There are other benefits including removing carbon dioxide and releasing oxygen.
But the benefits aren't just to the surrounding waterways and marshland.
''We are also connecting people with nature - that is one of the main purposes - getting these kids out and getting the ANZ staff out into their surroundings, having a good time, connecting with nature and doing the planting.''
The charity works with DoC, councils and organisations such as Maketū Ongatoro Wetland Society to find suitable land, source trees and bring in businesses and schools to carry out planting days.
He says the bank staff and students put in a lot of work, especially clearing the grass away to allow the planting.
Fairhaven School teacher Delwyn Weaver, Rata Pod leader, says children have been studying trees as part of the science curriculum.
Sariah Beatty with a handful of worms.
''We have been studying trees and their importance for our environment as well as the physical nature of trees.
''This was an opportunity for children to be involved in planting trees and seeing from the beginning not only how trees grow, but how they contributed to our environment and fresh water quality.''
She says children may not have had the opportunity to plant a tree before.
''So the process of how to plant a tree successfully and how it's going to be nurtured is part of something that was a hands-on experience for the children.''