We often use the terms ‘global change’ and ‘climate change’ interchangeably. This is not entirely correct and can distract us from finding solutions for a resilient future. 

Although climate change is serious, it is only one component of global change. Global change is a broader term referring to the influence of the increasing pressure of humans on the Earth’s natural resources. Interestingly, the most formidable influence of global change has not been climate change, but what scientists call ‘land transformation’, which is the conversion of one land cover or use to another.

Of all the Earth’s land biomes, grasslands are one of the most heavily impacted by land transformation, owing to their importance for agriculture. But grasslands are also one of the Earth’s most extensive biomes, covering 40.5% of the land surface, so what happens in grasslands is particularly significant for the Earth’s functioning and the well-being of humans.

Ecosystem services 

Grasslands provide invaluable ‘services’ that allow life to flourish. They are especially important for water production, as grazing lands, and for nutrient cycling and carbon storage. They are critical for mitigating climate change. Over the decades, there has been extensive transformation in grasslands, and scientists are now taking urgent stock of remaining grasslands.

This is a challenge. An estimated 40% of South Africa’s grasslands have been transformed into other land covers like cultivated fields or tree plantations, but there are some questions about what we call grasslands. Pristine ‘primary’ grasslands become ‘secondary’ if, for example, they have been ploughed or planted with trees but have since ‘recovered’ a grassy cover. Modern satellite and drone imagery cannot detect whether grassland is primary or secondary.

So, what’s the deal?

It’s a biggie – secondary grasslands are not known to recover their biodiversity and functioning! Current estimates indicate that the time grassland biodiversity takes to recover could be as much as a millennium, and that is if some ‘reservoir’ of biodiversity remains to propagate the recovery.

The bottom line is that for biodiversity and our own survival, we need to ensure that enough grasslands are maintained. This is especially the case in our mountain regions, which produce most of the country’s water and have exceptionally high levels of biodiversity.

The Drakensberg, for example, is home to some 2 500 plant species upon which other indigenous biodiversity depends. Maintaining such grasslands in their primary state makes the most economic sense.