The Acacia seed weevil is a biocontrol agent that has been successfully released in South Africa to combat the massive seed production of Black Wattel trees. The small insects are seed feeders with a life cycle that coinsides with the annual seed maturation of wattels between September to November The female weevil chews a small hole into the wall of developing seed pod and lays an egg on the young seed.
The newly hatched larvae feed on the seeds by burrowing into them. This damage prevents the seed from maturing. While the weevils take some time to develop into a viable population, once achieved they are able to reach 100% seed-damage.
The Madeira vine (Anredera cordifolia) is an easily identified vine that originates from South America. Mature plants have leaves that are generally large, heart-shaped, bright green and glossy. The plant is semi-succulent and when broken has a slimy texture. The flowering parts of the plant are long dainty catkins of tiny cream white flowers, complemented by a sweetish smell during flowering season in March and April. The vine spreads by means of brittle underground tubers and aerial stem tubers that root and resprout.
Madeira vine has been declared a category 1b invader in South Africa and must be controlled and wherever possible, removed and destroyed. These plants pose a very serious threat to our indigenous forests and coastal vegetation, as it is a landscape transformer due to its prolific reproduction rate.
The herbicide “Garlon” is registered for use on this plant – the mix is .5% (5ml to 1litre of water). The method is to locate and cut all the creeper stems at their base. Resist the temptation to remove the cut climbing stalks, this will result in numerous tubers dropping to the ground, simply leave them to die off and dry out over time. These plants are extremely robust and tubers will take root and sprout wherever they fall. Weeding of the plantlets is discouraged as this accelerates germination and also creates the problem of disposal.
The next step is to apply the registered herbicide as a foliar spray only on emerging plantlets under the trees and shrubs and to continue with regular follow-up sprays of regrowth every four months. Please note that the herbicide will affect any other broadleaf (non-grassy) plants, therefore spot-spraying the target plants may be more appropriate in areas where there is a mixture of vegetation types. Painting Garlon mixed in diesel at 3% on the stems is also an effective control measure.
The following link shows a youtube clip of a herbicide application method, used in Australia to combat Madeira vine. Click here
There is also an on-going project on ispot to map the distribution of Madeira vine in the Garden Route. If you would like to contribute to this project, the next time you spot Madeira vine take note of where you saw it, the date and a picture (if possible). Then the next time you are on your computer go to http://www.ispotnature.org and log the details of your observation.
A recent article published on the Southern Cape Landowners Initiative (SCLI) web page states that July/Aug is the window to release Dasineura Rubiformis. This little midge is an agent of Black Wattle seed destruction.
“It’s a midge that prevents black wattle from setting seed. It has taken off like a rocket in release sites and is fast becoming one of the most important aspects of black wattle control.”
SCLI wishes to get the biocontrol agent established in the Southern Cape, as a means to control the large issue of Black Wattle infestation in the area.
If you wish to assist with establishing these little agents, all you need to do is pick up some galls from the Garden Route Botanical Gardens Nursery – 49 Caledon Street.
“It is easy to release and it’s FREE!”
The window of opportunity to release the biocontrol agent is however small, so the time to act is now. If you would like more information please contact Cobus Meiring from SCLI at firstname.lastname@example.org
How has your awareness, learning and collaboration around invasive
plant management changed over the past 2 years?
We would appreciate 10 minutes of your time, to help us assess how your awareness, learning and collaboration has changed over the past two years through your participation in collaborative invasive alien plant initiatives, such as SCLI and KTT.
Your participation in the survey will make a big difference to our understanding of these issues and will help us make progress with the War on Weeds in the Garden Route. This
information will be used to adapt our strategies and approaches for collaborative invasive plant management.
Invasive Species South Africa will be offering a two day training course in all provinces around the country. The training is targeted at landscapers, horticulturist, conservationists, botanist, municipal parks officials, invasive species professionals and any one with a superb interest and knowledge in faun and flora.
The two day course is designed to equip you with knowledge on invasive species legislation and on herbicide application. All participants trained in this course will be registered as invasive species consultants and will be listed on the SAGIC database (www.sagic.co.za & http://www.invasives.org.za) and will receive a certificate to indicate that they have attended the workshops.
The modules are described below:
Module 1: Train to become an invasive species consultant
• NEMBA legislation and Invasive Species Regulations
• Landowners, estate agents & lawyers ‘duty of care’
• Control plan guidelines for organs of state & protected areas
• Permitting, compliance & directives
• Invasive species
Module 2: Introduction to herbicides and control methods
• Invasive species clearing using herbicides
• Herbicides and the law
• Selecting control methods for invasive species clearing
• Professional herbicide training
These modules will be offered in George on the 21st and 22nd of September 2016. The cost per module is R800 per person. For further information on how to register for these courses please refer to http://www.invasivespecies.org or alternatively click here.
Flower Valley Conservation Trust and the South African National Biodiversity Institute (SANBI) have teamed up to tackle invasive alien plants in the Overberg. The partners are working together to develop systems to detect and identify invasive alien plants in the Agulhas Biodiversity Initiative (ABI) Alien Clearing Programme area in the Overberg. The Flower Valley Conservation Trust coordinates ABI. Through support from the Table Mountain Fund (an associated trust of WWF-SA), the partners are also finding ways to monitor invasive alien species populations, the areas in which they grow, and how the population densities change over time, while capturing invasive alien clearing data in a way that is not administratively burdensome.
A researcher is now being sought to evaluate existing monitoring and evaluation tools used by Working for Water and other organisations. From here, cost effective and scientifically robust methodologies will be developed that land owners can use. The researcher will also be in a position to provide training support on how to control invasive alien species to landowners and other stakeholders on their private land.
Working for Water programmes are known to, in some instances, include costly record-keeping tools that have heavy administrative requirements. Many of these tools cannot be optimally used by private landowners. It’s hoped that user-friendly ways to capture and record information will be developed for landowners through this project.
Over the past few years our sustainability research group has been working with urban and township residents, authorities and farmers to address a universal problem: how to manage our rivers more sustainably. Managing a river is not unlike managing any other common pool resource where there are contested rights and responsibilities, complete with heroes, villains and watch-dogs.
The River is the life-blood of our town, its agriculture and tourism. Our long term research (and that of others) convinced us that working together was the Holy Grail of sustainable river management. This is because the river is a common ‘pool’ resource – it belongs to everyone. Everyone involved has to therefore from the outset agree that change is necessary and the status quo unworkable. Stakeholders also have to agree that the problem (how to manage the river more sustainably) is a wicked one with no clear-cut, final solution. The crocodile in the water is power relations. There are villains and victims: upstream users and those with large land and resource allocations are getting an unfair share of the water and they know this very well. Some are even polluting The River, thereby harming downstream users.
