From any of these trees you most probably can get carbon credits income while waiting for harvest income or watching them grow into a wonderful tree and wildlife filled area.
Ministry for Primary Industries staff are the people to let you know the size, shape, species and any other requirements to be eligible for the scheme.
The carbon credit income might be a considerable amount, depending on the tree species, area and carbon unit price, so it's worthwhile investigating. I would guess there are a lot of people, like me, with areas that are eligible but haven't done the paperwork to register them and are missing out.
To create an area big enough to qualify some spaced plantings to join smaller areas might be a solution.
Dairy farmers, cropping and some horticultural farms look to have more work to do to get to carbon neutrality. Usually these farms do not have the rough gully or steep hillside that is less productive that may be suitable for planting or retiring.
We need, as a country, to do a lot more research into mitigation options that are practical for the nation's farmers. EV tractors aren't around and I couldn't see a Nissan Leaf with a 3m power harrow on or towing a silage wagon.