An assessment of oil palm plantation aboveground biomass stocks on tropical peat using destructive and non-destructive methods

Acknowledgements The authors would like to thank the Director-General of the Malaysian Palm Oil Board for permission to publish these results. This study was carried out as part of a wider tropical peat research collaboration between MPOB, University of Exeter and University of Aberdeen and we would like to thank the MPOB staff and the Sarawak Oil Palm Berhard for help and support during the project. Specifically, from the Sarawak Oil Palm Berhard we would like to thank: Mr. Paul (group CEO), Mr. Chua Kian Hong (group plantation manager), Mr. Phang Seng Nam (regional plantation controller) and Mr. Sammy (Sabaju plantation manager) for being kind enough to allow this research to be carried out within their plantation and for the provision of logistical support. From MPOB we would like to thank the dedicated field technicians, Steward Saging and Ham Jonathon for their invaluable support.Peer reviewedPublisher PD

Mapping peat soil moisture under oil palm plantation and tropical forest in Sarawak

Water table conditions in drained peatlands affect peat decomposition, fluvial carbon and greenhouse gas emissions, and plant growth in oil palm plantations. This study illustrates the spatial heterogeneity of soil moisture profiles in cultivated tropical peat under oil palm plantation and uncultivated secondary forest, using maps. At a study plot under each land use the geographical coordinates of sampling points, tree locations and other features were recorded. Peat soil samples were taken at depths of 0–50 cm, 50–100 cm, 100–150 cm and 150–200 cm, and their moisture contents were determined. Overall, soil moisture content was higher in secondary forest than in oil palm plantation due to land management activities such as drainage and peat compaction in the latter. Significant differences were observed between the topsoil (0–50 cm) and deeper soil layers under both land uses. Soil moisture maps of the study plots interpolated using geographical information system (GIS) software were used to visualise the spatial distributions of moisture content in soil layers at different depths (0–50 cm, 50–100 cm, 100–150 cm, 150–200 cm). Moisture content in the 0–50 cm soil layer appeared to be inversely related to elevation, but the correlation was not statistically significant. On the other hand, there was a significant positive correlation between soil moisture content and the diameters of oil palm trunks. Palm trees with negative growth of trunk diameter were mostly located in subplots which were relatively dry and/or located near drains. The results of this study indicate that soil moisture mapping using GIS could be a useful tool in improving the management of peatland to promote oil palm growth.Peer reviewe

Mapping peat soil moisture under oil palm plantation and tropical forest in Sarawak

Water table conditions in drained peatlands affect peat decomposition, fluvial carbon and greenhouse gas emissions, and plant growth in oil palm plantations. This study illustrates the spatial heterogeneity of soil moisture profiles in cultivated tropical peat under oil palm plantation and uncultivated secondary forest, using maps. At a study plot under each land use the geographical coordinates of sampling points, tree locations and other features were recorded. Peat soil samples were taken at depths of 0–50 cm, 50–100 cm, 100–150 cm and 150–200 cm, and their moisture contents were determined. Overall, soil moisture content was higher in secondary forest than in oil palm plantation due to land management activities such as drainage and peat compaction in the latter. Significant differences were observed between the topsoil (0–50 cm) and deeper soil layers under both land uses. Soil moisture maps of the study plots interpolated using geographical information system (GIS) software were used to visualise the spatial distributions of moisture content in soil layers at different depths (0–50 cm, 50–100 cm, 100–150 cm, 150–200 cm). Moisture content in the 0–50 cm soil layer appeared to be inversely related to elevation, but the correlation was not statistically significant. On the other hand, there was a significant positive correlation between soil moisture content and the diameters of oil palm trunks. Palm trees with negative growth of trunk diameter were mostly located in subplots which were relatively dry and/or located near drains. The results of this study indicate that soil moisture mapping using GIS could be a useful tool in improving the management of peatland to promote oil palm growt

Oil palm (<i>Elaeis guineensis</i>) plantation on tropical peatland in South East Asia:photosynthetic response to soil drainage level for mitigation of soil carbon emissions

Acknowledgements The authors would like to thank the Director-General of the Malaysian Palm Oil Board (MPOB) for permission to publish these results. This study was carried out as part of a wider tropical peat research collaboration between MPOB, University of Exeter, University of Aberdeen and Newcastle University and we would like to thank the Sarawak Oil Palm Berhard (SOPB) for their help and support during the project. Specifically, at SOPB we would like to thank: Paul Wong Hee Kwong (group CEO), Chua Kian Hong (group plantation manager), Phang Seng Nam (regional plantation controller) and the Sabaju and Sebungan plantation managers for being kind enough to allow the research platform to be established within their plantations and the provision of logistical support when needed. At MPOB we would particularly like to thank the dedicated field technicians, without whose efforts and commitment this research would not have been possible, specifically Ham Jonathon, Muhammad Amira Ruzaizul Bin Bujang and Steward Saging. Finally, we would like to thank the anonymous reviewers for giving their valuable time to provide help and advice for the improvement of the paper. Funding The research was carried out as part of a project funded by the Malaysian Palm Oil Board (MPOB). The research was carried out with the support of Sarawak Oil Palm Berhard (SOPB) on whose land the research project was based.Peer reviewedPostprin