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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

Prof Jonathan Jansen bids farewell to Kovsies
2016-08-31

 

Dear Kovsie staff and students

This is my final message to you all.

I wish to use this opportunity for some brief reflections, share a word of gratitude, and convey a sense of the future for our beloved university.

Since the announcement of my departure, I have had more than a dozen breakfasts with mainly students, but also staff, to offer an opportunity for the final sharing of thoughts and, of course, goodbyes. The most common questions asked at those breakfast sessions were the following, with my responses. I repeat them here, since these might also be of interest or concern to you.

What are your proudest achievements?
Two things. The increase in the academic standard for the UFS, both in terms of admission standards and pass rates, but also in relation to the requirements for appointment and promotion especially of professors. This is important because in a globally competitive world, a university stands or falls by the quality of its degrees. And for this you need the best students and the best professors.

What would you do differently, given another chance?
Nothing. I believe that leadership is about doing the best you can with the cards you are dealt in the circumstances in which you are placed. There is no point in second-guessing past decisions. I have always been ambitious as a leader, knowing that most of my goals would be met, and that some would not. That is normal in large and complex organisations, and so, I do not sit around pondering regrets, only remembering with gratitude the things we could achieve together.

What did you learn?
A lot. I learnt that our students have tremendous capacity for greatness both in their academic pursuits but also in their ability to live, and learn, and love together. I have learnt never to underestimate the capacity of our youth to excel in whatever they do. Sometimes I felt I was more ambitious for our students and staff, than they were for themselves. But I have constantly been surprised by the capacity of young students to rise above bitterness and division, and to make great our campus, country, and continent.

I learnt, again, that the overwhelming majority of our staff and students are good people, respectful of each other, and determined to work together to heal our broken past and build a more just society. And I learnt that it is much more fulfilling to build up than to break down, to embrace than to exclude, and to love than to hate.

Were you frustrated with the pace of transformation?
Sometimes, yes. But fortunately I studied educational organisations all my life, mainly schools and universities. Universities are called institutions for a reason, and on century-old sites like the historic Bloemfontein Campus of the University of the Free State, there are core beliefs, values, and practices deeply ingrained in the culture of the place.

Anyone, therefore, who believes that transformation is easy, has obviously never tried to change an old university. It is difficult. You will get blowback. You will get bad press. You will, sadly, lose the support of some people. Some believe the university is changing too fast while others will tell you it is not changing fast enough. As you press for change, you find the university going two steps forward and one step back; in these circumstances, the solemn duty of the leader is simply to ensure that the overall momentum is always forward.

For such a time as this –
a commemorative journey:
2009-2016 (PDF book)

Description: Prof Jansen commemorative journey2 Tags: Prof Jansen commemorative journey

I therefore budget for disappointment even as I relish the many changes we have experienced together over the past seven years. If you want to obtain an objective sense of the scale of the changes at the UFS, ask those students and staff who were here in 2009, not those who came recently. They will tell you that we have a very different university, even though we all acknowledge that there is still some distance to travel. Our remarkable story of change is told in the recent Transformation Audit of the UFS, chaired by Prof Barney Pityana; that Audit Report will be released after it is read and studied by the University Council at its November meeting.

At an individual level, I learnt that most campus citizens change quickly and others more slowly, and that one has a duty to constantly push for change, but also to be patient about change. And I learnt that the ideal change retains the best of our past even as we embrace a more just and inclusive future in which all campus citizens feel that the university truly belongs to each and every one of them.

Are you optimistic about the future of our university?

Yes. The UFS is a very well-managed university thanks to the exceptional talent in the management of our finances, human resources and information technology environments. By the end of 2016, we will have record enrolments, from undergraduates to doctoral students, which is good for our future income. We run a tight ship with regard to the university’s finances, and we have greatly improved the academic standard of our qualifications; in this regard, I am very proud of my senior management team, and the talented middle management personnel, and those who make things work at the coalface of our operations.

I am very concerned, however, about future funding of the 26 public universities and the extremely vulnerable situation of at least 10 higher-education institutions. The economy is not growing and the costs of running a modern university are escalating. The delays in government commission reports on tuition fees do not help, and there seems no urgency ‘higher up’ to make the tough decisions.

We have to ensure free education for the poorest students — that is the position of your senior management – but we also need to guarantee the financial sustainability of our universities. The task of the UFS leadership, in this period of uncertainty, is to manage those two expectations as best we can. But this cannot happen without your assistance, and I do ask that you provide the new Rector and his or her team with the same understanding and support which I have enjoyed from you.

In conclusion
I am grateful.

To the many hundreds of students who have passed through my office and our home, and who sat in my many lectures and engaged me in your residences – thank you for enriching my sense of life and leadership. I am grateful that Grace and I could support and mentor many of you over the years and see you graduate. I am a better leader because of you.

To the staff of the three campuses – there is no university Rector, I can assure you, who enjoyed more love and support than what you offered me since the day I arrived here. Students come and go, but you have been my foundation year after year, and I thank you for that.

To parents, friends, and followers off-campus, in South Africa and abroad – thank you for hundreds of letters, emails, phone calls, prayers and ‘packages of support’ (from biltong to books). In the most difficult times, you rallied from everywhere with a word of support, often on social media. Know this: your words kept me calm in the storm.

Thank you, everyone.

Goodbye.

Prof Jonathan Jansen
Vice-Chancellor and Rector
University of the Free State

Description: Prof Jansen saying goodbey Tags: Prof Jansen saying goodbey

Prof Jonathan Jansen steps down as UFS Vice-Chancellor and Rector (16 May 2016)

 

 


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