Sediment sources and delivery following plantation harvesting in a weathered volcanic terrain, Coromandel Peninsula, North Island, New Zealand
Michael Marden A C , Donna Rowan A and Chris Phillips BA Landcare Research New Zealand Ltd, PO Box 445, Gisborne, New Zealand.
B Landcare Research New Zealand Ltd, PO Box 69, Lincoln, New Zealand.
C Corresponding author. Email: mardenm@landcareresearch.co.nz
Australian Journal of Soil Research 44(3) 219-232 https://doi.org/10.1071/SR05092
Submitted: 8 July 2005 Accepted: 6 February 2006 Published: 5 May 2006
Abstract
Sediment generation and vegetation recovery was measured over a 2-year post-harvest period in a 36-ha catchment of exotic forest located in andesitic terrain, Whangapoua Forest (36.46°S, 175.36°E), Coromandel, New Zealand. Slopewash, soil scraping (on-slope removal of the regolith by the repeated dragging of logs), and storm-initiated landsliding were identified as the principal sediment-generating processes. Slopewash and vegetation recovery rates were measured using field-based plots located on sites of shallow- and deep-disturbance and a regression relationship was established between sedimentation rate (accumulation (g)/day.mm rain.m2) and per cent vegetation cover for both plot types. At the basin scale, slopewash was calculated using the plot-based rates times the total area of deep- and shallow-disturbance sites as identified from a ground-based, transect survey and using sequential aerial photography. Sediment production, by soil scraping and landsliding, was determined by multiplying mean scar depth by the total affected area. In the first post-harvest year deep-disturbance sites generated 92% of total slopewash produced from both disturbance classes combined, and in year 2, slopewash halved. Half of the first post-harvest year’s slopewash-derived sediment was generated within the first 7 months following the completion of harvesting and before the application of desiccant. Thereafter, on deep-disturbance sites, slopewash rates declined further as sites became hardened against the generation of new sediment (i.e. sites became sediment limited). In contrast, during both the initial post-harvest recovery period and the post-desiccation period, the decline in sediment production on shallow-disturbance sites was more a consequence of site recolonisation. Sediment generated and redistributed by scalping and by landsliding occurred at the time of the respective events and coincided with the early part of the first post-harvest year. Collectively, soil scraping, slopewash, and landslides generated 1864 t (52 t/ha) of sediment, 88% of which remained on-slope. Of the sediment delivered to streams (228 t), landslides contributed 72%, soil scraping 26%, and slopewash 2%. For this harvested basin a single, storm-initiated, landsliding event was the most important hillslope process responsible for the generation of sediment and its delivery to streams, and slopewash was the least important.
Additional keywords: slopewash, forest harvesting, sediment generation, slope-channel linkages, Coromandel Peninsula, New Zealand.
Acknowledgments
The authors would like to thank the staff of Ernslaw One Limited for granting permission to undertake this study in Whangapoua Forest, and Mr Pieter Fransen for his assistance with the construction of sediment plots. Drs Les Basher and Barry Fahey provided constructive comments on various drafts of this manuscript. Figures were draughted by Janie Jansen, Anne Austin edited the script, and Guy Forrester provided statistical support. This research was supported by the Foundation for Research, Science and Technology (Contract No. CO4X0012).
Dyrness CT
(1965) Soil surface condition following tractor and high-lead logging in the Oregon Cascades. Journal of Forestry 63, 272–275.
Fahey BD, Coker RJ
(1989) Forest road erosion in the granite terrain of southwest Nelson, New Zealand. Journal of Hydrology [NZ] 28, 123–141.
Fahey BD, Coker RJ
(1992) Sediment production from forest roads in Queen Charlotte Forest and potential impact on marine water quality, Marlborough Sounds, New Zealand. New Zealand Journal of Marine and Freshwater Research 26, 187–195.
Fahey BD, Marden M
(2000) Sediment yields from a forested and a pasture catchment, coastal Hawke’s Bay, North Island, New Zealand. Journal of Hydrology [NZ] 39, 49–63.
Fahey BD,
Marden M, Phillips CJ
(2003) Sediment yields from plantation forestry and pastoral farming, coastal Hawke’s Bay, North Island, New Zealand. Journal of Hydrology [NZ] 42, 27–38.
Fransen PJB,
Phillips CJ, Fahey BD
(2001) Forest road erosion in New Zealand: overview. Earth Surface Processes and Landforms 26, 165–174.
| Crossref | GoogleScholarGoogle Scholar |
Furbish DJ, Rice RM
(1983) Predicting landslides related to clearcut logging, North-western California, U.S.A. Mountain Research and Development 3, 253–259.
Garrison GA, Rummell RS
(1951) First-year effects of logging on ponderosa pine forest range lands of Oregon and Washington. Journal of Forestry 49, 708–713.
Larsen MC,
Torres-Sanchez AJ, Concepcion IM
(1999) Slopewash, surface runoff and fine-litter transport in forests and landslide scars in humid-tropical steeplands, Luquillo experimental forest, Puerto Rico. Earth Surface Processes and Landforms 24, 481–502.
| Crossref | GoogleScholarGoogle Scholar |
Marden M, Rowan D
(1997) Vegetation recovery and indicative sediment generation rates by slopewash erosion from hauler-logged settings at Mangatu Forest. New Zealand Forestry 42, 29–34.
Megahan WF,
Monsen SB, Wilson MD
(1991) Probability of sediment yields from surface erosion on granite road fills in Idaho. Journal of Environmental Quality 20, 53–60.
Megahan WF,
Wilson M, Monsen SB
(2001) Sediment production from granitic cutslopes on forest roads in Idaho, USA. Earth Surfaces Processes and Landforms 26, 153–163.
| Crossref | GoogleScholarGoogle Scholar |
Mosley MP
(1980) The impact of forest road erosion in the Dart Valley, Nelson, New Zealand. New Zealand Journal of Forestry 23, 184–198.
Pearce AJ, Hodgkiss PD
(1987) Erosion and sediment yield from a landing failure after a moderate rainstorm, Tairua Forest. New Zealand Journal of Forestry 32, 19–22.
Phillips C,
Marden M, Rowan D
(2005) Sediment yield following plantation forest harvesting, Coromandel Peninsula, North Island, New Zealand. Journal of Hydrology [NZ] 44, 29–44.
Reid LM,
Dunne T, Cederholm CJ
(1981) Application of sediment budget studies to the evaluation of logging road impact. Journal of Hydrology [NZ] 20, 49–62.
Wemple BC,
Swanson FJ, Jones JA
(2001) Forest roads and geomorphic process interactions, Cascade Range, Oregon. Earth Surface Processes and Landforms 26, 191–204.
| Crossref | GoogleScholarGoogle Scholar |
Wooldridge DD
(1960) Watershed disturbance from tractor and skyline crane logging. Journal of Forestry 58, 369–372.
Ziemer RR
(1981c) Management of steepland erosion: An overview. Keynote address, Theme 4 Journal of Hydrology [NZ] 20, 8–16.