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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

Seasonal variations in the diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA).Long solid arrows represent the timing of rain addition treatments; short solid and dashed arrows represent the measurement time on Day 6 and Day 16 after the rain addition treatments, respectively.
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f3: Seasonal variations in the diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA).Long solid arrows represent the timing of rain addition treatments; short solid and dashed arrows represent the measurement time on Day 6 and Day 16 after the rain addition treatments, respectively.

Mentions: During the growing season, the diel hysteresis of RS and RH was positive while the diel hysteresis of RA was negative (Fig. 3). The values of diel hysteresis of RS and RH showed significant seasonal variations, with the minimum diel hysteresis of RS and RH occurring on June 26th and the maximum on August 26th (Fig. 3a,b). However, the diel hysteresis of RA were relatively stable during the growing season (Fig. 3c).


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)

Seasonal variations in the diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA).Long solid arrows represent the timing of rain addition treatments; short solid and dashed arrows represent the measurement time on Day 6 and Day 16 after the rain addition treatments, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Seasonal variations in the diel hysteresis of soil CO2 efflux (RS) and its components (RH and RA).Long solid arrows represent the timing of rain addition treatments; short solid and dashed arrows represent the measurement time on Day 6 and Day 16 after the rain addition treatments, respectively.
Mentions: During the growing season, the diel hysteresis of RS and RH was positive while the diel hysteresis of RA was negative (Fig. 3). The values of diel hysteresis of RS and RH showed significant seasonal variations, with the minimum diel hysteresis of RS and RH occurring on June 26th and the maximum on August 26th (Fig. 3a,b). However, the diel hysteresis of RA were relatively stable during the growing season (Fig. 3c).

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