Gardening on the urban edge

By Kay Montgomery Time of article published Mar 14, 2015

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‘THE Alien and Invasive Species Regulations passed in October 2014 have changed the playing field dramatically for properties on the urban edge,” says Louise Stafford, of the City of Cape Town’s Invasive Species Unit.

Landowners who do not have the required preventative measures in place may find their insurance company rejects their claims. They may also be held liable for the costs incurred, and claims against them if it can be proven that a fire started and spread from their property.

Dr Guy Preston, deputy director-general of Environmental Programmes in the Environmental Affairs Department, also confirmed earlier this week that they would begin a process to serve non-compliance notices on landowners along the urban fringe, instructing them to clear invasive aliens such as Port Jackson, gums, wattle, rooikrans and pine.

“The National Veld and Forest Fire Act also requires landowners in certain areas to put in firebreaks, become members of a fire protection society, and clear invasive alien plants,” Preston adds.

Stafford adds: “The city will work with the Department of Environmental Affairs to put pressure on landowners who do not abide by the new regulations.”

So why should gardeners on the urban periphery take note of these issues? After the Western Cape fires of 2000, it was estimated that more than 90 percent of the 8 370 hectares that burned was invaded by alien vegetation. The fire eventually destroyed 20 houses in Simon’s Town, and took nine days to extinguish.

The latest fires destroyed 6 000 hectares of vegetation. Thirteen homes were damaged and three were gutted. Five homes in suburbs north of Silvermine Road were damaged, one in Noordhoek, two homes were gutted in Tokai’s Almondbury Lane, one in the Steenberg Golf Estate and four in Klein Constantia.


residents furious about the fire damage are complaining about neighbours who did not deal with invasive alien species on their properties.

“Alien invasive trees, such as pines and gums, remain a major fire hazard because they created fire pathways through the slower-burning natural vegetation,” explains Table Mountain National Parks manager Paddy Gordon.

“Inspections are under way and non-compliance notices will be issued,” says Stiaan Kotze, biosecurity compliance officer in the Environmental Affairs Department.

Invasive species are not only a concern for landowners on the urban fringe, however. Every landowner in the country who sells a property infested with invasive aliens is now selling on a liability to the next owner. “By law, all buyers of property need to be made aware of all invasive alien species on the property by the sellers,” says Stafford.

The new Declaration of Invasive Species Form which has to be filled out by every seller of property, by law, has changed the rules dramatically for estate agents too.

Fires in fynbos:

Many fynbos plants cannot survive without fire, and need to burn generally every 12 to 18 years. Stafford says the predicament for Cape Town is that suburbia, invasive alien vegetation and fynbos co-exist in an unnatural combination.

The homes gutted in the latest fires were all beside large invasive alien trees. What is the difference between fires in areas of fynbos vegetation as opposed to those in areas infested by invasive aliens?

Fires in invasive alien vegetation:

l Burn much hotter than fynbos fires as they have a heavier fuel load (plant material, tree trunks).

l Move slowly and burn all the material present. This results in erosion and mud slides, loss of top soil and the slowing down recruitment of indigenous plants through seed germination.

l Are difficult to control as stumps smoulder for weeks, as is currently the case in the Tokai Forest.

l Cause damage to seedbeds by changing the upper soil structure, baking the soil and reducing the germination potential of some seeds – all on account of the extreme heat.

l Are difficult to control as smouldering alien plant-infested areas cause spot fires.

l Are the main causes of loss of property and infrastructure.

Pines and gums:

Homes surrounded by invasive alien pines and gum trees are at a particularly high risk in the case of runaway wildfires.

Why? According to scientists, gum trees (Eucalypts) have a high crude fat content, which is equivalent to high heat content. They also have low foliar moisture, therefore the vegetation and litter burn easily.

In addition, gum trees are also notorious for spreading spot fires because a number of the more common species, such as the saligna gum (Eucalyptus saligna), shed bark which hangs down in dry strips which ignite easily and are torn off in the high winds of a fierce fire.

These burning bark strips can be flung into houses when wind speeds are high and there are openings through which the particles can pass.

Pines also spot dangerously.

“Burning embers are the most common source of home ignition,” says Firewise expert Val Charlton. “Burning embers enter a home and set fire to something in the house. They are swirled around at high speed in the fire-generated winds and get forced into buildings through holes, ventilation ports and windows which have been cracked by the intense heat. Airborne debris may itself break windows in the case of particularly severe winds.”

Urban edge:

What should you be doing if you live on the urban edge?

l Managing fuel loads by controlling invasive plants.

l Create a fire break around your property to prevent fire from starting and spreading on to your property. All landowners are required by the Veld Forest Fire Act to make this happen.

l Train staff to combat fires.

l Keep sufficient suitable and serviceable firefighting equipment.

l Join a Fire Protection Association. Such associations consist of landowners who group together to share resources and plan mutually beneficial fire breaks

Report a problem:

Do you have a neighbour who is endangering your property by not controlling invasive species? Report your concerns:

l By e-mail: To Stiaan Kotze, Competent Authority, Biosecurity Unit, Department of Environmental Affairs: [email protected]

l To the hotline: 0800 205 005. The National Environmental Crimes and Incident Hotline is managed by Deloitte. Get a reference number and phone back for feedback in eight weeks.

l Attend an information forum: Interested in learning more about the Alien and Invasive Species Regulations? Attend a detailed briefing on the regulations: Western Cape Invasive Species Forum, April 14 (10am-2pm). Van Riebeeck Hall, Carinus Street, Kuils River. Booking essential. Entrance free. RSVP: [email protected]

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