Brambles, in particular, protect and nourish young fruit trees, and on farms bramble clumps (blackberry or one of its related cultivars) can be used to exclude deer and cattle from newly set trees. As the trees (apple, quince, plum, citrus, fig) age, and the brambles are shaded out, hoofed animals come to eat fallen fruit, and the mature trees (7 plus years old) are sufficiently hardy to withstand browsing. Our forest ancestors may well have followed some such sequences for orchard evolution, assisted by indigenous birds and mammals.

chapter 12.7 - Permaculture: A Designers' Manual (1988)