We have proposed in previous works a model built upon a tree structure called resource tree and a logic named BI-Loc which is an extension of BI. Recently, we have enriched this model with a manipulation language and a Hoare's triple semantics. In this work, we show how we can instantiate this model to represent XML data and express their specification as BI-Loc formulae. Furthermore, we propose a specialization of our language of manipulation in order to transform the XML documents and then give an axiomatization of this language. This work can be seen as a first step to use resource trees and BI-Loc for checking transformations of XML documents.