Can agriculture reach net zero emissions by 2050?

Significant GHG emissions reductions in agriculture are achievable through reducing emission intensity of production, but population growth and dietary changes may offset absolute emissions reductions. Emission reductions consistent with 2030 targets are achievable in many countries; attaining the 2050 targets will require innovation and systems transformation. Net zero agriculture cannot be achieved without sinks. Governance, economics, and sociocultural factors are the keys to food system transformations

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

This research was conducted under the REDD-ALERT project (Grant Agreement # 226310) with financial support from the European Commission Seventh Framework Programme [FP7/2007-2013]. It was also generously funded by the Australian Agency for International Development (AusAID) (Grant Agreement # 46167) and the Norwegian Agency for Development Cooperation (NORAD) (Grant Agreement #QZA-10/0468). This work is part of the Consultative Group on International Agricultural Research (CGIAR) programs on Trees, Forests and Agroforestry (FTA) and Climate Change, Agriculture and Food Security (CCAFS). Authors extend their gratitude to staff from Brawijaya University in Malang, the Indonesian Soil Research Institute (ISRI) in Bogor, and Balai Lingkungan Pertanian in Jakenan for laboratory support. We also thank Robbin Matthews and John Hillier, whose insights, feedbacks and recommendations contributed to improve the quality of the manuscript and to the modeling team of the School of Biological and Environmental Science from the University of Aberdeen for constructive discussions. Furthermore, we are very thankful to all assistants and to the REDD-ALERT Indonesia team who supported field work in Jambi. Finally, we are very grateful to the two anonymous reviewers for their constructive comments which contributed to improve this manuscript.Peer reviewedPublisher PD

Heightened fire probability in Indonesia in non-drought conditions: the effect of increasing temperatures

In Indonesia, drought driven fires occur typically during the warm phase of the El Niño Southern Oscillation. This was the case of the events of 1997 and 2015 that resulted in months- long hazardous atmospheric pollution levels in Equatorial Asia and record greenhouse gas emissions. Nonetheless, anomalously active fire seasons have also been observed in non-drought years. In this work, we investigated the impact of temperature on fires and found that when the July–October (JASO) period is anomalously dry, the sensitivity of fires to temperature is modest. In contrast, under normal-to-wet conditions, fire probability increases sharply when JASO is anomalously warm. This describes a regime in which an active fire season is not limited to drought years. Greater susceptibility to fires in response to a warmer environment finds support in the high evapotranspiration rates observed in normal-to-wet and warm conditions in Indonesia. We also find that fire probability in wet JASOs would be considerably less sensitive to temperature were not for the added effect of recent positive trends. Near-term regional climate projections reveal that, despite negligible changes in precipitation, a continuing warming trend will heighten fire probability over the next few decades especially in non-drought years. Mild fire seasons currently observed in association with wet conditions and cool temperatures will become rare events in Indonesia

Learning from REDD + : a response to Fletcher et al.

Learning from REDD plus : a response to Fletcher et al.Non peer reviewe

Soil nitrous oxide and methane fluxes from a land-use change transition of primary forest to oil palm in an Indonesian peatland

Despite the documented increase in greenhouse gas (GHG) emissions from Southeast Asian peat swamp forest degradation and conversion to oil palm over recent decades, reliable estimates of emissions of nitrous oxide (N2O) and methane (CH4) are lacking. We measured soil fluxes of N2O and CH4 and their environmental controls along a peatland transition from primary forest (PF) to degraded drained forest (DF) to oil palm plantation (OP) over 18 months in Jambi, Sumatra, Indonesia. Sampling was conducted monthly at all sites and more intensively following two fertilization events in the OP. Mean annual emissions of N2O (kg N ha−1 yr−1) were 1.7 ± 0.2 for the PF, 2.3 ± 0.2 for the DF and for the OP 8.1 ± 0.8 without drainage canals (DC) and 7.7 ± 0.7 including DC. High N2O emissions in the OP were driven by peat decomposition, not by N fertilizer addition. Mean CH4 annual fluxes (kg C ha−1 yr−1) were 8.2 ± 1.9 for the PF, 1.9 ± 0.4 for the DF, and 1.6 ± 0.3 for the OP with DC and 1.1 ± 0.2 without. Considering their 20-year global warming potentials (GWP), the combined non-CO2 GHG emission (Mg CO2-equivalent ha−1 yr−1) was 3.3 ± 0.6 for the PF and 1.6 ± 0.2 for the DF. The emission in the OP (3.8 ± 0.3 with or without DC) was similar to the PF because reductions in CH4 emissions offset N2O increases. However, considering 100-year GWP, the combined non-CO2 GHG emission was larger in the OP (3.4 ± 0.3 with DC and 3.5 ± 0.3 without) compared to both the PF and the DF (1.5 ± 0.2 and 1.2 ± 0.1, respectively). The increase in peat N2O emissions associated with the land-use change transition from primary forest to oil palm plantation at our sites provides further evidence of the urgent need to protect tropical peat swamp forests from drainage and conversion

