5. Conclusion

More and more importance is being given to plants in the city, particularly trees, in response to climate change, the need for nature in the city and the need to improve the quality of life. This means that plants are often exposed to artificial light at night, whether voluntarily or involuntarily, directly or indirectly. Although France has ambitious regulations on light pollution, the presence of plants is not taken into account in the rules. As a result, by 2024 there will be no obligation to take trees into account in night-time lighting projects. The aim of this article is above all to raise awareness of the sensitivity of plants to light, so as to boost proactive measures to reduce tree/lighting conflicts.

We know that plants have been using light to synchronize their rhythms with the alternation of day and night for millions of years, so we can imagine the...