were closely related to the peat formation including ancient back swamp, ancient
abandoned channels, salt marshes in coastal plains, and young coastal swamp (Ngo
et al. 1991b, 2010; Oanh et al. 2002; Nhan 1996).
The delta began forming after the sea receded during the mid-late Holocene and
late Holocene periods (Chiem 1993; Oanh et al. 2002; Tamura et al. 2009; Stattegger
et al. 2013). In the deposition process of ancient coastal swamps and marshes
sediments, the typical landscape associated with the formation of peatlands was
coastal wetlands developed from past shallow swamps and marshes covered by
dense mangroves and grasses, resulting in the formation of small peat-swamps and
marshes sparsely in the Plain of Reeds and the Long Xuyen Quadrangle (Ngo et al.
1991a, b; Chiem 1993; Nhan 1996; Nhan et al. 1996, 1998). Also in this period, a
series of old river beds were formed by the shifting river courses. Dense vegetation,
mainly ferns, grass species, and even Melaleuca grow along the rivers facilitated the
accumulation of organic-rich mud and peats derived from local vegetation after the
rivers shifted and abandoned its course, resulting in peat formation along the ancient
abandoned courses (Ngo et al. 1991a, b, c, 2010; Nhan 1996; Nhan et al. 1996,
1998). Besides ancient riverbeds and swamps that have peat layers located near the
soil surface, peat beds are found buried below the modern deltaic strata in the Plain
of Reed and the Long Xuyen Quadrangle (Ngo et al. 1987, 2010; Chiem 1993; Nhan
et al. 1996, 1998) (Fig. 29.1). Similarly, such layers of buried peat in ancient
abandoned river courses and freshwater swamp forests covered by sediments during
the mid-Holocene transgression are also found in Cambodia (Tamura et al. 2009;
Meynell 2017).
Not all, but some ancient abandoned river courses contained peat materials that
are found in the Plain of Reeds and the Long Xuyen Quadrangle (Fig. 29.1). Safford
et al. (2009) used pollen records and radiocarbon dating from sediment cores taken
from abandoned channel courses and back swamps in the Plain of Reeds. Preliminary results show that Melaleuca spp. and some grass species appeared in the delta
about 3000 years ago.
The accretion process and coastal plain expansion in the subsequent late Holocene period, mainly swamp/marsh sediments (bQ IV ), had formed the landscapes of
many coastal swamps. Among them, the U Minh swamps covered by dense vegetation were isolated and then gradually formed peat-swamps in the western part of
Ca Mau peninsula (Saurin 1962; Fontaine 1973; Ngo et al. 1991b; Nhan 1996)
(Fig. 29.1). By using radiocarbon dating (C
14 ), wood samples at a depth of 2 m from
the soil surface in U Minh peatlands were determined to be around 902 Æ 64 years
old (Ngo et al. 1991b; Nhan 1996; Uynh 2010). At similar depth, large Melaleuca
stumps found at the base of the U Minh peat deposits dated around 1000 years old
(Safford et al. 2009). Some swamps and ancient river courses had been covered by
vegetation and then their remnants accumulated in situ to form peatlands buried by a
thin layer of sediments (Ngo et al. 1991a; Thuyen 1996).
In the peatlands, a plant generation accumulated one after another, and hence
stratification can occur in peat profiles (Topcuoglu and Turan 2018). They have
accumulated thick horizons of organic matters and recorded information about past
vegetation dynamics, climate, and microbial processes (Topcuoglu and Turan 2018;
29 Management of Peatland in the Mekong River Delta of Vietnam
779
abandoned channels, salt marshes in coastal plains, and young coastal swamp (Ngo
et al. 1991b, 2010; Oanh et al. 2002; Nhan 1996).
The delta began forming after the sea receded during the mid-late Holocene and
late Holocene periods (Chiem 1993; Oanh et al. 2002; Tamura et al. 2009; Stattegger
et al. 2013). In the deposition process of ancient coastal swamps and marshes
sediments, the typical landscape associated with the formation of peatlands was
coastal wetlands developed from past shallow swamps and marshes covered by
dense mangroves and grasses, resulting in the formation of small peat-swamps and
marshes sparsely in the Plain of Reeds and the Long Xuyen Quadrangle (Ngo et al.
1991a, b; Chiem 1993; Nhan 1996; Nhan et al. 1996, 1998). Also in this period, a
series of old river beds were formed by the shifting river courses. Dense vegetation,
mainly ferns, grass species, and even Melaleuca grow along the rivers facilitated the
accumulation of organic-rich mud and peats derived from local vegetation after the
rivers shifted and abandoned its course, resulting in peat formation along the ancient
abandoned courses (Ngo et al. 1991a, b, c, 2010; Nhan 1996; Nhan et al. 1996,
1998). Besides ancient riverbeds and swamps that have peat layers located near the
soil surface, peat beds are found buried below the modern deltaic strata in the Plain
of Reed and the Long Xuyen Quadrangle (Ngo et al. 1987, 2010; Chiem 1993; Nhan
et al. 1996, 1998) (Fig. 29.1). Similarly, such layers of buried peat in ancient
abandoned river courses and freshwater swamp forests covered by sediments during
the mid-Holocene transgression are also found in Cambodia (Tamura et al. 2009;
Meynell 2017).
Not all, but some ancient abandoned river courses contained peat materials that
are found in the Plain of Reeds and the Long Xuyen Quadrangle (Fig. 29.1). Safford
et al. (2009) used pollen records and radiocarbon dating from sediment cores taken
from abandoned channel courses and back swamps in the Plain of Reeds. Preliminary results show that Melaleuca spp. and some grass species appeared in the delta
about 3000 years ago.
The accretion process and coastal plain expansion in the subsequent late Holocene period, mainly swamp/marsh sediments (bQ IV ), had formed the landscapes of
many coastal swamps. Among them, the U Minh swamps covered by dense vegetation were isolated and then gradually formed peat-swamps in the western part of
Ca Mau peninsula (Saurin 1962; Fontaine 1973; Ngo et al. 1991b; Nhan 1996)
(Fig. 29.1). By using radiocarbon dating (C
14 ), wood samples at a depth of 2 m from
the soil surface in U Minh peatlands were determined to be around 902 Æ 64 years
old (Ngo et al. 1991b; Nhan 1996; Uynh 2010). At similar depth, large Melaleuca
stumps found at the base of the U Minh peat deposits dated around 1000 years old
(Safford et al. 2009). Some swamps and ancient river courses had been covered by
vegetation and then their remnants accumulated in situ to form peatlands buried by a
thin layer of sediments (Ngo et al. 1991a; Thuyen 1996).
In the peatlands, a plant generation accumulated one after another, and hence
stratification can occur in peat profiles (Topcuoglu and Turan 2018). They have
accumulated thick horizons of organic matters and recorded information about past
vegetation dynamics, climate, and microbial processes (Topcuoglu and Turan 2018;
29 Management of Peatland in the Mekong River Delta of Vietnam
779