Model Selection for Ecosystem Respiration Needs to Be Site Specific: Lessons from Grasslands on the Mongolian Plateau

Land

Jiquan Chen¹  Huimin Zou²  Qingsong Zhu²  Meihui Duan²  Xianglan Li²  Changliang Shao³  Gang Dong⁴ 

[1] Center for Global Change and Earth Observations, Department of Geography, Michigan State University, East Lansing, MI 48823, USA;College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China;Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China;School of Life Science, Shanxi University, Taiyuan 030006, China;

关键词: ecosystem respiration;    model performance;    soil temperature;    soil moisture;    grassland;   

DOI  :  10.3390/land11010087

来源: DOAJ

【 摘 要 】

Selecting an appropriate model for simulating ecosystem respiration is critical in modeling the carbon cycle of terrestrial ecosystems due to their magnitude and high variations in time and space. There is no consensus on the ideal model for estimating ecosystem respiration in different ecosystems. We evaluated the performances of six respiration models, including Arrhenius, logistic, Gamma, Martin, Concilio, and time series model, against measured ecosystem respiration during 2014–2018 in four grassland ecosystems on the Mongolian Plateau: shrubland, dry steppe, temperate steppe, and meadow ecosystems. Ecosystem respiration increased exponentially with soil temperature within an apparent threshold of ~19.62 °C at shrubland, ~16.05 °C at dry steppe, ~16.92 °C at temperate steppe, and ~15.03 °C at meadow. The six models explained approximately 50–80% of the variabilities of ecosystem respiration during the study period. Both soil temperature and soil moisture played considerable roles in simulating ecosystem respiration with R square, ranging from 0.5 to 0.8. The Martin model performed better than the other models, with a relatively high R square, i.e., R² = 0.68 at shrubland, R² = 0.57 at dry steppe, R² = 0.74 at temperate steppe, and R² = 0.81 at meadow. These models achieved good performance for around 50–80% of the simulations. No single model performs best for all four grassland types, while each model appears suitable for at least one type of ecosystem. Models that oil moisture include models, especially the Martin model, are more suitable for the accurate prediction of ecosystem respiration than Ts-only models for the four grassland ecosystems.

【 授权许可】

Unknown