Weed, insect, and disease control may also be required for pastures. A healthy, productive pasture will resist invasion from most poisonous weeds and provide good quality forage. When pastures are overgrazed, horses will eat the grass and legume species down to the soil, which allows weeds to take over.
1 Melasma can be triggered by birth control pills because it increases hormones throughout the body. # 2  This is one of the most common causes of melasma. 3  Pregnancy: During pregnancy the body will become very hormonal and skin conditions like acne vulgaris and melasma/chloasma become very common.
Anyone can get melasma, but it is more common among young women. Melasma often appears during pregnancy, in the second or third trimesters. It is sometimes called the mask of pregnancy.. Doctors don't know exactly what causes melasma, but the condition is associated with the female hormones estrogen and progesterone.