From the cradle of mankind to an ecological crisis region
Despite their outstanding importance for humans, the global grasslands are a long way from an appreciation of this “ecological capital”, as the US scientists Caroline Strömberg and Carla Staver make clear in their work on the history of the emergence and the current problems of grassland habitats. The biologists remind us that our history is also closely linked to grassy habitats. Because it was in the savannahs that modern humans were able to develop two million years ago. And it was only the domestication of some of the more than 10,000 species of grasses such as wheat and barley, about 10,000 years ago, that made agricultural societies, and thus modern civilization, possible at all. Today there are half a dozen cultivated grass species that, along with corn and rice as the most important staple foods on earth, ensure the survival of mankind. Strömberg and Staver emphasize the importance of this type of habitat, even raising livestock is unthinkable without grassland.
Particularly endangered and poorly protected
The authors also take a look at the threats to which different grasslands are exposed worldwide. Due to changes in land use, they are particularly badly affected by overexploitation, climate change and direct destruction, Strömberg and Staver note. At the same time, they were among the least protected habitats almost everywhere.
As a result, 90 percent of the original grasslands in temperate climate regions have already been converted into areas used for agriculture or human settlements. According to the authors, only one percent of the remaining area is currently protected from development. “While the Amazonian rainforests have attracted media attention, the ongoing threat to the savannahs, particularly in Africa, South America and Asia, from afforestation, slash-and-burn and land conversion has gone unnoticed,” they lament. The effects of further destruction on the biological diversity of savannas, prairies, meadows and pastures would be devastating. Strömberg and Staver expect that 40 percent of all grassland-adapted vertebrate species will be lost in the next few decades. “The fate of the evolutionarily old grassland biomes is at stake, with fatal consequences for their different communities,” is the less than optimistic conclusion.
»Grasses could offer solutions to many of our current societal challenges if only we fully recognized their diversity and value«(Bianca Lopez, Pamela J. Hines, and Caroline Ash, Science Editors)
In an article on the chances of restoring destroyed grassland habitats, Elise Buisson and colleagues examine how important it is to preserve the few intact regions that still exist. Recent research suggests that grasslands recover from disturbances slowly and sometimes not at all, they write. At the same time, there are large knowledge gaps in research in this area. “At the beginning of the decade of ecosystem restoration that has just been proclaimed by the United Nations, advances in the science and practice of grassland regeneration are of crucial importance if we want to combat the decline in biological diversity,” the scientists conclude.