Invasive plants have a much bigger impact than we imagine

Invasive plants have a much bigger impact than we imagine

Authors Susana Clusella-Trullas physiological ecologist at the C·I·B, Stellenbosch University Raquel A Garcia Postdoctoral fellow at the CIB, Stellnbosch University, Stellenbosch University Disclosure statement Susana Clusella-Trullas receives funding from National Research Foundation, South Africa. Raquel A Garcia receives funding from the Centre of Excellence for Invasion Biology (CIB). Stellenbosch University provides support as an endorsing partner of The Conversation AFRICA. The Conversation is funded by Barclays Africa and seven universities, including the Cape Peninsula University of Technology, Rhodes University and the Universities of Cape Town, Johannesburg, Kwa-Zulu Natal, Pretoria, and South Africa. It is hosted by the Universities of the Witwatersrand and Western Cape, the African Population and Health Research Centre and the Nigerian Academy of Science. The Bill & Melinda Gates Foundation is a Strategic Partner. more Republish this articleRepublish our articles for free, online or in print, under Creative Commons licence. Invasive pine trees in the Western Cape have affected lizards causing their numbers to drop significantly. Author supplied   This article is the fifth in a series The Conversation Africa is running on invasive species. Most people would agree that invasive plants are unwanted. Invasive plants are plants that are intentionally or accidentally introduced by humans into areas outside of their natural habitat. These species can spread rapidly with negative consequences for native species. Invasive plant species have an impact on the diversity of local species, they affect water availability and damage the quality of soil nutrients. Once an alien plant has invaded a habitat, it changes the conditions of that environment. It does so by changing the light, solar radiation and temperature levels in the invaded patches. The quality and availability of food, shelter, nest sites, basking sites and perches are changed for a number of animals. They can also inflict big changes on native vegetation, altering the frequency of fires, nutrient cycling, water availability and soil erosion. For example, pine trees in the Western Cape Province of South Africa have spread beyond forestry plantations and invaded native fynbos habitat. In these invaded landscapes, the temperatures available to lizards for functioning optimally are generally cooler and the number of lizard species greatly reduced. In a few cases, some benefits of alien plants have been reported. For example, they can provide fire wood for local communities or add resources for animal species. But these benefits typically do not surpass the negative effects. Invasive plants have an impact on native species through complex interactions and processes. Unless these factors are properly understood, it is difficult to predict what sort of impact invasive plants will have. How much is known about these processes in South African habitats, where invasive alien plants are a key concern? To find the answer, we read all the studies on the impact...

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Peanut butter cassia

Peanut butter cassia

These pests are springing up all over Paradise Ridge. It literally grows like topsy - six months ago the seed germinated, now they are mature plants, standing a meter high, in full bloom and laden with seedpods. It is a very attractive plant, water wise and pest free, but please don't be tempted to retain it in your garden. They are extremely invasive and toxic to humans and animals. Peanut butter cassia: Senna didymobotrya Common name: Peanut butter cassia Scientific name: Senna didymobotrya (Fabaceae) Alternative common names: Oatmeal cassia, popcorn senna, wild senna (English); grondboontjiebotterkassia (Afrikaans); munwahuku (Shona) An evergreen, rounded shrub or small tree reaching up to 3m high. The young shoots are softly downy and 5cm long. Bright yellow flowers form in upright racemes. Green seed pods are downy, soft and flattened and turn dark brown. This senna has poisonous leaves. Additional Info Where does this species come from? Tropical Africa What is its invasive status in South Africa? CARA 2002 – Category 1 NEMBA – a. 1b in Eastern Cape, KwaZulu-Natal, Limpop, Mpumalanga and Western Cape. b. Not listed elsewhere. Where in South Africa is it a problem? KwaZulu-Natal, Mpumalanga, Limpopo and Eastern Cape How does it spread? Seeds Why is it a problem? Environmental and other impactsSenna didymobotrya is capable of forming dense impenetrable thickets that impede the growth and regeneration of native plants and affects the movement of wildlife. It invades grasslands, woodlands, forests, riparian zones (banks of watercourses) and coastal scrub. S. didymobotria can be termed a “bush encroacher”, a African  species that has become invasive. Such plants are likely to exist in a stable balance under natural conditions. However, under human-induced changes such as overgrazing, such species can increase in density to the detriment of other vegetation. Poisonous What does it look like? General description: A wide-spreading evergreen shrub to small tree growing up to 3m in height. Leaves: Dark green leaves with 8-21 pairs of leaflets in opposite pairs 2-5cm long. Flowers: Bright yellow flowers in upright racemes prevalent throughout the year. Fruit/seeds: Green pods turning dark brown that are softly downy and flattened Share this:Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Reddit (Opens in new...

