scholarly journals Measurement report: Leaf-scale gas exchange of atmospheric reactive trace species (NO<sub>2</sub>, NO, O<sub>3</sub>) at a northern hardwood forest in Michigan

2020 ◽  
Vol 20 (19) ◽  
pp. 11287-11304
Author(s):  
Wei Wang ◽  
Laurens Ganzeveld ◽  
Samuel Rossabi ◽  
Jacques Hueber ◽  
Detlev Helmig
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Tree Species ◽  
Leaf Surface ◽  
Compensation Point ◽  
Trace Gas ◽  
Red Maple ◽  
White Pine ◽  
Canopy Exchange ◽  
Leaf Level

Abstract. During the Program for Research on Oxidants: PHotochemistry, Emissions, and Transport (PROPHET) campaign from 21 July to 3 August 2016, field experiments on leaf-level trace gas exchange of nitric oxide (NO), nitrogen dioxide (NO2), and ozone (O3) were conducted for the first time on the native American tree species Pinus strobus (eastern white pine), Acer rubrum (red maple), Populus grandidentata (bigtooth aspen), and Quercus rubra (red oak) in a temperate hardwood forest in Michigan, USA. We measured the leaf-level trace gas exchange rates and investigated the existence of an NO2 compensation point, hypothesized based on a comparison of a previously observed average diurnal cycle of NOx (NO2+NO) concentrations with that simulated using a multi-layer canopy exchange model. Known amounts of trace gases were introduced into a tree branch enclosure and a paired blank reference enclosure. The trace gas concentrations before and after the enclosures were measured, as well as the enclosed leaf area (single-sided) and gas flow rate to obtain the trace gas fluxes with respect to leaf surface. There was no detectable NO uptake for all tree types. The foliar NO2 and O3 uptake largely followed a diurnal cycle, correlating with that of the leaf stomatal conductance. NO2 and O3 fluxes were driven by their concentration gradient from ambient to leaf internal space. The NO2 loss rate at the leaf surface, equivalently the foliar NO2 deposition velocity toward the leaf surface, ranged from 0 to 3.6 mm s−1 for bigtooth aspen and from 0 to 0.76 mm s−1 for red oak, both of which are ∼90 % of the expected values based on the stomatal conductance of water. The deposition velocities for red maple and white pine ranged from 0.3 to 1.6 and from 0.01 to 1.1 mm s−1, respectively, and were lower than predicted from the stomatal conductance, implying a mesophyll resistance to the uptake. Additionally, for white pine, the extrapolated velocity at zero stomatal conductance was 0.4±0.08 mm s−1, indicating a non-stomatal uptake pathway. The NO2 compensation point was ≤60 ppt for all four tree species and indistinguishable from zero at the 95 % confidence level. This agrees with recent reports for several European and California tree species but contradicts some earlier experimental results where the compensation points were found to be on the order of 1 ppb or higher. Given that the sampled tree types represent 80 %–90 % of the total leaf area at this site, these results negate the previously hypothesized important role of a leaf-scale NO2 compensation point. Consequently, to reconcile these findings, further detailed comparisons between the observed and simulated in- and above-canopy NOx concentrations and the leaf- and canopy-scale NOx fluxes, using the multi-layer canopy exchange model with consideration of the leaf-scale NOx deposition velocities as well as stomatal conductances reported here, are recommended.

scholarly journals Measurement report: Leaf-scale gas exchange of atmospheric reactive trace species (NO<sub>2</sub>, NO, O<sub>3</sub>) at a northern hardwood forest in Michigan

2020 ◽  
Author(s):  
Wei Wang ◽  
Laurens Ganzeveld ◽  
Samuel Rossabi ◽  
Jacques Hueber ◽  
Detlev Helmig
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Tree Species ◽  
Leaf Surface ◽  
Deposition Velocity ◽  
Compensation Point ◽  
Trace Gas ◽  
Red Maple ◽  
White Pine ◽  
Canopy Exchange

