Super rare
Population density
Population density is a measurement of population size per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key concept in population geography. In botany and agronomy, it is known as plant density.
On WikiTrade, every Wikipedia article is a card: the more the article is read, the rarer the card. Open free packs, complete your album, trade, bid and challenge others to general-knowledge duels.
Play for freeRead the article on WikipediaText from Wikipedia (CC BY-SA 4.0). WikiTrade is an independent site, not affiliated with Wikipedia or the Wikimedia Foundation.