QCD studies with $e^+ e^-$ annihilation data from 130 to 172 GeV

Hadronic events produced at LEP at centre-of-mass energies of 130, 136, 161 and 172 GeV have been studied and compared with QCD predictions. Distributions of event-shape observables, jet rates, momentum spectra and multiplicities are presented and compared to the predictions of several Monte Carlo models and analytic QCD calculations. From a fit of O(alpha_s^2)+NLLA QCD calculations to the differential two-jet rate, alpha_s has been determined at various energies. The mean charged particle multiplicities and the peak positions xi_star in the xi = ln(1/x_p) distribution have also been determined. These results have been compared to lower energy data and to analytic QCD or Monte Carlo predictions for their energy evolution.