Contents

Summary 213

I. Introduction 213
II. Source–sink model: carbohydrate signaling 214
III. Effect of ozone on above-ground sources and sinks 216
IV. Decreased allocation below ground 218
V. Carbon flux to soils 220
VI. Soil food web 223
VII. Summary, conclusions and future research 223

Acknowledgements 223


References 223



Summary
The role of tropospheric ozone in altering plant growth and development has been the subject of thousands of publications over the last several decades. Still, there is limited understanding regarding the possible effects of ozone on soil processes. In this review, the effects of ozone are discussed using the flow of carbon from the atmosphere, through the plant to soils, and back to the atmosphere as a framework. A conceptual model based on carbohydrate signaling is used to illustrate physiological changes in response to ozone, and to discuss possible feedbacks that may occur. Despite past emphasis on above-ground effects, ozone has the potential to alter below-ground processes and hence ecosystem characteristics in ways that are not currently being considered.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1469-8137.2003.00674.x

Source–sink balance and carbon allocation below ground in plants exposed to ozone

We hypothesized that changes in plant growth resulting from atmospheric CO 2 and O 3 enrichment would alter the flow of C through soil food webs and that this effect would vary with tree species. To test this idea, we traced the course of C through the soil microbial community using soils from the free-air CO 2 and O 3 enrichment site in Rhinelander, Wisconsin. We added either 13 C-labeled cellobiose or 13 C-labeled N-acetylglu- cosamine to soils collected beneath ecologically distinct temperate trees exposed for 3 years to factorial CO 2 (ambient and 200 µl l -1 above ambient) and O 3 (ambient and 20 µl l-1above ambient) treatments. For both labeled substrates, recovery of 13 C in microbial respiration increased beneath plants grown under elevated CO 2 by 29% compared to ambient; elevated O 3 eliminated this effect. Production of 13 C-CO2 from soils beneath aspen (Populus tremuloides Michx.) and aspen-birch (Betula papyrifera Marsh.) was greater than that beneath aspen- maple (Acer saccharumMarsh.). Phospholipid fatty acid analyses (13C-PLFAs) indicated that the microbial com- munity beneath plants exposed to elevated CO 2 metabo- lized more 13 C-cellobiose, compared to the microbial community beneath plants exposed to the ambient condi- tion. Recovery of 13C in PLFAs was an order of magni- tude greater for N-acetylglucosamine-amended soil com- pared to cellobiose-amended soil, indicating that sub- strate type influenced microbial metabolism and soil C cycling. We found that elevated CO2 increased fungal activity and microbial metabolism of cellobiose, and that microbial processes under early-successional aspen and birch species were more strongly affected by CO 2 and O 3 enrichment than those under late-successional maple.

/pdf/microbial-community-composition-and-function-beneath-ghi403kpll.pdf

Microbial community composition and function beneath temperate trees exposed to elevated atmospheric carbon dioxide and ozone

Risks associated with exposure of individual plant species to ozone (O3) are well documented, but implications for terrestrial biodiversity and ecosystem processes have received insufficient attention. This is an important gap because feedbacks to the atmosphere may change as future O3 levels increase or decrease, depending on air quality and climate policies. Global simulation of O3 using the Community Earth System Model (CESM) revealed that in 2000, about 40% of the Global 200 terrestrial ecoregions (ER) were exposed to O3 above thresholds for ecological risks, with highest exposures in North America and Southern Europe, where there is field evidence of adverse effects of O3, and in central Asia. Experimental studies show that O3 can adversely affect the growth and flowering of plants and alter species composition and richness, although some communities can be resilient. Additional effects include changes in water flux regulation, pollination efficiency, and plant pathogen development. Recent research is unraveling a range of effects belowground, including changes in soil invertebrates, plant litter quantity and quality, decomposition, and nutrient cycling and carbon pools. Changes are likely slow and may take decades to become detectable. CESM simulations for 2050 show that O3 exposure under emission scenario RCP8.5 increases in all major biomes and that policies represented in scenario RCP4.5 do not lead to a general reduction in O3 risks; rather, 50% of ERs still show an increase in exposure. Although a conceptual model is lacking to extrapolate documented effects to ERs with limited or no local information, and there is uncertainty about interactions with nitrogen input and climate change, the analysis suggests that in many ERs, O3 risks will persist for biodiversity at different trophic levels, and for a range of ecosystem processes and feedbacks, which deserves more attention when assessing ecological implications of future atmospheric pollution and climate change.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.2568

Current and future ozone risks to global terrestrial biodiversity and ecosystem processes

