TY - JOUR
T1 - Post-fire co-stimulation of gross primary production and ecosystem respiration in a meadow grassland on the Tibetan Plateau
AU - Wang, Dong
AU - Chen, Ji
AU - Felton, Andrew J.
AU - Xia, Longlong
AU - Zhang, Yuefang
AU - Luo, Yiqi
AU - Cheng, Xiaoli
AU - Cao, Junji
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/6/15
Y1 - 2021/6/15
N2 - Predicting post-fire ecosystem CO2 exchange requires an explicit understanding of the sensitivity of gross primary production (GPP), ecosystem respiration (ER) and net ecosystem exchange (NEE) to post-fire conditions. However, the simultaneous effects of fire on GPP, ER and NEE are rarely evaluated. We established a three-year manipulative fire experiment in a meadow grassland on the Tibetan Plateau to investigate the responses of GPP, ER and NEE to prescribed fire. We found that fire on average increased GPP by 13% and ER by 9%, leading to an increase in NEE by 20% across the three years. There was no clear relationship between post-fire changes in soil temperature and ecosystem CO2 exchange, yet reductions in soil volumetric moisture were positively related to changes in GPP, ER and NEE. These results suggest that post-fire stimulation of GPP, ER and NEE cannot be fully explained by changes in soil temperature and soil moisture. Besides, changes in GPP, ER and NEE were positively related to fire-induced increases in graminoid biomass, legume biomass and soil inorganic nitrogen. Taken together, our results suggest the interwoven control of biotic and abiotic factors on post-fire GPP, ER and NEE, yet also that shifts in plant functional type biomass may outweigh the negative effects of reduced soil moisture on ecosystem CO2 exchange. These results underscore how simultaneous documentation of GPP, ER and NEE dynamics can advance a mechanistic understanding of CO2 exchange under fire disturbance.
AB - Predicting post-fire ecosystem CO2 exchange requires an explicit understanding of the sensitivity of gross primary production (GPP), ecosystem respiration (ER) and net ecosystem exchange (NEE) to post-fire conditions. However, the simultaneous effects of fire on GPP, ER and NEE are rarely evaluated. We established a three-year manipulative fire experiment in a meadow grassland on the Tibetan Plateau to investigate the responses of GPP, ER and NEE to prescribed fire. We found that fire on average increased GPP by 13% and ER by 9%, leading to an increase in NEE by 20% across the three years. There was no clear relationship between post-fire changes in soil temperature and ecosystem CO2 exchange, yet reductions in soil volumetric moisture were positively related to changes in GPP, ER and NEE. These results suggest that post-fire stimulation of GPP, ER and NEE cannot be fully explained by changes in soil temperature and soil moisture. Besides, changes in GPP, ER and NEE were positively related to fire-induced increases in graminoid biomass, legume biomass and soil inorganic nitrogen. Taken together, our results suggest the interwoven control of biotic and abiotic factors on post-fire GPP, ER and NEE, yet also that shifts in plant functional type biomass may outweigh the negative effects of reduced soil moisture on ecosystem CO2 exchange. These results underscore how simultaneous documentation of GPP, ER and NEE dynamics can advance a mechanistic understanding of CO2 exchange under fire disturbance.
KW - Ecosystem respiration
KW - Gross primary production
KW - Meadow grassland
KW - Microbial biomass
KW - Net ecosystem exchange
KW - Plant community composition
KW - Prescribed fire
KW - Soil inorganic nitrogen
KW - Soil temperature
KW - Soil volumetric moisture
KW - Tibetan Plateau
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U2 - 10.1016/j.agrformet.2021.108388
DO - 10.1016/j.agrformet.2021.108388
M3 - Article
AN - SCOPUS:85103054271
SN - 0168-1923
VL - 303
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
M1 - 108388
ER -