Harvesting strategies to reduce suspended sediments in streams in fast-growing forest plantations

摘要

Intensive plantation management can affect catchment conditions, especially in large clear-cut areas that expose soil thereby encouraging sediment transport to streams. Harvesting strategies are needed to reduce these effects while enabling commercial logging. In this study, we examined the effects of harvested areas in suspended sediment production by selecting three catchments covered by Eucalyptus spp. forests with 15%, 60% and 88% harvested areas (hereafter H-15, H-60 and H-88, respectively) and monitoring suspended sediment during two years. We compared two approaches of estimating annual suspended sediment: weekly grab samples vs. weekly grab samples + bottle traps. Proportion harvest and suspended sediment yields were directly related on an annual basis. Such differences were more notable for H-15 and H-88; H-60 had intermediate values. Annual suspended sediment yields ranged from 3.0 to 208.2 kg ha(-1) year(-1), and in addition to harvest proportion, presence of buffer riparian forest possibly reduced concentrations of suspended sediments in streams. The use of weekly grab samples underestimated TSS yields. (C) 2021 European Regional Centre for Ecohydrology of the Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.