‘EXPECT MORE WILDFIRES’: EXPERTS

As the world heats up, we can expect more unwanted wildfires, warn the experts KnysnaPlett Herald : Tuesday, 07 August 2018, 08:19 All over the world, from Portugal to California, Mexico, Australia, Indonesia and South Africa, wildfires are killing more people and livestock and burning more property to the ground. Photos: Supplied KNYSNA NEWS – The world is getting hotter and drier and there are more wildfires than there have ever been. All over the world, from Portugal to California, Mexico, Australia, Indonesia and South Africa, wildfires are killing more people and livestock and burning more property to the ground. Scientists who study the weather believe that as the world gets hotter and drier, wildfires will take place more often and cause more damage. This is as likely to happen in the Western Cape as it is anywhere else. Effects felt all over And it’s not only the scientists who are saying that the world’s climate is changing and that there is what we have come to know as “global warming”. “People everywhere are feeling the effects of this change,” says Tessa Oliver, project manager for risk reduction at Landworks – acknowledged experts in land management and fire awareness strategies. “Who can forget the devastating wildfire that consumed Knysna, Brenton-on-Sea and the surrounding area in June last year,” Oliver adds. That wildfire – the worst in South Africa’s history, fanned by 100km winds – left several people dead, flattened close to 1 200 homes, damaged 360 more from Sedgefield to Plettenberg Bay and destroyed 7500ha of plantations as well as burning down 17 800ha of fynbos and indigenous forest. Communities, especially those living in homes that are on the border between towns and wilderness areas, are the most at risk from unwanted wildfires. Lack of awareness a challenge “The challenges faced by these communities include a lack awareness of what they can do to protect themselves,” says Oliver. Landworks has been appointed by the SA Insurance Association to conduct a “pilot” fire awareness project in Swellendam, Knysna and other vulnerable areas to alert and sensitise people to the risk that wildfires pose to their lives, their communities and their property, and empower them to help reduce that risk. The project will also create awareness about illegal burning and “mischief” ignitions that are being experienced according to local fire experts in the region. “There is no doubt that a significant factor in the intensity of the Knysna wildfire was the proliferation of alien invasive plants,” says wildfire expert Paul Gerber, fire adviser to the department of agriculture, forestry and fisheries. Aliens a major driving force These plants introduced to South Africa from other countries are usually bigger and faster growing...

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Invasive Water Lilies.

Invasive yellow water lilies (Nymphaea mexicana and hybrids) have invaded rivers, lakes and dams in South Africa. Dense infestations can increase siltation, block waterways and hamper recreational activities. Thick mats provide breeding grounds for mosquitoes and disrupt the aquatic environment by reducing light penetration. Rotting material increases nutrients and reduces oxygen in the water which can be fatal to fish. The degradation of water bodies reduces the biodiversity of the ecosystem. For more information and detailed descriptions download: http://invasives.org.za/component/k2/item/693-yellow-water-lily-nymphaea-mexicana http://www.arc.agric.za/arc-ppri/Newsletter%20Library/SAPIA%20News%20No.%2049,%20July%202018.pdf     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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Cat’s claw creeper (Dolichandra unguis-cati) (Bignoneaceae)

Cat’s claw creeper (Dolichandra unguis-cati)  (Bignoneaceae)

English: Cat’s Claw Creeper.  Afrikaans: Katteklouranker The weed The exotic vine Dolichandra unguis-cati (formerly Macfadyena unguis-cati) is a woody, evergreen creeper that has become a significant threat to biodiversity in many sensitive ecosystems around South Africa. The vine is originally native to central, and tropical South America, including the West Indies, but has become invasive in a number of regions of Southern Africa, Australia, New Zealand, India, Mauritius, China, New Caledonia and the USA, including Hawaii. This extensive range has been facilitated through the horticultural trade which distributed the plant as an ornamental. Showy yellow flowers coupled with its climbing habit made the fast-growing creeper ideal as a hedging plant or natural screen for unsightly walls and buildings. The plants’ ability to ‘climb’ is facilitated by its distinctive leaves which consist of two leaflets and a modified three-forked tendril. Each tendril is tipped with a tiny hardened hook which can attach to most surfaces enabling the vine to grow up walls, tree trunks and over other vegetation. It is these tendrils that resemble claws and the feature from which the plant draws its name. Within South Africa, although spreading, cat’s claw creeper is considered to be in the early stages of invasion due to its relatively small distribution. Nevertheless, the weed has formed some very dense infestations in Gauteng, Kwazulu-Natal, Limpopo, Mpumalanga and the North West. Within these provinces the weed has become a significant invader of cultivated orchards and plantations, riparian corridors, natural forest remnants and disturbed areas such as roadsides and urban spaces. Vigorous growth allows the vine to sprawl over other vegetation and, through a combination of both shading and weight, it can kill even the largest canopy trees. In the absence of climbing support, individual stems grow along the ground resulting in a thick carpet which precludes the growth and seed germination of indigenous understorey vegetation. ? ? ? ?Cat’s claw creeper infestation  ?Leaves with ‘claws’ ?Hedge in bloom   Control Due to the problems associated with cat’s claw creeper infestations, D. unguis-cati has been declared a category 1b weed in South Africa in terms of the Alien and Invasive Species Regulations (AIS), National Environmental Management: Biodiversity Act (Act No 10 of 2004), which necessitates its control or eradication where possible. No trade or planting is allowed.? The management of cat’s claw creeper is, however, extremely difficult and little has been achieved with either mechanical or chemical control. Control is hampered by the weed’s extensive vegetative growth, profuse seed production, and the presence of subterranean root tubers. Individual stems growing along the ground readily develop roots and tubers wherever nodes touch the ground and can develop into new plants if separated from the parent plant. The presence of tubers therefore, makes infestations extremely...

