Studies of hadronic event structure in e+e- annihilation from 30 to 209GeV with the L3 detector

In this Report, QCD results obtained from a study of hadronic event structure in high energy e+e− interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, alpha_s, from hadronic event shapes and the study of effects of soft gluon coherence in charged particle multiplicity and momentum distributions.