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Contextualizing waterscape health in a subtropical rangeland
Thesis (MScConsEcol)--Stellenbosch University, 2021.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2021
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| _version_ | 1867613946524991488 |
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| access_status_str | Open Access |
| author | Avidon, Stephen Noble |
| author2 | Esler, Karen J. |
| author_browse | Avidon, Stephen Noble Esler, Karen J. |
| author_facet | Esler, Karen J. Avidon, Stephen Noble |
| author_sort | Avidon, Stephen Noble |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScConsEcol)--Stellenbosch University, 2021. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/123784 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:44:13.588Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/123784 Contextualizing waterscape health in a subtropical rangeland Avidon, Stephen Noble Esler, Karen J. Malgas, Rhoda R. Samways, Michael J. Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. Agroecology -- South Africa-- Eastern Coastal Belt Ecoregion Ecosystem management Freshwater Rangelands -- Water-supply -- South Africa -- Eastern Coastal Belt Ecoregion Agriculture -- Environmental aspects Water quality management UCTD Thesis (MScConsEcol)--Stellenbosch University, 2021. ENGLISH ABSTRACT: Freshwater ecosystems are threatened globally by environmentally impactful agriculture. An ever- increasing population drives intensive agricultural production, putting immense pressure on freshwater ecosystem integrity. It is recognized that agriculture needs to be more environmentally sustainable. One way to achieve this is for agricultural production to align with, and support, local ecosystem functions while remaining within the other conventions (economic and social) of sustainable development. Livestock grazing areas (rangelands) are a major component of the total agricultural land use surface in Southern Africa. Within these rangelands, perennially inundated waterbodies across the landscape (waterscape) occur in a variety of hydrogeomorphic formats, both natural and artificial (depressions, deposition pools, weirs and dams) and are here referred to individually as waterbodies. Thus, the broad aim of this study is to gain some insight into the biotic and abiotic characteristics of waterscape health in rangelands of the Eastern Coastal Belt Ecoregion (ECBE). Artificial waterbodies, like excavated depressions, constructed dams and weirs are common features in rural South African rangelands. Often, these excavated or constructed waterbodies completely modify characteristics of those that occur naturally, impacting waterscape ecosystem functions. However, artificial waterbodies can also be complementary to naturally occurring waterbodies in degraded waterscapes, improving overall waterscape biodiversity and resilience. In chapter 2, I compare environmental variables and dragonfly assemblage composition of natural and artificial waterbodies to demonstrate that intact, high order, naturally occurring forested stream deposition pools are an irreplaceable habitat for threatened aquatic biodiversity in the ECBE, vulnerable to impoundment and channel modification. I also show that well-managed excavated depressions provide valuable habitats for lentic biota in the region. I suggest agro-conservation strategies that aim to reduce disturbance frequency and channel modification in and around high order stream channels. Farm managers should promote artificial depressions outside of stream channels as a primary source of livestock drinking water. Determining significant environmental and biological characteristics of healthy and compromised agro-ecological systems is vital to regional conservation planning and restoration. In chapter 3, I use the Dragonfly Biotic Index (DBI) to determine which biotic and abiotic variables drive waterbody health in the ECBE. I also illustrate the composition assemblage of dragonflies responsible for high and low DBI/ site scores. Again, I highlight the importance of reducing intensity and frequency of livestock disturbance in stream deposition pools. I recommend considering individual waterbody habitat heterogeneity as a key feature in maintaining waterbody integrity. Invasive tree clearing and facilitating a compositionally and structurally diverse woody riparian component, appropriate for its hydrogeomorphic type is fundamental to regenerating ecosystem functions. A transition towards sustainable livestock production means departing from resource intensive livestock systems. To achieve this, we need to identify appropriate scenarios for agroecology and contextualize agro-ecosystem. In the coastal plains of the ECBE, large savanna and azonal grasslands are suitable for well-managed ruminant livestock grazing, where ruminants play a vital role in maintaining ecosystem services. Here, analyzing local hydrogeomorphic features and biological attractors provides tangible methods to improve biodiversity conservation and perennial surface water resilience within a waterscape. This study also highlights that individual waterbody habitat heterogeneity is inimitable for biodiversity conservation at a global scale. I urge rangeland managers to consider and mimic all features of naturally occurring individual waterbodies within a waterscape for successful integration of rangelands and freshwater conservation. In the ECBE, extensive ruminant livestock keepers should increase frequency of depressions as a primary source of drinking water to reduce disturbance at streams. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2021-11-18T07:38:40Z 2021-12-22T14:21:14Z 2021-11-18T07:38:40Z 2021-12-22T14:21:14Z 2021-12 Thesis http://hdl.handle.net/10019.1/123784 en_ZA Stellenbosch University xii, 80 pages : illustrations (some color) application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Agroecology -- South Africa-- Eastern Coastal Belt Ecoregion Ecosystem management Freshwater Rangelands -- Water-supply -- South Africa -- Eastern Coastal Belt Ecoregion Agriculture -- Environmental aspects Water quality management UCTD Avidon, Stephen Noble Contextualizing waterscape health in a subtropical rangeland |
| title | Contextualizing waterscape health in a subtropical rangeland |
| title_full | Contextualizing waterscape health in a subtropical rangeland |
| title_fullStr | Contextualizing waterscape health in a subtropical rangeland |
| title_full_unstemmed | Contextualizing waterscape health in a subtropical rangeland |
| title_short | Contextualizing waterscape health in a subtropical rangeland |
| title_sort | contextualizing waterscape health in a subtropical rangeland |
| topic | Agroecology -- South Africa-- Eastern Coastal Belt Ecoregion Ecosystem management Freshwater Rangelands -- Water-supply -- South Africa -- Eastern Coastal Belt Ecoregion Agriculture -- Environmental aspects Water quality management UCTD |
| url | http://hdl.handle.net/10019.1/123784 |
| work_keys_str_mv | AT avidonstephennoble contextualizingwaterscapehealthinasubtropicalrangeland |