Study on landscape lighting of Zhangguan karst cave in Chongqing

Karst cave lighting promotes the development of karst cave tourism. However, the unscientific cave lighting causes the growth of the light plants in the cave, which destroys the special environment in the cave. In this paper,the relationship between the growth of light plant and the artificial light source of cave lighting are studied by measuring the intensity of light and plant growth and surveying the spectral energy distribution of the cave lighting source in the optical laboratory. The research results show that,(1) When the light intensity is higher than 20，000 lux, the green plant physiological system will be destroyed, which inhibits the growth of the light plant in the cave;(2)When the traditional light intensity is under 100 lux, it can’t provide enough energy for the growth of the light plant, which can achieve the purpose of preventing and controlling the growth of the light plant;(3) The artificial light source in the narrow light spectrum of 500-600 nm(yellow light and green light), such as yellow LED and green light LED, can inhibit the growth of green plants.