Abstract. During the Program for Research on Oxidants: PHotochemistry, Emissions, and Transport (PROPHET) campaign from July 21 to August 3, 2016, field experiments of leaf-level trace gas exchange of nitric oxide (NO), nitrogen dioxide (NO2), and ozone (O3) were conducted for the first time on the native American tree species Pinus strobus (eastern white pine), Acer rubrum (red maple), Populus grandidentata (bigtooth aspen), and Quercus rubra (red oak) in a temperate hardwood forest in Michigan, USA. We measured the leaf-level trace gas exchange rates and investigated the existence of an NO2 compensation point of 1 ppb, hypothesized based on a comparison of a previously observed average diurnal cycle of NOx (NO2 + NO) concentrations with that simulated using a multi-layer canopy exchange model. Known amounts of trace gases were introduced into a tree branch enclosure and a paired blank reference enclosure. The trace gas concentrations before and after the enclosures were measured, as well as the enclosed leaf area (single-sided) and gas flow rate to obtain the trace gas fluxes with respect to leaf surface. There was no detectable NO uptake for all tree types. The foliar NO2 and O3 uptake largely followed a diurnal cycle, correlating with that of the leaf stomatal conductance. NO2 and O3 fluxes were driven by their concentration gradient from ambient to leaf internal space. The NO2 loss rate at leaf surface, equivalently, the foliar NO2 deposition velocity toward the leaf surface, ranged from 0–3.6 mm s−1 for bigtooth aspen, and 0–0.76 mm s−1 for red oak, both of which are ~ 90 % of the expected values based on the stomatal conductance of water. The deposition velocity for red maple and white pine ranged from 0.3–1.6 mm s−1 and from 0.01–1.1 mm s−1, respectively, and were lower than predicted from the stomatal conductance, implying a mesophyll resistance to the uptake. Additionally, for white pine, the extrapolated velocity at zero stomatal conductance was 0.4 ± 0.08 mm s−1, indicating a non-stomatal uptake pathway. The NO2 compensation point was ≤ 60 ppt for all four tree species and indistinguishable from zero at the 95 % confidence level. This agrees with recent reports for several European and California tree species but contradicts some earlier experimental results where the compensation points were found to be on the order of 1 ppb or higher. Given that the sampled tree types represent 80–90 % of the total leaf area at this site, these results negate the previously hypothesized important role of a leaf-scale NO2 compensation point. Consequently, to reconcile these findings, further detailed comparisons between the observed and the simulated in- and above-canopy NOx concentrations, and the leaf- and canopy-scale NOx fluxes, using the multi-layer canopy exchange model with consideration of the leaf-scale NOx deposition velocities as well as stomatal conductances reported here, are recommended.

Growth responses of seven major co-occurring tree species of the northeastern United States to elevated CO2

1990 ◽  
Vol 20 (9) ◽  
pp. 1479-1484 ◽  
Author(s):  
F. A. Bazzaz ◽  
J. S. Coleman ◽  
S. R. Morse
Keyword(s):  
Tree Species ◽  
Sugar Maple ◽  
Growth Enhancement ◽  
Black Cherry ◽  
Red Maple ◽  
Growth Responses ◽  
White Pine ◽  
American Beech ◽  
Harvard Forest ◽  
Paper Birch

