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Contrasting diel hysteresis between soil autotrophic and heterotrophic respiration in a desert ecosystem under different rainfall scenarios.

Song W, Chen S, Zhou Y, Wu B, Zhu Y, Lu Q, Lin G - Sci Rep (2015)

Bottom Line: Diel variations of soil CO2 efflux and soil temperature were measured on Day 6 and Day 16 following the rain addition treatments each month during the growing season.We found contrasting responses in the diel hysteresis of R(A) and R(H) to soil temperature, with a clockwise hysteresis loop for R(H) but a counter-clockwise hysteresis loop for R(A).Rain addition significantly increased the magnitude of diel hysteresis for both R(H) and R(A) on Day 6, but had no influence on either on Day 16 when soil moisture was much lower.

View Article: PubMed Central - PubMed

Affiliation: Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China.

ABSTRACT
Diel hysteresis occurs often between soil CO2 efflux (R(S)) and temperature, yet, little is known if diel hysteresis occurs in the two components of R(S), i.e., autotrophic respiration (R(A)) and heterotrophic respiration (R(H)), and how diel hysteresis will respond to future rainfall change. We conducted a field experiment in a desert ecosystem in northern China simulating five different scenarios of future rain regimes. Diel variations of soil CO2 efflux and soil temperature were measured on Day 6 and Day 16 following the rain addition treatments each month during the growing season. We found contrasting responses in the diel hysteresis of R(A) and R(H) to soil temperature, with a clockwise hysteresis loop for R(H) but a counter-clockwise hysteresis loop for R(A). Rain addition significantly increased the magnitude of diel hysteresis for both R(H) and R(A) on Day 6, but had no influence on either on Day 16 when soil moisture was much lower. These findings underline the different roles of biological (i.e. plant and microbial activities) and physical-chemical (e.g. heat transport and inorganic CO2 exchange) processes in regulating the diel hysteresis of R(A) and R(H), which should be considered when estimating soil CO2 efflux in desert regions under future rainfall regime.

No MeSH data available.


Related in: MedlinePlus

Mean values of diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA) on Day 6 and Day 16 after different rain addition treatments during the growing season in 2009 (n = 4).The different letters indicate significant differences between rain addition treatments at P < 0.05.
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f4: Mean values of diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA) on Day 6 and Day 16 after different rain addition treatments during the growing season in 2009 (n = 4).The different letters indicate significant differences between rain addition treatments at P < 0.05.

Mentions: On Day 6, the rain addition had no influence on the diel hysteresis of RS (Fig. 4a), but significantly increased the amplitudes of diel hysteresis of the two respiration components (Fig. 4b,c). On Day 16, the rain addition had no significant effect on the diel hysteresis of RS and its components (Fig. 4d-f). There was no significant interaction effect of rain addition amount and rain addition time on the diel hysteresis of RA and RH on either Day 6 or 16 (Table S1). The value of diel hysteresis for RH was always higher than for RA on both measurement days. In addition, the amplitude of diel hysteresis positively corresponded with he increase in daily SWC for RS and its components on both measurement days (Fig. 5).


Contrasting diel hysteresis between soil autotrophic and heterotrophic respiration in a desert ecosystem under different rainfall scenarios.

Song W, Chen S, Zhou Y, Wu B, Zhu Y, Lu Q, Lin G - Sci Rep (2015)

Mean values of diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA) on Day 6 and Day 16 after different rain addition treatments during the growing season in 2009 (n = 4).The different letters indicate significant differences between rain addition treatments at P < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663751&req=5

f4: Mean values of diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA) on Day 6 and Day 16 after different rain addition treatments during the growing season in 2009 (n = 4).The different letters indicate significant differences between rain addition treatments at P < 0.05.
Mentions: On Day 6, the rain addition had no influence on the diel hysteresis of RS (Fig. 4a), but significantly increased the amplitudes of diel hysteresis of the two respiration components (Fig. 4b,c). On Day 16, the rain addition had no significant effect on the diel hysteresis of RS and its components (Fig. 4d-f). There was no significant interaction effect of rain addition amount and rain addition time on the diel hysteresis of RA and RH on either Day 6 or 16 (Table S1). The value of diel hysteresis for RH was always higher than for RA on both measurement days. In addition, the amplitude of diel hysteresis positively corresponded with he increase in daily SWC for RS and its components on both measurement days (Fig. 5).

Bottom Line: Diel variations of soil CO2 efflux and soil temperature were measured on Day 6 and Day 16 following the rain addition treatments each month during the growing season.We found contrasting responses in the diel hysteresis of R(A) and R(H) to soil temperature, with a clockwise hysteresis loop for R(H) but a counter-clockwise hysteresis loop for R(A).Rain addition significantly increased the magnitude of diel hysteresis for both R(H) and R(A) on Day 6, but had no influence on either on Day 16 when soil moisture was much lower.

View Article: PubMed Central - PubMed

Affiliation: Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China.

ABSTRACT
Diel hysteresis occurs often between soil CO2 efflux (R(S)) and temperature, yet, little is known if diel hysteresis occurs in the two components of R(S), i.e., autotrophic respiration (R(A)) and heterotrophic respiration (R(H)), and how diel hysteresis will respond to future rainfall change. We conducted a field experiment in a desert ecosystem in northern China simulating five different scenarios of future rain regimes. Diel variations of soil CO2 efflux and soil temperature were measured on Day 6 and Day 16 following the rain addition treatments each month during the growing season. We found contrasting responses in the diel hysteresis of R(A) and R(H) to soil temperature, with a clockwise hysteresis loop for R(H) but a counter-clockwise hysteresis loop for R(A). Rain addition significantly increased the magnitude of diel hysteresis for both R(H) and R(A) on Day 6, but had no influence on either on Day 16 when soil moisture was much lower. These findings underline the different roles of biological (i.e. plant and microbial activities) and physical-chemical (e.g. heat transport and inorganic CO2 exchange) processes in regulating the diel hysteresis of R(A) and R(H), which should be considered when estimating soil CO2 efflux in desert regions under future rainfall regime.

No MeSH data available.


Related in: MedlinePlus