Soil Environment in Sago Palm Forest

Masanori Okazaki,Yuka Sasaki

doi:10.1007/978-981-10-5269-9_14

Abstract

Soils (acid sulfate soils, peat soils, gley soils, and others) distributed under sago forest and their productivity of sago palm are described in this chapter. Sago palm in tropical lowland areas is growing with the formation of the communities behind the mangrove forest. The main sources of water for sago palm are rivers, which are present in the eutrophic environment and more or less affected by sea tides. Sago palm equipped with the mechanism to eliminate salt effect or regulate salt uptake in several ways can grow in brackish water. Acid sulfate soils are derived from sulfate ion (SO42−) in seawater. Sulfate ion is reduced to form sulfide compounds by sulfate-reducing bacteria in soils (potential acid sulfate soils). Sulfide compounds are oxidized to sulfate ion and hydrogen ion is produced by sulfur- and iron-oxidizing bacteria in soils (actual acid sulfate soils). The sago starch yield is observed to be extremely high near the coast and lower in the inland places (soil pH 3.3–3.8). The tropical woody thick peat soils called Histosols in the tropical rainforest climate of Southeast Asian islands are formed to transport small amount of sediments by the shorter rivers compared to large rivers of continents. The constituent components in water flowing into tropical peat soils ensure the normal growth of sago palm. In Sarawak no effect of nitrogen (N) application on leaf production of sago palm was found, which was explained by the findings of endophytes’ activities on the nitrogen fixation. The sago palm growth in Inceptisols of the Philippines and Indonesia at the different stages was larger than those in Histosols of Malaysia from the long-term growth study.

Highlights

Soils distributed under sago forest and their productivity of sago palm are described in this chapter
Distributed in both tropical and subtropical lowland areas affected by seawater, the dominant distribution of mangrove forest is present in tropical brackish water areas
Tropical lowland plants grow under relatively eutrophic nutrient conditions, while tropical peatland plants are under poor nutrient conditions and affected by rainfall and flowing groundwater with high reduction and oxidation potential (Table 14.1)

Summary

14.1 Natural Habitat of Sago Palm in Tropical Lowland Areas

Natural lowland forest in tropical areas consists of mangrove, tropical lowland, and tropical peatland forests, in that order moving inland from the sea (Okazaki et al 2008) (Fig. 14.1). Nipa and sago palm are present behind mangrove forest and form a large plant community Both tropical lowland forest and tropical peatland forest are found in brackish water areas, each with a different freshwater source. Peat soils: Acid sulfate soils: Gley soils: Other soil types: Tropofibrists, Tropohemists, Troposaprists Sulfaquents, Sulfaquepts, Sulfic Tropaquents Sulfic Humaquents, Sulfic Haplaquepts, Sultfic Haplaquents Hydraquents, Fluvaquents, Tropofluvents Oxisols, Entisols, Inceptisols in the cytoplasm using potassium ions as the osmotic pressure regulator (compatible solute). They concluded that small amounts of other compatible solutes such as proline and glycine betaine were produced. Ehara et al (2003, 2006) showed that sago palm roots excluded sodium ions using the barriers to inhibit sodium ion absorption

14.2 Soils Distributed Under Sago Palm Forest

14.5 Other Entisols and Inceptisols

Findings

14.6 Comparison of Sago Palm Growth Between on Inceptisols and Histosols