Oil palm modelling in the global land surface model ORCHIDEE-MICT

Abstract

Abstract. Oil palm is the most productive oil crop that provides ∼ 40 % of the global vegetable oil supply, with 7 % of the cultivated land devoted to oil plants. The rapid expansion of oil palm cultivation is seen as one of the major causes for deforestation emissions and threatens the conservation of rain forest and swamp areas and their associated ecosystem services in tropical areas. Given the importance of oil palm in oil production and its adverse environmental consequences, it is important to understand the physiological and phenological processes of oil palm and its impacts on the carbon, water and energy cycles. In most global vegetation models, oil palm is represented by generic plant functional types (PFTs) without specific representation of its morphological, physical and physiological traits. This would cause biases in the subsequent simulations. In this study, we introduced a new specific PFT for oil palm in the global land surface model ORCHIDEE-MICT (v8.4.2, Organising Carbon and Hydrology in Dynamic Ecosystems–aMeliorated Interactions between Carbon and Temperature). The specific morphology, phenology and harvest process of oil palm were implemented, and the plant carbon allocation scheme was modified to support the growth of the branch and fruit component of each phytomer. A new age-specific parameterization scheme for photosynthesis, autotrophic respiration and carbon allocation was also developed for the oil palm PFT, based on observed physiology, and was calibrated by observations. The improved model generally reproduces the leaf area index, biomass density and fruit yield during the life cycle at 14 observation sites. Photosynthesis, carbon allocation and biomass components for oil palm also agree well with observations. This explicit representation of oil palm in a global land surface model offers a useful tool for understanding the ecological processes of oil palm growth and assessing the environmental impacts of oil palm plantations.

Reply on RC1

“…Meanwhile, we also found that the age of OP stands influences LAI, as the LAI of OP increases stand age when OP is young, and then decrease LAI after a threshold of stand age. This observation agrees with previous studies reporting the plateau and decreases of oil palm LAI after the age of 10 (Xu et al, 2021), and the plateau and decrease of oil palm yield after age of 8-9 (Park et al, 2023). The stand age of most OP planted in Southeast Asia is approaching maturity (over half are planted before 2009) (Danylo et al, 2021).…”

MAPPING THE EXPANSION OF OIL PALM (Elais guineensis Jacq.) IN MEXICO — METHODOLOGY AND DEVELOPMENTS

“…LSMs simulate plant growth, biomass density, crop yields, and fluxes of energy, nutrients, water and carbon, which are used to make projections of global climate impacts. While the importance of adequately representing oil palm as a distinct plant functional type (PFT) within LSMs is beginning to be recognized, models that incorporate this difference are often calibrated with data from a few plantations in Malaysia and Indonesia (Xu et al, 2021), highlighting the importance of knowing whether oil palm plantations in Mexico, and more generally Latin America, follow different behaviors than those in Southeast Asia.…”

Bioterritorialidad y biocombustibles: el caso Boliviano

“…Complementando al anterior análisis, el desarrollo vegetativo y productivo de la palma aceitera (Figura 3), toma al menos 10 años para que sus rendimientos sean los máximos, manteniendo esta capacidad hasta los 25 años (Xu et al, 2021). Así, durante los primeros 5 años, la planta prioriza el desarrollo de tallo y follaje, incrementando esta capacidad fotosintética hasta los 10 años (Figura 3.A); desde el quinto año, la producción del fruto empieza a ser importante, estos rendimientos van incrementando gradualmente hasta el décimo año, donde alcanza su madurez productiva, momento desde el cual sus rendimientos son los más elevados y con cierta estabilidad en función del tiempo y el clima (Figura 3.B).…”