abstract: I'll describe some particular finite sums of Multiple zeta values which arise from J. Ecalle's arborification, a process which has been described by F. Fauvet and F. Menous as a surjective Hopf algebra morphism from the Hopf algebra of decorated rooted forests onto a Hopf algebra of shuffles or quasi-shuffles. This formalism holds for both the iterated sum picture and the iterated integral picture. It involves a decoration of the forests by the positive integers in the first case, by only two colours in the second case. Talk in english or in french according to the audience.