“The best time to plant a tree was 20 years ago. The second-best time is now,” is an old Chinese proverb. Now consider that a significant part of Johannesburg’s tree canopy is set to reach its full life expectancy within a decade or two.
Main Johannesburg has a proud, centuries-old tradition of tree planting, and can lay claim to being the largest man-made urban forest. It is reported that the greater Johannesburg area has now more than 10-million trees.
Johannesburg’s trees clean the city air for residents, and cool the urban heat island, dampen noise, decelerate traffic, slow storm water run-off, rejuvenate the soil, and even bring the rain, studies show.
Records show that Johannesburg’s urban forest was rooted in proactive, planning as far back as 1896 when 106 kilometres of trees were planted along the suburb of Kensington. Starting with the end in mind, Johannesburg City Parks and Zoo (JCPZ) guards and advances this legacy. Trees were planted across the City during Arbor Month 2020 to accelerate efforts to bridge the green-divide and mitigate the impacts of the Polyphagous Shot Hole Borer.
Battling a tree killer
Councillor Margaret Arnolds the MMC for Community Development joined by Councillor Mpho Moerane, the MMC for Environment and Infrastructure Services in the City of Joburg, are resolute in their support of tree-planting efforts.
A large portion of Joburg’s tree canopy will be reaching its full life expectancy in the next two to three decades. “The ageing tree canopy is more susceptible to the adverse impacts of inclement weather; pests and diseases such as the shot hole borer; unnecessary pruning and increasing urbanisation,” said Arnolds.
The shot hole borer beetle has caused both private and street trees to die in various City regions. The ambriosa beetle is native to Southeast Asia and bores small “gun-shot” like holes into the trees. The beetle, which attacks 56 tree species, damages the vascular bundles ultimately resulting in die-back. Currently there is no effective chemical solution and biological treatment to control the beetle.
JCPZ has developed an action plan for the appropriate removal of dead wood, embarked on widespread green landscaping through tree planting during Arbour month and, an awareness campaigns to inform communities about the beetle and its symbiont fungi. The removal of deadwood operation was undertaken from August until October as part of Arbor month 2020 activities.
Host tree species
On-going research is being undertaken in South Africa by leading experts to determine both reproductive or susceptible host trees and non-reproductive host trees. The commitment of the City of Johannesburg towards its environment, residents and investors is effectively portrayed in beautiful and safe public spaces.
Green landscaping programmes were launched throughout the City which included planting of indigenous trees in Gamka Park, Riverlea. 1000 fruit trees were distributed to homeowners in various regions and 3350 indigenous trees were planted during Arbor Month across Johannesburg.
Arnolds states: “The recent, steady decline in the City’s tree canopy requires integrated planning at multi-entity level to create a tree-lined Joburg in every part of the city.” She highlighted that while tree planting plans are being expedited to offset the trees that are lost, progress has been fragmented due to water restrictions; slow responses and space constraints that are guided by the wayleave process for clearance to plant trees in public spaces.
So, what can we all do?
“Space is limited in Joburg and we are calling on homeowners to plant trees in private spaces. A tree, no matter the season, works as a natural air sanitiser that keeps your air filtered from pollutants; deters erosion; acts as a coolant; provides a habitat for wildlife; serves as a food source; is often medically beneficial and has far reaching implications on mental health,” she said.
Arnolds appealed to residents to make tree planting a way of life to commemorate births, deaths and anniversaries. “The legacy of a tree planted to mark a family milestone is a lifelong gift,” she adds.
As street-side trees are JCPZ’s responsibility, communities are encouraged to report all dead-infested trees. JCPZ is currently targeting the removal of confirmed dead trees only, and not infested trees, to help preserve the existing urban canopy.