scholarly journals Seasonal isoprene emission rates and model comparisons using whole-tree emissions from white oak

1997 ◽  
Vol 102 (D20) ◽  
pp. 23963-23971 ◽  
Author(s):  
P. A. Pier ◽  
C. McDuffie
Keyword(s):  
Emission Rates ◽  
White Oak ◽  
Model Comparisons ◽  
Isoprene Emission ◽  
Whole Tree

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.

scholarly journals Isoprene emissions from a tundra ecosystem

2013 ◽  
Vol 10 (2) ◽  
pp. 871-889 ◽  
Author(s):  
M. J. Potosnak ◽  
B. M. Baker ◽  
L. LeStourgeon ◽  
S. M. Disher ◽  
K. L. Griffin ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Global Climate ◽  
Common Species ◽  
Emission Rates ◽  
Arctic Ecosystems ◽  
Field Station ◽  
Isoprene Emission ◽  
Tundra Ecosystem ◽  
Leaf Level ◽  
Field Campaigns

Abstract. Whole-system fluxes of isoprene from a moist acidic tundra ecosystem and leaf-level emission rates of isoprene from a common species (Salix pulchra) in that same ecosystem were measured during three separate field campaigns. The field campaigns were conducted during the summers of 2005, 2010 and 2011 and took place at the Toolik Field Station (68.6° N, 149.6° W) on the north slope of the Brooks Range in Alaska, USA. The maximum rate of whole-system isoprene flux measured was over 1.2 mg C m−2 h−1 with an air temperature of 22 °C and a PAR level over 1500 μmol m−2 s−1. Leaf-level isoprene emission rates for S. pulchra averaged 12.4 nmol m−2 s−1 (27.4 μg C gdw−1 h−1) extrapolated to standard conditions (PAR = 1000 μmol m−2 s−1 and leaf temperature = 30 °C). Leaf-level isoprene emission rates were well characterized by the Guenther algorithm for temperature with published coefficients, but less so for light. Chamber measurements from a nearby moist acidic tundra ecosystem with little S. pulchra emitted significant amounts of isoprene, but at lower rates (0.45 mg C m−2 h−1) suggesting other significant isoprene emitters. Comparison of our results to predictions from a global model found broad agreement, but a detailed analysis revealed some significant discrepancies. An atmospheric chemistry box model predicts that the observed isoprene emissions have a significant impact on Arctic atmospheric chemistry, including a reduction of hydroxyl radical (OH) concentrations. Our results support the prediction that isoprene emissions from Arctic ecosystems will increase with global climate change.

scholarly journals Edge Growth Form of European Buckthorn Increases Isoprene Emissions From Urban Forests

2021 ◽  
Vol 3 ◽  
Author(s):  
Aarti P. Mistry ◽  
Adam W. T. Steffeck ◽  
Mark J. Potosnak
Keyword(s):  
Invasive Species ◽  
Air Quality ◽  
Species Composition ◽  
Tree Species ◽  
Urban Forests ◽  
Google Earth ◽  
Urban Trees ◽  
Emission Rates ◽  
Isoprene Emission ◽  
Environmental Controls