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TEAM TAUGHT TO KILL INVASIVE ALIEN PLANTS

TEAM TAUGHT TO KILL INVASIVE ALIEN PLANTS

Ecoguard’s Peter Emslie demonstrates the correct method of mixing herbicides at an alien vegetation management seminar and herbicide applicator training session held in Brenton-on-Sea recently. Photo: Martin Hatchuel KNYSNA NEWS – The Environmental Management Workstream of the Garden Route Rebuild Initiative (GRRI) has implemented a pilot project to train a team of previously unemployed people in invasive alien plant eradication. The team attended an alien vegetation management seminar and herbicide applicator training session presented by the Southern Cape Landowners Initiative (SCLI), the Southern Cape Fire Protection Association (SCFPA), and the herbicide research and supply company, Ecoguard, in Brenton-on-Sea last week. “We’ve established this team of 24 people to help achieve the aims of the three priority projects of the Environmental Management Workstream: post-fire soil erosion mitigation, invasive alien plant control, and the establishment of fire breaks around communities still at risk,” said the SCFPA’s Paul Buchholz, who is also the project manager of the GRRI’s Environmental Management Workstream. Buchholz said that all team members have received training as brush-cutter operators, and in the application of herbicides, and that selected members will now be trained as chainsaw operators. Partnerships The Environmental Management Workstream is looking for partners to assist with the implementation of important projects such as post-fire invasive alien plant control. The invasive alien eradication team was established “as a result of a partnership between multiple players – including the Fund for the Reconstruction of Knysna and the Garden Route, the SCFPA, the Department of Environmental Affairs, the Eden District municipality, private companies like Ecoguard, and various landowners,” said Buchholz. “Partnerships will become increasingly important as the rebuild gathers momentum, because no single organisation could achieve all that we have to do, and no single institution can have sufficient resources to tackle all the environmental, socioeconomic and other challenges facing the region at the moment,” he said. “Besides achieving the immediate aim of preparing the team so that we can start using them on the ground, this programme is important because it’s providing the individuals involved with skill sets that will assist them to find work in the open market if they choose to move on,” said Buchholz. Read more on www.gardenrouterebuild.co.za ARTICLE: MARTIN HATCHUEL Share this:Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Reddit (Opens in new...

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REMOVE ALIENS OR FACE GREEN SCORPIONS

REMOVE ALIENS OR FACE GREEN SCORPIONS

Stiaan Kotze (right), head of the DEA’s Natural Resource Management compliance unit, is in charge of work conducted by the Green Scorpions. With Kotze is fellow Green Scorpion Japie Buckle. They are sitting among the rooikrans alien growth in Brenton-on-Sea, a particularly aggressive plant along the Cape coastline that is now sprouting vigorously in Brenton and along the Western Head. Photo: Supplied GARDEN ROUTE NEWS – It is no joke that if you are a landowner and have what is a being called a prolific growth of alien plants on your property after the fires, you are liable for getting rid of them. Failing to do so could result in the visit of a Green Scorpion who is able to order you to do it and failing that you will be subject to “severe penalties”, which can be financial in nature or even result in loss of property. “The Green Scorpions will be closely monitoring landowners’ efforts to comply with the relevant legislative frameworks,” says Cobus Meiring of the Southern Cape Landowners Initiative (SCLI). “The Department of Environmental Affairs (DEA: directorate biosecurity services) will be delegating personnel to the Knysna area to ensure that landowners comply with the legislation. “The Green Scorpions (as they are officially known), are departmental (DEA) officers, mandated to visit landowners with invasive alien plant infestations, and to serve directives on noncompliant landowners,” says Meiring. “The ultimate objective is to ensure, as far as possible, that the area will not be subjected (again) to a fire as severe as the 2017 wildfire. “Invasive alien plants, especially in the Rheenendal area, contributed to creating the immense heat that propelled the flames across the Knysna Estuary and into the town of Knysna and surrounds,” explains Meiring. He also warns, “Penalties imposed on non-compliant landowners follow a rigorous legal process, and can ultimately result in a financial penalty or, in extreme circumstances, even loss of property.” He says landowners in the Knysna burn scar are “overwhelmed by invasive alien plant regrowth”. SANParks employees clear what has now become a jungle of alien growth. Photo: Supplied Invasive plants proliferating “Recent community engagement and field verification processes conducted in the Knysna, Rheenendal and Plettenberg Bay areas are early indicators that rural properties affected by the severe 2017 fires are now subject to rigorous invasive alien plant regrowth. “Although several landowners are doing what they can to save their land from becoming jungles of invasive alien plants, there are many areas where, already, the amount of work required to suppress and control regrowth will exceed available resources,” says Meiring. Several affected conservancies, private landowners, and commercial (land management) entities have already initiated efforts to suppress and control the aggressive bounce-back of...

