most definintly you can use LowPAN with WSN. and it will always be a good idea to use as they use Less energy. you have to be specific with the Application in which u use them.
FYI, IPv6 Low Power and Lossy personal area network(6lowpan) is a network of physical embedded devices which is defined by (IEEE 802.15.4).
6lowpan layer is implemented in different operating systems and work as intermediate layer to overcome the incompatibilities between IPv6 format and the formats allowed by IEEE 802.15.4.
e.g. contiki OS. implement the 6lowpan adaption layer in the uIP stack. there are too many applications with different types of motes to be tested on.