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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
https://eprints.ums.edu.my/id/eprint/39470/
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spelling my.ums.eprints.394702024-08-09T00:17:22Z https://eprints.ums.edu.my/id/eprint/39470/ Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah 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 NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/39470/1/24%20PAGES.pdf text en https://eprints.ums.edu.my/id/eprint/39470/2/FULLTEXT.pdf Kogila Vani Annammala (2015) Impact of forest disturbance, fragmentation and restoration on erosion and sediment sources and transport within the Segama river catchment, Eastern Sabah. Doctoral thesis, Universiti Malaysia Sabah.
institution Universiti Malaysia Sabah
building UMS Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Sabah
content_source UMS Institutional Repository
url_provider http://eprints.ums.edu.my/
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
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
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
https://eprints.ums.edu.my/id/eprint/39470/
_version_ 1807050425451413504
score 13.211869

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