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How cities can work with nature when droughts take their toll

August 1, 2018 3.22pm SAST Authors Kevin Winter Senior Lecturer in Environmental & Geographical Science, University of Cape Town Peta Brom PhD candidate in Urban Ecology, University of Cape Town Disclosure statement Peta Brom receives funding from South African Systems Analysis Center (SASAC) Kevin Winter does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. Partners University of Cape Town provides funding as a partner of The Conversation AFRICA. The Conversation is funded by Barclays Africa and eight universities, including the Cape Peninsula University of Technology, Rhodes University, Stellenbosch 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. A residential rain garden in Portland’s Tabor to the River project. City of Portland Government  Email  Twitter  Facebook55  LinkedIn  Print Models of the earth’s changing climate suggest that extreme weather events, including droughts, will become more frequent. As city populations grow, it will be harder for governments to provide enough water for everyone. According to the World Resources Institute, the northern and southern parts of Africa will experience high to extremely high water stress if business as usual water usage continues until 2040. Faced with a drought, it’s tempting for city managers to reduce the amount of space that needs water. Parks, public areas and private gardens are usually the first to go. But there are good reasons to keep nature in cities, and there are ways to do it. Municipalities typically respond to a drought by limiting water use, and then to look at ways to cover spaces with artificial surfaces like paving instead of lawns and plants. But there are four reasons why that is a bad idea. Impervious surfaces seal the soil. Surface water can’t filter down to recharge the groundwater, and normal biological processes in the upper layers of soil are interrupted. Instead, rainwater goes into the storm-water system. Covering up nature reduces biodiversity and habitat quality. Urban nature becomes poorer and there’s less of it. Concrete, tar and masonry raise the temperature of built-up areas. Green open spaces mitigate this so-called urban heat island effect. Enjoying nature gives people the opportunity to be healthy and well. Beneficial urban nature Nature in cities is good for people – and good for nature itself. Cities with continuous corridors and larger natural areas in excess of 50 hectares support greater...

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How the first trees grew so tall with hollow cores – new research

How the first trees grew so tall with hollow cores – new research

Author Christopher M. Berry Senior Lecturer in Palaeobotany, Cardiff University Disclosure statement Chris Berry receives funding from NERC (Natural Environment Research Council) UK and National Geographic. Partners Cardiff University provides funding as a founding partner of The Conversation UK. 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.   Imagine a world without trees, and then try to think about the changes that would need to happen for these trees to evolve from the small primitive plants that came before them. I spend as much time as I can trying to find evidence for this transition, which is currently estimated to have happened between 390-380m years ago, in the Mid-Devonian Epoch. One plant type, the extinct cladoxylopsids – an ancient plant group now only found as fossils – has continually demanded my attention. Despite these fossils first being found in the 1850s, understanding of the plants was highly confused for decades. This is a common problem in the study of fossil plants, because the living plants fall apart when they die, and it is often hard to determine which parts of which fossils should be joined back together. But during the 2000s we had major successes in reconstructing Devonian cladoxylopsids, culminating in a series of extraordinary discoveries of complete or almost complete fossil trees in Scotland, Gilboa, New York and Germany. The picture that emerged of the earliest types of cladoxylopsid – by then recognised to be the first forms of tree to appear – was of a long tapering trunk, up to at least eight metres high, with distinctive short branches attached around the top to form a crown. From a distance, the trees would have looked like palms, with bases up to a metre in diameter. There were no leaves as such, just branched twig-like appendages which presumably had a photosynthetic function in the carbon dioxide rich atmosphere of those times. An artist’s impression of what cladoxylopsid trees looked like alive.In cladoxylopsids, however, the xylem grew in a ring of individual parallel strands around the outside of the trunk. Inside this zone, more xylem strands formed a complex network with many interconnections both to each other and to the outer parallel strands. The majority of the inside of the trunk was completely hollow. This unusual structure is confusing, and raises questions...

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