 | Deriving conservation targets for rivers |
| Expanded Title: | Freshwater ecosystems are the most threatened ecosystems globally, experiencing the fastest loss of biodiversity and the greatest number of species extinctions. The last national report of South African freshwater ecosystems estimates that over 80% of South African river ecosystems are threatened. The intimacy between catchment condition and river health is one reason why freshwater systems are amongst the most threatened systems globally.
Systematic conservation planning has been applied to numerous regions in many different countries, and provides a structured approach in identifying biologically significant areas which require conservation action. Surrogates for biodiversity are typically used to predict areas of unique biodiversity. Owing to their complexity as fluid, longitudinal systems which show continuous gradients and relatively high variability, conservation planning for freshwater systems is conceptually at least a decade behind the application of this process to terrestrial systems. In this study, Alpha, beta and gamma diversities of aquatic macroinvertebrates and fish were assessed in nine rivers, though fish were later taken out of the study due to their long distribution and rendering analyses inconclusive.
The study revealed that the blanket 20% target for river types is inadequate. In recognition of the fact that, the upper river zones are the key sections of river length driving species patterns, they therefore should be weighted more heavily in conservation planning than lowland zones. The study recommends an adjustment with at least a 20% target in lowland zones and a 40% target in the upper zones. |
| Date Published: | 01/03/2011 |
| Document Type: | Research Report |
| Document Subjects: | Ecosystem - Biodiversity protection |
| Document Format: | Report |
| Document File Type: | pdf |
| Research Report Type: | Standard |
| WRC Report No: | 1796-1-11 |
| ISBN No: | 978-1-4312-0073-3 |
| Authors: | Rivers-Moore NA |
| Project No: | K5/1796 |
| Originator: | WRC |
| Organizations: | Ground Truth |
| Document Size: | 2 331 KB |
| Attachments: | EXECUTIVE SUMMARY for KV 1796.pdf
TABLE OF CONTENTS for 1796.pdf
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