Man and nature can live in harmony around wetlands. Wetlands are vitally important to conserve as they are the fastest disappearing ecosystem globally. Wetlands provide a habitat for both aquatic and terrestrial vegetation and diverse animal species, offering natural services to people such as filtering water, a grazing area for livestock, and recreational activities such as bird watching. Papenkuils Wetland is such a place.

In October 2020, the Cape Winelands Biosphere Reserve (CWBR) team joined representatives of the Western Cape Government’s Department of Environmental Affairs and Development Planning (DEA&DP) who set out to explore what value Papenkuils Wetland provides to the Breede Valley Catchment. DEA&DP undertook a case study of the Papenkuils Wetland to assure support for its future conservation. The findings are now available to delve into and learn from online (link below).  

Contributing to the evaluation of the area, the CWBR droned portions of the wetlands, that assisted in defining wetland zones, as well as provided high resolution footage in hard-to-reach areas.

A scientific study of the Wetland was undertaken by DEA&DP, in collaboration with partners, where water quality was sampled, soil monitored, and the flora viewed. 

The Papenkuils Wetlands is the home for plants that are believed to have once covered extensive areas of the Breede River Catchment including at least seven International Union for Conservation of Nature (IUCN) red-listed plant species, and the under-conserved and endangered Breede Alluvium Fynbos vegetation type. (Extract from Papenkuils Wetland Story Map)

Go on a virtual exploration!

Check out the Papenkuils Wetland Story Map for interactive videos, maps, beautiful photographs of the fauna and flora discovered, and the CWBR drone footage that contributed to the research.

The website includes an introduction to the project and area, examples of the flora and fauna documented, history of the area, the research done thus far, and recommendations going forward.

4 reasons to protect wetlands

1. Wetlands are considered one of the most threatened ecosystems both globally and in South Africa.

2. The vegetation and soil structure of wetlands allows water to circulate through them. This provides ecosystem services because the water quality is enhanced as it passes through the system, which also stores and slowly releases water.

3. Wetlands are resilient in many ways but vulnerable to developments that divert water away from them, such as urbanization and agriculture.

4. Wetlands are vital biodiversity assets, sustaining a variety of animals and plants specific to the wetland community.

Extract from Green Grow the Rushes, Veld and Flora, September 2021

Situated across the border of Cape Winelands Biosphere Reserve, Papenkuils Wetland (in Breede Valley), lies South of Worcester and North of the Brand Vlei Dam.

Links of Interest:

Papenkuils Wetland Story Map

Green Grow the Rushes (PDF file) Go on a walk with the research team as they discover the biodiversity of the wetland.

Authors: Annabel Marian Horn, Nick Helme, Liz Day, Phil Mclean and Wilna Kloppers.

Photo credit: Nicholas Helme

Photo credit: Nick Helme

The sedge is recognised by its three sided stem and is a characteristic plant  showing us that this is a wetland area. (Image: Sedge - Family Cyperaceae by Nick Helme, inaturalist, Oct 27 2020 copyright)

Papenkuils Wetland. Photo credit: Annabel Marian Horn

The Socio-Economic Benefits of investing in Ecological Infrastructure (SEBEI) project teamed up with the Cape Winelands Biosphere Reserve (CWBR) to map invasive alien trees in the upper Berg-Breede catchments in 2019. The CWBR provided the drone footage which was instrumental in the ground-truthing of the classification results. A map of invasive alien trees in this region is a critical need, to understand where these alien trees are and to estimate the costs of clearing, to assist in management and ultimately the control of these problematic species.

Various approaches have been applied to map alien invasive trees in the Cape Floristic Region, with most being informed by expert estimates or based on in-field experience. The accuracy of these datasets is difficult to assess, but have, in general, been shown to overestimate density estimates. In this research, Dr’s Holden and Rebelo combined Google Earth Engine’s processing power, expert knowledge and drone technology to classify Sentinel 2a imagery to provide an accurate and up-to-date understanding of the occurrence and density of alien invasive trees in the upper regions of the Berg and Breede catchments at a 10m spatial resolution.

They combined bands with the highest discriminatory power from the available 13 spectral bands along with a number of spectral indices for the classification, which resulted in a 93% accuracy with both the training and validation datasets. Although the resulting maps reflect early 2019 invasions for the study area, the methodology and data captured can be used to rerun the routines to continuously update our understanding of alien invasive tree coverages in the catchments.

The importance of using expert knowledge combined with drone technology is highlighted for training classifiers to distinguish effectively between alien invasive trees and indigenous vegetation. This work forms part of the larger SEBEI project which aims to encourage investment into ecological infrastructure by developing an evidence-base of the impacts of ecological infrastructure interventions.

An up-to-date layer of invasive alien trees is a critical step towards modelling the hydrological benefits of investing in the clearing of alien invasive trees in strategic water source areas, an additional focus of the SEBEI project. Dr’s Rebelo and Holden launched a first draft of this alien tree map in September 2019. If you would like to request a copy, you can e-mail them on petra.holden@uct.ac.za or arebelo@sun.ac.za.

Acknowledgements: This project is fully funded by the Danish International Development Agency.

Dr Petra Holden; Dr Alanna Rebelo

African Climate and Development Initiative, University of Cape Town

Conservation Ecology & Entomology, Stellenbosch University

PHOTO: The Mapping Workshop held in the Berg-Breede catchment to get stakeholder input into the alien tree maps produced. (PHOTO credit: SEBEI)

PHOTO: Ecological Infrastructure (the Riviersonderend palmiet wetland) invaded by alien vegetation (Black Wattle) (PHOTO credit: Alanna Rebelo)

PHOTO: Ecological Infrastructure (the Holsloot River) invaded by alien vegetation (here Black Wattle trees) (PHOTO credit: Alanna Rebelo)

Introduction by Guy Palmer

This article sets out very clearly the situation with regard to water supply and the management of the upper catchments and the problems related there to.

The principle management authority for the upper catchments, CapeNature, has the data to plan and execute this exercise properly given the correct financial and physical support. The top down approach to catchment management has been advocated for years but, as explained in the article, logic and finances do not always talk the same language. The core of the Cape Winelands Biosphere Reserve forms part of the extensive upper mountain catchment of the Western Cape and is strategically placed to above some of the major dams supplying water to the Cape metropole and further.

These catchments are also part of the Cape Floral Region Protected Areas World Heritage Site.

Follow this link to read the article: 'Aliens are greatest threat to Cape Town’s water security'

Written by jasper Singsby and Mark Botha

https://www.groundup.org.za/article/aliens-are-greatest-threat-cape-towns-water-security/