Characteristics and causes of grassland microclimate

Grassland is an important part of urban green space, and its improvement on microclimate environment needs quantitative evaluation. Therefore, the water and heat fluxes, CO2 fluxes and their environmental factors of grassland and bare land were continuously observed in Beijing in May. The results show that the net radiation energy obtained by the grassland on sunny days is about 65,438+0/2 of that of vegetation transpiration and soil evaporation, and 65,438+03% of that of sensible heat. The net radiation energy obtained by bare land is about 1/3, and the sensible heat is about 2/5. At noon, the grassland temperature is about 65438 00℃ lower than the bare land and about 4℃ higher than the air temperature. The water vapor concentration of grassland is about 3 g/m3 higher than that of bare land, and about 1/3 higher, which has the function of humidification. During the growing season of plants,

Grassland is mainly planted with herbs and shrubs, which is suitable for the development of animal husbandry. It has a unique ecosystem and is a renewable natural resource. The grassland area in the world accounts for about 1/2 of the total land area, which is the most basic means of production and base for developing grassland animal husbandry.

Grassland is a compound plant community, which consists of grass, flowering plants and light-loving plants. The ratio of flowering plants to light-loving plants has changed. Lawn has been kept in a low state for a long time, while grass with rich species can only be pruned once or twice a year, and grass with few species can be pruned many times a year, sometimes as many as six times. In addition to local factors (such as soil and climate), restorative pruning also helps to adjust species composition. Grassland has its own growth law, flowering law, fruiting law and seed maturity law: generally speaking, grassland rarely needs maintenance and management, but it is not resistant to trampling.