Soil development along an elevational transect in the arid White Mountains, California.

Arid mountain ecosystems are unique environments characterized by low precipitation, extreme diurnal temperature, sparse vegetation, abundant coarse fragments, and dust. To understand the complex processes driving soil genesis in these regions, 11 sites along an elevational transect, ranging from 2200 to 4300 m above sea level in the White Mountains of California were examined on primarily granodiorite and quartzite lithologies. Soils were described and sampled, and physical and chemical properties including particle size distribution, bulk density, pH, and organic and inorganic carbon were determined. At low elevations, rainfall facilitates rapid water infiltration and flux through soil macropores, causing deep translocation of fine‐earth material. Conversely, higher elevations receive more snowfall, which directs infiltration toward pores in the soil matrix resulting in shallower soil development but relatively greater chemical weathering. Dominant lithologies in the range appear to influence soil development through the potential for rocks to be embedded at the land surface. Surface rock embedding further modifies the potential for macropore versus matrix flow influencing the depth of soil development and degree of weathering. These findings reveal the combined effects of climate and lithology on soil formation and may guide future studies of arid mountains. Core Ideas: Climate and lithology exert strong controls on the soil formation in the arid White Mountains of California.At lower elevations, infiltrating meteoric water carries dust via soil macropores, forming relatively deep soils.At higher elevations, snowmelt infiltrates via matrix pores, intensifying weathering but forming shallower soils.Granodiorite soils have greater potential to form vesicular horizons than quartzite due to surface rock embedding.Larger macropores in quartzite soils compared to granodiorite allow deeper preferential flow. Plain Language Summary: Arid mountains occupy large areas, support important ecosystems, and control water cycling in desert landscapes. However, soil development and its influence over water movement, especially in response to climate variability, is poorly understood. Situated in the rain shadow of the Sierra Nevadas, the White Mountains of California offer a unique setting to study the interaction of soils, climate, geology, and vegetation in arid mountains. We found that rainfall facilitates rapid water movement into large pores at lower elevations, resulting in relatively deep soils. At higher elevations, snowmelt encourages water movement through the soil matrix yielding shallower soils with greater chemical weathering. Rock type was important with the weathering of granodiorite creating conditions to concentrate dust near the land surface minimizing the depth of water movement into soils compared to quartzite. These findings reveal the complex factors controlling soil development in arid mountains. [ABSTRACT FROM AUTHOR]