All ecosystems are dynamic – and grassland’s no exception.
Just like any ecosystem, grassland is in a constant state of flux. And that’s good. Because if it was static it would be a dead ecosystem.
Flux is an essential ecological process that's controlled by two characteristics: “Resistance” and “Resilience”. These two together contribute to a healthier, more stable ecosystem.
In a nutshell, Resistance is the ability of an ecosystem to remain at equilibrium despite disturbances like fire or invasive species. And Resilience is the speed it recovers after disturbance.
For grassland this is important.
Because grassland contains a unique combination of grasses and herbaceous plants that have adapted to grazing and fire. And they need both the grazing and the fire to maintain their structure and biodiversity.
Together the fires and grazing animals help to prevent the encroachment of woody plants, shrubs and trees.
Grazing also stimulates plant growth. It triggers new growth points and new shoots – a bit like pruning a shrub does. And as a result it promotes regrowth and rejuvenation (as well as storing more carbon).
The animals also recycle nutrients that enrich the soil. And in doing so disperse seeds which helps to promote biodiversity. In fact, species-rich semi-natural grassland usually boasts more than 15 and sometimes up to 40 beneficial plant species per square metre.
Together the animals and the fires spur competition among plant species. And it's this competition that prevents a dominant species from taking over.
In effect, they create the opposite of a monoculture.