We soon understood that our academic skills, while useful to analyse and describe the consequences, were not good enough to understand the root causes of the threats to The River. These causes were rooted in human behaviour, something we knew little about. We had to draw on new theories such as those about institutions for common property management. We had to dabble in techniques of integrated coaching and started consulting with environmental psychologists. We made friends with weird authors such as Habermas, Oström, Dietz, Folke and Gibson. We re-trained ourselves, taking courses in Time to Think, integrated coaching, place attachment, Theories of Change and environmental education, skills no self-respecting scientist would seriously consider. We even formed a Social Learning study group. But we had a trump card: our neutral position as non-aligned academics, something we had to cherish and protect at all cost. We were the bridging organization that this complex, fragile system (The River and its people) needed, to transform itself.
Our first quest, after understanding who the players were and how history shaped their current realities, was to get to know them better. We learnt that there were no angels – everyone had a skeleton or two in the cupboard. We also learnt that there were amazing success stories everywhere – individuals and groups who were leading the way in doing transformative things. We went out of our way to make friends with progressive farmers, fishing groups, community-based organizations and ratepayers who were doing things differently and whose initiatives promised transformation.
With this information in hand we started a series of dialogues, founded in Time to Think and Crucial Conversation principles. The way we structured and facilitated these dialogues was crucial, and so we developed five principles. The first principle we developed was to ‘make it safe’ for everyone participating in the dialogue – we did not want any individual or group to approach this big challenge defensively, because those who felt threatened would almost certainly disengage from the process. To add to this, the psychologists told us that defensiveness was the enemy of creativity (one only needs to look at sports teams on a losing streak to understand this rule of thumb). The second principle was to convince everyone to put their information and assumptions on the table, to create some shared awareness. The third principle was to identify an issue or issues affecting everyone – a common cause which all users of the river understood; something that they simply had to address collectively in order to survive. The fourth principle was for everyone to realize that they had the capacity to take action and to do something. The final principle was to agree on a way forward – a co-created action plan.
Since then we have facilitated many dialogues about rivers. We always start these dialogues with a brief presentation to get everyone on the same page, using neutral language to sketch the status quo. We make sure everyone gets credit for the progressive things they are doing. Then we move to small group discussions, in the form of a Knowledge Café of some kind (complete with good quality coffee and nice music) to make sure everyone gets a word in. We agree on rules of the dialogue: mutual respect, being clear about assumptions, listening with fascination, and not dominating the conversation. We make the purpose of the conversation clear right from the start so everybody knows why they are there and what they wish to achieve. We even use props such as a talking jar and timer to make sure nobody speaks for more than a minute at a time. And we always reflect and agree on a way forward by the end of the conversation. We have, through trial and error, learnt what to do and what to avoid and are still learning as we muddle along.
Using these principles and methods, coupled with constant reflection and learning, we managed to (by hook or by crook) start a new journey with a core group of water users. People living with The River have agreed on roles such as a monthly item in the ratepayers association newsletter; regular newspaper articles; collective action such as community ‘hacking days’; a community blog where information could be shared; and, crucially, a Forum for a joint management plan for the river, with a focus on the entire catchment from top to bottom. The stakeholders even agreed on a common slogan: “Our rivers are our future – beyond our back yards”.
This process is far from perfect and the new journey only just began. Many land owners have told us about changes, sometimes subtle, in their management practices. It seems people are thinking about the consequences of their actions before doing something. There are still many problems, but at least people are engaging with each other and learning about ways to address these, without anyone feeling threatened and getting defensive. We are working closely with the newly formed Catchment Management Agency at a regional level to test this approach in other river systems.
What we have learnt about collaborative river management is:
It’s crucial to do good background research and to then objectively share this with role players – to allow them to challenge their own realities and assumptions
It all starts with relationships and trust building
It’s vital to make all role players feel safe and unthreatened – especially those who don’t have the moral high ground. The ones who have broken the rules of river management in the past mostly feel embarrassed and will simply withdraw when feeling hurt or hammered
The Holy Grail in river management is when upstream users (the haves) and downstream users (the have-nots) agree on a common problem, develop a collective awareness, and strive towards a common goal
The enemy of river management is not illegal activity – law enforcement can easily take care of that. The real enemy is fractured relationships, fractured governance, deepening conflicts and, ultimately, failure to work together.
Forestry, together with local stakeholders and conservation organisations, is playing an
increasingly pivotal role in conservation efforts in the southern Cape. Attitudes are changing and former adversaries are finding common ground and working together to control the spread of invasive alien plants in the mountain catchments, which are having serious impacts on fire risk and water resources. The complexity of this task is amplified by government’s strategy for forestry in the Western Cape, which has veered from exiting 45 000 ha of forestry to partial reversal of that strategy, and the resulting delays which have disrupted normal forestry and conservation operations. Added to this is the lack of resources and capacity of state organisations to effectively manage land handed back to the authorities by forestry in terms of its exit strategy. At stake is the economic viability of the forestry and downstream timber industry in the region, and the health of the catchments themselves.
The main issues are:
The Government’s forestry exit strategy and
the lengthy delays in re-commissioning exit
plantations subsequently earmarked for return
to forestry; and its inability to manage exited
plantation areas handed back after clear-felling;
The dwindling timber industry;
The effects of climate change and increasing
drought on water resources and fire risk;
Alien invasive vegetation infestations and their
negative impact on water resources, biodiversity
and fire risk.
Water Research Commission calls on Southern Cape landowners for input
At a recent workshop on the green economy, hosted by the Water Research Commission of South Africa (WRC) in Pretoria, the Southern Cape Landowners Initiative (SCLI), was requested to make a presentation on related developments in the region, such as the WWF initiative to clear the Waboomskraal catchment from invasive alien plants. (The Southern Cape, Through SCLI, is a national best-practice example into engaging stakeholders on environmental impacts).
What is a green economy?
UNEP defines a green economy (GE) as one that results in “improved human well-being and social equity, while significantly reducing environmental risks and ecological scarcities” (UNEP 2010).
Says Cobus Meiring from SCLI, “The Southern Cape is a strong proponent for the green economy, and we are blessed with a progressive business chamber, strong academic representation through NMMU, pro- active communities and a very supportive Eden District and George municipalities”.
