植物和光的关系(国外英文资料).docVIP

植物和光的关系 The relationship between plants and light The nature of light Light is composed of wavelength range is very wide of the electromagnetic wave, the main wavelength range is 150 ~ 4000 nm, in which the wavelength of visible light between 380 ~ 760 nm, depending on the wavelength of the visible spectrum and can be divided into red, orange, yellow, green, blue, blue, violet seven kinds of colors of light. A wavelength of less than 380nm is ultraviolet light, which is greater than 760nm and is infrared, and they are not visible. Ultraviolet light, which has a wavelength of less than 290nm, is absorbed by the ozone layer in the upper reaches of the atmosphere, so only ultraviolet light, which has a wavelength of 290 to 380nm, can reach the ground. Ultraviolet light has a killer and carcinogenic effect on people and creatures, so the damage to the ozone layer is severe. In all solar radiation, the infrared region accounts for about 50 to 60 percent, and the ultraviolet light is about 1 percent, while the rest is visible. Visible light has the greatest ecological significance because only visible light can be used and converted into chemical energy in photosynthesis. The red and violet light in the visible areas of the plants visible light is the highest absorption rate, so these two are called physiological active light; The green light is absorbed very little by the leaves, which is called physiological nullify light. (2) changes in light and its effect on plants The light quality refers to the component of the spectrum, and its spatial pattern is that the short wave light decreases with the latitude and increases with elevation. Long wavelengths are the opposite. The change of time is the increase of the winters long wave light and the increase of short summer light. There is more light in the middle of the day and more light in the morning. Different wavelengths of light have different effects on plants, such as the physiological effects mentioned above. Plant l