Forest health refers to the state and ability of forest as a structure to maintain its good existence and renewal and play the necessary ecological service function, that is, forest ecosystem health. It has four attributes: (1) nature-society compound attribute; (2) Multidimensional; (3) nonlinear; (4) Dynamic equilibrium characteristics. Forest health in a narrow sense follows the content of early forest health in the United States, and mainly emphasizes whether there are pests and diseases and fire threats in the forest. The other kind can be called generalized forest health, which mainly aims at regional and forest ecosystems, and requires that forest resources can not only meet the reasonable needs of human beings, but also maintain their own stability and healthy development. This kind of forest is a healthy forest. In China, the research in this field tends to forest health in a broad sense [1].

Forest health mainly includes

(1) Modern forest not only has environmental and resource attributes, but also is the infrastructure of modern society. It should be considered as a structure, that is, the evaluation object (forest) should be concrete, and the space-time scale and functional connotation of the evaluated "forest" cannot be changed at will. (2) The connotation of forest health has the meaning of "restoration". (3) The modern concept of health takes into account the characteristics of forest ontology and social function, and emphasizes the limitation of forest function. (4) Consider both present performance (state) and internal potential (ability). (5) Emphasize the specificity of forest health value orientation, that is, under the condition of meeting the needs of nature and society for forest functions, the forest should be in a good state. This also determines that modern forest management has a great degree of particularity.

Forest health core

To achieve the best service function of forests, it is necessary to maintain the stability and biodiversity of forest ecosystems in accordance with natural processes through scientific construction and management of forests, enhance the adjustment ability, reduce the losses caused by fires, forest diseases and insect pests, environmental pollution, man-made deforestation and natural disasters, update the sustainable ecosystems in time, restore and maintain the balance of ecosystems from destruction, and meet the needs of multi-objective, multi-value, multi-purpose, multi-product and multi-service levels.