French forests are currently facing serious health challenges due to climate change and the spread of invasive species. Since 2018, extreme weather events—such as unusually high temperatures and prolonged droughts—have increasingly stressed forest ecosystems. In 2022, the situation reached an unprecedented level of intensity in the Haut-Jura region, a trend that has led to various consequences, including the rapid spread of the typographer beetle. This insect has damaged nearly 25% of the local resinous trees, such as pines and firs, since 2018. Additionally, invasive species like the pine nematode—a microscopic worm carried by a type of beetle—have been detected in the Landes region. This nematode can kill a tree in a few weeks. Other threats, such as the oak reticulated bug and the pine spittlebug, are being closely monitored. To address these threats, France relies on the Forest Health Department (DSF), established in 1989 and now part of the regional directorates for food, agriculture, and forestry (DRAAF). The DSF provides forest managers and officials with detailed information on the health of forests through annual reports, specialized monitoring, and regional consultations. It also acts as a bridge between researchers and forestry professionals. In the Bourgogne-Franche-Comté region, the Forest Health Pole employs four full-time staff and mobilizes 32 observer correspondents from various forest-related organizations, including the National Forestry Office and the Chambers of Agriculture. These individuals serve as "sentinels," providing continuous and precise data on forest health. To monitor and evaluate forest conditions, several methods are used. The "comprehensive health watch" involves daily field visits by observers and DSF staff, resulting in nearly 950 observations annually. A "systematic network" covers France with observation points spaced 16 kilometers apart, enabling the long-term tracking of tree health. Specific surveys, such as "road samplings," assess the health of particular tree species across large forest areas, while young plantations are closely monitored. In addition, plant protection inspectors help track invasive species linked to international trade. Together, these efforts generate more than 2,000 observations each year. Forest observers look for subtle signs of distress, such as unusual leaf loss, dead branches, wounds on the bark, or strange discharges. A diagnostic tool called "DEPERIS" is used to assess the health of trees on a scale from A (healthy) to F (dying), based on branch mortality and the condition of the tree's crown. This method is widely used by forest owners and managers to identify early signs of disease or infestation. When a problem is identified, the DSF reports it to forest owners and managers. For common pests like the bark beetle, the response typically involves reporting and informing. If the issue involves a "quarantine" organism—a species that is particularly dangerous—the State activates an Emergency Sanitary Intervention Plan (PNISU), which includes strict eradication measures or restrictions on the sale of affected wood. Early detection has proven effective in managing invasive species, such as the Asian longhorn beetle, which was recently eradicated from most of France thanks to swift action. Continued vigilance and prompt reporting from forest owners and managers are crucial to maintaining the health of France’s forests.