.
3.5.1 Carbon Stocks of Perennial Vegetation
In Chieng Khoi commune (for further details of the study area, refer to Fig. 1.1 in
Chap. 1), the Rapid Carbon Stock Appraisal (RaCSA) approach, one of several
tools provided by the World Agroforestry Centre’s ‘Trees in multi-Use Landscapes
in Southeast Asia’ (TUL-SEA) project (TUL-SEA 2010), was used to generate data
on perennial biomass and related C stocks, as well as C stock changes. Figure 3.14
shows the land use pattern to be found in Chieng Khoi commune in 2007 (Zemek
et al. 2009).
Ten representative perennial land-use systems were defined and surveyed using
a nested sampling plot design (Fig. 3.15). Overall, 20 Â 100 m
2 nested sample plots
were established, representing two plots per LUT. The LUTs were:(1) protected
natural tropical semi-deciduous forest, (2) grazed secondary forest, and (3) bamboo
forest, as well as plantations of (4) Tectona grandis, (5) Mangifera spp.,
(6) Dimocarpus longan, (7) Musa spp. (basjoo and paradisiaca), (8) Chukrasia
tabularis, (9) Pinus massoniana, and (10) a mixed fruit tree plantation (including
Artocarpus heterophyllus, Tamarindus spp., Dimocarpus longan and Mangifera
134
H.L. Fro ¨hlich et al.