“It is true that the Southern Cape is no exception to the effects of climate change, and we should be doing a lot more if we are to prepare for the future sustainability of the region”.
“Managing water resources and reducing negative factors, such as invasive alien plants, (which have a huge bearing on our natural infrastructure and economic well- being), is to be addressed on a continuous basis”.
The Southern Cape Landowners Initiative is a public platform for landowners and land managers involved in the control and eradication of invasive alien plants. The SCLI is supported by the Table Mountain Fund.
What is the Water Research Commission?
“The Water Research Commission is mandated to support research into areas that may contribute to the development of the green economy in South Africa.” The business sector, as well as landowners and effected communities, are key to advancing this vital present and future objective.
These days legislation regulating the prevalence of invasive alien plants on private land comes into play when buying and selling property, so landowners are paying a lot more attention to the matter than previously was necessary. “So, where does your responsibility as a land owner start in dealing with invasive species, asks Meiring?” According to the laws governing invasive alien plants on private land, landowners should be aware of which invasive alien plants are growing on their land, and eradicate those plants where they occur”.
Continues Meiring, “for landowners in urban areas invasive species are not such a big deal, but for landowners in rural and semi- urban areas this could be seriously problematic. A prime example is smallholdings on Wilderness Heights, Knysna and on the outskirts of Mossel Bay, where land is carpeted by black wattle, pines and blue gums (not to mention pampas grass, Madeira vein and Lantana”.
“Costs to clear land densely covered by invasive species (for instance black wattle) could be as high as R10 000 per hectare for an initial clearing operation by contractors. For many landowners the task to clear their land, and to keep their land clear of regrowth, is often simply too costly and time consuming to consider”.
Nevertheless, continues Meiring, ” the pressure on landowners to bring the state of their land up to a standard, (free of invasive alien plants), and the matter can no longer be ignored”. “Question is how does land owners deal with the costs associated with invasive alien plant management?”
“Often easier said than done, landowners whose properties are badly affected by invasive species should devise a simple strategy in tackling the problem, and deal with it in sections rather than biting off more than they can handle and keep under control”.
“Land cleared of invasive plants generally recovers by itself if re- growth of invasive species are kept under control, and although natural vegetation is the ideal, even grass cover is preferable to wattle jungles.”
“So, our advice to effected landowners is to take it one step at a time, make steady progress and curtail costs as you go along”.
The Southern Cape Landowners Initiative (SCLI) is a public platform for all landowners with an interest in the eradication and control of invasive alien plants. Enquiries: email@example.com
People, Poison and Pangas headed for the Witfontein Forests above the exclusive suburbs of Heatherlands and Glenbarrie. These forests are infested with every sort of alien. In particular, the invader tree fern from Australia is taking over the area, thus dooming Alsophila capensis (Cape Tree Fern) to extinction. In almost every garden in these affluent suburbs, Sphaeropteris cooperi (Aussie Tree fern) flourishes, producing huge amounts of spore to fuel the invasion. No action is taken to stem the tide. The plant is not proclaimed a noxious weed and is freely available in local nurseries. Even the conservation-minded ignore the problem and are happily giving house-room and TLC to this Doomsday plant.
Prix, who is the curator of the Southern Cape Herbarium, organised that we take a team of EPWP workers with us into the forests to destroy as many aliens as we could in a morning. They are employed at the Garden Route Botanical Garden and we badly needed their help. We are grateful that the trustees and senior staff made this joint alien clearing project possible. We started off with 9 and ended with 6 guys, as the going got tougher during the course of the day. We were also delighted that Greg and Cheryl Devine from the High Altitude Team of the Mountain Club were able to join 8 Outramps members for the morning.
Searing heat made it imperative that we should work mainly in the shade of the indigenous forest and the pine plantations. So we chopped, slashed and pulled out Aussie invaders and poisoned them with Garlan to prevent resprouting. The ferns that we pulled out, were hung in tree forks to prevent the roots touching the ground. It was heavy work, but rewarding to see 4m high Ferns and massive Bugweeds crashing to the ground. However, it would be naïve to think that we had even dented the numbers. You would require an army to do that. We also need to eradicate every single specimen of the fern that grows in the Southern Cape. They carry a huge number of spores that travel for many kilometers. See Nicky’s photo of “The Bad and the Good” and compare the spore numbers. The Alsophila capensis frond is on the right of the picture. Our own Tree Fern produces fewer spores and is very selective in its habitat requirements on the banks of streams and in deep shade. The invader will grow anywhere, even managing to thrive in full sun.
And if you thought that this monster was the only problem, think again. The beautiful Kahili Ginger plant with its exquisite yellow flowers (Hedychium gardnerianum), is also taking over. There is Bugweed, Wattle, a plethora of Pines and lots of the invasive Nephrolepis Fern, Cannas, Pampas Grass and Lantana, to mention but a few. If we are to preserve this area as a playground for mountain-bikers, hikers and dog-walkers, there needs to be a concerted effort from all these groups to eradicate the aliens. And time is running out. After the good rains of recent months, the invaders have made huge strides and the indigenous forest is shrinking. The Department of Water Affairs and Forestry also desperately needs to come to the party. It would seem that they control the land. One of the well-trained “Working for Water” teams would be the answer to the problem. It would keep them busy for months.
On a lighter note, WAGS chose Pepsi Pools as their Wednesday objective. The prevailing high temperatures made it the ideal choice for a hot day, with swimming in the stunning pools being an excellent option. We are hoping to go to Joubertina on Friday to hunt for Helichrysum outeniquense, which is Presumed Extinct. Jan Vlok has hunted and not found it, so we probably don’t even have an outside chance. It is described as, “Known only from the type collection. Allied to H. felinum but distinguished by its different habit, woollier leaves, and smaller heads with bracts in fewer series, arranged in a spreading corymbose panicle.” The original plant was discovered by the famous botanical explorer, Elsie Esterhuysen. But in February, it is necessary to look at temperatures before making field trip decisions. If it’s too hot on Friday, we will once again head for the forests and the shade.
CREW Group, Southern Cape
[The KTT blog team would like to thank Di Turner for sending us this wonderful article and giving us permission to use the accompanying photographs that were taken by the Outramps CREW members.]
On the 16th of February 2016, the SRU hosted a follow up focus group with professionals from SANParks, MTO, Southern Cape Landowners Initiative (SCLI) and SRU/NMMU research associates. A previous workshop held after the SCLI seminar in December 2015 highlighted that current invasive plant monitoring techniques, as used by Working for Water, fall short and the data collected is ineffective for practicing adaptive management. One of the main deficiencies of the current method is its lack of feedback to learning and adaptation.
