scholarly journals Relationships among Isoprene Emission Rate, Photosynthesis, and Isoprene Synthase Activity as Influenced by Temperature

1992 ◽  
Vol 98 (3) ◽  
pp. 1175-1180 ◽  
Author(s):  
Russell K. Monson ◽  
Charles H. Jaeger ◽  
William W. Adams ◽  
Edward M. Driggers ◽  
Gary M. Silver ◽  
...  
Keyword(s):  
Emission Rate ◽  
Isoprene Emission ◽  
Isoprene Synthase

scholarly journals Photosynthesis and Related Physiological Parameters Differences Affected the Isoprene Emission Rate among 10 Typical Tree Species in Subtropical Metropolises

2021 ◽  
Vol 18 (3) ◽  
pp. 954
Author(s):  
Junyao Lyu ◽  
Feng Xiong ◽  
Ningxiao Sun ◽  
Yiheng Li ◽  
Chunjiang Liu ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Tree Species ◽  
Urban Areas ◽  
Emission Rate ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Single Species ◽  
Photosynthetic Parameters ◽  
Emission Rates ◽  
Isoprene Emission

Volatile organic compound (VOCs) emission is an important cause of photochemical smog and particulate pollution in urban areas, and urban vegetation has been presented as an important source. Different tree species have different emission levels, so adjusting greening species collocation is an effective way to control biogenic VOC pollution. However, there is a lack of measurements of tree species emission in subtropical metropolises, and the factors influencing the species-specific differences need to be further clarified. This study applied an in situ method to investigate the isoprene emission rates of 10 typical tree species in subtropical metropolises. Photosynthesis and related parameters including photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate, which can influence the emission rate of a single species, were also measured. Results showed Salix babylonica always exhibited a high emission level, whereas Elaeocarpus decipiens and Ligustrum lucidum maintained a low level throughout the year. Differences in photosynthetic rate and stomatal CO2 conductance are the key parameters related to isoprene emission among different plants. Through the establishment of emission inventory and determination of key photosynthetic parameters, the results provide a reference for the selection of urban greening species, as well as seasonal pollution control, and help to alleviate VOC pollution caused by urban forests.

Isoprene synthase activity and its relation to isoprene emission inQuercus roburL. leaves

1999 ◽  
Vol 22 (5) ◽  
pp. 495-504 ◽  
Author(s):  
A. LEHNING ◽  
I. ZIMMER ◽  
R. STEINBRECHER ◽  
N. BRÜGGEMANN ◽  
J. ‐P. SCHNITZLER
Keyword(s):  
Isoprene Emission ◽  
Isoprene Synthase

scholarly journals Responses of isoprene emission and photochemical efficiency to severe drought combined with prolonged hot weather in hybrid Populus

2020 ◽  
Vol 71 (22) ◽  
pp. 7364-7381
Author(s):  
Zhihong Sun ◽  
Yan Shen ◽  
Ülo Niinemets
Keyword(s):  
Emission Rate ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Characteristics ◽  
Antioxidant Enzyme Activities ◽  
Severe Drought ◽  
Effective Quantum Yield ◽  
Isoprene Emission ◽  
Hot Weather

Abstract Isoprene emissions have been considered as a protective response of plants to heat stress, but there is limited information of how prolonged heat spells affect isoprene emission capacity, particularly under the drought conditions that often accompany hot weather. Under combined long-term stresses, presence of isoprene emission could contribute to the maintenance of the precursor pool for rapid synthesis of essential isoprenoids to repair damaged components of leaf photosynthetic apparatus. We studied changes in leaf isoprene emission rate, photosynthetic characteristics, and antioxidant enzyme activities in two hybrid Populus clones, Nanlin 1388 (relatively high drought tolerance) and Nanlin 895 (relatively high thermotolerance) that were subjected to long-term (30 d) soil water stress (25% versus 90% soil field capacity) combined with a natural heat spell (day-time temperatures of 35–40 °C) that affected both control and water-stressed plants. Unexpectedly, isoprene emissions from both the clones were similar and the overall effects of drought on the emission characteristics were initially minor; however, treatment effects and clonal differences increased with time. In particular, the isoprene emission rate only increased slightly in the Nanlin 895 control plants after 15 d of treatment, whereas it decreased by more than 5-fold in all treatment × clone combinations after 30 d. The reduction in isoprene emission rate was associated with a decrease in the pool size of the isoprene precursor dimethylallyl diphosphate in all cases at 30 d after the start of treatment. Net assimilation rate, stomatal conductance, the openness of PSII centers, and the effective quantum yield all decreased, and non-photochemical quenching and catalase activity increased in both control and water-stressed plants. Contrary to the hypothesis of protection of leaf photosynthetic apparatus by isoprene, the data collectively indicated that prolonged stress affected isoprene emissions more strongly than leaf photosynthetic characteristics. This primarily reflected the depletion of isoprene precursor pools under long-term severe stress.

scholarly journals Why are estimates of global terrestrial isoprene emissions so similar (and why is this not so for monoterpenes)?

2008 ◽  
Vol 8 (16) ◽  
pp. 4605-4620 ◽  
Author(s):  
A. Arneth ◽  
R. K. Monson ◽  
G. Schurgers ◽  
Ü. Niinemets ◽  
P. I. Palmer
Keyword(s):  
Net Primary Productivity ◽  
Emission Rate ◽  
Chemical Oxidation ◽  
Climate Data ◽  
Global Estimate ◽  
Isoprene Emission ◽  
Process Understanding ◽  
Starting Point ◽  
Emission Capacity ◽  
Relief Phase

Abstract. Emissions of biogenic volatile organic compounds (BVOC) are a chief uncertainty in calculating the burdens of important atmospheric compounds like tropospheric ozone or secondary organic aerosol, reflecting either imperfect chemical oxidation mechanisms or unreliable emission estimates, or both. To provide a starting point for a more systematic discussion we review here global isoprene and monoterpene emission estimates to-date. We note a surprisingly small variation in the predictions of global isoprene emission rate that is in stark contrast with our lack of process understanding and the small number of observations for model parameterisation and evaluation. Most of the models are based on similar emission algorithms, using fixed values for the emission capacity of various plant functional types. In some cases, these values are very similar but differ substantially in other models. The similarities with regard to the global isoprene emission rate would suggest that the dominant parameters driving the ultimate global estimate, and thus the dominant determinant of model sensitivity, are the specific emission algorithm and isoprene emission capacity. But the models also differ broadly with regard to their representation of net primary productivity, method of biome coverage determination and climate data. Contrary to isoprene, monoterpene estimates show significantly larger model-to-model variation although variation in terms of leaf algorithm, emission capacities, the way of model upscaling, vegetation cover or climatology used in terpene models are comparable to those used for isoprene. From our summary of published studies there appears to be no evidence that the terrestrial modelling community has been any more successful in "resolving unknowns" in the mechanisms that control global isoprene emissions, compared to global monoterpene emissions. Rather, the proliferation of common parameterization schemes within a large variety of model platforms lends the illusion of convergence towards a common estimate of global isoprene emissions. This convergence might be used to provide optimism that the community has reached the "relief phase", the phase when sufficient process understanding and data for evaluation allows models' projections to converge, when applying a recently proposed concept. We argue that there is no basis for this apparent relief phase. Rather, we urge modellers to be bolder in their analysis, and to draw attention to the fact that terrestrial emissions, particularly in the area of biome-specific emission capacities, are unknown rather than uncertain.

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