Coping with network failures has become a major networking challenge. The concept of tunable survivability provides a quantitative measure for specifying any desired level (0%-100%) of survivability, thus offering flexibility in the routing choice. Previous works focused on implementing this concept on unicast transmissions. However, vital network information is often broadcast via spanning trees. Accordingly, in this study, we investigate the application of tunable survivability for efficient maintenance of spanning trees under the presence of failures. We establish efficient algorithmic schemes for optimizing the level of survivability under various QoS requirements. In addition, we derive theoretical bounds on the number of required trees for maximum survivability. Finally, through extensive simulations, we demonstrate the effectiveness of the tunable survivability concept in the construction of spanning trees. Most notably, we show that, typically, negligible reduction in the level of survivability results in major improvement in the QoS performance of the resulting spanning trees.