scholarly journals Light compensation points in shade-grown seedlings of deciduous broadleaf tree species with different successional traits raised under elevated CO2

Plant Biology ◽  
2015 ◽  
Vol 18 ◽  
pp. 22-27 ◽  
Author(s):  
M. Kitao ◽  
T. Hida ◽  
N. Eguchi ◽  
H. Tobita ◽  
H. Utsugi ◽  
...  
Climate ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 79 ◽  
Author(s):  
Mitsutoshi Kitao ◽  
Hiroyuki Tobita ◽  
Satoshi Kitaoka ◽  
Hisanori Harayama ◽  
Kenichi Yazaki ◽  
...  

Understanding plant response to excessive light energy not consumed by photosynthesis under various environmental stresses, would be important for maintaining biosphere sustainability. Based on previous studies regarding nitrogen (N) limitation, drought in Japanese white birch (Betula platyphylla var. japonica), and elevated O3 in Japanese oak (Quercus mongolica var. crispula) and Konara oak (Q. serrata) under future-coming elevated CO2 concentrations, we newly analyze the fate of absorbed light energy by a leaf, partitioning into photochemical processes, including photosynthesis, photorespiration and regulated and non-regulated, non-photochemical quenchings. No significant increases in the rate of non-regulated non-photochemical quenching (JNO) were observed in plants grown under N limitation, drought and elevated O3 in ambient or elevated CO2. This suggests that the risk of photodamage caused by excessive light energy was not increased by environmental stresses reducing photosynthesis, irrespective of CO2 concentrations. The rate of regulated non-photochemical quenching (JNPQ), which contributes to regulating photoprotective thermal dissipation, could well compensate decreases in the photosynthetic electron transport rate through photosystem II (JPSII) under various environmental stresses, since JNPQ+JPSII was constant across the treatment combinations. It is noteworthy that even decreases in JNO were observed under N limitation and elevated O3, irrespective of CO2 conditions, which may denote a preconditioning-mode adaptive response for protection against further stress. Such an adaptive response may not fully compensate for the negative effects of lethal stress, but may be critical for coping with non-lethal stress and regulating homeostasis. Regarding the three deciduous broadleaf tree species, elevated CO2 appears not to influence the plant responses to environmental stresses from the viewpoint of susceptibility to photodamage.


2021 ◽  
Author(s):  
Xiaowei Zang ◽  
Xianzhen Luo ◽  
Enqing Hou ◽  
Guihua Zhang ◽  
Xiaofeng Zhang ◽  
...  

Abstract Rising atmospheric CO2 concentration ([CO2]) and nitrogen (N) deposition are changing plant growth, physiological characteristics, and chemical compositions; however, few studies have explored such impacts in a heavy-metal-contaminated environment. In this study, we conducted an open-top chamber experiment to explore the impacts of two years of elevated atmospheric [CO2] and N addition on the growth, physiological characteristics, and chemical compositions of five subtropical tree species in a cadmium (Cd)-contaminated environment. Results showed that N addition significantly increased concentration of leaf N and protein in five tree species, and also decreased payback time (PBT) and leaf C:N ratios and increased tree relative height growth rate (RGR-H) and basal diameter growth rate (RGR-B) in Liquidambar formosana and Syzygium hainanense. Elevated [CO2] increased leaf maximum photosynthetic rate (Amax) and concentration of total non-structural carbohydrates (TNC) and shortened PBT to offset the negative effect of Cd contamination on RGR-B in A. auriculiformis. The combined effects of elevated [CO2] and N addition did not exceed their separate effects on RGR-H and RGR-B in Castanopsis hystrix and Cinnamomum camphora. N addition significantly increased the concentration of leaf Cd by 162.1% and 338.0%, and plant Cd bio-concentration factor (BCF) by 464% and 861% in C. hystrix, and C. camphora, respectively, compared to Cd addition. Among the five tree species, the decreases in PBT and the increases in Amax, RGR-B, and concentrations of leaf protein in response to N and Cd addition under elevated [CO2] were average higher 86.7% in A. auriculiformis than other species, suggesting that the mitigation of the negative effects of Cd pollution by elevated [CO2] and N addition among five species was species-specific. Overall, we concluded that N addition and elevated [CO2] reduced Cd toxicity, and increased the growth rate in A. auriculiformis, S. hainanense and L. formosana, while maintained the growth rate in C. hystrix, and C. camphora by differently increasing photosynthetic rate, altering the leaf chemical compositions, and shortening PBT.


2017 ◽  
Vol 44 (11) ◽  
pp. 1075 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Vinod K. Jacob ◽  
Chris J. Blackman ◽  
Renee A. Smith ◽  
Mark G. Tjoelker ◽  
...  

The effects of elevated CO2 on the short-term temperature response of leaf dark respiration (R) remain uncertain for many forest tree species. Likewise, variation in leaf R among populations within tree species and potential interactive effects of elevated CO2 are poorly understood. We addressed these uncertainties by measuring the short-term temperature response of leaf R in 15 provenances of Eucalyptus grandis W. Hill ex Maiden from contrasting thermal environments grown under ambient [CO2] (aCO2; 400 µmol mol–1) and elevated [CO2] (640 µmol mol–1; eCO2). Leaf R per unit area (Rarea) measured across a range of temperatures was higher in trees grown in eCO2 and varied up to 104% among provenances. However, eCO2 increased leaf dry mass per unit area (LMA) by 21%, and when R was expressed on a mass basis (i.e. Rmass), it did not differ between CO2 treatments. Likewise, accounting for differences in LMA among provenances, Rmass did not differ among provenances. The temperature sensitivity of R (i.e. Q10) did not differ between CO2 treatments or among provenances. We conclude that eCO2 had no direct effect on the temperature response of R in E. grandis, and respiratory physiology was similar among provenances of E. grandis regardless of home-climate temperature conditions.


Forests ◽  
2017 ◽  
Vol 8 (3) ◽  
pp. 70 ◽  
Author(s):  
Salwan Al‐Maliki ◽  
David Jones ◽  
Douglas Godbold ◽  
Dylan Gwynn‐Jones ◽  
John Scullion

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