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What does the Law Say?

What does the Law Say?

The Department of Environmental Affairs (DEA) published the amended regulations on Alien and Invasive Species (AIS) in terms of the National Environmental Management: Biodiversity Act 01 August 2014. The AIS Regulations have been through extensive public consultation, and have secured agreement from various key industries, including the nursery industry, landscape industry, plantation industry, game ranchers industry, agricultural industry, pet-traders industry, bass and carp angling representatives and other key groups. Alien and Invasive Species (AIS) in terms of the National Environmental Management: Biodiversity Act, on Friday 1st August 2014. A total of 559 alien species are now listed as invasive, in four different categories. A further 560 species are listed as prohibited, and may not be introduced into the country. Category 1a: Invasive species which must be combatted and eradicated. Any form of trade or planting is strictly prohibited. Category 1b: lnvasive species which must be controlled, where possible removed and de-stroyed. Any form or trade or planting is strictly prohibited. Category 2: lnvasive species, or species deemed to be potentially invasive, for which a permit is required to carry out a restricted activity. Category 2 species include commercially imported species such as pine, wattle and gum trees. Category 3: lnvasive species which may remain in prescribed areas or provinces. However, conditions apply. Further planting, propagation, trade, or gifting is prohibited. WHAT IS REQUIRED OF A PROPERTY OWNER AFTER 1 OCTOBER 2014? Declaration of Invasive Species NEMBA (2004): Chapter 5, Part 2, page 60, 73 (2) A person who is the owner of land on which a listed invasive species occurs must notify any relevant competent authority in writing of the listed invasive species occurring on that land. NEMBA Alien and Invasive Species Regulations (2014): Chapter 7, Section 29, (1), (2), (3): The seller of any immovable property must, prior to the conclusion of the relevant sale agreement, notify the purchaser of that property in writing of the presence of listed invasive species on that property. PENALTIES Failing to comply with the law by ignoring directives or denying access to property can incur imprisonment of up to ten years, or a fine not exceeding R10,000,000! Share this:Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Reddit (Opens in new...

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Alien Invasive Species Introduction.

Alien Invasive Species Introduction.

“If we give our very best to all the children of today, and if we pass on our planet in the fullness of her beauty and natural richness, we will be serving the children of the future” ~Nelson R Mandela Alien Invasive Species (A.I.S) Species that grow and reproduce quickly, and spread aggressively with potential to cause harm, are given the label of “invasive”.  An invasive species can be any kind of living organism – an amphibian, plant, insect, fish, fungus, bacteria or even an organism’s seeds or eggs that is not native to an ecosystem and which causes harm. They are the biggest threat to plant and animal biodiversity: they have become established in over 10million hectares of land in South Africa, and the cost of controlling them is estimated at R600 million a year over 10 years. WHY ARE A.I.S. SUCH A THREAT TO THE ENVIRONMENT? The impacts of alien invasive species are immense, insidious and usually irreversible.  They may be as damaging to native species and ecosystems on a global scale as the loss and degradation of habitats. WHERE DO INVASIVE SPECIES SOME FROM? Thousands of alien species have been introduced into the country over the past 350 years, and hundreds of them have become invasive. WHAT ARE THE CONSEQUENCES OF INVASIVE SPECIES? They reduce water supplies, increase erosion, exacerbate wildfires, degrade valuable range lands, threaten the health of people and livestock, reduce productivity in agriculture, and impact negatively on our remarkable biodiversity.  The economic damage caused by these invasions has been estimated at billions of Rands per year, and is set to grow as invasive species spread, and as more species are introduced and become invasive.  The heavy use of chemical pesticides, insecticides and herbicides to control invasive pests has in itself had detrimental consequences to ecosystems across the world, leading to pollution of soil and water, as well as causing harm to plants, animals and people working in the fields. WHAT CAN BE DONE TO DETER THE SPREAD OF A.I.S.? Promote the planting of indigenous species, or safe exotic species that have stood the test of time. Eradicate and control invasive introduced species and possible replace with in suitable indigenous plants Reduce the rate of spread of invasives and reduce the impacts of existing invasions Gain support of individuals, organizations and businesses in the private and public sectors. Create awareness of the problem of A.I.: the risks associated with any activity involving biological invasions, the legal requirements that regulate the ownership, cultivation, trade and transport of alien species.     Share this:Click to email this to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in...

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