Urban trees provide numerous benefits, such as cooling from transpiration, carbon sequestration, and street aesthetics. But volatile organic compound emissions from trees can combine with anthropogenic nitrogen oxide emissions to form ozone, a harmful air pollutant. The most commonly-emitted of these compounds, isoprene, negatively impacts air quality and hence is detrimental to human health. In addition to environmental controls such as light and temperature, the quantity of isoprene emitted from a leaf is a genus-specific trait. Leaf isoprene emission is enzymatically controlled, and species are typically classified as emitters or non-emitters (near-zero emission rates). Therefore, the species composition of urban forests affects whole-system isoprene production. The process of plant invasion alters species composition, and invasive tree species can be either emitters or non-emitters. If an invasive, isoprene-emitting tree species displaces native, non-emitting species, then isoprene emission rates from urban forests will increase, with a concomitant deterioration of air quality. We tested a hypothesis that invasive species have higher isoprene emission rates than native species. Using existing tree species inventory data for the Chicago region, leaf-level isoprene emission rates of the six most common invasive and native tree species were measured and compared. The difference was not statistically significant, but this could be due to the variability associated with making a sufficient number of measurements to quantify species isoprene emission rates. The most common invasive species European buckthorn (Rhamnus cathartica, L.) was an emitter. Because European buckthorn often invades the disturbed edges common in urban forests, we tested a second hypothesis that edge-effect isoprene emissions would significantly increase whole-system modeled isoprene emissions. Using Google Earth satellite imagery to estimate forested area and edge length in the LaBagh Woods Forest Preserve of Cook County (Chicago, IL, USA), edge isoprene emission contributed 8.1% compared to conventionally modeled forest emissions. Our results show that the invasion of European buckthorn has increased isoprene emissions from urban forests. This implies that ecological restoration efforts to remove European buckthorn have the additional benefit of improving air quality.

scholarly journals Assessment of high (diurnal) to low (seasonal) frequency variations of isoprene emission rates using a neural network approach

2008 ◽  
Vol 8 (7) ◽  
pp. 2089-2101 ◽  
Author(s):  
C. Boissard ◽  
F. Chervier ◽  
A. L. Dutot
Keyword(s):  
Air Temperature ◽  
Low Frequency ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Climatic Data ◽  
Emission Rates ◽  
Neural Network Approach ◽  
Isoprene Emission ◽  
Frequency Variations

Abstract. Using a statistical approach based on artificial neural networks, an emission algorithm (ISO-LF) accounting for high to low frequency variations was developed for isoprene emission rates. ISO-LF was optimised using a data base (ISO-DB) specifically designed for this work, which consists of 1321 emission rates collected in the literature and 34 environmental variables, measured or assessed using National Climatic Data Center or National Centers for Environmental Predictions meteorological databases. ISO-DB covers a large variety of emitters (25 species) and environmental conditions (10° S to 60° N). When only instantaneous environmental regressors (instantaneous air temperature T0 and photosynthetic photon flux density L0) were used, a maximum of 60% of the overall isoprene variability was assessed with the highest emissions being strongly underestimated. ISO-LF includes a total of 9 high (instantaneous) to low (up to 3 weeks) frequency regressors and accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate investigated. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks (T21) and to L0 and T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability.

Isoprene emission from phytoplankton monocultures: the relationship with chlorophyll-a, cell volume and carbon content

2010 ◽  
Vol 7 (6) ◽  
pp. 554 ◽  
Author(s):  
B. Bonsang ◽  
V. Gros ◽  
I. Peeken ◽  
N. Yassaa ◽  
K. Bluhm ◽  
...  
Keyword(s):  
Carbon Content ◽  
Cell Volume ◽  
Chlorophyll A ◽  
Marine Species ◽  
Emission Rates ◽  
Terrestrial Vegetation ◽  
Terrestrial Plants ◽  
Chl A ◽  
Isoprene Emission ◽  
Regional Budget

Environmental context Isoprene, a natural product of both terrestrial vegetation and marine organisms, is rapidly oxidised in the atmosphere, and thereby plays a key role in the regional budget of oxidants. Although isoprene production from terrestrial plants has been extensively investigated, production processes and emission rates from marine species are still poorly understood. We present results from laboratory experiments showing that isoprene is emitted from living phytoplankton cells at variable rates depending on the light intensity, cell volume, and carbon content of the plankton cells. Abstract We report here isoprene emission rates determined from various phytoplankton cultures incubated under PAR light which was varied so as to simulate a natural diel cycle. Phytoplankton species representative of different phytoplankton functional types (PFTs) namely: cyanobacteria, diatoms, coccolithophorides, and chlorophytes have been studied. Biomass normalised isoprene emission rates presented here relative to the chlorophyll-a (Chl-a) content of the cultures showed that the two cyanobacteria (Synechococcus and Trichodesmium) were the strongest emitters with emission rates in the range of 17 to 28 µg C5H8 g–1 Chl-a h–1. Diatoms produced isoprene in a significantly lower emission range: 3 to 7.5 µg C5H8 g–1 Chl-a h–1 and Dunaliella tertiolecta was by far the lowest emitter of our investigated plankton cultures. Despite the group specific differences observed, a high emission rate variance was observed to occur within one phytoplankton group. However, a combination of literature and our own data showed a clear relationship between the actual cell volume and the isoprene emission rates. This relationship could be a valuable tool for future modelling approaches of global isoprene emissions.

