Forty-eight years of agroforestry monitoring in Kalimantan: a case study of management history and planted Agathis tree growth

Are agroforestry systems still realistic methods to balance forestation and livelihood for small-scale farmers? To answer this question, the author continuously monitored a 48-year agroforestry management system from the perspective of land management history and tree growth. The study plot is located in Tenggarong district, East Kalimantan Province, Borneo, Indonesia. The site covers a total area of 2 ha and has been managed by a farmer since 1974. Chronological data on the cultivated crops and tree growth were collected through direct observations and mensuration by local university researchers. As of 2022, an Agathis forest with a standing stock volume of 632.4 m³ had been created by agroforestry practices. On the other hand, the average income he generated was US$ 1231/year from 1974 to 2016. The gross cash income of the farmer was below or at the same level as the provincial minimum wage for 23 years or 48% of the entire management period. The results of the current study showed that the main income source changed over the years. This change was influenced by many factors, such as family member life stage, social demand supported by the increasing population, Agathis tree growth and farmer age. In response to change, the farmer planted many kinds of crops and selected the most profitable commodity in each period. Due to this trial-and-selection approach, his income source was diversified and generated a stable cash income not only throughout the year, but also throughout the 48 years management period. The results of the current case study showed that the agroforestry system is a realistic method for forestation and long-term management for small-scale farmer. On the other hand, it is not the optimal method if the purpose is to maximize cash income.