×

Warning

JUser: :_load: Unable to load user with ID: 504

Notice

Thank you for visiting our website.

Please note that the site is not fully functional at the moment as we are in the process of re-developing. We hope that you will find the available resources helpful in the meantime.

German wasp | Vespula germanica

German wasp

Vespula germanica

Coral bush | Ardisia crenata

Coral bush

Ardisia crenata

Purple loosestrife | Lythrum salicaria

Purple loosestrife

Lythrum salicaria

Pom pom weed | Campuloclinium macrocephalum

Pom pom weed

Campuloclinium macrocephalum

Canarybird bush | Crotalaria agatiflora

Canarybird bush

Crotalaria agatiflora

Peanut butter cassia | Senna didymobotrya

Peanut butter cassia

Senna didymobotrya

Rubber vine | Cryptostegia grandiflora

Rubber vine

Cryptostegia grandiflora

1 2 3 4 5 6 7

Environmental Programmes

In order to tackle our country’s socio-economic challenges, the government adopted the Outcomes based approach to improve government performance and providing focus on service delivery. find out more

The extent of the alien Tamarix invasion in South Africa

The extent of the alien Tamarix invasion in South Africa
Solomon W. NEWETE1, Samalesu G. Mayonde1, Marcus J. Byrne1,2
1School of Animal, Plant and Environmental Sciences, University of the Witwatersrand
2Centre for Invasion Biology, School of AP&ES, University of the Witwatersrand

Tamarix L. is one of four genera from the Old world family of Tamaricaceae. In South Africa it is represented by one indigenous (Tamarix usneoides) and two exotic (T. chinesis and T. ramosissima) species. The first record of the exotic species in this country is from the early 1900s, when they were introduced for erosion control on mine dumps. These plants have however escaped their original sites and invaded several riparian zones across South Africa. This study investigates the extent and identity of the exotic Tamarix species and their hybrids in the Eastern, Western and Northern Cape provinces, where they are most prevalent. Twelve different riparian zones were surveyed by recording plant density/quadrat, stem density/plant, plant canopy area and height. Leaf specimens were randomly collected from eight different plants for molecular identification of the Tamarix in each site. Only one of the 12 sites had a pure population of the native T. usneoides (Kakamas River, Northern Cape) and the insect abundance and diversity was greater on the indigenous species. Hybrids of the two exotic Tamarix species were the most widespread taxon found, followed by hybrids of the native T. usneoides with the exotic T. chinesis, which accounted for 80% of the total sites with exotic/native hybrids. Tamarix canopy covers 15-90% of the river bank, with the highest being in the Eastern and Western Cape provinces. This study therefore, gives evidence that these two provinces require an urgent management intervention to contain the spread of the weed and its hybrids. 

Read 3201 times Last modified on Tuesday, 03 May 2016 12:25

General News Updates

2019 National Symposium on Biological Invasio…

26-02-2019

This is your invitation to South Africa's 2019 National Symposium on Biological Invasions. The convention is hosted by the Centre for Invasion Biology (CIB), University of Stellenbosch, and the Biolo... Read more

2019 Invasive Species Training

22-01-2019

During the past five years (2014-2018), ISSA invasive species trainers have trained 4 000 in the identification of invasive species and laws pertaining to invasive species across South Africa.  ... Read more

Alien Grass Working Group

04-09-2018

Who are we? The South African National Alien Grass Working Group was jointly initiated by the South African Biodiversity Institute (SANBI) and the Centre for Excellence in Invasion Biology (C·I·B) in... Read more

Permits for planting indigenous Cynodon?

01-03-2018

On 16 February, 2018, South Africa's Department of Environmental Affairs issued amendments to the regulations and lists relating to the National List of Invasive Species.  Updates to the draft&n... Read more

Invasive species training 2018 dates released

28-02-2018

Interested in invasive species?  How much do you know about NEMBA invasive species compliance for landowners and organs of state? The South African Green Industries Council (SAGIC) have released... Read more

Communications post for Africa advertised

25-01-2018

The Nature Conservancy has advertised a brand new post:  Communications Manager, Africa Region. Knowledge of invasive species and water would be an asset in this post. See details below:    Job Titl... Read more