Abstract:
Clear-cutting can be recognized as an economical way of timber harvesting in terms of
profit and time-saving. Simultaneously, the rapid change within any ecosystem caused
by the removal of entire vegetation causes serious environmental problems. Thus, the
study was carried out to determine the key consequences of a post-clearcutting scenario
(on aspects such as regeneration, soil erosion, and carbon storage). The study area,
“Perawaththa Pinus Plantation” underwent a clear-cut during the period from 2014
to 2016. The study area is a sloppy land in the Nonpareil area in Belihuloya within
the Mid country Southern Intermediate zone of Sri Lanka. After the clear-cutting,
the Forest Department has planted native plant species and together with an exotic
Eucalyptus sp. with the intention of converting the needle-leaf Pinus plantation forest
into a broadleaf forest. However, the study found that natural regeneration of the exotic
Pinus caribaea (as original stand) outperformed the supported attempt at restoring
native broadleaf species, resulting in P. caribaea dominating the area (% of regenerating
plants) after five years of clear-cutting. The growth rate of P. caribaea was calculated
as 1.68cm in diameter per year based on the DBH increment. Plot data represents
16 plant species regenerating in the area after the clear-cut belonging to 10 plant
families, representing 9 introduced species (incl. Eucalyptus sp.) and 7 species that are
regenerating naturally (incl. P. caribaea). The mean annual soil erosion was calculated
by employing the InVEST SDR model, and it has increased from 3.1 tons·ha−1·yr−1 to
423.8 tons·ha−1·yr−1 in the post clear-cut scenario. The mean value of carbon storage
determined using the InVEST carbon model, also changed dramatically from 253.7
tons·ha−1 to 27 tons·ha−1 respectively, in between the years of 2013 and 2017. The
findings of the study provide on the ground impacts of clear-cutting, which should
be validated with multiple sampling sites and used for decision and policy-making in
plantation forest management.
