scholarly journals Exact evaluation of gross photosynthetic production from the oxygen triple-isotope composition of O2: Implications for the net-to-gross primary production ratios

2011 ◽  
Vol 38 (14) ◽  
pp. n/a-n/a ◽  
Author(s):  
Maria G. Prokopenko ◽  
Olivier M. Pauluis ◽  
Julie Granger ◽  
Laurence Y. Yeung
Keyword(s):  
Primary Production ◽  
Isotope Composition ◽  
Gross Primary Production ◽  
Photosynthetic Production ◽  
Exact Evaluation ◽  
Net To Gross

scholarly journals New constraints on biological production and mixing processes in the South China Sea from triple isotope composition of dissolved oxygen

2021 ◽  
Author(s):  
Hana Jurikova ◽  
Osamu Abe ◽  
Fuh-Kwo Shiah ◽  
Mao-Chang Liang
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
South China ◽  
Isotope Composition ◽  
Gross Primary Production ◽  
Northeast Monsoon ◽  
Production Rates ◽  
Mixing Processes ◽  
China Sea ◽  
Net Heterotrophy

Abstract. South China Sea (SCS), world’s largest marginal sea, plays an important role in the global as well as regional biogeochemical cycling of carbon and oxygen. However, its overall metabolic balance, primary production rates, and their link to East Asian Monsoon forcing still remain poorly constrained. Here, we report seasonal trends in triple oxygen isotope composition (17Δ) of dissolved O2, a tracer for biological O2, gross primary production (GP; inferred from δ17O and δ18O values), and net community production (NP; evaluated from oxygen–argon ratios) from the SouthEast Asian Time-series Study (SEATS) in SCS. Our results suggest stable mixed-layer GP rates of 1.8 g C m−2 d−1 and NP of −0.02 g C m−2 d−1 during the summer southwest monsoon, indicating the prevalence of net heterotrophy. During winter months characterised by stronger northeast monsoon forcing, the system is more dynamic with variable production rates, which may shift the metabolism from net heterotrophy to net autotrophy (NP up to ~0.15 g C  m−2 d−1). These findings underscore the importance of monsoon intensity on tilting the carbon balance from source to sink in a warm oligotrophic sea, and on driving the regional circulation pattern. Finally, our data from the deeper regions show that SCS circulation is strongly affected by monsoon wind forcing, with a larger part of the water column down to at least 400 m depth fully exchanged during a winter, suggesting the 17Δ of deep O2 as a valuable novel conservative tracer for probing mixing processes from a new perspective.

scholarly journals Variations in triple isotope composition of dissolved oxygen and primary production in a subtropical reservoir

2016 ◽  
Vol 13 (24) ◽  
pp. 6683-6698 ◽  
Author(s):  
Hana Jurikova ◽  
Tania Guha ◽  
Osamu Abe ◽  
Fuh-Kwo Shiah ◽  
Chung-Ho Wang ◽  
...  
Keyword(s):  
Primary Production ◽  
Isotope Composition ◽  
Environmental Parameters ◽  
Order Of Magnitude ◽  
Lakes And Reservoirs ◽  
Net To Gross ◽  
Feitsui Reservoir ◽  
Incubation Method ◽  
Mass Balance Approach

Abstract. Lakes and reservoirs play an important role in the carbon cycle, and therefore monitoring their metabolic rates is essential. The triple oxygen-isotope anomaly of dissolved O2 [17Δ =  ln(1+δ17O) − 0.518  ×  ln(1 + δ18O)] offers a new, in situ, perspective on primary production, yet little is known about 17Δ from freshwater systems. We investigated the 17Δ together with the oxygen : argon ratio [Δ(O2 ∕ Ar)] in the subtropical Feitsui Reservoir in Taiwan from June 2014 to July 2015. Here, we present the seasonal variations in 17Δ, GP (gross production), NP (net production) and the NP ∕ GP (net to gross ratio) in association with environmental parameters. The 17Δ varied with depth and season, with values ranging between 26 and 205 per meg. The GP rates were observed to be higher (702 ± 107 mg C m−2 d−1) in winter than those (303 ± 66 mg C m−2 d−1) recorded during the summer. The overall averaged GP was 220 g C m−2 yr−1 and NP was −3 g C m−2 yr−1, implying the reservoir was net heterotrophic on an annual basis. This is due to negative NP rates from October to February (−198 ± 78 mg C m−2 d−1). Comparisons between GP rates obtained from the isotope mass balance approach and 14C bottle incubation method (14C–GP) showed consistent values on the same order of magnitude with a GP ∕ 14C–GP ratio of 1.2 ± 1.1. Finally we noted that, although typhoon occurrences were scarce, higher than average 17Δ values and GP rates were recorded after typhoon events.

