The distribution of sago palm species is shown in Fig. 3.1. Sago grows mostly in the islands of Southeast Asia and also in Melanesia. It includes most of Indonesia, Malaysia, southern Philippines, southern Thailand, Papua New Guinea (PNG), Solomon Islands, Vanuatu, Fiji, and Samoa. It is argued that in Southeast Asia, including islands and mainland areas, taro, yam, and sago formerly were the staple foods before rice largely replaced these crops, and it is claimed that sago is one of the oldest food plants (Spencer 1963).
The way the people use sago varies depending on the area. Using sago as a starch source often refers to the palms being under a system of semi-cultivation, and the distinction whether the people cultivate sago intentionally or use naturally occurring sago is unclear. The degree of cultivation varies from one area to another.
There are several ways that the local people are involved with sago. First, in some areas sago starch is the staple food for local people. In these areas, the people get starch from sago as a way of subsistence. Second, in some areas, commercialization of sago starch is practiced. Sago is collected, and the starch is processed industrially in factories. Here, the sago starch is exploited as a means of earning cash. Third, in other areas, although they have sago forests or sago palms near their living areas, sago is not used very much. It is only supplementary to other food, only consumed as emergency food, or it is no longer consumed, although it was formerly eaten.
In some areas, sago is the staple food for local people, and these areas include lowlands in Indonesia, Malaysia, and PNG, with some parts of highlands also included. In Indonesia, Papua Province has huge sago forests, more than 1 million ha in total (Ehara 2015), and the people heavily depend on sago as staple food. Also in other areas, such as the Moluccas, northern Sulawesi, and northern Kalimantan, the people utilize sago as a staple food. In Malaysia, Sarawak and Sabah, there are areas where the local people utilize sago as one of their staple foods. Papua New Guinea has a large area where sago is the staple food. Figure 3.2 shows the distribution of land usage of PNG, and it indicates the areas where sago is the staple food. This includes lowland areas in the northern and southern parts of New Guinea Island, and also some areas in smaller islands, including Manus and northern New Ireland. The total area of sago-growing area in PNG is estimated to be around 1 million ha (Power 2002). In some parts of Bougainville, especially in Eivo and Siwai, which are not shown in Fig. 3.2, sago is produced regularly as food (Connell and Hamnett 1978).
As for the commercialization of sago, there are examples only in Malaysia and Indonesia. In Malaysia, there are small-scale sago factories in Sarawak and Sabah. In Indonesia, sago plantations are found in Riau, Sumatra, and Papua Province, as well as small-scale factories (see Chaps. 6, 7, and 8).
In other areas, sago is not used very much. In the current countries of Fiji and Vanuatu, it is believed that sago was once used as a food (Barrau 1959), but at present there is little evidence of its use as food with the exception of Espiritu Santo Island, Vanuatu, and Rotuma Island, Fiji (Connell and Hamnett 1978). In the Solomon Islands, there are some records of its use as a food crop. For example, in the islands of Anuta and Tikopia, sago remains an alternative food to taro, after a cyclone, and in Kwaio and Baegu of northern Malaita, sago was used in times of great scarcity (ibid). There are some areas where it is recorded that the people formerly but no longer consume sago. In many areas where sago grows, sago starch is not eaten, but the palm parts are used for other purposes, such as thatching material.