Abstract(1) Net assimilation and respiration rates were measured at intervals after re-moistening, following various periods of desiccation, inHookeria lucens, Hylocomium splendens, Neckera crispa, Plagiochila spinulosa, Plagiothecium undulatum, Rhacomitrium lanuginosum, Rhytidiadelphus loreus, Saccogyna viticulosa, Scorpiurium circinatum and Tortula ruraliformis.(2)Rhacomitrium lanuginosumwas extremely resistant, recovering apparently normally after 239 days' desiccation at 32% R.H.;Plagiochila spinulosaandHookeria lucenswere the most sensitive.(3)Rhacomitrium lanuginosumandTortula ruraliformiswere most quickly damaged at the highest humidity (76%) andPlagiothecium undulatumat the lowest humidity tested (32%).(4)Saccogyna viticulosaandScorpiurium circinatumcombined relatively rapid impairment and slow recovery of assimilation with the capacity to survive long dry periods.(5) Dark respiration was relatively slow (commonlyc. 5–20% of net assimilation). It usually showed a slight initial stimulation and a longer-term build-up following moderate or prolonged desiccation.(6) Desiccation responses of bryophytes can be characterized in terms of parameters defining rate of loss of photosynthetic capacity with desiccationtime, rate of recovery after short periods of desiccation, and survival.