We examined how elevated CO2 affected the growth of seven co-occurring tree species: American beech (Fagusgrandifolia Ehrh.), paper birch (Betulapapyrifera Marsh.), black cherry (Prunusserotina Ehrh.), white pine (Pinusstrobus L.), red maple (Acerrubrum L.), sugar maple (Acersaccharum Marsh.), and eastern hemlock (Tsugacanadensis (L.) Carr). We also tested whether the degree of shade tolerance of species and the age of seedlings affected plant responses to enhanced CO2 levels. Seedlings that were at least 1 year old, for all species except beech, were removed while dormant from Harvard Forest, Petersham, Massachusetts. Seeds of red maple and paper birch were obtained from parent trees at Harvard Forest, and seeds of American beech were obtained from a population of beeches in Nova Scotia. Seedlings and transplants were grown in one of four plant growth chambers for 60 d (beech, paper birch, red maple, black cherry) or 100 d (white pine, hemlock, sugar maple) under CO2 levels of 400 or 700 μL•L−1. Plants were then harvested for biomass and growth determinations. The results showed that the biomass of beech, paper birch, black cherry, sugar maple, and hemlock significantly increased in elevated CO2, but the biomass of red maple and white pine only marginally increased in these conditions. Furthermore, there were large differences in the magnitude of growth enhancement by increased levels of CO2 between species, so it seems reasonable to predict that one consequence of rising levels of CO2 may be to increase the competitive ability of some species relative to others. Additionally, the three species exhibiting the largest increase in growth with increased CO2 concentrations were the shade-tolerant species (i.e., beech, sugar maple, and hemlock). Thus, elevated CO2 levels may enhance the growth of relatively shade-tolerant forest trees to a greater extent than growth of shade-intolerant trees, at least under the light and nutrient conditions of this experiment. We found no evidence to suggest that the age of tree seedlings greatly affected their response to elevated CO2 concentrations.

Impact of Deer Browsing on Regeneration in Mixed Stands in Southern New England

1995 ◽  
Vol 12 (3) ◽  
pp. 115-120 ◽  
Author(s):  
David B. Kittredge ◽  
P. Mark S. Ashton
Keyword(s):  
New England ◽  
Tree Species ◽  
Sugar Maple ◽  
Red Maple ◽  
White Pine ◽  
Mixed Stands ◽  
Tree Species Composition ◽  
Southern New England ◽  
Pine Seedlings ◽  
Species Specific

Abstract Browsing preferences by white-tailed deer were evaluated for 6 tree species in northeastern Connecticut. Deer density averaged 23/mile². Deer exhibited no species-specific preferences for seedlings greater than 19 in. For seedlings less than 19 in., hemlock and black birch were preferred. Red maple, sugar maple, and white pine seedlings were avoided. Red oak seedlings were neither preferred nor avoided. A much higher proportion of seedlings greater than 19.7 in. in height was browsed, regardless of species. Browsing preferences for species in the smaller seedling class, combined with a lack of preference for species in the larger class may result in future stands with less diverse tree species composition. Deer densities in excess of 23/mile² may be incompatible with regeneration of diverse forests in southern New England. North. J. Appl. For. 12(3):115-120.

scholarly journals Modelling bi-directional fluxes of methanol and acetaldehyde with the FORCAsT canopy exchange model

2016 ◽  
Author(s):  
Kirsti Ashworth ◽  
Serena H. Chung ◽  
Karena A. McKinney ◽  
Ying Liu ◽  
Bill J. Munger ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Atmospheric Chemistry ◽  
Forest Canopy ◽  
Global Scale ◽  
Exchange Model ◽  
Forest Site ◽  
Canopy Exchange ◽  
Harvard Forest ◽  
Leaf Level ◽  
Underlying Mechanisms

Abstract. The FORCAsT canopy exchange model was used to investigate the underlying mechanisms governing foliage emissions of methanol and acetaldehyde, two short chain oxygenated volatile organic compounds ubiquitous in the troposphere and known to have strong biogenic sources, at a northern mid-latitude forest site. The explicit representation of the vegetation canopy within the model allowed us to test the hypothesis that stomatal conductance regulates emissions of these compounds to an extent that its influence is observable at the ecosystem-scale, a process not currently considered in regional or global scale atmospheric chemistry models. We found that FORCAsT could only reproduce the magnitude and diurnal profiles of methanol and acetaldehyde fluxes measured at the top of the forest canopy at Harvard Forest if light-dependent emissions were introduced to the model. With the inclusion of such emissions FORCAsT was able to successfully simulate the observed bi-directional exchange of methanol and acetaldehyde. Although we found evidence that stomatal conductance influences methanol fluxes and concentrations at scales beyond the leaf-level, particularly at dawn and dusk, we were able to adequately capture ecosystem exchange without the addition of stomatal control to the standard parameterisations of foliage emissions, suggesting that ecosystem fluxes can be well enough represented by the emissions models currently used.

