Water and nutrient dynamics of Pinus caribaea plantation forests on
former grassland soils in Southwest Viti Levu, Fiji
Researcher: M.J.
Waterloo
Current affiliation: Acacia Water, Gouda, The Netherlands
Supervisors:
Collaborators:
- T.T. Rawaqa - Fiji Pine Commission Ltd., Lautoka, Viti Levu, Fiji.
Duration: 1989-1994; periodic repeat soil sampling continued until
present
Funding: The Netherlands Foundation for the Advancement of Tropical Research
(WOTRO), grant no. W84-295); Vrije Universiteit Amsterdam
Key research questions / objectives
- To quantify the dry-season water use of (fire-climax) grassland and of a
chronosequence of Pinus caribaea plantation forests on comparable soils.
- To quantify the various components of the water and nutrient cycles throughout
the plantation rotation period (15-20 years) to evaluate plantation impacts on
streamflow and the maintenance of on-site soil fertility.
- To quantify the effects of mechanised harvesting of merchantable timber, and
burning of slash material on water yield, water quality, and soil properties.
Research methodology
Research plots were established in Pennisetum
polystachyon grassland and 5, 10 and 15-year old
Caribbean pine forest plantations plots to study the water balance
and nutrient cycle. Evaporation was measured with a meteorological
set-up and by the soil moisture depletion/zero flux plane
methods. Rainfall interception losses were measured by comarison
of throughfall and stemflow measurements with above-canopy
precipitation. Precipitation, throughfall, stemflow, litter
percolate and soil moisture were analysed to determine the
nutrient fluxes. Biomass studies were done to evaluate the
nutrient content of the standing forest.
Harvesting of Caribbean pine trees in the Oleolega catchment in
Viti Levu, Fiji (July, 1991).
A 2.5-year hydrological catchment study was carried out in the
Oleolega catchment, which remained under mature forest for the
first year of the study and then was logged and
burned. Precipitation and runoff amounts and hydrochemistry were
measured continuously throughout this period. Separate soil
physics, biomass and soil nutrient studies were carried out to
quantify changes in nutrient status during the experiment.
The results of the study were published in several papers and
in a comprehensive PhD thesis. Links to these documents are
given below.
Publications
- Waterloo, M.J., Bruijnzeel, L.A., Werlemann, F., et
al. Changes in site nutrient status over three successive
rotations of Pinus caribaea in Viti Levu,
Fiji. Forest Ecology and Management (in
preparation).
- Waterloo,
M.J., Schellekens, J., Bruijnzeel, L.A. & Rawaqa, T.T. (2007).
Changes in catchment runoff after harvesting and burning of a Pinus caribaea
plantation in Viti Levu, Fiji. Forest Ecology and Management 251,
31-44.
- Waterloo,
M.J., Bruijnzeel, L.A., Vugts, H.F. & Rawaqa,
T.T. (1999). Evaporation from Pinus caribaea
plantations on former grassland soils
under maritime tropical conditions. Water Resources Research 35,
2133-2144.
- Waterloo, M.J., Schellekens, J., Bruijnzeel, L.A., Assenberg, P.N., Vugts, H.F.
& Rawaqa, T.T. (1997). The chemical composition of bulk precipitation in
south-western Viti Levu, Fiji. Journal of Tropical Ecology 13,
427-447.
- Waterloo, M.J. (1994). Water and
nutrient dynamics of Pinus caribaea
plantation forests on former grassland soils in Southwest Viti
Levu, Fiji. Doctoral Dissertation, Vrije Universiteit
Amsterdam, 478 pp.
- M.J. Waterloo, F.J. Beekman, L.A. Bruijnzeel and
K.F.A. Frumau (1993). The
impact of converting grassland to pine forest on water yield in
Viti Levu, Fiji In J. S. Gladwell, editor, Hydrology of Warm
Humid Regions. International Association of Hydrological
Sciences Publication 216: 149-156.
- Vugts, H.F., Waterloo, M.J., Beekman, F.J., Frumau,
K.F. & Bruijnzeel, L.A. (1993). The
temperature variance method, a powerful tool in the estimation
of actual evapotranspiration rates. In J. S. Gladwell,
editor, Hydrology of Warm Humid Regions, International
Association of Hydrological Sciences Publication 216:
251-260.
Dr. Maarten J. Waterloo
Last modified: Wed Dec 30 12:57:06 CET 2015
