Complex sentence: Species richness is particularly high in grasslands of low soil fertility such as serpentine barrens and calcareous grasslands, where woody encroachment is prevented as low nutrient levels in the soil may inhibit the growth of forest and shrub species.
Split into simpler sentences: Species richness is particularly high in grasslands of low soil fertility such as serpentine barrens and calcareous grasslands. Also prevent woody encroachment as low nutrient levels in the soil may inhibit the growth of forest and shrub species.