Why did Mesoamerican civilizations develop dense populations?

Mesoamerican civilizations developed dense populations primarily through the adoption of highly productive, intensive agricultural systems that allowed for year-round settlement.12

The foundation of this growth was the domestication of staple crops, most notably corn, beans, and squashes. As these agricultural practices became more effective, societies shifted from mobile, low-density hunting-gathering groups to sedentary village life.31

In the drier highlands, where land was limited, populations achieved high density through specialized techniques such as:
* Irrigation: Managing water to extend growing seasons and avoid frost damage.42
* Terracing: Constructing earth and stone structures to prevent soil erosion and conserve moisture on slopes.42
* Chinampas: Creating highly productive artificial islands in swampy or lake environments, which were essential for feeding large urban centers like Tenochtitlán.42

While lowland areas often relied on slash-and-burn agriculture, which generally supported lower population densities, the use of raised-field farming in some regions also enabled greater concentration of people. These agricultural advancements, combined with organized trade networks and social stratification, supported the rise of large, prosperous urban centers.521