Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah

This research focuses on terrain of contrasting land-use in Eastern Sabah, Malaysian Borneo. Differences in soil erosion rate were assessed between primary forest (Danum Valley),naturally regenerating selectively logged forest and rehabilitated logged forest (Malua), and oil palm plantation land and...

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Main Author:	Kogila Vani Annammala
Format:	Thesis
Language:	English English
Published:	2015
Subjects:	SD390.5-390.7 Forest meteorology Forest microclimatology
Online Access:	https://eprints.ums.edu.my/id/eprint/39470/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/39470/2/FULLTEXT.pdf
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spelling	my-ums-ep.394702024-08-09T00:17:22Z Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah 2015 Kogila Vani Annammala SD390.5-390.7 Forest meteorology. Forest microclimatology This research focuses on terrain of contrasting land-use in Eastern Sabah, Malaysian Borneo. Differences in soil erosion rate were assessed between primary forest (Danum Valley),naturally regenerating selectively logged forest and rehabilitated logged forest (Malua), and oil palm plantation land and adjacent forest fragments at the Sabahmas Plantation of Wilmar International. Second part of this research uses multi-proxy sediment fingerprinting approach to reconstruct changes in sedimentation rate and the relative contributions of different sub-catchments to the downstream sediment budget of the large Segama catchment over the past 150 years. Networks of 50-70 erosion bridge transect sites were established in the various land-use types on slopes of 0-50o to study on erosion pattern. Downstream evidence was derived from a sediment core on high lateral bench on the Lower Segama below the confluence of the Urik tributary. Bed-sediment samples were taken from channel-margin sites at low flow for the major upstream tributary catchments (the hypothesized sediment sources) of the Segama River. The core sectioned materials were analysed for (i) fallout radionucides 137Cs and 210Pb (ii) particle size distributions and (iii) major and minor elemental composition (by X-Ray Fluorescence). Results indicated that logged forest rehabilitated by enrichment planting experienced much reduced erosion (1.22 mm yr-1 and less) compared with un-rehabilitated logged forest (1.48-8.55 mm yr-1) and primary forest 0.18 mm yr-1. Within the oil palm areas, erosion rates at sites without conservational measures were high (6.38-43.72 mm yr-1), whereas sites with soil conservation practices, erosion rates were 0.31-5.31 mm yr-1. Recent enrichment of the downstream sediment with alkali and alkaline earth elements were apparent. These elements are considered as mobile elements during weathering and are more susceptible to retention, sorption at top of the core may be linked to increased inputs from sections of the catchment that have been recently disturbed (e.g. converted to oil palm). Input of fallout 210Pb in the middle and upper sections of the core profile marked dilution of activity concentration by periods of enhanced rates of accretion. Concentrations of 137Cs were measured at mass depths of 8.86 and 58.64 kg m-2, however a third peak was not achieved thus the dating using 137Cs could not be performed. Using only results from 210Pb dating, the peaks and troughs were found to tally with the known history of logging within the Segama catchment. The use of radiochronology in combination with sediment fingerprinting capable of revealing changes in the sedimentation rate and the relative contributions from different parts of the upstream catchment with their land-uses and land management practices. 2015 Thesis https://eprints.ums.edu.my/id/eprint/39470/ https://eprints.ums.edu.my/id/eprint/39470/1/24%20PAGES.pdf text en public https://eprints.ums.edu.my/id/eprint/39470/2/FULLTEXT.pdf text en validuser dphil doctoral Universiti Malaysia Sabah Fakulti Sains dan Sumber Alam
institution	Universiti Malaysia Sabah
collection	UMS Institutional Repository
language	English English
topic	SD390.5-390.7 Forest meteorology Forest microclimatology
spellingShingle	SD390.5-390.7 Forest meteorology Forest microclimatology Kogila Vani Annammala Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
description	This research focuses on terrain of contrasting land-use in Eastern Sabah, Malaysian Borneo. Differences in soil erosion rate were assessed between primary forest (Danum Valley),naturally regenerating selectively logged forest and rehabilitated logged forest (Malua), and oil palm plantation land and adjacent forest fragments at the Sabahmas Plantation of Wilmar International. Second part of this research uses multi-proxy sediment fingerprinting approach to reconstruct changes in sedimentation rate and the relative contributions of different sub-catchments to the downstream sediment budget of the large Segama catchment over the past 150 years. Networks of 50-70 erosion bridge transect sites were established in the various land-use types on slopes of 0-50o to study on erosion pattern. Downstream evidence was derived from a sediment core on high lateral bench on the Lower Segama below the confluence of the Urik tributary. Bed-sediment samples were taken from channel-margin sites at low flow for the major upstream tributary catchments (the hypothesized sediment sources) of the Segama River. The core sectioned materials were analysed for (i) fallout radionucides 137Cs and 210Pb (ii) particle size distributions and (iii) major and minor elemental composition (by X-Ray Fluorescence). Results indicated that logged forest rehabilitated by enrichment planting experienced much reduced erosion (1.22 mm yr-1 and less) compared with un-rehabilitated logged forest (1.48-8.55 mm yr-1) and primary forest 0.18 mm yr-1. Within the oil palm areas, erosion rates at sites without conservational measures were high (6.38-43.72 mm yr-1), whereas sites with soil conservation practices, erosion rates were 0.31-5.31 mm yr-1. Recent enrichment of the downstream sediment with alkali and alkaline earth elements were apparent. These elements are considered as mobile elements during weathering and are more susceptible to retention, sorption at top of the core may be linked to increased inputs from sections of the catchment that have been recently disturbed (e.g. converted to oil palm). Input of fallout 210Pb in the middle and upper sections of the core profile marked dilution of activity concentration by periods of enhanced rates of accretion. Concentrations of 137Cs were measured at mass depths of 8.86 and 58.64 kg m-2, however a third peak was not achieved thus the dating using 137Cs could not be performed. Using only results from 210Pb dating, the peaks and troughs were found to tally with the known history of logging within the Segama catchment. The use of radiochronology in combination with sediment fingerprinting capable of revealing changes in the sedimentation rate and the relative contributions from different parts of the upstream catchment with their land-uses and land management practices.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Kogila Vani Annammala
author_facet	Kogila Vani Annammala
author_sort	Kogila Vani Annammala
title	Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
title_short	Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
title_full	Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
title_fullStr	Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
title_full_unstemmed	Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah
title_sort	impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the segama river catchment, eastern sabah
granting_institution	Universiti Malaysia Sabah
granting_department	Fakulti Sains dan Sumber Alam
publishDate	2015
url	https://eprints.ums.edu.my/id/eprint/39470/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/39470/2/FULLTEXT.pdf
_version_	1811770515533070336

Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah

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