Transition from pasture to native forest land-use along stream continua: effects on stream ecosystems and implications for restoration

Three first-order, hill country, pasture streams in Waikato, New Zealand, w ere chosen to investigate the effects of patches of late-succession indigen ous riparian forest on water quality, epilithon, stream morphology, and aqu atic macro-invertebrates. Sites were situated in open pasture and at two di stances (c. 50 and 300 m) into a forest remnant on each stream. Shade, chan nel width, and epilithon biomass were restored to conditions similar to a n ative forest control site within 300 m of the streams entering the native f orest remnants, whereas water chemistry and levels of surficial fine sedime nt changed more slowly. Invertebrate community composition showed shifts to wards the native forest condition just 50 m into the forest remnants, and f ull recovery had occurred within 300 m. Results from this study suggest tha t discontinuous restoration of riparian margins could mitigate some changes associated with pastoral land use, but sediment and water quality problems may not be solved.