Ozone contamination threatens plant health, making it harder for pollinators to find flowers

Over the past few decades, rising levels of ozone pollution have been disrupting pollination, affecting the livelihoods
of plants and the animals that pollinate them.
In a review published Sept.
29 in the journal Trends in Ecology and Evolution, researchers explain how excess ground-level ozone destroys plant leaves, alters plant flowering patterns, and becomes an obstacle
to pollinators finding flowers.

Evgenios Agathokleous, an ecologist at Nanjing University of Information Science and Technology, said: "There is a lot of debate about the direct effects of pesticides on pollinators, which is a topic of great concern to society, but now it is found that ozone is a silent threat
to pollinators and pollinators.
" "These effects of ozone have been overlooked
.
"

Ozone gas can be either a friend or an enemy
to Earth.
At an altitude of 12 kilometers above sea level, the stratosphere is naturally formed and helps protect the planet from harmful sunlight
.
But below this region, ozone is a destructive pollutant
.
Tropospheric ozone is produced
by a photochemical reaction between volatile organic compounds (emitted by vegetation, typically found in substances such as paints and aerosols) and nitrogen oxides (nitrogen oxides released when fossil fuels are burned).
Tropospheric ozone levels have been rising because a warming climate has created the optimal conditions
for its formation.

Agathokleous said: "Ozone pollution affects the time and duration
of flowering in a way that is not synchronized with the activity of pollinators.
" "It also changes the color of the flowers and disturbs the pollinator's visual signals
.
" Ozone contamination also reacts directly with pollen, reducing pollen quality, but also indirectly altering the amount of
pollen.
”

Ozone contamination can also damage the leaves of plants almost immediately, leaving signs of damage of different colors and shapes, and discoloring
the leaves.
When damaged, the leaves are difficult to photosynthesize and provide the plants with the energy
they need to grow.
Plants release their own organic volatile compounds that act as chemical signals to facilitate communication between plants and remind pollinators to wait for the presence of
flowers.
Ozone pollution appears to destroy these chemical signatures
.

Agathokleous said: "Changes in the composition of volatile mixtures can also have a serious impact on pollinators because they may not recognize the host plant and its qualities
as it has in the past.
" "In plant tissues, ozone contamination may reduce the amount of nutrients necessary for insects, increase the content of chemicals harmful to insects, and reduce the overall quality
of plant tissues.
"

Journal Reference:

1. Evgenios Agathokleous, Zhaozhong Feng, Josep Peñ uelas.
   Ozone pollution disrupts plant– pollinator systems.
   Trends in Ecology & Evolution, 2022; DOI: 10.
   1016/j.
   tree.
   2022.
   08.
   004