Answer:
Monoculture
Explanation:
Rising human numbers have increased pressure on the land; selective agriculture or monoculture (the use of one or two favored crops) has reduced biodiversity.
In the 17th century the Dutch practised monoculture (spices) in the Indonesian colony for the benefit of the Dutch Republic and a little later the British in India cultivated opium in large quantities for the Chinese market.
During the classic Maya empire (roughly from 200 to 800 C.E.) the main crops were just corn (sacred in all Mesoamerica) and beans.
There is an interesting monocultural parallel with certain crops (marihuana, avocado) produced in Mexico nowadays, there is one difference though:
Corn, beans and gourds were necessary for surviving; spices, opium and marihuana were not.