The focus group participants critically discuss indicators of monitoring successful invasive plant management programmes that promote the healthy functioning of social-ecological systems. Four variables for monitoring were identified for discussion. These were diversity, connectivity, learning and slow variables.In the discussion its was noted that there are social, landscape and species level indicators that should be considered for monitoring short and long term success of invasive plant management programmes.
Some of these included;
Successive participation and representation of a diversity stakeholders involved in invasive plant management activities
Transfer of knowledge between stakeholders
Adaptation in policy, planning and practices
Change in abundance of indigenous verses invasive flora
Indicators of soil health
Indicators of social and landscape fragmentation
long term impact of clime change for plant species composition
The SRU plans to follow up these findings in a workshop with Working for Water implementers in March 2016, to assess and prioritize the monitoring indicators identified from this focus group.
Although it sounds like some space invasion, the term actually refers to any species of plant, animal or micro-organism that become problematic in areas where they do not naturally (indigenously) occur.
Most people think alien invaders only refer to plants, and although at the Garden Route Botanical Garden plants are our main concern, we have numerous other alien invaders.Port Jackson, black wattle, rooi pitjie and blackwood are by far the most ‘popular’ in our area and 90% of local residents know what they look like and are aware of the reasons we need to get rid of them.
We do however, have numerous other alien invaders in our beautiful Garden Route. These invaders compete with our local, indigenous species for food and habitat and in the case of plants use excessive amounts of water and take up space. They also prey on our indigenous species and cause their numbers to dwindle or become completely extinct. Read more here.
Role players in the war against weeds pledged to work closer together towards clearing our fynbos areas of invasive plants, more specifically black wattle, in order to conserve water.
At a South Cape Land Initiative seminar held on the 10th of December 2015, Prof. Christo Fabricius, of Nelson Mandela Metropolitan University (NMMU), said it would make sense to rethink current strategies and adapt them. Even change tack if the goal of freeing up targeted areas on the Garden Route is not being achieved.
He urged role players, which included SANParks, CapeNature, Working for Water and private landowners, to use the breaks during the seminar held at the Far Hills Hotel to network and reach consensus on how to target achievable goals. Read more here.
The Precious Tree Project concentrates on establishing forest patches, by planting indigenous and endemic forest tree species in The Garden Route area of South Africa. The Garden Route, although lush with vegetation has less that 30% of its indigenous forest formally protected. This projects long term goal is to improve that figure.
The Precious Tree Project wishes to initially plant 1000 Trees in the Wilderness area, there after expanding their operation to many more trees in the Garden Route and beyond. They have selected 25 properties, where land owners are already showing initiative in restoring indigenous forest, and plant 40 Trees in close proximity to each other (25 properties x 40 Trees = 1000 Trees). These patches of forest consist of pioneer Trees such as the Cape Beech, mixed with slower growing trees such as the Outeniqua Yellowwood, to create and simulate the natural forest environment.
How you can get involved?
Sponsor as many Trees as you wish @ R150 a tree, via their EFT facility or simply adding a tree to your bill at Cocomo Restaurant in Wilderness. Alternatively, like their Facebook page http://www.facebook.com/precioustreeproject to find out when their next planting session takes place and join in by getting your hands dirty planting trees.
GEORGE NEWS – “The Wilderness community reacted well when called upon to clear public areas of invasive alien plants – and on their day off as well,” said Cobus Meiring, of the Southern Cape Landowners Initiative (SCLI) – a non-profit organisation that undertakes environmental projects in the Garden Route.
On the 1st of October 2015, World Habitat day, we ventured out into nature, at the old municipal servitude in Wilderness Heights, to fight the good fight in the war on weeds. It was a community effort, with many local residents and conservancies, including Constantia Kloof and Touw River.
There were over ninety people that attended, coming to help hack and to show support for the initiative. The local authorities, such as SANParks, George Municipality and Southern Cape Fire Protection Association, were also there en mass, shining the light for co-operative governance.
Each team was allocated a 20 x 30 m stand that was to be theirs to hack. The stands were all heavily invaded by Eucalyptus, Black Wattle and Pine, not to mention completely water logged after the heavy rains from the night before.
After a vital safety demo by Jonathan Britton, from the Garden Route National Park, the teams set off to get started. It was truly an impressive sight to see how the land completely transformed in such a short amount of time. Many indigenous trees, that were nearly invisible before, started to appear as the alien vegetation around them was cleared.
There was laughter, chatting, sweat and huge smiles on the faces of all. People were truly having a wonderful time giving back to nature and connecting with their community.
After four and a half hours of strenuous work, we could see that people were tired and hungry! It’s a good thing that we had prepared a braai just down the road at Bergzicht nursery. Everyone happily made their way over. With a cool drink in one hand, and a Boeri roll in the other, we ended off the day by acknowledging the enthusiastic and hardworking teams with a few prizes.
It was an incredible day and would not have gone so smoothly without the planning and organisation of many incredible people.
Thank you to everyone who participated, we could not have done it without you.
We would like to thank everyone who attended the community hacking day yesterday, we had a great turnout and the area looks incredible. With over 90 people in attendance, the Hacking Day was a huge success and a lot of fun!
The periwinkles have been with us for many, many years and came into the country, respectively from Madagascar and India and central and southern Europe where Vincamajor and Vinca minor are indigenous. Both have been used in the pharmaceutical industry and medicinally. Madagascar periwinkle (Catharanthus roseus) is used to treat Hodgkin’s disease and V. major and V. minor to stimulate blood circulation and muscle action. Both plants are in the Apocynaceae family.
During the 80s Catharanthus roseus was described as “unsurpassed for the odd shady corner where with its sprawling habit and glossy green leaves it would be most at home”. Previously listed as a special effect weed it is not currently listed however, be aware that the whole plant is poisonous.
V. major and V. minor were described under one heading as a trailing perennial and vigorous groundcover that would grow well in rocky areas, seaside gardens and sloping banks. The size of the blue flowers is the only significant difference between these two. These are also poisonous. V. major‘Variegata’, the cream and green version, was a firm favourite with gardeners in general during the 70s and 80s – they were just everywhere.
The cotoneasters have been on the ‘weeds’ watch for a long time. Their invasive tendencies are evidenced across the globe and reclassification to Cat.1b (must be controlled) of all the species listed below makes good sense.
