eprintid: 10181201
rev_number: 20
eprint_status: archive
userid: 699
dir: disk0/10/18/12/01
datestamp: 2024-01-25 09:39:31
lastmod: 2024-12-01 07:10:24
status_changed: 2024-01-25 09:39:31
type: thesis
metadata_visibility: show
sword_depositor: 699
creators_name: Unger, Lilian Eva
title: Using palaeolimnology to inform lake restoration in Madagascar
ispublished: unpub
divisions: UCL
divisions: B03
divisions: C03
divisions: F26
note: Copyright © The Author 2023. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request.
abstract: Madagascar is a biodiversity hotspot with many endemic species, including the Madagascar Pochard. Once present at Lake Alaotra, this species was feared extinct by the 1990s. It was rediscovered at Lake Matsaborimena in 2006, where it probably persisted due to its isolation. After a captive breeding programme, ducks were released onto Lake Sofia in 2018, chosen because of its extensive papyrus marsh, the pochard’s nesting habitat. However, the lake is somewhat degraded and levels of macroinvertebrates, the pochard’s food source, are low, so it is being restored by the Wildfowl and Wetlands Trust. It is crucial to understand the current and historical physical, chemical, and biological features of these three lakes to inform their management for the pochard. This was achieved by conducting surveys and installing sediment traps at Lakes Matsaborimena and Sofia, as well as extracting sediment cores from all three sites to be dated and analysed for multiple biological and chemical indicators. In Lake Matsaborimena a pulse of the erosional indicators ca. 1470 AD corresponds with a diatom indicated switch to a turbid state. The lake takes 400 years to recover. In Lake Sofia a similar shift occurs after increasing erosional inputs ca. 1830 AD, indicated by a loss of macrophyte, and associated macroinvertebrate remains. Here erosion remains high, and the lake does not recover. It is hypothesised that the source of erosion at these sites is increasing human activity. There are high erosional inputs to Lake Alaotra prior to human arrival, this is likely due to a corresponding period of limited papyrus marsh. The key implication for lake restoration is that erosional inputs must be reduced, either through land use management or papyrus marsh restoration, for ecological recovery. This will boost the pochard’s food source at Lake Sofia to ensure the population’s long-term survival.
date: 2023-11-28
date_type: published
oa_status: green
full_text_type: other
thesis_class: doctoral_embargoed
thesis_award: Ph.D
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2107986
lyricists_name: Unger, Lilian
lyricists_id: LEUNG15
actors_name: Unger, Lilian
actors_id: LEUNG15
actors_role: owner
full_text_status: public
pagerange: 1-208
pages: 208
institution: UCL (University College London)
department: Geography
thesis_type: Doctoral
citation:        Unger, Lilian Eva;      (2023)    Using palaeolimnology to inform lake restoration in Madagascar.                   Doctoral thesis  (Ph.D), UCL (University College London).     Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10181201/10/Unger_10181201_thesis.pdf
document_url: https://discovery.ucl.ac.uk/id/eprint/10181201/11/Unger_10181201_thesis%20data%20appendix.xlsx