Exploring Relationships Between Soil Structure and Climate Across the Conterminous USA.

Soil structure develops in response to complex interactions between parent material, climate, relief, organisms, and time. However, very little is known about the exact nature of this development especially in response to climate. The goal of this research, therefore, was to examine the expression of soil structure along multiple climosequences of the conterminous USA. We used the USDA-NRCS National Cooperative Soil Survey-Soil Characterization Data to investigate relationships between soil structure and climate. Size was calculated using the geometric mean diameter of the structure size class recorded for each horizon and grade was placed on an ordinal scale ranging from structureless (0) to strongly-structured conditions (3). Structure type was quantified using a recent dataset that documented geometric values for each of the common ped type classes. A variety of multivariate statistical approaches were used to examine relationships between soil structure and climate while accounting for the influences of physical, chemical, and biological differences between the soil materials. The results and implications of this examination will be presented and discussed.