Within most archaeological sites, Mesolithic plant exploitation strategies are generally inferred from the study of carbonized plant remains of ligneous origin, providing some insights about plants used for fuel or subsistence. As a result, our perception of Mesolithic plant use has long been biased, this being particularly true for Western European contexts. Peatbog sites represent rare opportunities to better understand the role plants played in the closing landscapes of the Preboreal-Boreal. Krzyz 7, located in Greater Poland, is such a site with exceptional preservation conditions. The aim of this paper is to present our first results on plant use provided by the analysis of botanical macroremains (wood and bark, seedsand fruits, charcoal) and organic chemistry (GC-MS). Subsistence, woodworking and adhesive production systems are then discussed in the light of relevant archaeological, paleoenvironmental, experimental and/or ethnoarchaeological data.