Rigging techniques used to strengthen weak unions in high valued trees using steel cable systems (static) or polypropylene rope systems (dynamic). We can also strengthen cracked trunks using machine-threaded metal rods passing through the trunk and secured with washers and nuts. These techniques are used as a last resort since it can limit the movement of stems and branches which modifies wind response and may cause unexpected failures. Also, injuries caused by the installation may lead to decay.
