School trips help to bond families and can change children's lives, a study has indicated.
Trips encourage children to respect the environment, the study found
Children who learned about nature fostered feelings of "pride and ownership", the study published by the National Trust found.
It comes as the government prepares to publish its manifesto on school trips, in response to falling numbers.
A growing culture of negligence claims has impacted on the number of teachers willing to organise excursions.
Report author Dr Alan Peacock, an expert in education outside the classroom at Exeter University, said the impact of school trips on children "should not be underestimated".
His "Changing Minds" study found children involved in nature-based school work developed a stronger concern for the environment.
Families also bonded well if their child was involved in such projects as they were more likely to visit nature reserves and the countryside together, he said.
Teachers reported parents were more likely to become involved in school meetings, which in turn developed a "community spirit".
Dr Peacock interviewed current and former pupils involved in eight of the National Trust's Guardianship Schemes, which work in partnership with schools.
He found children's career choices were also influenced in one in 10 cases.
"But it is also the quality of the experience that is vital for lasting impact," he said.
"To work best, school trips should not be seen as a one-off or special day but as providing an extension of their classroom learning into the real world.
"This fosters feelings of pride and ownership that stay with children for life."
Currently under consultation, the government's manifesto on education outside the classroom proposes that teachers need to be supported to organise safe school excursions.
Its aims include encouraging schools to collaborate with each other and with organisations, such as the National Trust, to make the most of such visits.
The National Trust's Guardianship Scheme began 15 years ago and now involves more than 100 schools.