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 postclearcutting
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, the Southern Intermediate zone of Sri
Lanka. After the clear-cutting, the Forest Department has planted native plant species
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 the
natural regeneration of the exotic Pinus caribaea (as the original stand) outperformed
the supported attempt at restoring native broadleaf species, resulting in P. caribaea
dominating the area (90% 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 15 plant species regenerating in the area after
the clear-cut belonging to 10 plant families, representing eight introduced species
(incl. Eucalyptus sp.) and seven 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, between the years 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 forest plantation
management.