Effect of elevated CO2 concentration and vapour pressure deficit on isoprene emission from leaves of Populus deltoides during drought

2004 ◽  
Vol 31 (12) ◽  
pp. 1137 ◽  
Author(s):  
Emiliano Pegoraro ◽  
Ana Rey ◽  
Edward G. Bobich ◽  
Greg Barron-Gafford ◽  
Katherine Ann Grieve ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Vapour Pressure ◽  
Populus Deltoides ◽  
Global Climate ◽  
Stomatal Closure ◽  
Vapour Pressure Deficit ◽  
Co2 Concentration ◽  
Emission Rates ◽  
Isoprene Emission ◽  
Long Term Effect

To further our understanding of the influence of global climate change on isoprene production we studied the effect of elevated [CO2] and vapour pressure deficit (VPD) on isoprene emission rates from leaves of Populus deltoides Bartr. during drought stress. Trees, grown inside three large bays with atmospheres containing 430, 800, or 1200 μmol mol–1 CO2 at the Biosphere 2 facility, were subjected to a period of drought during which VPD was manipulated, switching between low VPD (approximately 1 kPa) and high VPD (approximately 3 kPa) for several days. When trees were not water-stressed, elevated [CO2] inhibited isoprene emission and stimulated photosynthesis. Isoprene emission was less responsive to drought than photosynthesis. As water-stress increased, the inhibition of isoprene emission disappeared, probably as a result of stomatal closure and the resulting decreases in intercellular [CO2] (Ci). This assumption was supported by increased isoprene emission under high VPD. Drought and high VPD dramatically increased the proportion of assimilated carbon lost as isoprene. When measured at the same [CO2], leaves from trees grown at ambient [CO2] always had higher isoprene emission rates than the leaves of trees grown at elevated [CO2], demonstrating that CO2 inhibition is a long-term effect.

scholarly journals Variability of BVOC emissions from a Mediterranean mixed forest in southern France with a focus on <i>Quercus pubescens</i>

2014 ◽  
Vol 14 (11) ◽  
pp. 17225-17261 ◽  
Author(s):  
A.-C. Genard-Zielinski ◽  
C. Boissard ◽  
C. Fernandez ◽  
C. Kalogridis ◽  
J. Lathière ◽  
...  
Keyword(s):  
Mixed Forest ◽  
Ground Level ◽  
Individual Variability ◽  
Diurnal Variations ◽  
Emission Rates ◽  
Quercus Pubescens ◽  
Southern France ◽  
Isoprene Emission ◽  
Canopy Effect ◽  
Net Assimilation

