carrying capacity

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The maximum number of persons or things that a vehicle or a receptacle can carry.
• noun Ecology The maximum number of individuals that a given environment can support without detrimental effects.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The number of people or things that a vehicle is designed to carry
• noun The number of individuals of a particular species that an environment can support