Effects of conversion from leguminous acacia to non-leguminous eucalyptus on soil N2O emissions in tropical monoculture plantations

• Published in: Forest ecology and management 2021-02, Vol.481, p.118702, Article 118702
• Main Authors: Ishizuka, Shigehiro, Mori, Taiki, Nakayama, Yuki, Kawabata, Chiaki, Konda, Ryota, Sasaki, Takuya, Sawa, Yukiko, Hamotani, Yuki, Gobara, Yukari, Kuwashima, Kei, Wicaksono, Agus, Heriyanto, Joko, Hardjono, Arisman, Ohta, Seiichi
• Format: Article
• Language: English
• Subjects: Acacia mangium; Eucalyptus pellita; Fast growing tropical tree plantation; Indonesia; Nitrous oxide
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2020.118702

•N2O emission from soils was measured after a conversion from acacia to eucalyptus.•The N2O flux at the eucalyptus stands was as large as that at the acacia stands.•The mitigation potential of the conversion were not observed in short period. Tropical monoculture leguminous tree plantations are important nitrous oxide (N2O) sources, especially in the Asian tropics. We evaluated the effect of conversion from leguminous Acacia mangium to non-leguminous Eucalyptus pellita on N2O emissions. A 4-year monitoring experiment was conducted in three areas in South Sumatra, Indonesia. In each area, we established acacia and eucalyptus plantation sites adjacent to one another after the harvest of acacia trees. In contrast to our expectation, the averaged N2O flux at the eucalyptus stands (1.07 mg m−2 day−1 of N) was not significantly different from that at the acacia stands (0.96 mg m−2 day−1 of N). This result was attributable to the higher soil NO3 content in the eucalyptus stands than that in the acacia stands, which was due to the lower N requirement of eucalyptus than that of acacia. In conclusion, converting leguminous acacia to non-leguminous eucalyptus was not an effective option to mitigate N2O emissions in the short term.