Some farmers switch to what they feel are more expedient crops. See Pakistan's mango orchards disappearing as weather shifts, an excerpt of which says: "an estimated five to seven percent of the total area under mango orchards is being cleared every year in Pakistan, in part because of climate change-induced problems."
Besides being delicious and nutritious, mangoes make good gifts and are symbolic of attainment. There is a lot to learn about their horticultural and huge environmental significance, as well as the cultural and political lore (See for example: Mango Facts)
Mangoes have been produced in Pakistan for about two thousand years. Other countries that have exported mangoes include India, Indonesia, China, Thailand, and Mexico. There are several varieties of mangoes. There is a popular variety called Chaunsa that originated in Pakistan.
An article in the Global Post explains that the U.S.A. banned import of Pakistan mangoes for about ten years "because Pakistan’s mangoes didn’t meet U.S. standards of pest control and post-harvest management. With improvements made in the industry, however, the floodgates have opened." During the ban, some die-hard U.S.A. fans of the Chaunsa would drive to Canada to buy Chaunsa. Following a year of negotiations including efforts by Secretary of State Hillary Clinton and others, the U.S.A. lifted its import restrictions on Pakistani mangoes and the first shipments arrived this summer (2011).