Another View of Gas Exchange Model: Reflection of Leaf Surface Air to Stomatal Conductance

2010 ◽  
Vol 113-116 ◽  
pp. 14-17
Author(s):  
Meng Hu ◽  
Shao Zhong Kang ◽  
Tai Sheng Du ◽  
Ling Tong
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Surface ◽  
Leaf Gas Exchange ◽  
Exchange Process ◽  
Negative Relationship ◽  
Co2 Concentration ◽  
Reflection Function ◽  
Use Efficiency ◽  
Gas Exchange Process

A reflection function was established, based on leaf gas exchange process and tested with experimental data of eight kinds of plants, i.e. tomato, muskmelon, capsicum, maize, grape, onion, Haloxylon Ammodendron Bunge and Caragana Karshiskii Kom, with multifarious biological characteristic, water and growing status. The function indicated that the leaf stomatal conductance could be linearly reflected by the ratio of humidity and CO2 concentration at leaf surface, and the behaviour of its slope could be recognized as an indicator of leaf gas exchange efficiency, which had a negative relationship with leaf water use efficiency (WUE). The results maybe increase our understanding of potential influences of leaf stomatal conductance on photosynthetic and transpiration gas exchange and leaf WUE.

Comparative Study of Oak Species for Intercepting Particle Pollution

2001 ◽  
Vol 7 (S2) ◽  
pp. 532-533
Author(s):  
Kamran K. Abdollahi ◽  
Zhu H. Ning
Keyword(s):  
Surface Morphology ◽  
Tree Species ◽  
Leaf Surface ◽  
Acer Rubrum ◽  
Red Maple ◽  
Particulate Pollution ◽  
Platanus Occidentalis ◽  
Quercus Virginiana ◽  
Celtis Occidentalis ◽  
Particle Pollution

Trees can act as efficient biological filters to remove significant amounts of particulate pollution from urban atmospheres (Nowak, et al. 1994 ). Recent controlled environment studies have indicated that tree's ability in intercepting and removing particle pollution varies among species. Studies by Abdollahi et al. (2000) confirmed that there were significant differences among different tree species in intercepting particle pollution. Live Oaks (Quercus virginiana), River Birch ( Betula nigra),and Sugar hackberry (Celtis occidentalis) are statistically more efficient at capturing pollutant particles of less than 2.5 microns (PM2.5) than tree species such as Red Maple (Acer Rubrum),Southern Magnolia (Magnolia grandiflora),and Sycamore (Platanus occidentalis).Other Studies also suggested that the leaf surface morphology of these trees might play an important role in interception and removal of PM2.5.The main objectives of this study were to quantify the relative ability of selected oak species (Quercus spp.) in removing particle pollution of less than 2.5 microns (PM2.5) and to characterize oak leaf surface morphology.

scholarly journals Gas Exchange and Growth of Selected Transplanted and Nontransplanted Landscape Tree Species

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 444A-444
Author(s):  
D. Thayne Montague ◽  
Roger Kjelgren ◽  
Larry Rupp
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Tree Species ◽  
Shoot Elongation ◽  
Acer Platanoides ◽  
Growth Data ◽  
Total Leaf Area ◽  
Area Increase ◽  
New Location