This amendment aligns with legislation in several other countries where the plants have become naturalised. In regions where climatic conditions are favourable many escapees from cultivation have become invasive weeds, such as the many Chinese species naturalised in northwestern Europe.
C.glaucophyllus is a declared invasive weed in Australia and California and C.simonsii is listed on the New Zealand National Pest Plant Accord, preventing its sale and distribution.
Popular garden shrubs, easily grown from seeds and cuttings, cotoneasters are grown for their attractive arching growth habit and exceptionally decorative fruit. Cotoneaster is a genus of woody plants in the rose family (Rosaceae), native to the temperate regions of Asia, Europe and North Africa.
The chandelier plant (Bryophyllum delagoense) was introduced to South Africa from Madagascar as an ornamental garden plant. With its succulent structure and very pretty orange-red flowers during mid-winter it was widely used in rockeries.
Like so many others it has since escaped from the garden environment and is now listed as a Category 1b: Invasive species which must be controlled and wherever possible, removed and destroyed.
Any form of trade or planting is strictly prohibited.
Impacts: The plant invades hot, dry rocky areas and urban open space. While not yet a very serious threat in our area, isolated patches have established themselves in barren areas in road reserves. Bryophyllum delagoense reproduces rapidly from vegetative offsets that form at the leaf tips as well as from seed. The plant is also considered to be poisonous to humans and animals.
Identification: An erect perennial, hairless, succulent herb or shrublet. Leaves have a cylindrical shape and are grey-green mottled with darker green to reddish spots. The apex of the leaf has two to nine small teeth producing plantlets in their axils. The flowers are tubular, 30 to 40mm long, pendant, pale orange to deep magenta in broad terminal clusters up to 15mm wide (June to July).
Control: Biological control agents are under investigation. No herbicide is registered at this stage therefore the only effective control is hand-weeding. Remove and destroy the entire plant, do not place with the rest of your garden refuse as you will only be transferring the problem to another area. Bear in mind that the plant easily reproduces vegetatively.
Any of the indigenous cotyledon or kalanchoe species make excellent substitutes.
GEORGE NEWS – Lecturers and students of NMMU’s George Campus planted indigenous trees on Monday 14 September to strengthen one of the forest corridors.
Jason Julius, project manager and former chairman of the Green Campus Forum (GCF), said, “Although the trees are relatively young and have been fenced off to prevent them being eaten by the animals on campus, it is expected that they will be playing a very important role in approximately 50 years’ time and onward.”
It is essential that forest corridors be established so that wildlife can crisscross the picturesque NMMU George Campus. It is upsetting to see dead snakes and bushbuck become roadkill on the campus. It is our responsibility to assist the animals that share our campus to be able to move safely.
The George Millers Forum (GMF), an entity created to speak for the forestry value chain, was established on Thursday 10 September in the George Industrial Area. At the meeting it was said that there is a definite link between managing and controlling invasive alien plants and a healthy forestry industry. Cobus Meiring, of Natural Bridge Communication, said thousands of jobs were lost over the last few years due to closures of sawmills in Knysna, Great Brak and other Southern Cape sawmills.
GEORGE NEWS – A community hacking day, aimed at ridding the Whites Road municipal servitude in Wilderness Heights of invasive alien plants and weeds, will take place on World Habitat Day, Thursday 1 October, from 08:30 to 14:00.
The Kaaimans-to-Touw (KTT) Eco Restoration Forum, in collaboration with NMMU’s Sustainability Research Unit (SRU), George Municipality, SANParks and the Southern Cape Landowners Initiative, will be hosting the day. The programme will serve as a demonstration and learning site for invasive alien plant management, offering scope for implementation of experimental design and monitoring by NMMU students.\
Preliminary Reserve Determination Studies for the Selected Surface Water, Groundwater, Estuaries and Wetlands in the Gouritz Section of Water Management Area 8
You are hereby cordially invited to attend a stakeholder meeting in the Wilderness on 16 October 2015 during which you will be informed of the outcome of the study to determine the Preliminary Reserve for selected surface (rivers, estuaries and wetlands) and groundwater resources in the Gouritz section of Water Management Area (WMA) 8. This study has been commissioned by the Department of Water and Sanitation’s Chief Directorate: Water Ecosystems in terms of Section 16 of the National Water Act (Act No. 36 of 1998) and is referred to as the Gouritz Reserve Determination Study (GRDS).
The aim of the meeting is to provide stakeholders with an overview of the results of the studies, and give feedback on the Recommended Ecological Categories (REC) proposed for the various water resources studied. In the case of surface water, for example, the REC is expressed in terms of the volume of water required in the river at a certain point and at certain times.
Date: 16 Oct 2015
Time: 09:00- 15:00
Venue: Wilderness Hotel, George Rd, Wilderness
For catering purposes it would be appreciated if you could please confirm your attendance by no later than Friday 2 October 2015. Please reply via any of the contact details below.
Enquiries & R.S.V.P.: (Distributed on behalf of the Department of Water & Sanitation)
Bea Whittaker: Communication consultants to the GRDS.
Guest blogger Paul Rixom from the Touw River Conservancy (Vice Chairman):
Between 16th and 27th March 2015 two teams from Working For Water carried out alien clearing operations on my plot on Taaibos Street, Wilderness Heights at no cost to myself.
This was initiated through Juanita and Adrian Wilmans, secretary and chairman respectively of the Touw River Conservancy. Juanita obtained the necessary ‘Application for Clearing Assistance’ forms which I and two other land owners completed (see map).
As part of the application a rough plan was drawn of the plot with the areas of alien infestation marked and also any alien trees which are required to be kept in the garden area near the house for windbreaks or privacy. These trees were also documented on a ‘Demarcation Application’ form.
The two locally sourced clearing teams, making up about 24 workers, were mainly ladies and were supervised by Elizabeth of Working for Water. The teams were almost entirely self sufficient only requesting extra drinking water on hot days. Elizabeth was very careful during the operation coming to see me on several occasions to check on the position of internal and boundary fences.
The following photographs were taken during and after the clearing operation. The plot slopes gently and then progressively steeper in a northerly direction to the ephemeral stream at the bottom. Most of the wattle was situated in the middle and lower part of the plot and this was generally felled and herbicide applied to the stumps. Closer to the stream on the steeper slopes are closely spaced pine trees, some quite large, these were mainly ring barked and treated with herbicide. Close to the stream was a very dense area of bramble, probably related to the original position of an old garden. This difficult area of bramble was cut down and treated and during this operation a pile of corrugated iron was uncovered representing the remains of an old building. There was a nice surprise when a small grove of yellowwoods were discovered close to the stream after the bramble was cleared.
