Envirothon

Soils develop as a result of the interactions of climate, living organisms, and landscape position as they influence parent material decomposition over time. Notice in this example how the soil profiles change from weakly developed to well developed with time. Older terraces, or soils on second bottom positions, usually have developed B horizons. Recent soils deposited in first bottom positions usually do not have a developed B horizon. Instead, they may have stratified layers varying in thickness, texture, and composition.

Insect soil bio: Ecosystem engineers such as ants and [|earthworms] primarily alter the physical structure of soil but also have an influence on the overall rates of nutrient cycling and energy flows. These organisms initiate fragmentation of organic residues and take [|organic matter] deeper into soil profiles. They also create pores that allow water and plant roots (as well as other soil biota) access to deeper parts of the profile. 

Soil biota play a major role at all levels in micro-food webs whereby energy is transferred from one organism to another and as a consequence nutrients are recycled through the soil environment. For example, bacteria, archaea and fungi decompose plant litter through enzyme degradation to sequester nutrients and these organisms are in turn eaten by predatory protozoa, nematodes & arthropods. This predation helps maintain specific populations and keeps the predator prey balance in check. At the same time, however, litter transformers are breaking down dead organic matter, including remains of biota from all levels of the food web. =Why is soil biology important?= There are three components of soil biology for land managers to consider; i) the natural processes themselves (soil engineering, litter transformation and micro-food web participation), ii) the impact of management on these processes, and iii) the combined effect of the first two on plant performance). The processes that are mediated by soil biology impact on plant (and animal) production systems by modifying the soil physical, chemical and biological environment within which plants grow and persist. []