WhaT is a collection of trees and shrubs called?

An arboretum, or the plurial, arboreta, is a collection of trees in the narrow sense. Today, an arboretum is more commonly a botanical garden containing living collections of woody plants. Specialist arboreta are known as pinetum (conifers), salicetums (willows), populetums (poplars), and quercetums (oak).

Other Words for groups of trees include: clump, copse, forest, grove, orchard, plantation, thicket, or stand.