Sunlight reduces plant diversity in grasslands

Now, Spohn and 34 colleagues from different parts of the world show that plant diversity in global grasslands was negatively correlated with sunlight: Increased levels of sunlight generally mean a lower diversity. But it was not all solar radiation that was important. It was intense sunlight in the wavelengths used in photosynthesis that constrained the number of plant species. Neither UV-B radiation, temperature, precipitation, dryness index nor atmospheric nitrogen deposition were as closely related with plant diversity as intense sunlight.