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31 October 2021 | Story Elsabé Brits
Grassland

In the vast, flat grasslands of South Africa a host of magnificent plant and animal species flourish, but not all of them are large. Insects and spiders share the landscape, and they are sometimes the uncelebrated heroes of a fragile ecology.

Walking through grasslands one often ignores what is under our feet, but these creatures are vitally important for the wellbeing of any ecosystem.

Grasslands are the dominant vegetation in the central parts of the country, covering most of the Free State and Gauteng and large parts of the North West, Mpumalanga, KwaZulu-Natal and the Eastern Cape, explains Prof Charles Haddad from the Department of Zoology and Entomology in the Faculty of Natural and Agricultural Sciences at the University of the Free State (UFS).

Insects fulfil a myriad of ecosystem functions and deliver crucial services in grasslands. They are the most important group of pollinators, such as bees, flies, and beetles, and are critical to the breakdown of plant and animal waste, especially flies and beetles. They are predators and parasites of other invertebrates, especially spiders, beetles, wasps and flies. The more species in an ecosystem, the greater the number of interacting organisms that can contribute to food webs.

Unfortunately, grasslands are the most threatened biome in South Africa, largely as a consequence of historical agricultural expansion of crop and livestock farming. More recently, urban development, invasive plants and silviculture have impacted on the remaining natural grasslands.

“Little is known about the impact of these activities on terrestrial biodiversity. The presumption is that the destruction and fragmentation of natural grassland reduces the natural vegetation available to indigenous organisms. This creates problems for insects to find suitable plants to feed on, which has a negative impact on their predators and parasites.

“Most anthropogenic influences affect indigenous biodiversity negatively, with very few exceptions. Generally, it is exotic invasive species that benefit the most from disturbance, habitat changes or destruction,” says Prof Haddad.

Spiders

More than 900 species of spiders have been recorded in our grasslands and some 2 300 in the country. Spiders are predators of other invertebrates, especially insects, and play an important role in the natural control of their populations.

They are very resilient to disturbance but are susceptible to chemicals used on crops, the effects of alien plants, and competition with exotic spider species, says Prof Haddad.

Among the interesting spider species one can find in grasslands is a rich diversity of trapdoor spiders, which live in burrows in the ground. Many of them have narrow associations with specific soil types and are often good bioindicators for conservation management.

Some plant-dwelling spiders are uniquely adapted to living on grasses and have slender, pale bodies to camouflage themselves on the stalks of grasses. In contrast, tree-dwelling spiders are often brown with tubercles on their bodies to blend in with the bark of trees to help them ambush their prey, says Prof Haddad.

Termites

Termites are some of the most populous animals on Earth, and the effects they have are most profound in the grasslands. Termites are one of the few animals that can break down cellulose from dead wood and grass. This is made possible through their symbiotic association with tiny microorganisms in their alimentary canal, such as protozoans and bacteria. The microorganisms secrete the enzyme cellulase, which the termites cannot produce themselves, allowing for the breakdown of cellulose in the ingested plant material and the release of the component nutrients for use by the termites. Therefore, these insects play an integral role in the reintroduction of nutrients from the dead plants into the soil.

This enables them to utilise the molecules in the grass that would have otherwise been inaccessible. Their faeces, therefore, contain broken-down nutrients that the roots of plants can absorb.

Many termite species live in underground nests that are great in aerating the soil. Others build large mounds which are extensions of the nests above the soil surface. These mounds, particularly those of the snouted harvester termites, are a familiar feature in most grassland landscapes in the country. These nests and mounds also offer shelter to other organisms, such as spiders, scorpions, lizards, snakes, millipedes, and various insects.

Termites are an important food source for enigmatic animals such as the aardvark and aardwolf, as well as some spiders and beetles, says Prof Haddad. 

Mosquitoes 

Liezl Whitehead, a master’s student in the Department of Zoology and Entomology at the UFS, explains the role of how even mosquitoes are essential.

Mosquitoes are vitally integrated into the ecosystem even as larvae, where they feed on aquatic microorganisms, thereby affecting species interactions and ecosystem dynamics within the aquatic habitat.

Adult mosquitoes feed on nectar as their main food source, and in the process also serve as plant pollinators. Many female mosquitoes do, however, require a blood meal for egg production, where they then transmit a multitude of pathogens. Interestingly, these pathogens play a vital role in the ecosystem, where they help to regulate host population sizes, thereby maintaining the integrity of the ecosystem.

“In recognising the significance of all forms of life, one also realises that mosquitoes play an essential role in the life cycle of numerous other organisms, including protozoans [single-celled microscopic organisms], nematodes [often referred to as roundworms, but they are not closely related to true worms], and mites that depend on mosquitoes for their development and dispersal.

The abundance and widespread nature of mosquitoes contributes to their significant role in the grassland food chain, where the larvae are consumed by countless aquatic organisms, including insects, fish and amphibians. The adults are consumed by a multitude of arthropods and vertebrates, including dragonflies, birds and bats.