Two follow up clearing operations are promised, the first being in early 2016.
It is hoped that in due course other plot owners in Wilderness Heights, particularly adjacent to the east flowing stream will apply for assistance in the hope that a more regular water flow will be established.
AGRICULTURAL NEWS – In the early 1950s the morning glories (Ipomoea indica) were promoted as an excellent plant for covering unsightly fencing, embankments and the walls of outbuildings. Its popularity was fueled by enthusiastic descriptions such as “growing with cheerful abandon in almost any soil” and therefore perfectly suited for the above purposes.
Also to the Ipomoea’s advantage, is the fact that it grows very quickly and is self-seeding.
Clearly with so much going for it the recipe for becoming invasive was perfect. Ipomoea indica is known by several common names, including blue morning glory and blue dawn flower. It is a soft perennial vine native to Hawaii and the New World tropics.
It is also found throughout the tropical and warm areas across the globe as an introduced species where it has in many places become naturalised and is often regarded as a noxious weed. In both Australia and New Zealand it has become an invasive species. Predisposed to moist and rich soil, it can and does grow in a wide array of soil types. Ipomoea purpurea, the purple or common morning glory, is native to Mexico and Central America.
Description: Ipomoea indica and I.purpurea are twining and climbing plants. I.purpurea is an annual and I.indica is a perennial. In both cases the plants flower prolifically and make a stunning display of strong colour. The flowers are long and trumpet-shaped.
PART 3: INVASIVE ALIEN PLANTS IN SOUTH AFRICA: Riparian invasions
Self-established stands of alien invasive trees are common in many parts of South Africa. They mainly invade non-riparian settings but sometimes invade riparian habitats. There are clear visual differences in the physical attributes of trees that occupy riparian and non-riparian zones. A study carried out by Dzikiti and others in 2013 looked at the single tree water use of Pinus pinaster and Pinus halepensis in these zones. Their work concluded that self-sown stands of Pine trees in riparian zones use at least 36% – 40% more water than those occurring in non-riparian settings. This justifies the high priority that should be given to clearing invasive trees in riparian zones. An interesting note is that the method they used for measuring water use employed a technique that measures the rate at which sap flows in the stem.
The same tree species in a riparian area will use a lot more water than in a non-riparian area.
These sap flow velocities did not differ for the different settings (riparian and non-riparian) and thus the difference in water use was attributed to larger size of the trees in riparian zones.
The impacts of invasive alien plants on the water flows in South Africa based on riparian invasions are usually misunderstood. Water-use by riparian trees is higher than in the adjacent dry land areas and has significant impacts on river functioning. Priorities for clearing alien invasions should therefore also be set according to the distance of alien plants from rivers or water bodies. Invader species such as Wattles and Eucalyptus are mainly invaders of riparian zones where they frequently become dominant.
Professor Martin Hill is the recipient of the NSTF-GreenMatter Award “by an individual or an organisation towards achieving biodiversity conservation, environmental sustainability and a Greener Economy”. He received this award on 9 July for his work on invasive aquatic weeds, particularly in the field of community engagement.
Professor Hill, along with his colleagues and students of the Biological Control Research Group (BCRG) at Rhodes, have shown that it is possible to restore aquatic ecosystems invaded by weeds, including water hyacinth. They simultaneously trained disabled people for jobs in this industry.
The BCRG work with schools and communities to mass-breed insects for biological control and run training courses. This not only improves people’s lives directly, but also benefits everyone by improving water quantity and quality.
This has resulted, not only in more water being available for Langvlei and the natural vegetation, but has also decreased the fire risk for the resident of the area.
The SCFPA is a non-profit and public benefit organisation which operates in the area. Their objectives include empowering local communities in assisting them to become more aware of the risks of fire. Also to capacitate them to act proactively to reduce the hazards (including IAPs) to their assets and allow them to act as first response to fire emergencies.
For more information, visit their website, or contact:
044 302 6912
“Unwanted wild fires can be prevented if we work together!”
GEORGE NEWS – The Klip River forms an important water resource for Oudtshoorn in the Waboomskraal area.
In a joint effort to clear the catchment area, which is overgrown with pine trees and black wattle trees, WWF South Africa, SAB Miller, GIZ, the Department of Environmental affairs and local company Natural Infrastructure Services have embarked on a three-year clearing programme.
This week Gerhard Otto, of Eden District Disaster Management, remarked on the long-term plans for alien clearing by saying, “Urgent clearing of invasives along the entire Klip River is required to ensure that summer water supply to Oudtshoorn from the bore holes near Blossoms (on the Klip River) is secure”.
Situated on the northern slope of the Outeniqua Mountain, as you drive across to Oudtshoorn and Willowmore, Waboomskraal is an agricultural node vital to the production of hops (an important ingredient in the production of beer), as well as the export of fruit. This scenic area has been farmed for almost two centuries, and is an entry point for visitors on their way to the Garden Route.
Invasive Alien Species (IAS) are a multibillion rand problem for South Africa.
Currently there are 28 000 people employed in IAS management with the potential of being increased to 55 000 in the next few years. There are 383 Invasive plant species which are listed in the National Environmental Management: Biodiversity Act (NEMBA) of 2004. For more information, see this Department of Environmental Affairs document: Do the NEMBA regulations affect you?
On Wednesday the 24th of June 2015, the Department of Environmental Affairs (DEA) Biosecurity Advocacy Programme, held an information forum at George City Hall. The forum was part of a national roadshow series to inform the public and environmental organisations about the new NEMBA regulations that were released in August 2014.
There are now four categories listed under NEMBA for Invasive species. These categories are:
Category 1a: Invasive species which much be combatted and eradicated. Any form of trade and planting is prohibited.
Category 1b: Invasive species which must be controlled and wherever possible, removed and destroyed. Any form of trade or planting is strictly prohibited.
Category 2: Invasive species or species deemed to be potentially invasive, in that a permit is required to carry out a restricted activity. Category 2 species include commercially important species such as pine, wattle and gum trees. Plants in riparian areas are Cat 1b.
Category 3: Invasive species which may remain in prescribed areas or provinces. Further planting, propagation or trade is however prohibited. Plants in riparian areas are Cat 1b.” These new regulations have potentially big impacts for all landowners with invasive species on their land including local, provincial and national government organisation.
