Ecology of Temperate Grasslands: PTE Listening: Fill in the Blanks practice questions

The dense network of underground roots is perhaps the most remarkable feature of prairie vegetation. Unlike agricultural crops that have shallow root structures, perennial prairie grasses develop extensive root systems that can penetrate several metres into the earth. These massive underground networks bind the soil particles together, creating an effective against wind and water erosion during severe storms. Furthermore, when older roots decay, they add tremendous amounts of carbon to the soil, its structure and allowing it to retain moisture during prolonged periods. This underground biomass also supports an immense of microbial life essential for nutrient cycling.

Large native herbivores exert a profound influence on the composition of grassland ecosystems. By selectively feeding on dominant tall grass species, grazing mammals prevent these fast growing plants from completely smaller flowering herbs. This selective pressure creates a mosaic of varied vegetation heights, which significantly habitat availability for ground nesting birds and small mammals. Additionally, the physical movement of herds across the landscape breaks up hardened soil crusts and presses seeds into the ground, thereby successful germination after rainfall. Moderate grazing intensity is therefore widely recognised as a vital for sustaining high biological diversity across temperate rangelands.