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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

Well-established root system important for sustainable production in semi-arid grasslands
2015-02-24

Plot layout where production and root studies were done
Photo: Supplied

The importance of a well-established root system for sustainable production in the semi-arid grasslands cannot be over-emphasised.

A study of Prof Hennie Snyman from the Department of Animal and Wildlife and Grassland Sciences at the University of the Free State is of the few studies in which soil-water instead of rainfall has been used to estimate above- and below-ground production of semi-arid grasslands. “In the past, plant ecological studies have concentrated largely on above-ground parts of the grassland ecosystem with less emphasis on root growth. This study is, therefore, one of the few done on root dynamics in drier areas,” said Prof Snyman.

The longevity of grass seeds in the soil seed bank is another aspect that is being investigated at present. This information could provide guidelines in grassland restoration.

“Understanding changes in the hydrological characteristics of grassland ecosystems with degradation is essential when making grassland management decisions in arid and semi-arid areas to ensure sustainable animal production. The impact of grassland degradation on productivity, root production, root/shoot ratios, and water-use efficiency has been quantified for the semi-arid grasslands over the last 35 years. Because of the great impact of sustainable management guidelines on land users, this study will be continuing for many years,” said Prof Snyman.

Water-use efficiency (WUE) is defined as the quantity of above- and/or below-ground plant produced over a given period of time per unit of water evapotranspired. Sampling is done from grassland artificially maintained in three different grassland conditions: good, moderate, and poor.

As much as 86, 89 and 94% of the roots for grasslands in good, moderate and poor conditions respectively occur at a depth of less than 300 mm. Root mass is strongly seasonal with the most active growth taking place during March and April. Root mass appears to be greater than above-ground production for these semi-arid areas, with an increase in roots in relation to above-ground production with grassland degradation. The mean monthly root/shoot ratios for grasslands in good, moderate, and poor conditions are 1.16, 1.11, and 1.37 respectively. Grassland degradation lowered above- and below-ground plant production significantly as well as water-use efficiency. The mean WUE (root production included) was 4.79, 3.54 and 2.47 kg ha -1 mm -1 for grasslands in good, moderate, and poor conditions respectively.

These water-use efficiency observations are among the few that also include root production in their calculations.

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