“Their elimination from the ecosystem would thereby impact multiple processes within the ecosystem, affecting food webs, pollination and the presence of many other associated organisms,” Whitehead adds. 

A vital food source, urgent protection needed

Prof Liesl van As, Head of the Department of Zoology and Entomology at the UFS says that although the Grassland biome covers an area of 339 237 km2, less than 2% is formally protected. In 2004, the National Spatial Biodiversity Assessment (NSBA) identified the Grassland biome as the most threatened habitat, with more than 30% already irreversibly transformed. A year later, the Grassland Biodiversity Spatial Priority Assessment identified 37% of the land as being important for conservation and suggested that 12% needs to be under formal protection by 2028.

Most of the South African grassland literature refers to the almost 400 plant species, the 34 endemic mammals, and the dozen or so globally threatened bird species, with almost no mention to representatives of the Arthropoda (including spiders, termites and mosquitoes).

Invertebrates are the main components of faunal diversity in grasslands, playing substantial roles in ecosystem processes, including nutrient cycling, pollination, and being a vital food source in food webs (Die een se dood is die ander een se brood).

“These invertebrate communities are heavily dependent on plant diversity and production within a given ecosystem, but for some reason, they don’t get the full recognition and attention compared to the larger animals. Maybe it is because they are not so visible due to their smaller size?

“A visit to www.grasslands.org.za and the Grassland Society of Southern Africa draws our attention towards the fact that although progress has been made in the awareness of the sensitivity of grassland habitats, gaps still exist concerning the biodiversity of the remaining natural fauna. To follow up on this, I am of the opinion that when it comes to invertebrates, such as the spiders, termites and mosquitoes we are now writing about, knowledge and public awareness (citizen science) is contributing to reducing this gap” says Prof Van As.

According to her, in their department, a number of colleagues from Animal Behaviour, Arachnology, Nematology, Applied Agricultural Entomology, Environmental Entomology and Dipterology, to name a few, have been involved in research projects for the past few decades, with a focus on the grassland area, closer to home.  Through their effort and contributions, they are making a scientific difference. 

News Archive

Top-class musicians appointed in UFS Odeion String Quartet
2008-11-02

 

From the left are: Denise Sutton, first violinist and leader of the string quartet, Sharon de Kock, second violinist, Jeanne-Louise Moolman, violist, and Anmari van der Westhuizen, cellist. 
 Photo: Dries Myburgh

 The University of the Free State (UFS) has recently appointed four acclaimed, top class musicians in its Odeion String Quartet. The quartet, which was established in 1991, is the only resident quartet at a South African university.

The new members who have been appointed are: Denise Sutton, first violinist and leader of the string quartet, Sharon de Kock, second violinist, Jeanne-Louise Moolman, violist, and Anmari van der Westhuizen, cellist. Anmari is the latest addition to the quartet.

Denise Sutton is well-known, inter alia, as longtime concert master of the PACT orchestra, as leader of the Rosemunde Quartet, for her involvement with the Chamber Orchestra of South Africa (COSA), and as a inspiring teacher at the University of Pretoria.

Jeanne-Louise Moolman has about twenty years experience as principal violist of professional orchestras in Gauteng and was leader of the violas in the Johannesburg Philharmonic Orchestra and COSA. She was also a founder member of the Rosemunde Quartet.

Sharon de Kock, formerly from Cape Town, studied at the University of Cincinnati, played in symphony orchestras in Peru, Costa Rica and the USA, and was a violin teacher in Mexico and Costa Rica until her return to South Africa in 2007.

Anmari van der Westhuizen, formerly from Stellenbosch, is one of the most sought-after cellists in South Africa, has been the conductor and director of the UCT String Ensemble since 1999, and spent eight years as soloist and chamber musician in Europe from 1988-1996.

The new quartet will be launched at a concert on 6 November 2008 in the Odeion on the Main Campus in Bloemfontein.

The new appointments follow after three former members of the quartet – Jürgen Schwietering, John Wille and Abrie de Wet – retired or left Bloemfontein at more or less the same time. Michael Haller, longtime cellist of the quartet, will also be retiring at the end of 2008. These developments mean that the Odeion String Quartet is literary brand new.

The new appointment creates exciting new opportunities for learners and students to be taught by excellent lecturers at the music department of the UFS. The new players also strengthen the Free State Symphony Orchestra significantly, since they will fill the four principal positions in the strings.

“The Odeion String Quartet is a flagship of the UFS and it symbolises our commitment to the arts. It also plays an important strategic role in the development of symphony orchestra music and classical music training in the Free State. It is an essential part of UFS regional collaboration with e.g. the Free State Symphony Orchestra, the Mangaung Strings Programme, the Free State Musicon, the Free State provincial Department of Arts and Culture and Pacofs.This is why a real attempt was made to obtain top class musicians, to attract the best in the country. We are pleased that such a strong group could be appointed,” said Prof. Frederick Fourie, chairperson of the String Quartet’s management committee and outgoing Rector and Vice-Chancellor of the UFS.

