What species of pine are they? Pines tend to grow fast but are short lived but I would only remove them if they are >40cm dbh. For the rewood the only thing you

What species of pine are they? Pines tend to grow fast but are short lived but I would only remove them if they are >40cm dbh. For the rewood the only thing you could do would be to thin and remove competition if there are trees to close, you could also prune if you want. (I study forestry science in New Zealand where we grow a lot of Californian species)