the water may be attributed to the complexation with copper and zinc as organic
poly-ligand.
27.5.3 Soil Classification
According to the 1938 USDA classification, the peat soils in Thailand can be
classified into a great soil group Bog Soils or as called by Dudal and Moorman
(1964), the Organic Soils. However, attempts were made to classify these soils
according to the USDA Soil Taxonomy (Soil Survey Staff 2014) as shown in
Table 27.2.
27.6 Succession of the Peat Forest Species
As mentioned earlier, peat swamp forest is a unique vegetation with a high proportion of endemic taxa. So far, 88 families and 298 species of flowering plants and
13 families and 18 species of ferns have been recorded, 48 species of which are
regarded as new species in Thailand (Niyomtham 1989). The emergence of this
original forest in the soft and nutrient-poor soil under permanent waterlogged
condition is quite interesting.
Table 27.2 Peat swamp soils classification
Physiographic
regions
USDA soil taxonomy
After Dudal
and Moorman
(1964)
Common
terms
(provisional)
Soil series
Current classification at
family level
Southern
peninsula
(1) Narathiwat
series
Dysic, isohyperthermic,
Typic Haplofibrists
Organic soil
Peat soil
(2) Narathiwat
variants
(a) Dysic, isohyperthermic,
Fluvaquentic Haplofibrists
Organic soil
Peat soil
(b) loamy, dysic,
isohyperthermic, Terric
Haplofibrists
Organic soil
Peat soil
(3) Kab Daeng
series
Loamy, dysic,
isohyperthermic, Terric
Sulfihemists
Organic soil
Muck soil
(4) others
Dysic, isohyperthermic,
Typic Sulfihemists
Organic soil
Muck soil
Remarks:
(1) Soil variant is a temporary name to a soil which has at least one differentiating characteristic
unlike any known existing taxonomic units at series level and is found to cover an area of <20 km
2
.
In Thailand, new soil series will be proposed if the area of a named soil variant exceeds 20 km
2
(2) Dysic is a modifier indicating the pH value of the soil is <4.5 (in 0.01 M CaCl 2 ) in all layers of
organic soil materials within the control section
27 Sustainable Management of Peatland in Thailand
741
poly-ligand.
27.5.3 Soil Classification
According to the 1938 USDA classification, the peat soils in Thailand can be
classified into a great soil group Bog Soils or as called by Dudal and Moorman
(1964), the Organic Soils. However, attempts were made to classify these soils
according to the USDA Soil Taxonomy (Soil Survey Staff 2014) as shown in
Table 27.2.
27.6 Succession of the Peat Forest Species
As mentioned earlier, peat swamp forest is a unique vegetation with a high proportion of endemic taxa. So far, 88 families and 298 species of flowering plants and
13 families and 18 species of ferns have been recorded, 48 species of which are
regarded as new species in Thailand (Niyomtham 1989). The emergence of this
original forest in the soft and nutrient-poor soil under permanent waterlogged
condition is quite interesting.
Table 27.2 Peat swamp soils classification
Physiographic
regions
USDA soil taxonomy
After Dudal
and Moorman
(1964)
Common
terms
(provisional)
Soil series
Current classification at
family level
Southern
peninsula
(1) Narathiwat
series
Dysic, isohyperthermic,
Typic Haplofibrists
Organic soil
Peat soil
(2) Narathiwat
variants
(a) Dysic, isohyperthermic,
Fluvaquentic Haplofibrists
Organic soil
Peat soil
(b) loamy, dysic,
isohyperthermic, Terric
Haplofibrists
Organic soil
Peat soil
(3) Kab Daeng
series
Loamy, dysic,
isohyperthermic, Terric
Sulfihemists
Organic soil
Muck soil
(4) others
Dysic, isohyperthermic,
Typic Sulfihemists
Organic soil
Muck soil
Remarks:
(1) Soil variant is a temporary name to a soil which has at least one differentiating characteristic
unlike any known existing taxonomic units at series level and is found to cover an area of <20 km
2
.
In Thailand, new soil series will be proposed if the area of a named soil variant exceeds 20 km
2
(2) Dysic is a modifier indicating the pH value of the soil is <4.5 (in 0.01 M CaCl 2 ) in all layers of
organic soil materials within the control section
27 Sustainable Management of Peatland in Thailand
741