Effetti dell'ozono troposferico sugli ecosistemi vegetali cinesi e italiani

Responsabili di progetto

Mauro Centritto, Zhaozhong Feng

Accordo

CINA - CAS (Nuovo Accordo) - Chinese Academy of Sciences

Bando

CNR-CAS 2017-2019

Dipartimento

Scienze bio-agroalimentari

Area tematica

Scienze bio-agroalimentari

Stato del progetto

Nuovo

Proposta di ricerca

Ozone pollution is a serious concern worldwide, and in particular in China. Ozone is a strong greenhouse gas and a severe phytotoxic pollutant. Ozone is an important air quality issue, causes serious health problems, damages materials and ecosystems, and drives climate change (Paoletti 2007; Kampa&Castanas 2008). Ground-level background O3 concentrations have doubled since pre-industrial times and continue to increase due to climate changes because are strongly dependent on temperature (Vingarzan 2004; IPCC 2007). In China, high ambient O3 concentration has been the most serious air pollutant in summer at most places in Northern China. In Italy, ambient O3 levels often exceed the critical levels for plant protection. Ozone plays a key role on plant physiological disturbances, by producing species-specific visible injury, growth loss, and higher vulnerability to secondary stressors. Impacts on vegetation are difficult to assess because ozone does not accumulate into the plant tissues but generates oxidative free radicals that aspecifically damage plant membranes and overall metabolism. In particular, there is a serious need to:
1. Improve knowledge about ozone impacts on carbon sequestration and water control by terrestrial plant ecosystems in China and Italy. Ozone is known to impair photosynthesis and thus the capacity of plant ecosystems to sequester carbon dioxide, and to reduce the plant ability to control water loss through stomata. Quantitative estimates, however, are still limited to a few plant species and conditions. In particular, modern experimental facilities are needed, e.g. free-air controlled-experiments (FACE) similar to the CO2 FACE. Use of chambers, in fact, has proven to be misleading due to many weaknesses (e.g. strong ventilation for keeping a constant ozone concentration, low irradiation, etc) in particular in the case of forest species (only young plants can be handled into the chambers). CNR and CAS possess two of the five ozone FACEs at present running in the world. Joint experiments will greatly advance the present level of knowledge about ozone impacts on the provision of ecosystem services in China.
2. Summarise our understanding of ozone impacts on emission of biogenic volatile organic compounds (BVOC), with focus on Chinese forest species. VOC and in particular BVOC contribute to the photochemical formation of ozone in the air. Defining which tree species show the lowest potential of ozone formation is critical for urban greening. Feedbacks on overall air quality (e.g. haze) are expected. We plan measurements of BVOC emission after ozone exposure in Chinese plant species. Our results will improve urban planning and air quality control strategies in the densely populated cities of Eastern Asia.
3. Model stomatal ozone uptake of forests in China and Italy. An inventory of available models of atmospheric chemistry/transport will be carried out with an aim of testing the possibility to generate the meteorological, soil and air quality data that are needed for calculating large-scale (nation -wide) stomatal uptake of ozone (POD) of the major forest ecosystem types of China and Italy. The metric POD is now considered the best index for summarizing ozone risk to vegetation. Large-scale data of POD for China are not yet available. Our results will allow to inform policy makers with the most updated metric of ozone risk assessment to plant ecosystems.
This proposal is a continuation of previous successful informal collaborations between our institutions, e.g. the recent Professorship for Senior International Scientist of the Chinese Academy of Sciences assigned to Elena Paoletti (2016-2017), with the organization of the international conference 'Ozone and Plants' in Beijing in 2014 and the publication of four joint papers: HOSHIKA Y., Carriero G., FENG Z., Zhang Y., PAOLETTI E.: 2014, Determinants of stomatal sluggishness in ozone-exposed deciduous tree species. Science of the Total Environment, 481: 453-458; Carriero C., Tuovinen J.-P., Clarke N., Matteucci G., Matyssek R., Wieser G., Mikkelsen T.N., Fischer R., Cudlin P., Serengil Y., Boscaleri F., Calfapietra C., FENG Z., PAOLETTI E.: 2014, Latest achievements on climate change and forest interactions in a polluted environment. Open Journal of Forestry, 4: 197-207; FENG, Z., PAOLETTI E., Bytnerowicz A., Harmens H.: 2015, Ozone and plants. Environmental Pollution, 202: 215-216; Yuan X., Calatayud V., Gao F., FARES S., PAOLETTI E., Tian Y., FENG Z.: 2016, Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar. Plant, Cell & Environment, 39: 2276-2287.; FENG Z, FARES S, Loreto F, PAOLETTI E.: Climate change drivers of isoprenoid emission from vegetation: a meta-analytic review. Submitted.

China and Italy possess extensive and invaluable know-how and facilities to answer the fundamental question about ozone impacts on plant ecosystems. CNR is world leader in environmental protection, e.g. in the field of plant biodiversity, BVOC and ozone impacts on plant ecophysiology. CAS is emerging as the main Chinese institutions in the study of pollution ecology and effects on plants. CNR and CAS have a mutual interest and willingness to strengthen their cooperation.

References
IPCC WGI Climate Change 2007: The Physical Science Basis: Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.
Kampa M, Castanas E 2008 Human health effects of air pollution. Environ Pollut 151, 362-367.
Paoletti E 2007 Ozone impacts on forests. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, 2 (No. 68), 13.
Vingarzan R 2004 A review of surface ozone background levels and trends. Atm Environ 38, 3431-3442.

Obiettivi della ricerca

The scope is to strengthen the cooperation of China and Italy in the area of the protection of plant ecosystems from ozone pollution, with the following major aims:
1. To improve our knowledge about ozone impacts on major forest species carbon sequestration and water control in China and Italy, in order to consolidate the scientific basis for protecting plant ecosystems from ozone pollution;
2. To summarise ozone impacts on emission of biogenic volatile organic compounds, with focus on Chinese forest species, in order to expand our knowledge of the species-specific contribution of urban forest species to air quality;
3. To model stomatal ozone uptake of terrestrial plant ecosystems in China and Italy, in order to move towards the novel ozone risk assessment metric POD
4. To raise a generation of young experts on ozone and plants, in China and Italy
5. To organize a major international conference in China in order to raise awareness about the effects of ozone pollution on terrestrial ecosystems
6. To develop joint project proposals in order to further consolidate the scientific cooperation between the participating countries

This bilateral agreement is a great opportunity of collaboration for our research teams, and in particular for our early-stage collaborators. The expected results are novel and of great significance in the international context, and will provide both countries with innovative findings about how plant ecosystems respond to ozone pollution.

Ultimo aggiornamento: 01/05/2025