[en] The Kolmogorov spectra of low-frequency short-wave potential and magnetic fluctuations are obtained in a plasma with finite ion and electron pressures, βi ∼ βe ∼ 1. Magnetic nonlinearities are found to make the dominant contribution to the renormalized width of the convective spectrum and result in its essential broadening, that gives rise to a reduced anomalous electron heat conductivity. (orig.)