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Conservation biogeography of South African dragonflies (Odonata)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2008
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| _version_ | 1867613781961474048 |
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| access_status_str | Open Access |
| author | Simaika, John P. |
| author2 | Samways, Michael J. |
| author_browse | Samways, Michael J. Simaika, John P. |
| author_facet | Samways, Michael J. Simaika, John P. |
| author_sort | Simaika, John P. |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/1710 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:36.774Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/1710 Conservation biogeography of South African dragonflies (Odonata) Simaika, John P. Samways, Michael J. Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. Dragonflies Freshwater management Freshwater conservation Habitat quality indicators Freshwater invertebrate distribution mapping Red Listing Biodiversity indices Theses -- Conservation ecology and entomology Dissertations -- Conservation ecology and entomology Dragonflies -- South Africa Dragonflies -- South Africa -- Geographic distribution Water quality biological assessmentn -- South Africa Habitat (Ecology) -- South Africa Indicators (Biology) -- South Africa Conservation Ecology and Entomology Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. The great pressures on freshwaters require their conservationists and managers to develop methods to rapidly and accurately assess their condition. Dragonflies are excellent indicators of habitat integrity and are effective organisms for this purpose. However, assessment must be done at the correct spatial scale. My aim here is to optimize the spatial resolution at which species are mapped, using three different concepts and methods in freshwater invertebrate distribution mapping, with special emphasis on IUCN Red Listing. The first is the extent of occurrence (EOO) concept, using the minimum convex polygon, and the second, the area of occupancy (AOO) concept, using IUCN and quaternary catchments. The third approach uses a river layer to compare the suitability of grids as opposed to catchments in mapping. In this study I found that area estimation based on minimum convex polygons should not be encouraged for aquatic organisms. This study also suggests that the IUCN concept of area of occupancy (AOO) should be redefined simply as occurrence, referring to known point-locality presences only and, if future data allow, to known absences. The IUCN extent of occurrence (EOO), for aquatic species, should be defined as ‘the sum of the smallest hydrological units identified of presently known, inferred or projected occurrences of a taxon, excluding cases of vagrancy, that are used to estimate the threat to a taxon’. A single hydrological unit is also the conservation or management unit. Currently, that unit is the quaternary catchment. Dragonflies have excellent potential as indicators of habitat integrity. For this purpose, my aim was to develop the Dragonfly Biotic Index (DBI) for South Africa and compare the DBI to another index, the Average Taxonomic Distinctness Index (AvTD), which was believed to have potential in assessments. The DBI and AvTD are correlated, which suggests that they could be used on a complementary basis to prioritize sites. The DBI is a low-cost, easy-to-use method and is already used for measuring habitat recovery. It has great potential for environmental assessment and monitoring freshwater biodiversity, especially as a complement to freshwater quality assessments that use macroinvertebrate scores. I thus recommend its integration into freshwater management and conservation schemes. Masters 2008-11-12T09:19:46Z 2010-06-01T08:31:15Z 2008-11-12T09:19:46Z 2010-06-01T08:31:15Z 2008-12 Thesis http://hdl.handle.net/10019.1/1710 en Stellenbosch University application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Dragonflies Freshwater management Freshwater conservation Habitat quality indicators Freshwater invertebrate distribution mapping Red Listing Biodiversity indices Theses -- Conservation ecology and entomology Dissertations -- Conservation ecology and entomology Dragonflies -- South Africa Dragonflies -- South Africa -- Geographic distribution Water quality biological assessmentn -- South Africa Habitat (Ecology) -- South Africa Indicators (Biology) -- South Africa Conservation Ecology and Entomology Simaika, John P. Conservation biogeography of South African dragonflies (Odonata) |
| title | Conservation biogeography of South African dragonflies (Odonata) |
| title_full | Conservation biogeography of South African dragonflies (Odonata) |
| title_fullStr | Conservation biogeography of South African dragonflies (Odonata) |
| title_full_unstemmed | Conservation biogeography of South African dragonflies (Odonata) |
| title_short | Conservation biogeography of South African dragonflies (Odonata) |
| title_sort | conservation biogeography of south african dragonflies odonata |
| topic | Dragonflies Freshwater management Freshwater conservation Habitat quality indicators Freshwater invertebrate distribution mapping Red Listing Biodiversity indices Theses -- Conservation ecology and entomology Dissertations -- Conservation ecology and entomology Dragonflies -- South Africa Dragonflies -- South Africa -- Geographic distribution Water quality biological assessmentn -- South Africa Habitat (Ecology) -- South Africa Indicators (Biology) -- South Africa Conservation Ecology and Entomology |
| url | http://hdl.handle.net/10019.1/1710 |
| work_keys_str_mv | AT simaikajohnp conservationbiogeographyofsouthafricandragonfliesodonata |