Soil Respiration in Relation to Photosynthesis of Quercus mongolica Trees at Elevated CO2

Abstract. Global climate change in the real world always exhibits simultaneous changes in multiple factors. Prediction of ecosystem responses to multi-factor global changes in a future world strongly relies on our understanding of their interactions. However, it is still unclear how nitrogen (N) deposition and elevated atmospheric carbon dioxide concentration [CO2] would interactively influence forest floor soil respiration in subtropical China. We assessed the main and interactive effects of elevated [CO2] and N addition on soil respiration by growing tree seedlings in ten large open-top chambers under CO2 (ambient CO2 and 700 μmol mol−1) and nitrogen (ambient and 100 kg N ha−1 yr−1) treatments. Soil respiration, soil temperature and soil moisture were measured for 30 months, as well as above-ground biomass, root biomass and soil organic matter (SOM). Results showed that soil respiration displayed strong seasonal patterns with higher values observed in the wet season (April–September) and lower values in the dry season (October–March) in all treatments. Significant exponential relationships between soil respiration rates and soil temperatures, as well as significant linear relationships between soil respiration rates and soil moistures (below 15%) were found. Both CO2 and N treatments significantly affected soil respiration, and there was significant interaction between elevated [CO2] and N addition (p<0.001, p=0.003, and p=0.006, respectively). We also observed that the stimulatory effect of individual elevated [CO2] (about 29% increased) was maintained throughout the experimental period. The positive effect of N addition was found only in 2006 (8.17% increased), and then had been weakened over time. Their combined effect on soil respiration (about 50% increased) was greater than the impact of either one alone. Mean value of annual soil respiration was 5.32 ± 0.08, 4.54 ± 0.10, 3.56 ± 0.03 and 3.53 ± 0.03 kg CO2 m−2 yr−1 in the chambers exposed to elevated [CO2] and high N deposition (CN), elevated [CO2] and ambient N deposition (CC), ambient [CO2] and high N deposition (NN), and ambient [CO2] and ambient N deposition (CK as a control), respectively. Greater above-ground biomass and root biomass was obtained in the CN, CC and NN treatments, and higher soil organic matter was observed only in the CN treatment. In conclusion, the combined effect of elevated [CO2] and N addition on soil respiration was apparent interaction. They should be evaluated in combination in subtropical forest ecosystems in China where the atmospheric CO2 and N deposition have been increasing simultaneously and remarkably.

Download Full-text

Does Elevated CO2 Affect the Physiology and Growth of Quercus Mongolica under Different Nitrogen Conditions?

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.277-279.528 ◽

2005 ◽

Vol 277-279 ◽

pp. 528-535

Author(s):

Oh Hyun Kyung ◽

Yeonsook Choung

Keyword(s):

Water Use Efficiency ◽

Elevated Co2 ◽

Water Use ◽

Physiological Activity ◽

Photosynthesis Rate ◽

Total Biomass ◽

High Nitrogen ◽

Quercus Mongolica ◽

Use Efficiency ◽

Nitrogen Conditions

The response of Quercus mongolica, one of the major tree species in Northeast Asia and the most dominant deciduous tree in Korea, was studied in relation to elevated CO2 and the addition of nitrogen to soil in terms of its physiology and growth over two years. Plants were grown from seed at two CO2 conditions (ambient and 700 µL L-1) and with two levels of soil nitrogen supply (1.5 mM and 6.5 mM). Elevated CO2 was found to significantly enhance the photosynthesis rate and water use efficiency by 2.3-2.7 times and by 1.3-1.8 times, respectively. Over time within a growing season, there was a decreasing trend in the photosynthesis rate. However, the decrease was slower especially in two-year-old seedlings grown in elevated CO2 and high nitrogen conditions, suggesting that their physiological activity lasted relatively longer. Improved photosynthesis and water use efficiency as well as prolonged physiological activity under high CO2 condition resulted in an increase in biomass accumulation. That is, in elevated CO2, total biomass increased by 1.7 and 1.2 times, respectively, for one- and two-year-old seedlings with low nitrogen conditions, and by 1.8 and 2.6 times with high nitrogen conditions. This result indicates that the effect of CO2 on biomass is more marked in high nitrogen conditions. This, therefore, shows that the effect of CO2 is accelerated by the addition of nitrogen. With the increase in total biomass, the number of leaves and stem diameter increased significantly, and more biomass was allocated in roots, resulting in structural change. Overall, the elevated CO2 markedly stimulated the physiology and growth of Q. mongolica. This demonstrates that Q. mongolica is capable of exploiting an elevated CO2 environment. Therefore, it will remain a dominant species and continue to be a major CO2 sink in the future, even though other resources such as nitrogen can modify the CO2 effect.

Download Full-text

Soil Respiration in Mini-Beech Stands under Elevated CO2

Impacts of Global Change on Tree Physiology and Forest Ecosystems - Forestry Sciences ◽

10.1007/978-94-015-8949-9_24 ◽

1997 ◽

pp. 179-185 ◽

Cited By ~ 2

Author(s):

Valérie le Dantec ◽

Eric Dufrêne ◽

Bernard Saugier

Keyword(s):

Soil Respiration ◽

Elevated Co2

Download Full-text

Effects of Elevated CO2 Concentration and Nitrogen Addition on Soil Respiration in a Cd-Contaminated Experimental Forest Microcosm

Forests ◽

10.3390/f11030260 ◽

2020 ◽

Vol 11 (3) ◽

pp. 260

Author(s):

Bo Yao ◽

Qiwu Hu ◽

Guihua Zhang ◽

Yafeng Yi ◽

Meijuan Xiao ◽

...

