Pathologie forestière
Forest pathology is the research of both biotic and abiotic maladies affecting the health of a forest ecosystem, primarily fungal pathogens and their insect vectors. It is a subfield of forestry and plant pathology. Forest pathology is part of the broader approach of forest protection. Insects, diseases and severe weather events damaged about 40 million ha of forests in 2015, mainly in the temperate and boreal domains. There are a number of abiotic factors which affect the health of a forest, such as moisture issues like drought, winter-drying, waterlogging resulting from over-abundance or lack of precipitation such as hail, snow, rain. Wind is also an important abiotic factor as windthrow (the uprooting or breaking of trees due to high winds) causes an obvious and direct loss of stability to a forest or its trees. Often, abiotic factors and biotic factors will affect a forest at the same time. For example, if wind speed is 80 km per hour then many trees which have root rot (caused by a pathogen) are likely to be thrown. Higher wind speeds are necessary to damage healthier trees. Fire, whether caused by humans or lightning, and related abiotic factors also affect the health of forest. The effects of man often alter a forest's predisposition to damage from both abiotic and biotic effects. For example, soil properties may be altered by heavy machinery. Other abiotic factors Nutrient imbalances: deficiencies, chemicals (toxic salts, herbicides, air pollutants) Stemflow which can concentrate dry deposits which via soil acidification can kill surrounding plants. Temperature Fungi: Ascomycota, Basidiomycota and Fungi imperfecti There is a . Oomycota: Phytophthora Bacteria Phytoplasmas Viruses Insects There is a . Ips (genus) bark beetles Bark beetle Ambrosia beetle Cerambycidae Black arches Some of these factors act in concert (all do to a degree). For example, Amylostereum areolatum is spread by the sirex woodwasp. The fungus gains access to new trees to live off, and the woodwasp larvae gain food.