Gas exchange and growth of transplanted and non-transplanted Acer platanoides `Schwedleri' and Tilia cordata `Greenspire' trees were investigated. This study was conducted on trees planted in 1991 in a field nursery near Logan, Utah. In Spring 1995, three trees of each species were moved with a tree spade to a new location within the nursery and three non-transplanted trees were selected as controls. To simulate landscape conditions, all trees were watered at the time of planting and once per week during the growing season. Pre-dawn water potential, dawn-to-dusk stomatal conductance, mid-day photosynthesis, and growth data were collected over a 2-year period. Transplanted trees of each species were under more water stress (indicated by more negative pre-dawn water potential) than non-transplanted trees. However, pre-dawn water potential of transplanted A. platanoides recovered to near non-transplanted levels, while transplanted T. cordata did not. Dawn-to-dusk studies in 1995 and 1996 showed that stomatal conductance was lower throughout the day in transplanted trees. Once again, transplanted A. platanoides recovered to near non-transplanted levels, while transplanted T. cordata did not. A similar trend for mid-day photosynthesis was found for both species in 1995 and 1996. Transplanted trees of each species had less stem area increase, shoot elongation, and total leaf area than non-transplanted trees for each year. These data indicate that transplanted A. platanoides can recover to near non-transplant pre-dawn water potential and gas exchange levels earlier, and therefore establish faster, than transplanted T. cordata. However, after 2 years neither transplanted tree species were able to fully recover to non-transplanted growth rates.

scholarly journals The dynamic chamber method: trace gas exchange fluxes (NO, NO<sub>2</sub>, O<sub>3</sub>) between plants and the atmosphere in the laboratory and in the field

2012 ◽  
Vol 5 (5) ◽  
pp. 955-989 ◽  
Author(s):  
C. Breuninger ◽  
R. Oswald ◽  
J. Kesselmeier ◽  
F. X. Meixner
Keyword(s):  
Gas Exchange ◽  
Chemical Reactions ◽  
Field Conditions ◽  
Compensation Point ◽  
Trace Gas ◽  
Chamber System ◽  
Deposition Velocities ◽  
Dynamic Chamber ◽  
Exchange Flux

Abstract. We describe a dynamic chamber system to determine reactive trace gas exchange fluxes between plants and the atmosphere under laboratory and, with small modifications, also under field conditions. The system allows measurements of the flux density of the reactive NO-NO2-O3 triad and additionally of the non-reactive trace gases CO2 and H2O. The chambers are made of transparent and chemically inert wall material and do not disturb plant physiology. For NO2 detection we used a highly NO2 specific blue light converter coupled to chemiluminescence detection of the photolysis product, NO. Exchange flux densities derived from dynamic chamber measurements are based on very small concentration differences of NO2 (NO, O3) between inlet and outlet of the chamber. High accuracy and precision measurements are therefore required, and high instrument sensitivity (limit of detection) and the statistical significance of concentration differences are important for the determination of corresponding exchange flux densities, compensation point concentrations, and deposition velocities. The determination of NO2 concentrations at sub-ppb levels (<1 ppb) requires a highly sensitive NO/NO2 analyzer with a lower detection limit (3σ-definition) of 0.3 ppb or better. Deposition velocities and compensation point concentrations were determined by bi-variate weighted linear least-squares fitting regression analysis of the trace gas concentrations, measured at the inlet and outlet of the chamber. Performances of the dynamic chamber system and data analysis are demonstrated by studies of Picea abies L. (Norway Spruce) under field and laboratory conditions. Our laboratory data show that the quality selection criterion based on the use of only significant NO2 concentration differences has a considerable impact on the resulting compensation point concentrations yielding values closer to zero. The results of field experiments demonstrate the need to consider photo-chemical reactions of NO, NO2, and O3 inside the chamber for the correct determination of the exchange flux densities, deposition velocities, as well as compensation point concentrations. Under our field conditions NO2 deposition velocities would have been overestimated up to 80%, if NO2 photolysis has not been considered. We also quantified the photolysis component for some previous NO2 flux measurements. Neglecting photo-chemical reactions may have changed reported NO2 compensation point concentration by 10%. However, the effect on NO2 deposition velocity was much more intense, ranged between 50 and several hundreds percent. Our findings may have consequences for the results from previous studies and ongoing discussion of NO2 compensation point concentrations.

Sign in / Sign up

Export Citation Format

Share Document