Editing Ozone depletion (section)

==== Effects on plant life ====

Over the years, the Arctic ozone layer has depleted severely. As a consequence species that live above the snow cover or in areas where snow has melted abundantly, due to hot temperatures, are negatively impacted due to UV radiation that reaches the ground.<ref>{{Cite journal |last1=Barnes |first1=P. W. |last2=Robson |first2=T. M. |last3=Neale |first3=P. J. |last4=Williamson |first4=C. E. |last5=Zepp |first5=R. G. |last6=Madronich |first6=S. |last7=Wilson |first7=S. R. |last8=Andrady |first8=A. L. |last9=Heikkilä |first9=A. M. |last10=Bernhard |first10=G. H. |last11=Bais |first11=A. F. |date=2022-03-01 |title=Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021 |url=https://doi.org/10.1007/s43630-022-00176-5 |journal=Photochemical & Photobiological Sciences |language=en |volume=21 |issue=3 |pages=275–301 |doi=10.1007/s43630-022-00176-5 |issn=1474-9092 |pmc=8860140 |pmid=35191005}}</ref> Depletion of the ozone layer and allowing excess UVB radiation would initially be assumed to increase damage to plant DNA. Reports have found that when plants are exposed to UVB radiation similar to stratospheric ozone depletion, there was no significant change in plant height or leaf mass, but showed a response in shoot biomass and leaf area with a small decrease.<ref>{{Cite journal|last1=Searles|first1=Peter S.|last2=Flint|first2=Stephan D.|last3=Caldwell|first3=Martyn M.|date=2001-03-01|title=A meta-analysis of plant field studies simulating stratospheric ozone depletion|journal=Oecologia|language=en|volume=127|issue=1|pages=1–10|doi=10.1007/s004420000592|pmid=28547159|bibcode=2001Oecol.127....1S|s2cid=7049908|issn=1432-1939}}</ref> However, UVB radiation has been shown to decrease quantum yield of photosystem II.<ref>{{Cite journal|last1=Xiong|first1=Fusheng S.|last2=Day|first2=Thomas A.|date=2001-02-01|title=Effect of Solar Ultraviolet-B Radiation during Springtime Ozone Depletion on Photosynthesis and Biomass Production of Antarctic Vascular Plants|journal=Plant Physiology|language=en|volume=125|issue=2|pages=738–751|doi=10.1104/pp.125.2.738|issn=0032-0889|pmid=11161031|pmc=64875}}</ref> UVB damage only occurs under extreme exposure, and most plants also have UVB absorbing flavonoids which allow them to acclimatize to the radiation present. Plants experience different levels of UV radiation throughout the day. It is known that they are able to shift the levels and types of UV sunscreens (i.e. flavonoids), that they contain, throughout the day. This allows them to increase their protection against UV radiation.<ref>{{Cite journal |date=2017 |title=Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2016 |url=http://xlink.rsc.org/?DOI=C7PP90001E |journal=Photochemical & Photobiological Sciences |language=en |volume=16 |issue=2 |pages=107–145 |doi=10.1039/C7PP90001E |issn=1474-905X |pmc=6400464 |pmid=28124708|last1=United Nations Environment Programme |first1=Environmental Effects Assessment Panel |hdl=11336/183828 }}</ref> Plants that have been affected by radiation throughout development are more affected by the inability to intercept light with a larger leaf area than having photosynthetic systems compromised.<ref>{{Cite journal|last1=Allen|first1=Damian J.|last2=Nogués|first2=Salvador|last3=Baker|first3=Neil R.|date=1998-11-01|title=Ozone depletion and increased UV-B radiation: is there a real threat to photosynthesis?|url=https://academic.oup.com/jxb/article/49/328/1775/516230|journal=Journal of Experimental Botany|language=en|volume=49|issue=328|pages=1775–1788|doi=10.1093/jxb/49.328.1775|issn=0022-0957|doi-access=free}}</ref> Damage from UVB radiation is more likely to be significant on species interactions than on plants themselves.<ref>{{Cite journal|last=Björn|first=Lars Olof|date=1996-12-01|title=Effects of ozone depletion and increased UV-B on terrestrial ecosystems|journal=International Journal of Environmental Studies|volume=51|issue=3|pages=217–243|doi=10.1080/00207239608711082|bibcode=1996IJEnS..51..217B |issn=0020-7233}}</ref>

Another significant impact of ozone depletion on plant life is the stress experienced by plants when exposed to UV radiation. This can cause a decrease in plant growth and an increase in oxidative stress, due to the production of nitric oxide and hydrogen peroxide.<ref>{{Cite journal |last1=Bornman |first1=J. F. |last2=Barnes |first2=P. W. |last3=Robinson |first3=S. A. |last4=Ballaré |first4=C. L. |last5=Flint |first5=S. D. |last6=Caldwell |first6=M. M. |date=2015 |title=Solar ultraviolet radiation and ozone depletion-driven climate change: effects on terrestrial ecosystems |url=http://xlink.rsc.org/?DOI=C4PP90034K |journal=Photochemical & Photobiological Sciences |language=en |volume=14 |issue=1 |pages=88–107 |doi=10.1039/C4PP90034K |pmid=25435216 |s2cid=10176384 |issn=1474-905X|doi-access=free |hdl=20.500.11937/28562 |hdl-access=free }}</ref> In areas where substantial ozone depletion has occurred, increased UV-B radiation reduces terrestrial plant productivity (and likewise carbon sequestration) by about 6%.<ref>{{Cite journal |date=2011 |title=Environmental effects of ozone depletion and its interactions with climate change: 2010 assessment : Executive summary |url=http://xlink.rsc.org/?DOI=c0pp90043e |journal=Photochemical & Photobiological Sciences |language=en |volume=10 |issue=2 |pages=178–181 |doi=10.1039/c0pp90043e |pmid=21253669 |s2cid=40238255 |issn=1474-905X|doi-access=free }}</ref><ref>{{Cite journal |last1=Björn |first1=L. O. |last2=Callaghan |first2=T. V |last3=Gehrke |first3=C. |last4=Johanson |first4=U. |last5=Sonesson |first5=M. |date=November 1999 |title=Ozone depletion, ultraviolet radiation and plant life |url=https://doi.org/10.1016/S1465-9972(99)00038-0 |journal=Chemosphere – Global Change Science |volume=1 |issue=4 |pages=449–454 |bibcode=1999ChGCS...1..449B |doi=10.1016/s1465-9972(99)00038-0 |issn=1465-9972}}</ref>

Moreover, if plants are exposed to high levels of UV radiation, it can elicit the production of harmful [[volatile organic compound]]s, like isoprenes. The emission of isoprenes into the air, by plants, can severely impact the environment by adding to air pollution and increasing the amount of carbon in the atmosphere, ultimately contributing to climate change.<ref>{{Cite journal |last1=Bornman |first1=Janet F. |last2=Barnes |first2=Paul W. |last3=Robson |first3=T. Matthew |last4=Robinson |first4=Sharon A. |last5=Jansen |first5=Marcel A. K. |last6=Ballaré |first6=Carlos L. |last7=Flint |first7=Stephan D. |date=2019 |title=Linkages between stratospheric ozone, UV radiation and climate change and their implications for terrestrial ecosystems |url=http://xlink.rsc.org/?DOI=C8PP90061B |journal=Photochemical & Photobiological Sciences |language=en |volume=18 |issue=3 |pages=681–716 |doi=10.1039/C8PP90061B |pmid=30810560 |hdl=10138/307029 |s2cid=73506953 |issn=1474-905X}}</ref>