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The planting of degraded land with tree plantations may be effective at improving land use sustainability and profitability but it can also have significant effects on stream hydrology. In this paired catchment study, we report the stream hydrological response to partial (62%) afforestation of a steep pastoral catchment in the western Waikato Region, North Island, New Zealand. We comprehensively analyse the hydrological regime changes over a 23-year period (including eight years before pine planting) with reference to a native-forested 'control' catchment. Our results show that afforestation has markedly affected stream hydrology. Seven years after planting, the total annual runoff was 380 mm lower than predicted for the catchment in pasture. Two phases of plantation thinning resulted in the difference between measured and predicted runoff reducing to only 129 mm. Peak flows reduced by ∼50% while total stormflow reduced by ∼30% – which we attribute to canopy interception attenuating and delaying water yield. The impact of plantation establishment on low flows is not so clear, although afforestation appears to have reduced low flows by ∼25%. This study provides information on the hydrological impact of afforestation within a hitherto poorly-represented New Zealand environment (i.e. high rainfall, sedimentary lithology-based, North Island hill country). [ABSTRACT FROM AUTHOR]

The article presents a study on the effects of applying integrated catchment management (ICM) on stream flow, macroinvertebrates, and water temperature in Waikato, New Zealand. It states that ICM is deemed as the tool to improve the economic and environmental performance of the hill farm used for grazing sheep and cattle. The study found out that six years after the ICM implementation, the macroinvertebrates has demonstrated a rapid recovery towards its metric values and faunal composition.