人和动物会生病,树木除了虫害外也会生病。树木病害的病原分为生物性和非生物性两种,前者主要是真菌、细菌、病毒、类菌质体,以及线虫、藻类、螨类等引起树木的传染性病害;后者是指不适于林木正常生活的水分、温度、光照、营养物质、空气污染等因素,引起树木的生理性病害。对树木威胁最大的是传染性病害。树木病害有个特点,发病初期往往不易被人们觉 People and animals get sick, and trees get sick except for pests. Pathogen of tree disease is divided into two kinds of biological and non-biological, the former mainly fungi, bacteria, viruses, mycoplasma, and nematodes, algae, mites and other diseases caused by trees; the latter refers to not suitable Normal life of trees water, temperature, light, nutrients, air pollution and other factors, causing the physiological disease of trees. The biggest threat to trees is contagious disease. Tree disease has a characteristic, early onset is often not easy to be people feel