Carbon stock potential at several agarwood-based agroforestry practices in Sragen and Karanganyar, Central Java']Java

Agroforestry practices have a pivotal role to reduce the CO2 concentration in the atmosphere and they subsequently store the carbon in part of stems, branches, roots, and crowns of the trees composing their vegetation communities. The objective of the research is to determine the carbon stocks in the three agroforestry practices. These are Multilayer Tree Garden (MTG), Taungya (TGY), and Home Garden (HMG). The research was carried out from May 2017 to November 2017 at Sragen and Karanganyar Regency, Central Java. A plot size of 20 m x 100 m for big trees, 5 m x 40 m for small trees, and 1 m x 1 m for understory vegetation was used in the sampling. The carbon stock was measured by Chave's allometric equation. The carbon stock in the multilayer tree garden is the highest (44.47 Mg C/ha) compared with the taungya (38.81 Mg C/ha) and home garden (31.41 Mg C/ ha). Meanwhile, the above-ground carbon stock in the home garden practice is the biggest (14.97 Mg C/ha or 48 %) among the multilayer tree garden (9.67 Mg C/ ha or 23%) and taungya (6.11 Mg C/ha or 16%). A 14-year-old G. versteegii in the taungya practice has the biggest carbon stocks (2.46 Mg C/ ha) compared to the multilayer tree garden (1.73 Mg C/ha) and home garden (0.56 Mg C/ ha).