Table 1.

Search terms used in database searches.

Early childhood search terms	Operator	Environmental education search terms
(childcare OR “day care*” OR “early childhood” OR “early elementary” OR “early primary” OR infants OR kindergarten OR “nursery school*" OR preschool* OR “primary grade*” OR toddler* OR “young child” OR “young children”	AND	(“conservation education” OR “education for sustainability” OR “education for sustainable development” OR “environmental education” OR “forest kindergarten*” OR “forest school*” OR gardening OR “nature preschool*" OR “nature-based preschool*” OR “outdoor classroom*" OR “school garden*" OR “sustainability education”)

Note. The asterisk “*" is a truncation symbol, which directs the search engine to find all forms of a given word. The term forest school*, for example, returns results containing “forest school” or “forest schools.”