Due to clear variations in a relatively small area, mountains represent natural laboratories for evolutionary and ecological studies. In a large degree, these variations are driven by changes in climate and soil that occur along altitudinal gradients and influence the ecology, evolution and geography of species. In spite of being old and eroded, the southern Brazilian mountains provide enough variation and heterogeneity to influence species distribution and diversity. The best-known Brazilian mountain range is the Espinhaço (the Backbone mountains). The Espinhaço is a large natural watershed divider of major ecological importance in eastern Brazil. The altitudinal gradient in the Espinhaço Mountains is low when compared to other tall mountains in the world as it only varies from ca. 650 to 2.072 m a.s.l. at the Sun Peak (Pico do Sol). This chapter synthesizes the results of 10 studies that have collectively examined the soil, climate to better understand patterns and processes associated with biodiversity of key groups of organism, including of plants, termites, dung beetles, ants, butterflies, arbuscular mycorrhizal fungi, insect herbivores and birds in an altitudinal gradient (from 800 to 1400 m a.s.l.) at Espinhaço mountain range. In this mountain range, the soils are primarily poor and the vegetation is dominated by rupestrian grasslands, and both are known to vary along the altitudinal gradient hence providing opportunities for variation in the associated organisms.