A semantic network is a structure for representing knowledge as a pattern of interconnected nodes and edges. This paper focuses on the means linear logic offers to represent these networks. In order to compare our inferences, we have chosen one nonmonotonic logic: default logic [9] serves as a reference. The main result proves the equivalence between linear logic and default logic in taxonomic default theories. We hope this will help to better understand the relations between nonmonotonicity and defeasible knowledge representation.