Domestication of Dyera polyphylla (Miq.) Steenis in peatland agroforestry systems in Jambi, Indonesia

摘要

As part of a broader pattern of recovery after decline called forest transition, tree cover and carbon stocks have increased through agroforestry systems in many parts of Indonesia. The associated tree diversity transition implies that only the most useful parts of local tree flora are promoted. Swampland jelutong, Dyera polyphylla, has been domesticated in peat areas Jambi province, Indonesia. We discuss jelutong domestication in two coastal districts, referring to seven steps in a gradual change from products collected from communal natural forests to specific genotypes managed on private farms. Domestication of D. polyphylla in Jambi was in the initial stages three decades ago, when jelutong latex was directly tapped from the trees in its natural habitat of peat swamp forests. Tapping jelutong latex stopped in 2005 following the national regulation taxing forest products. Some farmers then started jelutong cultivation, motivated by the profitability of trading jelutong latex in the past. Our on-farm study showed that jelutong can be planted in various mixed agroforestry systems, with rubber, coffee or oil palm as dominants. Planted jelutong with good farm management showed diameter growth rates of 1.3 to 1.9 cm year(-1). On-farm trials showed that dolomite as soil ameliorant did not affect diameter growth, but had some effect on height. Jelutong planted between young oil palm had the best performance, while jelutong that was underplanted in mature rubber gardens grew slowly. Slow market revival currently constrains further tree domestication of jelutong.