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20 July 2020 | Story Leonie Bolleurs | Photo Supplied
The view from one of the offices in the Marion Island research station, with fresh snowfall in the interior of the island in the background.

Liezel Rudolph, lecturer and researcher in the Department of Geography at the University of the Free State (UFS), is strongly convinced that the Southern Hemisphere’s past glacial cycles will provide valuable insights to help predict and prepare for future climate change. Climate is changing fast and the magnitude of change we have seen over the last 30 years has taken a hundred or several hundred years to occur in the past. 

It is not only temperatures that are rising, but changes in wind patterns, rain cycles, oceanic circulation, etc., are also observed. As we do not know how the earth will respond or adapt to such rapid and drastic changes in climatic patterns, this poses various threats.

Link between landscape responses and climate change

Rudolph focuses her research on reconstructing the past climate of Marion Island. 

She had the wonderful opportunity to visit the island for the past three years with study and project leaders, Profs Werner Nel from the University of Fort Hare and David Hedding from UNISA, she departed on a ship to Marion Island to conduct fieldwork.They published their research findings of fieldwork conducted in 2017 and 2018.  

According to Rudolph, research in Antarctica, the Southern Ocean, and islands such as Marion Island is very important. South Africa is the only African country with research stations that have the ability to explore these regions.

“Marion Island has many landforms that could only have been created by glacial erosional or depositional processes, with glaciers currently absent from the island. To determine when the island was last in a full glacial period, we date the formation ages of these landforms.”

“In the short time we have been visiting the island, it was impossible to notice any drastic changes in the island climate. That is why we use these very old landforms to tell us more about periods before humans visited the island,” she says. 

Rudolph believes that understanding the link between landscape responses and climate change of the past can help to better predict some of the climate change processes that are currently threatening the planet.

“There’s a principle in geography called ‘uniformitarianism’, whereby we assume that the earth-surface processes we observe today, are the same as those that have been active in the past,” says Rudolph.

As scientists, they thus look at evidence of past geomorphic processes (which remain in the landscape in various forms, e.g. residual landforms, stratigraphic sequences, etc.) to piece together what the past climate was like. In the same way, they also use this principle to predict how certain earth processes will change in the future, along with climate changes.

“In return, we understand how the climate and the earth’s surface interact, and we can better predict how the earth will respond to climate change,” Rudolph adds. 

Society to play its part in climate change

In the long run, we as the public should play our part in readying society for the effects of climate change. 

Rudolph says society can play a positive role in terms of climate change by educating themselves with unbiased, scientifically sound information on the true state of climate change and by responding within their own spheres of influence.

“Don’t leave everything up to politicians and policy. As the public, you can start to make progress by assessing the effects that climate change may have on your industry, business or society, and strategise on how to adapt your processes to deal with these changes.”

“Be responsible with our natural resources, reduce your waste, support local businesses that are sustainable, and volunteer at a local environmental protection/clean-up organisation. All the small efforts will eventually add up to substantial change,” she says. 

News Archive

Sunflowers are satellite dishes for sunshine, or are they?
2016-07-20

Eighty-six percent of South Africa’s
sunflowers are produced in the
Free State and North West provinces.

Helen Mirren, the English actress, said “the sunflower is like a satellite dish for sunshine”. However, researchers at the University of the Free State (UFS) have found that too much of this sunshine could have a negative effect on the growth of sunflowers, which are a major source of oil in South Africa.

According to Dr Gert Ceronio from the Department of Soil, Crop, and Climate Sciences at the UFS, extremely high soil temperatures play a definite role in the sprouting of sunflower seedlings. Together with Lize Henning, professional officer in the department, and Dr André Nel from the Agricultural Research Council, he is doing research on biotic and abiotic factors that could have an impact on sunflowers.

Description: Sonneblom 2 Tags: Sonneblom 2

Various degrees of deformity (bad-left
to none-right) in seedlings of the same
cultivar at very high soil temperatures.
Photo: Dr Gert Ceronio

Impact of high temperatures on sunflower production

The Free State and North West provinces, which produce 86% of South Africa’s sunflowers, are afflicted especially by high summer temperatures that lead to extremely high soil temperatures.

Dr Ceronio says: “Although sunflower seeds are able to germinate at temperatures from as low as 4°C to as high as 41°C, soil temperatures of 35°C and higher could have a negative effect on the vegetative faculty of sunflower seedlings, and could have an adverse effect on the percentage of sunflowers that germinate. From the end of November until mid-January, this is a common phenomenon in the sandy soil of the Free State and North West provinces. Soil temperatures can easily exceed the critical temperature of 43°C, which can lead to poor germination and even the replanting of sunflowers.”

Since temperature have a huge impact not only on the germination of sunflower seeds, but also on the vegetative faculty and sprouting of sunflower seedlings, Dr Ceronio suggests that sunflowers should be planted in soil with soil temperatures of 22 to 30°C. Planting is usually done in October and early November. Unfortunately, this is not always possible, as soil moisture is not optimal for growth. Farmers are then compelled to plant sunflowers later.

Impact of herbicides on sunflower growth

“High soil temperatures, combined with the herbicide sensitivity of some cultivars, could lead to the poor development of seedlings," says Dr Ceronio.

The use of herbicides, such as ALACHLOR, for the control of weeds in sunflowers is common practice in sunflower production. It has already been determined that ALACHLOR could still have a damaging effect on the seedlings of some cultivars during germination and sprouting, even at recommended application dosages.

“The purpose of the continued research is to establish the sensitivity of sunflower cultivars to ALACHLOR when exposed to high soil temperatures,” says Dr Ceronio.

 

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