The observed total suspended solids (TSS) yield a year after forest harvesting in hill dipterocarp forest of Peninsular Malaysia

Abstract

The management of forested catchment areas has become important as water originates from upper catchment is the main source of raw water supply for the downstream users. The purpose of this study is to determine the total suspended solids (TSS) in the river system that are affected by conventional forest harvesting practices in Peninsular Malaysia. The study sites were located at Jengai Forest Reserve in Dungun, Terengganu. The commercial forest logging was implemented in the Compartment 44 and compartment 60 as control catchment. Kerak and Angka River catchments are in compartment 44 while, Jera River catchment is in compartment 60. Forest harvesting operation started in November 2016 and ended in October 2017 with tree cutting activities from May 2017 to September 2017. Observation of rainfall from June 2017 to December 2018 and observation of TSS for a one-year period after logging completed from November 2017 to October 2018. As shown by the Kerak River catchment, the TSS started to increase from November 2017 to January 2018 with TSS 5.8 times higher, followed by 15.4 times higher from February to April 2018 and 10 times higher from May to October 2018 compared to undisturbed catchment. These findings are important for forest managers to understand the effects of forest canopy opening to river water quality and as a guideline in the management of forest production for timbers in this country.