How does replacing natural forests with rubber and oil palm plantations affect soil respiration and methane fluxes?

Abstract

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 (CH 4) and respiration (CO 2) 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 CH 4 fluxes. The soil acted as a sink for CH 4 (kg CH 4-CÁha −1 Áyr −1) in the undisturbed forest (−1.4 AE 1.0) and young rubber plantation (−1.7 AE 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 AE 0.9, −0.2 AE 0.3, and 0.2 AE 0.7 kgÁha −1 Áyr −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 CO 2-CÁha −1 Áyr −1) was higher in the oil palm plantation (17.1 AE 1.9) than in the undisturbed forest (13.9 AE 1.2) while other land-use systems respired at a similar level to the undisturbed forest (13.1 AE 1.4, 15.9 AE 1.7, and 14.1 AE 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 CH 4 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.

Nutrient response efficiency, soil greenhouse gas fluxes, and nutrient leaching losses from a large-scale oil palm plantation under conventional and reduced management practices

“…Also, the soil CH 4 uptake at our site was larger than that reported by Aini et al (2020) (ranging from −1 to 13 μg C m −2 h −1 ) for an oil palm plantation on sandy clay loam Cambisol soil in Jambi, Indonesia, which they explained by the high WFPS (> 80%) during their measurement period. Clay content or soil texture is the main site factor that correlate positively to soil CH4 fluxes (Veldkamp et al 2013), indicating that the higher the clay content the lower is the soil CH 4 uptake.…”

“…Overall, the differences in soil properties and root biomass among these spatially distinct management zones ) potentially drive the spatial variation of soil GHG fluxes from oil palm plantations (Hassler et al 2015Aini et al 2020). Thus, estimating soil GHG emissions from oil palm plantations should take into account the spatial variability among management zones within a site or plot.…”

Responses of soil greenhouse gas emissions to land use conversion and reversion—A global meta‐analysis

“…such as land for corn or maize growing; plantation (Plan.) like plantation of oil palm, rubber, pine, bamboo, orchard, or tea (Aini et al, 2020; Liu, Jiang, et al, 2011); herb including natural grassland, natural savanna, or slightly disturbed pasture; secondary forest (Secf.) denoted the naturally regrowing forest after the logging or destruction of the primary forest; urban was the surface for human activities; other land uses (Others) included clear‐cut forest, degraded forest, postburn land.…”

“…such as land for corn or maize growing; plantation (Plan.) like plantation of oil palm, rubber, pine, bamboo, orchard, or tea (Aini et al, 2020;Liu, Jiang, et al, 2011); herb including natural grassland, natural savanna, or slightly disturbed pasture; secondary forest (Secf. )…”

Aerobic Methanotrophy and Co-occurrence Networks of a Tropical Rainforest and Oil Palm Plantations in Malaysia

“…Predominantly, well-aerated soils are a sink for atmospheric methane, but may also transiently emit methane when conditions turn anoxic (e.g., after a rainfall) [8][9][10][11]. In both instances, aerobic methanotrophs catalyze the oxidation of methane.…”