insights into the factors controlling the levels and distribution of these soil properties can be gained from the derived regression models.
Some authors have made reference to the relief, climate, and pedologic
origin of tepetates [13, 14].
Douglas and Tedrow (1960:296) noted that "the zone of organic concentration is usually well within the permafrost and is not affected by present-day pedologic
processes." There has been considerable debate in the soils literature regarding the origin of this organic matter.
In this particular study, the [EC.sub.a] survey does not establish exactly what pedologic
changes have taken place in the compacted soils, but it provides evidence that there are differences in soil properties between the compacted and non-compacted soils.
A region was defined as an area with homogeneous pedologic
and climatic conditions and, when useful, presence versus absence of irrigation (about 15% of the considered trials were irrigated).
The lithologic and pedologic
characteristics of the section are described and interpreted below by considering sediments and soils formed during certain blocks of time.
The sedimentary structure (as opposed to pedologic
structure) or sedimentary fabric of glacial tills may be used in determining the genesis of the deposit; however, tills are typically massive and show few types of sedimentary structures.
, and hydrologic interactions in a closed drainage system.
What we do know is that a soil's biodiversity appears to be an important influence on such pedologic
processes as soil building, carbon storage, nutrient availability, and pest management.
By using both lithologic and pedologic
criteria, we were able to choose alluvial samples that spanned the entire Holocene.