The light-harvesting pigment chlorophyll is found in great abundance wherever conditions are conducive for photosynthetic organisms to live. Although chlorophyll facilitates very efficient absorption of visible light (wavelengths between 400 and 700 nanometers) by these organisms, no organism can utilize all of the absorbed energy for photosynthesis under full sunlight. In addition plants are often exposed to environmental stress (for example, temperature extremes in winter and summer, limiting water or nutrients, and high salinity) that reduces photosynthesis further.