I have a number of different trees on my land, including plum, pear, apple, magnolia, pussy willow, silver birch, oak, walnut. I diligently mow up as many leaves as l can to make leaf mold. My question is: are there any particular leaves which have more nutrients, when composted, than others? I wonder if l should be more selective in what l collect. I do wonder whether oak leaves and walnut in particular, are worth the effort?