Since Narathiwat Province is the only area where the original peat swamp forest
still remains in Thailand, most studies were conducted there. From the studies
(Niyomtham 1989; Suzuki and Hara 1995), the natural swamp forests in Thailand
were summarized as Baccaurea bracteata-Endiandra macrophylla community and
to a lesser extent, the genera Campnosperma, Horsfieldia, Elaeocarpus and Eugenia
were also commonly found. The total number of plant species in the community
ranged from 38 to 51 trees per 1050–1600 square meters. The unique characteristic
of these trees, some of which have height ranging up to 30 m tall and 1 m in
diameter, is that they have a huge and exposed root system. Most trees exhibit
several forms of stilt roots, buttresses, pneumatophores as well as supporting or
breathing roots. Such a unique floristic characteristic can be attributed to a number of
factors such as the need to support themselves in peat soil which has a very low
bearing capacity and to obtain oxygen as well as nutrients in the submerged
environment.
It is interesting to note that the Gynotroches axillaris is also found in the peat
forest but is relatively rare (Suzuki and Hara 1995). The Gynotroches species are
included in the Rhizophoraceae family which most mangroves in Thailand belong
to. Thus, it might indicate some ecological relationships of the mangrove ecosystem
in the past and the peat swamp forest at present.
The degradation of original peat swamp forests in Thailand has occurred extensively since the 1970s. Most uses could be attributed to logging and conversion of
the areas for agricultural production aiming at rice production. At present, most of
these areas, however, have been left abandoned due to a number of soil limitations
and flood damage in the rainy season.
Under the traditional culture, the peat swamps were drained, the forest was cut
after a brief drying period, and all biomass was burnt, resulting in the total loss of the
original forest. After a few years of cultivation, with improper management and
drainage control, the peat layer was lost due to subsidence and burning, groundwater
table went down and the soil converted to typical acid sulfate soil. Therefore, these
factors have brought about the extensive degradation of the primary forest and the
habitat to open wood, treeless grassland, and problematic acid sulfate soil. In order to
illustrate the man-made succession of the plant species, see the following chart
(Fig. 27.13).
To visualize the present condition of the vegetation in Narathiwat swamp, the
actual vegetation profile is presented in Fig. 27.14.
27.7 Agricultural Potential and Management Strategies
27.7.1 Agricultural Potential
In order to assess the long-term agricultural prospects for the peat soils in Thailand, it
is imperative to consider a number of factors concerning the soil potential to produce
742
P. Vijarnsorn
still remains in Thailand, most studies were conducted there. From the studies
(Niyomtham 1989; Suzuki and Hara 1995), the natural swamp forests in Thailand
were summarized as Baccaurea bracteata-Endiandra macrophylla community and
to a lesser extent, the genera Campnosperma, Horsfieldia, Elaeocarpus and Eugenia
were also commonly found. The total number of plant species in the community
ranged from 38 to 51 trees per 1050–1600 square meters. The unique characteristic
of these trees, some of which have height ranging up to 30 m tall and 1 m in
diameter, is that they have a huge and exposed root system. Most trees exhibit
several forms of stilt roots, buttresses, pneumatophores as well as supporting or
breathing roots. Such a unique floristic characteristic can be attributed to a number of
factors such as the need to support themselves in peat soil which has a very low
bearing capacity and to obtain oxygen as well as nutrients in the submerged
environment.
It is interesting to note that the Gynotroches axillaris is also found in the peat
forest but is relatively rare (Suzuki and Hara 1995). The Gynotroches species are
included in the Rhizophoraceae family which most mangroves in Thailand belong
to. Thus, it might indicate some ecological relationships of the mangrove ecosystem
in the past and the peat swamp forest at present.
The degradation of original peat swamp forests in Thailand has occurred extensively since the 1970s. Most uses could be attributed to logging and conversion of
the areas for agricultural production aiming at rice production. At present, most of
these areas, however, have been left abandoned due to a number of soil limitations
and flood damage in the rainy season.
Under the traditional culture, the peat swamps were drained, the forest was cut
after a brief drying period, and all biomass was burnt, resulting in the total loss of the
original forest. After a few years of cultivation, with improper management and
drainage control, the peat layer was lost due to subsidence and burning, groundwater
table went down and the soil converted to typical acid sulfate soil. Therefore, these
factors have brought about the extensive degradation of the primary forest and the
habitat to open wood, treeless grassland, and problematic acid sulfate soil. In order to
illustrate the man-made succession of the plant species, see the following chart
(Fig. 27.13).
To visualize the present condition of the vegetation in Narathiwat swamp, the
actual vegetation profile is presented in Fig. 27.14.
27.7 Agricultural Potential and Management Strategies
27.7.1 Agricultural Potential
In order to assess the long-term agricultural prospects for the peat soils in Thailand, it
is imperative to consider a number of factors concerning the soil potential to produce
742
P. Vijarnsorn