scholarly journals Variations in triple isotope composition of dissolved oxygen and primary production in a subtropical reservoir

2016 ◽  
Author(s):  
Hana Jurikova ◽  
Tania Guha ◽  
Osamu Abe ◽  
Fuh-Kwo Shiah ◽  
Chung-Ho Wang ◽  
...  
Keyword(s):  
Primary Production ◽  
Isotope Composition ◽  
Environmental Parameters ◽  
Order Of Magnitude ◽  
Lakes And Reservoirs ◽  
Net To Gross ◽  
Feitsui Reservoir ◽  
Incubation Method

Abstract. Lakes and reservoirs play an important role in the carbon cycle, and therefore, monitoring their metabolic rates is essential. The triple oxygen isotope anomaly of dissolved O2 [17Δ = ln(1+δ17O) − 0.518×ln(1+δ18O)] offers a new, in situ, perspective on primary production, but is yet to be evaluated in freshwater systems. We investigated the 17Δ together with oxygen-argon ratio (δO2/Ar) in the subtropical Feitsui Reservoir in Taiwan from June 2014 to July 2015. Here, we present the seasonal variations in 17Δ, GP (gross production), NP (net production) and the NP/GP (net to gross ratio) in association with environmental parameters measured. The 17Δ varied with depth and season, with values ranging between 19 and 186 per meg. The 17Δ GP rates were lower from April to September averaging 215±93 mg C m−2 d−1 and higher from October to January averaging 523±66 mg C m−2 d−1. The estimated average annual 17Δ GP was 104 g C m−2 year−1 and the average annual NP was 22 g C m−2 year−1. Overall, the NP/ GP varied slightly between 0.02 and 0.36 and the reservoir was net autotrophic in the mixed layer. Comparisons between 17Δ GP rates and the production rates estimated by in vitro 14C bottle incubation method (14C GP) were consistent on the same order of magnitude, with the 17Δ GP/14C GP ratio of 1±0.8 throughout the study. Although typhoon occurrences were scarce, higher than average 17Δ values and 17Δ GP rates were recorded after typhoon events.

scholarly journals Estimation of crop gross primary production (GPP): fAPARchl versus MOD15A2 FPAR

2014 ◽  
Vol 153 ◽  
pp. 1-6 ◽  
Author(s):  
Qingyuan Zhang ◽  
Yen-Ben Cheng ◽  
Alexei I. Lyapustin ◽  
Yujie Wang ◽  
Feng Gao ◽  
...  
Keyword(s):  
Primary Production ◽  
Gross Primary Production

scholarly journals Soil drying weakens the positive effect of climate factors on global gross primary production

2021 ◽  
Vol 129 ◽  
pp. 107953
Author(s):  
Huan Chen ◽  
Xiaoyong Bai ◽  
Yangbing Li ◽  
Qin Li ◽  
Luhua Wu ◽  
...  
Keyword(s):  
Primary Production ◽  
Gross Primary Production ◽  
Soil Drying ◽  
Climate Factors ◽  
Positive Effect

scholarly journals Can vegetation index track the interannual variation in gross primary production of temperate deciduous forests?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Fan Liu ◽  
Chuankuan Wang ◽  
Xingchang Wang
Keyword(s):  
Primary Production ◽  
Vegetation Index ◽  
Near Infrared ◽  
Deciduous Forest ◽  
Gross Primary Production ◽  
Growing Season ◽  
Temperate Deciduous Forest ◽  
Near Infrared Reflectance ◽  
Modis Ndvi ◽  
Temperate Deciduous

Abstract Background Vegetation indices (VIs) by remote sensing are widely used as simple proxies of the gross primary production (GPP) of vegetation, but their performances in capturing the inter-annual variation (IAV) in GPP remain uncertain. Methods We evaluated the performances of various VIs in tracking the IAV in GPP estimated by eddy covariance in a temperate deciduous forest of Northeast China. The VIs assessed included the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), and the near-infrared reflectance of vegetation (NIRv) obtained from tower-radiometers (broadband) and the Moderate Resolution Imaging Spectroradiometer (MODIS), respectively. Results We found that 25%–35% amplitude of the broadband EVI tracked the start of growing season derived by GPP (R2: 0.56–0.60, bias < 4 d), while 45% (or 50%) amplitudes of broadband (or MODIS) NDVI represented the end of growing season estimated by GPP (R2: 0.58–0.67, bias < 3 d). However, all the VIs failed to characterize the summer peaks of GPP. The growing-season integrals but not averaged values of the broadband NDVI, MODIS NIRv and EVI were robust surrogates of the IAV in GPP (R2: 0.40–0.67). Conclusion These findings illustrate that specific VIs are effective only to capture the GPP phenology but not the GPP peak, while the integral VIs have the potential to mirror the IAV in GPP.

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