Abstract. We aimed at quantifying Biogenic Volatiles Organic Compounds (BVOC) emissions in June from three Mediterranean species located at the O3HP site (Southern France): Quercus pubescens, Acer monspessulanum and C. coggygria (for isoprene only). As Q. pubescens was shown to be the main BVOC emitter with isoprene representing ≈ 99% of the carbon emitted as BVOC, we mainly focused on this species. C. coggygria was found to be a non-isoprene emitter (no other BVOC were investigated). To fully understand both the canopy effect on Q. pubescens isoprene emission and the inter-individual variability (tree to tree and within canopy), diurnal variations of isoprene were investigated from nine branches (seven branches located to the top of canopy at ≈ 4 m Above Ground Level, and two inside the canopy at ≈ 2 m a.g.l.). Q. pubescens daily mean isoprene emission rates (ERd) fluctuated between 23.1 and 97.7 μg C gDM−1 h−1 and were exponentially correlated with net assimilation (Pn). Q. pubescens daily mean Pn ranged between 5.4 and 13.8, and 2.8 and 6.4 μmol CO2 m−2 s−1 for sunlit and shaded branches respectively. Both ERd and isoprene emission factors (Is) assessed according to Guenther et al. (1993) algorithm, varied by a factor of 4 among the sunlit branches. While sunlit branches ERm was clearly higher than for shaded branches, there was an non-significant variability on Is (58.5 to 76.5 μg C gDM−1 h−1). Diurnal variations of isoprene emission rates (ER) for sunlit branches were also investigated. ER were detected at dawn 2 h after Pn became positive and, exponentially dependent on Pn. Diurnal variations of ER were not equally well described along the day by temperature (CT) and light (CL) parameters according to G93 algorithm. Temperature had more impact than PAR in the morning emission increase. ER was no more correlated to CL × CT between solar noon (maximum ER) and mid-afternoon, possibly due to thermal stress of the plant. A comparison between measured and calculated emissions using two isoprene algorithms (G93 and MEGAN) highlighted the difficulty in assessing isoprene emissions under Mediterranean environmental conditions with current isoprene models.

scholarly journals Simulating precipitation decline under a Mediterranean deciduous Oak forest: effects on isoprene seasonal emissions and predictions under climatic scenarios

2017 ◽  
Author(s):  
Anne-Cyrielle Genard-Zielinski ◽  
Christophe Boissard ◽  
Elena Ormeño ◽  
Juliette Lathière ◽  
Ilja M. Reiter ◽  
...  
Keyword(s):  
Water Stress ◽  
Seasonal Variations ◽  
Land Surface ◽  
Environmental Changes ◽  
Seasonal Pattern ◽  
Land Surface Model ◽  
Surface Model ◽  
Emission Rates ◽  
Drought Intensity ◽  
Isoprene Emission

Abstract. Seasonal variations of Q. pubescens physiology and isoprene emission rates (ER) were studied from June 2012 to June 2013 at the O3HP site (French Mediterranean) under natural (ND) and amplified (+30 %, AD) drought. While AD significantly reduced the stomatal conductance to water vapour over the season excepting August, it did not significantly limit CO2 net assimilation, which was the lowest in summer. ER followed a significant seasonal pattern, whatever the drought intensity, with mean ER maxima of 78.5 and 104.8 µgC gDM−1 h−1 in July (ND) and August (AD) respectively. Isoprene emission factor increased significantly by a factor of 2 in August and September under AD (137.8 and 74.3 µgC gDM−1 h−1) compared to ND (75.3 and 40.21 µgC gDM−1 h−1), but no changes occurred on ER. An isoprene algorithm (G14) was developed using an optimised artificial neural network trained on our experimental dataset (ER + O3HP climatic and edaphic parameters cumulated over 0 to 21 days before measurements). G14 assessed more than 80 % of the observed ER seasonal variations, whatever the drought intensity. In contrast, ER was poorly assessed under water stress by MEGAN empirical isoprene model, in particular under AD. Soil water (SW) content was the dominant parameter to account for the observed ER variations, regardless the water stress treatment. ER was more sensitive to higher frequency environmental changes under AD (0 to −7 days) compared to ND (7 days). Using IPCC RCP2.6 and RCP8.5 climate scenarios, SW and temperature calculated by the ORCHIDEE land surface model, and G14, an annual 3 fold ER relative increase was found between present (2000–2010) and future (2090–2100) for RCP8.5 scenario compared to a 70 % increase for RCP2.6. Future ER remained mainly sensitive to SW (both scenarios) and became dependent to higher frequency environmental changes under RCP8.5.

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