This exchange refers to the exchange of plants, animals, and diseases between the Old World and the New World. The exchange of crops such as potatoes, maize, and sugarcane from the Americas increased the productivity of farming in Europe, while the introduction of livestock such as horses, pigs, and cattle from Europe led to the emergence of large-scale ranching in the Americas. Diseases such as smallpox, measles, and influenza from Europe, however, had a devastating impact on indigenous populations in the Americas.