Replacement of forest by agricultural systems is a major factor accelerating the emissions of greenhouse gases; however, related field studies in the tropics are very scarce. To evaluate the impact of forest transition to plantations on soil methane (CH₄) and respiration (CO₂) fluxes, we conducted measurements in an undisturbed forest, a disturbed forest, young and old rubber plantations, and an oil palm plantation on mineral soil in Jambi, Sumatra, Indonesia. Methane fluxes and their controlling variables were monitored monthly over fourteen months; soil respiration was measured less frequently. All of the plantations were managed by smallholders and had never been fertilized. To assess the effect of common management practices in oil palm plantations, we added urea at a rate of 33.3 kg N/ha and thereafter monitored intensively soil CH₄ fluxes. The soil acted as a sink for CH₄ (kg CH₄‐C·ha⁻¹·yr⁻¹) in the undisturbed forest (−1.4 ± 1.0) and young rubber plantation (−1.7 ± 0.7). This was not the case in the other land‐use systems which had fluxes similar to fluxes in the undisturbed forest, with 0.4 ± 0.9, −0.2 ± 0.3, and 0.2 ± 0.7 kg·ha⁻¹·yr⁻¹ in the disturbed forest, old rubber plantation, and oil palm plantation, respectively. In the oil palm plantation, there was no inhibitory effect of nitrogenous fertilizer on methanotrophy. Annual soil respiration (Mg CO₂‐C·ha⁻¹·yr⁻¹) was higher in the oil palm plantation (17.1 ± 1.9) than in the undisturbed forest (13.9 ± 1.2) while other land‐use systems respired at a similar level to the undisturbed forest (13.1 ± 1.4, 15.9 ± 1.7, and 14.1 ± 1.0 in the disturbed forest, young, and old rubber plantations, respectively). Substrate (litterfall and soil) availability and quality exerted a strong control over annual fluxes of both gases along the land‐use gradient. Temporal variation in CH₄ was extremely high and in respiration fluxes was moderate, but was not specifically linked to seasonal variation. Further comprehensive and long‐term research is critically needed to determine more thoroughly the direction and magnitude of changes in soil trace gas emissions as affected by forest‐to‐plantation conversion in the tropics.

中文翻译：

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用橡胶和油棕人工林代替天然林如何影响土壤呼吸和甲烷通量？

农业系统取代森林是加速温室气体排放的主要因素；但是，热带地区的相关实地研究非常少。评估森林过渡到人工林对土壤甲烷（CH ₄）和呼吸作用（CO _{2）的影响}）通量，我们在印度尼西亚苏门答腊岛占碑的原始森林，受干扰的森林，老旧橡胶种植园和矿物土壤上的油棕种植园进行了测量。在十四个月内每月监测一次甲烷通量及其控制变量。土壤呼吸的测量频率较低。所有的人工林都由小农经营，从未施肥。为了评估常见管理措施对油棕种植园的影响，我们以33.3 kg N / ha的比例添加尿素，然后对土壤CH ₄流量进行了严格监测。土壤充当CH ₄的汇（kg CH ₄ -C·ha ^-1 ·yr ^-1）（-1.4±1.0）和橡胶幼林（-1.7±0.7）。这不是在其中具有类似于在未受干扰的森林通量通量其他土地使用系统的情况下，具有0.4±0.9，-0.2±0.3，和0.2±0.7公斤·公顷^-1 ·年^-1在扰动森林，旧橡胶种植园和油棕种植园。在油棕种植园中，氮肥对甲烷氧化菌没有抑制作用。年土壤呼吸（Mg CO ₂ -C·ha ^-1 ·yr ^-1）在油棕种植园（17.1±1.9）高于未受干扰的森林（13.9±1.2），而其他土地利用系统的呼吸水平与未受干扰的森林相似（13.1±1.4、15.9±1.7和14.1± 1.0，分别位于受干扰的森林，年轻和古老的橡胶种植园）。基质（凋落物和土壤）的可利用性和质量对两种气体沿土地利用梯度的年通量有很强的控制作用。CH _4的时间变化极高，呼吸通量适中，但与季节变化没有特别联系。迫切需要进行进一步的长期综合研究，以更彻底地确定热带地区森林到人工林转换对土壤微量气体排放变化的方向和幅度。