Why would a rough steep mountain habitat have a higher rate of speciation than a large open grass land?

A rough, steep mountain habitat offers diverse microclimates and varying elevations, creating distinct ecological niches that can lead to isolation of populations and increased opportunities for adaptation. This geographical complexity fosters divergent evolutionary paths as species adapt to specific conditions. In contrast, a large open grassland tends to have more homogenous conditions, which can limit the potential for speciation due to fewer barriers to gene flow among populations. Thus, the rugged terrain of mountains promotes greater biodiversity through speciation.