Modeling the spatial distribution of soil organic carbon and carbon stocks in the Casanare flooded savannas of the Colombian Llanos

Abstract Flooded savannas are valuable and extensive ecosystems in South America, but not widely studied. In this study, we quantify the spatial distribution of soil organic carbon (SOC) content and stocks in the Casanare flooded savannas. We sampled 80 sites at two soil-depth intervals (0-10 and 10-30 cm), where SOC values ranged from 0.41% in the surface and 0.23% in the sub-surface of drier soils to over 14.50% and 7.51%, in soils that experienced seasonal flooding. Spatial predictions of SOC were done through two digital soil mapping (DSM) approaches: Expert-Knowledge (EK) and Random-Forest (RF). Although both approaches performed well, EK was slightly superior at predicting SOC. Covariates derived from vegetation cover, topography, and soil properties were identified as key drivers in controlling its distribution. Total SOC stocks were 55.07 Mt with a mean density of 83.1±24.3 t·ha -1 in the first 30 cm of soil, with 12.3% of this located in areas that experience long periods of flooding (semi-seasonal savannas) , which represented only 7.9% of the study area (664,752 ha). Although the study area represents only 15% of the total area of the Casanare department, the intensive pressure of human development could result in the reduction of its SOC stocks and the release of important amounts of greenhouse gases into the atmosphere. At regional level, the impact of a large-scale land use conversions of the flooded Llanos del Orinoco ecosystem area (15 Mha) could transform this area in a future source of important global emissions if correct decisions are not taken regarding the land management of the region

Impacts of land use and land cover dynamics on ecosystem services in the Yayo coffee forest biosphere reserve, southwestern Ethiopia

Land management to increase food production while conserving the environment and associated ecosystem services (ESs) is one of the major development and research challenges of the 21st Century. Any land-use practice or change to obtain a particular ecosystem service affects the other ES positively or negatively. The dynamics of these changes is more marked in biodiversity hotspot areas like UNESCO registered Yayo coffee forest biosphere reserve in southwestern Ethiopia. We used a time series InVEST modeling framework to estimate six ESs and analyze their spatial and temporal dynamics due to land-use/cover change over the last 31 years. Pearson correlation coefficients and k-mean clustering were employed to analyze tradeoffs/synergies and to cluster ESs supply spatially. The analysis also considers land-use change impact in the three management zones (core, transition and buffer) of the Yayo biosphere area. The production efficient frontier is used to identify the optimal combination of ESs and to suggest where an increase of one ES is possible without decreasing the others. Mostly, the highest change is observed in the transition zone followed by buffer zones. Positive correlation (synergies) are observed between regulating ecosystem services. Negative correlations (tradeoffs) are observed between provision ecosystem services. The clustering analysis shows that the spatial ESs can be divided in two clusters (bundle): cluster 1 with “High regulating ESs” that can be characterized by core zone and some forest patches in the central part of the biosphere reserve, and cluster 2 with “High provisioning ESs areas'' that can be characterized by cultivated lands at transition and buffer zones. The result shows that the existing ES pairs are far from the Pareto efficient combination(s), confirming that landscape optimization for ES bundles are rarely possible on the ground due to many reasons and indicating the need for well thought land restoration strategies and land management practices that are forest type and context specific