Current elevated concentrations of ozone in the atmosphere, as they are observed during summer seasons, can cause severe effects on plant vegetation. This study was initiated to analyze whether ozone-stressed plants also transfer signals below ground and thereby alter the bacterial community composition in their rhizospheres. Herbaceous plants, native to Germany, with tolerance (Anthoxanthum odoratum, Achillea millefolium, Poa pratensis, Rumex acetosa, and Veronica chamaedrys) and sensitivity (Matricaria chamomilla, Sonchus asper, and Tanacetum vulgare) to ozone, raised in the greenhouse, were exposed in open-top chambers to two different ozone regimes, i.e., "summer stress" and a normal ozone background. DNA of bacterial cells from the rhizospheres was directly extracted, and partial sequences of the 16S rRNA genes were PCR amplified with primers targeting the following phylogenetic groups: Bacteria, alpha-Proteobacteria, Actinobacteria, and Pseudomonas, respectively. The diversity of the amplified products was analyzed by genetic profiling based on single-strand conformation polymorphism (SSCP). Neither the tolerant nor the sensitive plants, the latter with visible above-ground damage, showed ozone-induced differences in any of the SSCP profiles, with the single exception of Actinobacteria-targeted profiles from S. asper. To increase the stress, S. asper was germinated and raised in the continuous presence of an elevated level of ozone. SSCP profiles with Bacteria-specific primers combined with gene probe hybridizations indicated an ozone-related increase in a Xanthomonas-related 16S rRNA gene and a decrease in the respective gene from the plant plastids. The fact that only this latter unrealistic scenario caused a detectable effect demonstrated that ozone stress has a surprisingly small effect on the structural diversity of the bacterial community in rhizospheres.

Effect of Elevated Tropospheric Ozone on the Structure of Bacterial Communities Inhabiting the Rhizosphere of Herbaceous Plants Native to Germany

This report provides a synthesis of current knowledge on the effects of ground-level ozone on ecosystem services and biodiversity. 

Ecosystems provide an array of services upon which humans depend for food, fresh water, climate regulation, aesthetic enjoyment and spirtual fulfilment. The increased global population along with increased standards of living and other socio-political, economic, technological and societal changes, mean that our interventions can have profound negative effects on the the quality of the services provided by ecosystems. As well as having a direct impact on human health, ozone pollution also affects human well-being indirectly via effects on ecosystem services and biodiversity. This report provides a review of current knowledge of the impacts of ozone on biodiversity and supporting, provisioning, regulating and cultural services. Included are effects of ozone on primary production, carbon, nutrient and water cycling, air quality, crop and timber production, flowering and pollination, and aesthetics of the natural environment, together with the interactions with climate change. Approaches for valuing the cost of ozone pollution impacts on ecosystem services are also discussed.

Ozone pollution: impacts on ecosystem services and biodiversity

Our study examined the influence of elevated ozone levels on the growth and mycorrhizal colonization of two populations of Elymus glaucus L. (blue wildrye). We hypothesized that ozone would reduce carbon availability to the plants, particularly below ground, and would affect mycorrhizal colonization. Because of the wide geographic range of E. glaucus, two populations of plants were selected from areas of contrasting ozone histories to examine intraspecies variation in response to ozone. Two populations of E. glaucus (southern California versus northern California) exposed in a factorial experiment involving ozone, mycorrhizal inoculation with Glomus intraradices Schenck and Smith, and plant source population. Ozone had a subtle effect on leaf area and number of tillers but did not affect overall root:shoot ratio in either population. The impact of ozone on above-ground growth characteristics was most pronounced in the southern population that came from a high-ozone environment, while below-ground responses such as reduced arbuscular colonization was most pronounced in the northern population which originated in a low-ozone environment. Further analysis of soil characteristics from the northern population of plants revealed a significant reduction in active soil bacterial biomass and an increase in total fungi per gram dry weight soil, suggesting a possible role for ozone in altering soil processes. Whether or not population differences in response to ozone were due to genetic shifts resulting from prior ozone remains to be determined. However, these subtle but important differences in population response to ozone above- and below-ground have significant implications in any attempt to generalize plant response, even within a species. Future research efforts need to include better characterization of intraspecific variation in response to ozone as well as possible adaptive strategies that may result from chronic ozone exposure.

Differences in above- and below-ground responses to ozone between two populations of a perennial grass

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Lidia C. Yoshida

Author Tools

Chat about Author

Papers

Differences in above- and below-ground responses to ozone between two populations of a perennial grass