Keyword(s):

Heavy Metal ◽

Soil Respiration ◽

Soil Carbon ◽

Elevated Co2 ◽

Root Biomass ◽

Fine Root ◽

Hydrolytic Enzymes ◽

N Deposition ◽

Fine Root Biomass ◽

N Addition

Forests near rapidly industrialized and urbanized regions are often exposed to elevated CO2, increased N deposition, and heavy metal pollution. To date, the effects of elevated CO2 and/or increased N deposition on soil respiration (Rs) under heavy metal contamination are unclear. In this study, we firstly investigated Rs in Cd-contaminated model forests with CO2 enrichment and N addition in subtropical China. Results showed that Rs in all treatments exhibited similar clear seasonal patterns, with soil temperature being a dominant control. Cadmium addition significantly decreased cumulative soil CO2 efflux by 19% compared to the control. The inhibition of Rs caused by Cd addition was increased by N addition (decreased by 34%) was partially offset by elevated CO2 (decreased by 15%), and was not significantly altered by the combined N addition and rising CO2. Soil pH, microbial biomass carbon, carbon-degrading hydrolytic enzymes, and fine root biomass were also significantly altered by the treatments. A structural equation model revealed that the responses of Rs to Cd stress, elevated CO2, and N addition were mainly mediated by soil carbon-degrading hydrolytic enzymes and fine root biomass. Overall, our findings indicate that N deposition may exacerbate the negative effect of Cd on Rs in Cd-contaminated forests and benefit soil carbon sequestration in the future at increasing atmospheric CO2 levels.

Download Full-text

Can publication bias affect ecological research? A case study on soil respiration under elevated CO2

New Phytologist ◽

10.1111/j.1469-8137.2010.03499.x ◽

2010 ◽

Vol 190 (3) ◽

pp. 517-521 ◽

Cited By ~ 14

Author(s):

Wouter I. J. Dieleman ◽

Ivan A. Janssens

Keyword(s):

Soil Respiration ◽

Publication Bias ◽

Elevated Co2 ◽

Ecological Research

Download Full-text

Soil respiration in model plantations under conditions of elevated CO2 in the atmosphere (Hokkaido Island, Japan)

Russian Journal of Ecology ◽

10.1134/s1067413611060099 ◽

2012 ◽

Vol 43 (1) ◽

pp. 24-28 ◽

Cited By ~ 2

Author(s):

O. V. Masyagina ◽

T. Koike

Keyword(s):

Soil Respiration ◽

Elevated Co2 ◽

Hokkaido Island

Download Full-text

Growth overcompensation against O3 exposure in two Japanese oak species, Quercus mongolica var. crispula and Quercus serrata, grown under elevated CO2

Environmental Pollution ◽

10.1016/j.envpol.2015.06.034 ◽

2015 ◽

Vol 206 ◽

pp. 133-141 ◽

Cited By ~ 25

Author(s):

Mitsutoshi Kitao ◽

Masabumi Komatsu ◽

Kenichi Yazaki ◽

Satoshi Kitaoka ◽

Hiroyuki Tobita

Keyword(s):

Elevated Co2 ◽

Quercus Serrata ◽

Quercus Mongolica

Download Full-text

Seasonal Variation of Soil Respiration in the Mongolian Oak (Quercus mongolica Fisch. Ex Ledeb.) Forests at the Cool Temperate Zone in Korea

Forests ◽

10.3390/f11090984 ◽

2020 ◽

Vol 11 (9) ◽

pp. 984

Author(s):

Gyung Soon Kim ◽

Seung Jin Joo ◽

Chang Seok Lee

Keyword(s):

Soil Respiration ◽

Environmental Parameters ◽

Field Measurements ◽

Temperate Zone ◽

Short Time Scale ◽

Strongly Correlated ◽

Quercus Mongolica ◽

Cool Temperate ◽

Mongolian Oak ◽

Short Time

To investigate the variation in seasonal soil respiration (SR) as a function of soil temperature (Ts) and soil water content (SWC) in Mongolian oak (Quercus mongolica) forests in urban (Mt. Nam) and well-reserved (Mt. Jeombong) areas in South Korea, we conducted continuous field measurements of SR and other environmental parameters (Ts and SWC) using an automated chamber system. Overall, the SR rates in both stands were strongly correlated with the Ts variable during all seasons. However, abrupt fluctuations in SR were significantly related to episodic increases in SWC on a short time scale during the growing season. The integrated optimal regression models for SR using Ts at a depth of 5 cm and SWC at a depth of 15 cm yielded the following: the SR rate in Mt. Nam = SR(Ts) + ΔSR(Ts) = 104.87 exp(0.1108Ts) − 10.09(SWC)2 + 604.2(SWC) − 8627.7 for Ts ≥ 0 °C, and the SR rate in Mt. Jeombong = SR(Ts) + ΔSR(Ts) = 95.608 exp(0.1304Ts) − 33.086(SWC)2 + 1949.2(SWC) − 28499 for Ts ≥ 0 °C. In both cases, SR = 0 for Ts < 0 °C. As per these equations, the estimated annual total SRs were 1339.4 g C m−2 for Mt. Nam and 1003.0 g C m−2 for Mt. Jeombong. These values were quite similar to the measured values in field. Our results demonstrate that the improved empirical equation is an effective tool for estimating and predicting SR variability and provide evidence that the SR of Q. mongolica forests in the cool temperate zone of Korean Peninsula depends on Ts and SWC variables.

Download Full-text