All about the different types of grasses of Southern Africa
BY: Tasneem Johnson-Dollie
Part of field guiding is uncovering the spectacular in something seemingly mundane – like talking up grasses for example. But you may be surprised by just how interesting the different types of grasses can be, and how important they are to our ecosystems.
While the rustling sound they make can set the scene for some pretty romantic moments, it’s not often that grasses themselves grab our attention. But without this type of South African vegetation we wouldn’t see all of the animals and other plants that call this country home.
There are some excellent online field guide courses that can fill you in on South African foliage. But while you’re here, let’s find out more about the different types of grasses of Southern Africa and learn some interesting facts about the grassland biome.
Why are grasses important?
The different types of grasses belong to the family known as Poaceae, which includes grasses, reeds and bamboos. Scientists have described grasses as being the most important plant species in the world. This is because:
- plant life outweighs all other lifeforms on Earth, and grasses make up around 20% of all plants on Earth – meaning they contribute to Earth’s ecosystems in a big way
- the different types of grasses can inhabit a diverse range of habitats all around the world
- grasses are useful to human beings in a variety of ways, like feeding cattle, providing fuel for cooking and heating, being used for medicinal purposes, and building structures.
And today, a good patch of lawn is even useful for keeping up with the Joneses!
But, imagine going on safari without spotting your favourite animals in a grassland biome. Or missing out on seeing the sights of Africa because of all the dust blowing around. Grasses are a big part of why we can all enjoy these African attractions.
There are more than 10,000 identified grass species in the world and many more that have yet to be classified. So, to stop us from getting tangled up trying to understand this type of South African vegetation, let’s tease through the different types of grasses by taking a look at their different categories.
The different types of grasses of South Africa
Today scientists classify the different types of grasses according to their spikelet structure, anatomy of the leaf blade, starch grain structure, cytology, embryo structure and photosynthetic physiology. This basically means that what matters is how the plants grow, how they look when they’re mature and how they produce and store their food.
This system has lead to the classification of eight sub-families within the different types of grasses of Southern Africa:
- Arundinoideae – reeds that grow in the tropics and Southern Hemisphere
- Bambusoideae – bamboos that are endemic to every continent except Europe and Antartica
- Ehrhartoideae – crop-type grasses including rice
- Pooideae – cereals (like wheat, barley oat and rye), as well as pasture grasses
- Aristidoideae – herbaceous grass-types found in the tropics, subtropics and temperate zones
- Danthonioideae – herbaceous to partially-woody grass types that grow in open grasslands, shrublands and woodlands
- Panicoideae and Chloridoideae – tropical grasses with specific adaptations that allow them to tolerate warm and dry habitats.
These different types of grasses can be found growing all across Southern Africa, and come together in the wild to give the grassland biome a distinctly South African feel. But what is a grassland biome?
What is a grassland biome and how do different types of grasses contribute to it?
Think of wide-open grassy plains where trees and shrubs may make an appearance but aren’t as prominent as the swathes of spiky grasses spread all around. What you’re seeing in your mind is the answer to the question, “What is a grassland biome?”.
But there’s a difference between the big grassy patch beside the park where you live and a biome that’s dependent on this type of South African vegetation. You see, the different types of grasses found in a grassland biome actually determines the types of animals that can survive in these wide-open spaces.
For example, the temperate grasslands of North America are home to the types of grasses that store nutrients in their roots for parts of the year, making it the perfect habitat for burrowing animals. In contrast, grasses found in the savannah grassland biome generally store nutrients in their leaves and makes this environment fitting for grazing animals. So a slight change in the different types of grasses growing in a grassland biome can mean seeing prairie dogs instead of elephants!
Besides setting the scene for the types of animals you’ll find in grassland biomes, grasses are also some of the only plants that can grow in poor soils, recover after frequent fires, tolerate frost and cope with frequent grazing. This makes them a viable and vital part of grassland biomes in South Africa where these conditions are common.
Six interesting facts about the grassland biome
And just when you thought you couldn’t learn any more about the different types of grasses, here are six interesting facts about the grassland biome:
- Grassland biomes are also known as prairies, pampas, steppes and savannahs.
- 25% of the Earth is covered by grassland biomes.
- Because grasses grow in dense clumps, they prevent soil erosion by trapping the soil and preventing it from being washed away.
- Grasses have evolved to grow at their bases instead of their tips to protect themselves from grazing and fires.
- Grasses purify the air in the grassland biome by releasing oxygen and trapping dust.
- Giant bamboo is the largest variety of grass and can grow to be taller than 40 metres.
While grasses are part of one of the toughest families in the plant kingdom, there are quite a few things that affect the health of grassland biomes.
Environmental pollution and poaching are some of the major challenges facing grassland biomes today. And more and more of the grassland biome of South Africa is being affected each year.
So, where the grassland biome once stretched further than the eye could see, we’re now seeing bald spots dotting this type of terrain.
How to learn more about the different types of grasses of South Africa
Getting to know more about the different types of grasses of South Africa is a great way to get involved in work that conserves grassland biomes.