The Nature of Things

Grasslands (39x3)

Date de diffusion: Nov 05, 1998

Over the last 200 years, the prairie grasslands of North America have undergone a radical transformation. The fertile soil, formed slowly over thousands of years, has been taken over by agriculture for crops like grain, oil seeds and forages for livestock. The buffalo have gone, replaced by millions of cattle. Breaking up the soil and removing the protective layer of grass has created severe erosion. Heavy machines compact the soil, limiting its ability to store precious moisture. Exposed to the air, soil dries to a powder and blows away. It was a frenetic period of transcontinental railway construction in the 1900s that opened the centre of the continent to millions of settlers.