Because the plants are blooming to early and they can freeze
It is an essential element for plant life, but when there is too much of it in water, it can speed up eutrophication (a reduction in dissolved oxygen in water bodies caused by an increase of mineral and organic nutrients) of rivers and lakes. Soil erosion is a major contributor of phosphorus to streams.
The plant pigments that are involved in photosynthesis are chlorophyll pigments, mostly chlorophyll A. They are found in chloroplasts.
D : the number of generations in one population
