AUTHOR=Ai Jinlong , Qi Xiaowen , Zhang Rensen , He Mingye , Li Jingyang , Xu Ronghan , Li Yapeng , Sarmah Sangeeta , Wang Huan , Zhao Junfang 

TITLE=A novel approach for ecosystem respiration simulation in drylands

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2023.1186272

DOI=10.3389/fevo.2023.1186272

ISSN=2296-701X

ABSTRACT=<p>Terrestrial ecosystem respiration (Reco) in drylands (arid and semi-arid areas) contributes to the largest uncertainty of the global carbon cycle. Here, using the Reco data from 24 sites (98 site-years) in drylands from Fluxnet and corresponding MODIS remote sensing products, we develop a novel semi-empirical, yet physiologically-based remote sensing model: the ILEP_Reco model (a Reco model derived from ILEP, the acronym for “integrated LE and EVI proxy”). This model can simulate Reco observations across most biomes in drylands with a small margin of error (R<sup>2 </sup>= 0.56, RMSE = 1.12 gCm<sup>−2</sup>d<sup>−1</sup>, EF = 0.46, MBE = −0.06 gCm<sup>−2</sup>d<sup>−1</sup>) and performs significantly better than the previous model: Ensemble_all. The seasonal variation of Reco in drylands can be well simulated by the ILEP_Reco model. When we relate ILEP to the Q10 model, the corresponding ILEP_Q10 values in all 98 site-years distribute quite convergently, which greatly facilitates fixing the ILEP_Q10 value as a constant in different site-years. The spatial variation of Reco in drylands is then defined as reference respiration at the annual mean ILEP, which can be easily and powerfully simulated by the ILEP_Reco model. These results help us understand the spatial-temporal variations of Reco in drylands and thus will shed light on the carbon budget on a regional scale, or even a global one.</p>