If you would like to report issues of non-compliance this may be done on the National Environmental Crimes & Incident Hotline: 0800 205 005
The presentations from the workshop can be downloaded here.
Well actually, Government is getting tough on landowners who have invasive species on their property and individuals and businesses who deal in listed species.
Invasive species are controlled by the National Environmental Management Biodiversity Act (NEMBA) (Act 10 of 2004) – Alien and Invasive Species (AIS) regulations, which were gazetted on 1 August 2014 and became law on 1 October 2014. The AIS Regulations list 4 different categories of invasive species that must be managed, controlled or eradicated from areas where they may cause harm to the environment, or that are prohibited to be brought into South Africa.
Until now, many landowners have simply ignorred their legal obligations to clear their properties of invasive alien vegetation. Landowners cite the high costs of alien clearing and the levels of alien infestation on state property as reasons for not prioritising alien clearing in their annual operational plans and budgets. The Gazetting of the new regulations in August 2014 has seen the Minister of Environmental Affairs, Mrs Edna Molewa, sign off a budget of R200 million over the next three years to build up the Department’s capacity to regulate invasive alien species. This is in addition to R4.2 billion budget to control these species through the internationally renowned Working for Water Programme over the same period.
“The costs of controlling invasive alien species are very high. We need to prioritize our efforts to secure the greatest returns on investment. An obvious example would be the pine trees from Europe, Asia and North America that are invading our mountain catchments, and could have unaffordable consequences for water security, as they use far more water than the indigenous plants they displace,” said Minister Molewa.
The whitefly Bemisia tabaci (USDA image PD USDA ARS via Wikimedia Commons)
A species of whitefly that transmits cassava mosaic virus has been detected in South Africa for the first time. The whitefly, Bemisia tabaci is a cryptic species complex containing some important agricultural pests and virus vectors. The term ‘cryptic species complex’ means that Bemisia tabaci is considered to be a complex of at least 24 different species that look almost identical but are in fact genetically different. Researchers from a range of organisations including the University of Johannesburg, the University of Witwatersrand and ARC-Vegetable and Ornamental Plant Institute conducted surveys to investigate the diversity and distribution of Bemisia tabaci species in 8 provinces in South Africa. The study aimed to update the information regarding the different Bemisia tabaci types present in the country.
PART 2: INVASIVE ALIEN PLANTS IN SOUTH AFRICA: WHAT ABOUT WATER QUALITY
The impacts of invasive species on surface water runoff are reasonably understood. This has led to the prioritisation of areas that should be cleared of alien invasions through programmes such as Working for Water, established in 1995. However, there is not much information on the impacts of alien plant invasions on water quality. As such, not much has been done to prioritise clearing on the basis of water quality. Some of the alien invasion impacts on water quality are discussed below:
The higher evaporation rates of alien vegetation reduce stream flows. This reduction in the amount of water in rivers reduces the flushing capacity of the rivers, in turn increasing nutrients, pollutants and salinity concentrations (Nagler et al, 2008). This reduces the resilience and buffering capacity of hydrological ecosystems.
Alien invasions change the structure and amount of biomass (carbon and nutrient dynamics) in an ecosystem (Kalff, 2002). This can increase the amount of metabolised nutrients and could escalate natural eutrophication processes. If previously non-woody ecosystems are invaded by woody species, the increase in biomass implies higher fuel loads and could increase the frequency of fires and their intensity. This escalates erosion and sedimentation rates of rivers, streams and wetlands, which has flow consequences to downstream users.
Invasions of aquatic weeds are also associated with a range of impacts on water quality. Dense mats of these weeds can impede water flow, which increases the rate of siltation in water bodies and inhibit the diffusion of air into water, resulting in lower concentrations of dissolved oxygen (Tellez et al, 2008). Lower oxygen concentrations combine with the above-mentioned problems and accelerate eutrophication (Chamier et al, 2012)
All of South Africa’s accessible water is already allocated for use, with agriculture, mining and industry being the biggest users. The impacts of invasive alien plants on water quality, while not considered to be as important as those on water quantity, should also be addressed.
When managing IAPs around river courses, solutions should integrate issues around quantity and quality, as they are intricately linked (Chamier et al, 2012).
Established in 2010/ 2011 through Natural Bridge Communications, the Southern Cape Landowners Initiative is the confluence of local conservation entities, environmental project managers, field managers, researchers and communication experts.
The SCLI has consistently proved to be the most successful partnership and conservation constituency builder in the domain of IAP management and natural infrastructure conservation in the Southern Cape since 2010.
Example of SCLI activities
Developing the Registered Care Taker Initiative, aimed at involving participating landowners in land stewardship
Hosting a public participation workshop in George aimed at introducing landowners to key role players and to enhance methods in controlling IAPs.
Facilitating a workshop in Knysna to determine where clearing in the southern Cape in taking place, who is funding it, what the challenges are etc.
Establishing Fire Risk management working groups with the aim of determining where IAPs pose the biggest wild fire threat and how to address it
Regular articles in local media on land owner response to IAPs, as well as establish our own web presence
Opening channels of communication between key government stakeholders, e.g. CapeNature, DAFF, DEA, DOA, ESKOM, NMMU, SANParks, SANRAL, Transnet etc.
Establishment of Natural Infrastructure Services (a non- profit and fully representative entity to act as implementing agent for local conservation entities and Working for Water)
Establishing and promoting the weed- free and plant migration corridor concept
Development of a stakeholder database
Act as a channel to assist land owners where they need input or information
If you would like to get involved, please contact:
AGRICULTURAL NEWS – Eucalyptus trees are seen as a threat to native plants and scarce water resources, requiring the eradication of these trees at a considerable cost. Broiler producer Hugh Davison has found a way to turn these trees into a valuable asset – using them to heat up his broiler houses.
Temperature control is an essential part of successful broiler production, especially during the first two weeks of a chick’s life. Many producers in South Africa use liquid petroleum gas (LPG) to heat up their broiler houses, but Hugh Davison, who farms at Cordale Farms between Caledon and Hermanus, decided two years ago to use wood instead.
PART 1: THE INCREASED WATER USE OF INVASIVE ALIEN TREES: SOME REASONS
It has become general knowledge that invasive alien plants often have much increased water usage compared with native vegetation and especially in water scarce landscapes. However, Calder and Dye (2001) pointed out that the reasons for this increased water use are perhaps less understood. Yet they are of importance especially when there is need to efficiently channel resources for alien plant clearing. Understanding some of these reasons can facilitate prioritization of areas for clearing IAPs.