Most string quartets abroad are affiliated with a higher education institution, which enables a higher level of playing as there is more time for preparation and to study the repertoire. “We appreciate the university’s confidence in us and for the opportunity to explore the intricacies of ensemble playing. We hope that we can produce inspiring performances for our audiences and students,” said Denis Sutton, new leader of the string quartet.

Abridged CVs

Denise Sutton studied at the University of Stellenbosch (US) and obtained the degree B.Mus. with distinction. After this, she studied in Amsterdam with Theo Olof and Nap de Klijn, as well as in London. She was leader and second violinist in the Scottish Chamber Orchestra and did a successful audition for the English Chamber Orchestra. In South Africa she had a long career as concert master and leader of symphony orchestras. From 1980 she was concert master of the TRUK Orchestra for almost twenty years and from 2000 until 2005 she was member of the Johannesburg Festival Orchestra and the Chamber Orchestra of South Africa (COSA). She was also a founding member and leader of the Rosamunde String Quartet, one of the leading string quartets in the country. Denise had a very successful part-time teaching practice at the University of Pretoria (UP) and at a number of schools. She was also involved in postgraduate training. Her students include various competition winners and a number of them are playing professionally.

Jeanne-Louise Moolman studied at the UP under Prof. Alan Solomon where she obtained the B.Mus and B.Mus.Hons. degrees with distinction. She won among others the ATKV Forté and the Oude Meesters competitions and in 1985 she was the first winner of the prestigious 75th Commemorative Prize of the University of Natal. She has about twenty years experience as principal violist of various professional orchestras in Gauteng. Until her appointment at the UFS she was leader of the viola section in the Johannesburg Philharmonic Orchestra and COSA. She is an experienced chamber musician who regularly performs in various combinations with some of South Africa’s leading musicians. This includes Gerard Korsten, Phillipe Graffin, Jürgen Schwietering, the pianists Lamar Crowson and Albie van Schalkwyk, as well as clarinet player Robert Pickup. Jeanne-Louise was also a founding member of the Rosamunde String Quartet. She lectured on a part time basis at the UP and the Pro Arte Music School.

Sharon de Kock obtained the degrees B.A. Mus. and M.Mus. at the College-Conservatory of Music (CCM) of the University of Cincinnati in the United States of America (USA) in 2002 and 2004 respectively. Some of her teachers include the well-known concert violinist Chee-Yun Kim, Prof. Kurt Sassmannshaus and Piotr Milewski, all alumni of Julliard. From 2004 to 2006 she was violinist lecturer at two universities and a music conservatorium in Puebla, Mexico. She was also violin lecturer at a music school in Costa Rica and was associated with the Hugo Lambrechts Centre in Cape Town since 2007. Her orchestra participation includes among others the Opera Orchestra in Trujillo, Peru, the Sinfónica Nacional de Costa Rica in Costa Rica, as well as the Kentucky Symphony Orchestra, the Richmond Symphony Orchestra and the Dayton Philharmonic Orchestra. She also participated in the Luca Music Festival in Italy, the Grandin Music Festival in Portugal, the Pacific Music Festival in Japan and the Aspen Music Festival in the USA. Sharon performed regularly abroad as soloist and received various awards. This includes among others the CCM chamber music competition 2003 and the Baur Orchestral Competition and Heermann competition winner for violin at the CCM in 1995. In 1990 she won the first prize in the Sanlam competition.

Anmari van der Westhuizen was the winner at several national competitions such as the Forté and Oude Meester Competitions and in 1985 was the first winner of the prestigious University of Natal 75th Anniversary Prize. She is today one of the most sought-after cellists in South Africa. Anmari, a cum laude graduate of the Stellenbosch University, was awarded the Grosses Konzertdiplom with distinction at the Mozarteum in Salzburg and the Konzertexamendiplom at the Hochschule für Musik in Cologne, working under Heidi Litschauer and Maria Kliegel respectively. During her stay Europe from 1988 to 1996 she appeared as soloist and chamber musician in such groups as the Koehne String Quartet in Vienna, also appearing at international festivals in Austria, Italy and Spain. Anmari has made several CD recordings. Since 1999 she has been the conductor and director of the UCT String Ensemble. A founder member of the UCT Trio, the Collage Ensemble and I Grandi Violoncellisti, Anmari still performs regularly throughout South Africa, and is invited by the Austrian Composers Union as solo cellist.

Media Release
Issued by: Lacea Loader
Assistant Director: Media Liaison
Tel: 051 401 2584
Cell: 083 645 2454
E-mail: loaderl.stg@ufs.ac.za  
29 October 2008
 

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