Design and Performance of an Exposure System for Measuring the Response of Crops to Acid Rain and Gaseous Pollutants in the Field

Johnston, John W.; Shriner, D.S.; Abner, C.H.

doi:10.1080/00022470.1986.10466127

Cited by 20 publications

(6 citation statements)

References 11 publications

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“…Seven days after planting the seedlings were transferred to 9 open-top field ozone exposure chambers (3 m diameter x 24 m height) of the type originally described by Heagle, Body & Heck (1973). The chambers and ozone exposure system used in this study have been described in detail by Johnston, Shriner & Abner (1986); Adams et al, (1988) and McEvers, Bowers & Edwards (1988). Ozone treatments consisted of a subambient (charcoal-filtered air), ambient, and elevated levels.…”

Section: Ozone Exposures and Experimental Designmentioning

confidence: 99%

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Soil nitrogen and chronic ozone stress influence physiology, growth and nutrient status ofPinus taedaL. andLiriodendron tulipiferaL. seedlings

Tjoelker

Luxmoore

1991

New Phytologist

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SUMMARYThe effects of soil nitrogen availability and chronic ozone stress on carbon and nutrient economy were investigated in loblolly pine {Pinus taeda L,) and yellow-poplar {Liriodendron tulipifera L.). One-year-old seedlings were planted individually in pots in forest soil of low (58/ig g"'), medium (96/ig g"') or high (172/fg g"^) initial concentrations of soluble nitrogen. The seedlings were exposed to ozone in open-top 6eld chambers at sub-ambient (charcoalfiltered air), ambient, and elevated (ambient+ 60 nl T^ O3) (32, 56, 108 nl 1"' O3, 7 h seasonal mean, respectively) levels for 18 weeks. At final harvest loblolly pine dry matter increased by 50"0 at the highest soil N level relative to the iow with the largest gains in new needle biomass. Elevated ozone reduced the biomass of current-year needles by 20% in plants grown at the highest N level. Higher soil N supply increased the concentration of nitrogen in needles, stimulated current-year needle photosynthesis and increased needle and whole-plant wateruse efficiencies. Ozone treatment had no significant effect on photosynthesis or water-use efficiency in either species, although ozone exposure tended to reduce stomatal conductance in loblolly pine. The low N treatment increased the proportion of dry matter allocated to fine roots in yellow-poplar, but whole-plant dry weight had not responded to N fertilization at the final harvest, suggesting other limitations on growth. Ozone exposure increased leaf abscission and doubled leaf turnover in yellow-poplar. Although yellow-poplar was highly sensitive to ozoneinduced leaf abscission, final whole-plant dry weights were not aFfected. The indeterminate growth habit of yellow-poplar permitted compensatory leaf growth which may have ameliorated effects of chronic ozone stress on biomass gain. Ozone exposure also decreased shoot weight more than root weight, resulting in higher root:shoot ratios in loblolly pine and a similar trend in higher fine root:leaf ratios in yellow-poplar. Greater proportional allocation of carbon to roots in response to nutrient deficiency may preclude an increased allocation to shoots often observed in response to air pollution stress. Interspecific differences in growth response to chronic ozone and nutrient stress may be influenced by differences in leaf growth habit.

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Section: Ozone Exposures and Experimental Designmentioning

confidence: 99%

“…The chambers and ozone exposure system used in this study have been described in detail by Johnston, Shriner & Abner (1986); Adams et al, (1988) and McEvers, Bowers & Edwards (1988). Ozone treatments consisted of a subambient (charcoal-filtered air), ambient, and elevated levels.…”

Section: Ozone Exposures and Experimental Designmentioning

confidence: 99%

Soil nitrogen and chronic ozone stress influence physiology, growth and nutrient status ofPinus taedaL. andLiriodendron tulipiferaL. seedlings

Tjoelker

Luxmoore

1991

New Phytologist

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“…17.7b) (Johnston et al, 1986). (b) Illustration of the control circuitry for the automatic operation of rain exclusion and simulant distribution systems for an open-top chamber (Johnston et aI., 1986).…”

Section: Systems For Controlling Both Wet and Dry Depositionmentioning

confidence: 99%

“…Rainfall simulators have been developed for open-top chambers equipped with rainfall exclusion covers (Johnston et al, 1986;Fig. 17.7b) (Johnston et al, 1986).…”

Section: Systems For Controlling Both Wet and Dry Depositionmentioning

confidence: 99%

Field methods used for air pollution research with plants

Winner¹,

Greitner²

2000

Plant Physiological Ecology

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“…Air is forced through a plenum around the base of the chamber and exits the chamber through the top. Many chambers have covers to exclude ambient rainfall and are fitted with nozzles to simulate wet deposition of pollutants (Johnston et al 1986). Open-top chambers differ in size and overall design, but all are based on the same general principles of flow and exposure.…”

Section: Tree Community and Stand-level Productivitymentioning

confidence: 99%

Air Pollution and Forest Ecosystems: A Regional to Global Perspective

Taylor¹,

Johnson²,

Andersen³

1994

Ecological Applications

111

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Changes in the atmospheric concentrations of a number of air pollutants over the last century are hallmarks of the magnitude and extent of human impact on the environment. Some of these changes are important to ecologists because many pollutants, acting singly or in combination, affect ecological systems in general and forests in particular. The greatest concern lies with chronic levels of tropospheric ozone, cumulative deposition of hydrogen ion, nitrogen, and sulfur via wet and dry processes, a select number of airborne chemicals (e.g., mercury) that tend to bioaccumulate in continental landscapes, and ultraviolet—B radiation through the loss of stratospheric ozone. Because the atmospheric residence time of most pollutants of concern to ecologists is measured on time frames extending from a few weeks to decades, pollutant distribution and effects are regional to global in dimension. We present evidence that ambient levels of some air pollutants in North America are affecting managed and unmanaged forests, and that the two most important pollutants are tropospheric ozone and chronic nitrogen loading. Further evidence indicates that while concentrations of some air pollutants have been declining over the last decade in North America, others are expected to remain unchanged or increase, including tropospheric ozone. We conclude that air pollution is affecting many North American forests and some remote forests around the globe. In the immediate future, the concern for air pollution effects on forests and associated natural resources will broaden to include interactions with changes in climate and pollution effects in the world's developing countries. There has been a rapid evolution in air pollution studies in ecology, shifting away from the agricultural paradigm of single—factor experimentation toward new methodologies that are ecologically and multidisciplinarily based. This shift has been promoted by the recognition that air pollution is one of several factors influencing forest productivity, community dynamics, and biogeochemistry, and that effects arise through long—term exposures. This evolution in methodologies will become even more marked in the future as new ecological approaches are adopted and an understanding is developed of how air pollution interacts with changes in climate. One of the most promising methodologies is process level modeling, which utilizes the large base of data in tree physiology and forest ecology, watershed chemistry, and atmosphere— forest canopy meteorology to develop models of tree physiology and growth and to subsequently scale these investigations to the levels of forest stands and landscapes.

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Design and Performance of an Exposure System for Measuring the Response of Crops to Acid Rain and Gaseous Pollutants in the Field

Cited by 20 publications

References 11 publications

Soil nitrogen and chronic ozone stress influence physiology, growth and nutrient status ofPinus taedaL. andLiriodendron tulipiferaL. seedlings

Soil nitrogen and chronic ozone stress influence physiology, growth and nutrient status ofPinus taedaL. andLiriodendron tulipiferaL. seedlings

Field methods used for air pollution research with plants

Air Pollution and Forest Ecosystems: A Regional to Global Perspective

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