Here are some reasons:
1. Difference in height
Trees usually evaporate more water than shorter and annual vegetation crops such Fynbos and or grasslands. Interception of rain is higher from trees than from shorter crops and that facilitates higher rates of evaporation from tree canopies. This is similar to the clothes line effect as clothes pegged on a washing line will dry faster than those laid out flat on the ground. A stronger pull is required to evaporate water from a lower surface than a higher one.
2. Difference in rooting depth
In drier climates trees usually adapt to these conditions by developing deeper rooting systems. This enables them to access more soil water during the dry periods, a characteristic not generally exhibited by shorter or annual vegetation. This also leads to higher evaporation rates overall.
3. Difference in senescence
Most crops and grassland have a characteristic pattern of development where green leaf area increases rapidly after germination or winter dormancy, and peaks towards maturity before degrading. This senescence of short vegetation, particularly montane grassland in South Africa is often a major cause of reduced evaporation when compared to evergreen trees, of which most IAPs are.
The article points out that the concept of biological invasions poses tensions on what nature is and what it ought to be, and addressing these tensions requires policy makers to consider that the concept is dynamic and evolving.
Three facets of biological invasions are: their cultural dimension, their potentially positive environmental effects and the benefits they can provide in the context of global change.
1. Aesthetics play a major role in how invasive species are managed, with some species being underlined as ugly and annoying etc. They reiterate that some invasive species are not given management attention because of their attractiveness or usefulness. Different parts of the world have different cultural understandings of nature. The reliance of invasion biology science on words that are sourced from other fields, such as the military and medical, shows the cultural perspective. Examples of these shine through in the militant approaches taken locally: War on weeds, Invasive Alien Plants.
2. Most studies do not usually give an indication of any positive ecological consequences that might arise from biological invasions, in a world where many natural conditions are already altered. Tassin and Kull mention that in some cases native species benefit from increase in resource availability, with some invasive species becoming food sources, creating habitat or protective structures or being useful in the control of problematic native species. For example: Some endangered bird species get fruit all year round in Australia from IAP.
3. The adaptive dimension of invasive species in the face of global changes can be considered as forming novel ecosystems which could lead to positive social and economic gains, such as invasive fruiting species like the Mango and Guava trees.
The authors mention that in conditions of climate and land cover change novel ecosystems resulting from plant invasions often maintaining certain critical ecosystem services such as productivity and carbon storage. The review paper concluded that while there is need to assert the negative consequences of biological invasions, there should also be efforts to look at the multi-facets of the consequences and think about the landscapes that society wants. The authors emphasize that, our world is already a biodiversity melting pot and that global change will make it more mixed, thus biological invasions should be addressed in all dimensions and without any “blind spots”.
The recently formed Kaaimans-to-Touw (KTT) eco-restoration forum is striding forward. The ‘domain’ of the Forum is the rivers and watersheds that end up in the Kaaimans and Touw River mouths, and its vision is to be a ‘laboratory’ of learning about strategies that work for ecological restoration, and improving people’s lives. We acknowledge that we don’t know everything and therefore we need to learn from our collective experiences, success and errors. By promoting the success stories, we hope that ‘success will breed more success.’ The Forum also aims to promote a sense of community; a sense of meaning and place through discussing objectives that everyone can subscribe to, and then taking action and learning from each other.
Support for the Forum is growing by the day. The Department of Environmental Affairs, Department of Environmental Affairs and Development Planning, SANParks, the Touw River Conservancy, the Constantia Kloof Conservancy, George Municipality, Natural Infrastructure Services, Eden District Municipality and Cape Nature have committed themselves to participating. Members are beginning to realize the benefits of working together. By participating, members are able to ‘pool’ their funding and resources and make a much bigger difference than if they worked alone – every small investment contributes to addressing the bigger problem within the action domain. Also, everyone can claim ownership for the successes of joint actions taken. The scientific basis for invasive weed management is being strengthened. The Forum is also becoming a platform for applying for funds to make this work. Ultimately, members are motivated by the feeling of making a difference and contributing positively.
Over the past month, significant progress has been made. Following a meeting with George Municipality officials, the mayoral committee has agreed to seriously consider allocating funds to alien plant management in the catchments of the Garden Route Dam on municipal land. Samantha Mc Culloch of the NMMU Sustainability Research Unit gave presentations to the Constantia Kloof Conservancy and Southern Cape Landowners Initiative (SCLI). The Touw River Conservancy has also received funds from Working for Water for alien plant management in three localities within the domain, and the Wilderness Bird Sanctuary reports that they are beginning to get the better of Lantana and Madeira vine within the Sanctuary. Constantia Kloof Conservancy reports that they are now in ‘maintenance mode’ after years of alien plant management. The SRU and SANParks are making progress with mapping and monitoring in the Touw River area. Christo Fabricius also facilitated a meeting in the Eastern Cape where the Umzimvubu Catchment is being positioned as a similar learning site to the Kaaimans-to-Touw Forum.
We need to keep up the momentum. The next steps are to raise awareness of alien plants amongst property consultants and nursery owners by summarizing the implications of the new National Environmental Management (Biodiversity) Act (NEMBA). A workshop, facilitated by WESSA, is aiming to further understanding of these regulations. More information on that here. An important outcome is to create a strategic adaptive management plan that will prioritize areas for the management of invasive weeds, especially (but not only) Black Wattle in the area between the Kaaimans and Touw Rivers.
A discussion was held with stakeholders living in the Kaaimans to Touw area on the 5th of May. Read more here.
Half of South Africa’s wetlands have been destroyed and those that remain are the most threatened of the country’s ecosystems (Driver et al., 2012). One cause of the wetlands’ reduction can be attributed to the spread of invasive species. Certain alien plants consume larger quantities of water than indigenous species (Gorgens and van Wilgen, 2004). Those invaders introduced to upper catchments spread quickly and reduce the flow of water. This limits water available downstream to wetlands, thus reducing their distribution and function (Richardson and van Wilgen, 2004). As freshwater supply in South Africa is dependent upon wetlands, invaders that restrict water to these areas in turn threaten the country’s already stressed water supply (Turpie et al., 2008). Therefore in order to secure the future of South Africa’s water sources, it is important to manage those alien plants which diminish wetlands.
Many of us are familiar with the common IAP species, however, there are many others some of which are considered high alert emerging weeds. The South African National Biodiversity Institute (SANBI) has a useful identification tool to identify and report some of these emerging weeds. If you want to find out what other plants you need to put on your radar follow the link below.