Soil Food Webs

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Introduction

Food webs are used to know different energy interactions in a given ecosystem. The soil's food web is very dynamic and the living part of soil and it is very complex and interchanging depending on it's ecosystem. The interactions found in the food web are soil organisms living all or part of their lives in the soil while producing energy and working together with plants to survive. These interactions carried out in the soil by soil organisms and plants are a vital (NRCS)

The organisms found in the soil food web carry out a large amount of microbial processes such as decomposition, mineralization, immobilization, respirations, and fixation along with many others. These processes help support above and below-ground plant growth and their processes make nourishment for plants possible.

Biological Interaction

The start of all biological interactions within any soil food web would start with organic matter. Organic matter is a key component when it comes to fueling any interaction in the food web such as decomposition and is made up of humus and active organic material. Without any organic matter, microbes will not be present to fuel the plant with essential nutrients. Soil organic matter is the storehouse for the energy and nutrients used by plants and other organisms. Bacteria, fungi, and other soil dwellers transform and release nutrients from organic matter. These microshredders, immature oribatid mites, skeletonize plant leaves. This starts the nutrient cycling of carbon, nitrogen, and other elements. (NRCS) Organic matter is recycled back into the food web when organisms of higher trophic levels die off and are decomposed by the nutrients that were used to create food for them in the very beginning.

Environment

There are many different ecosystems in the world and the soil food web is affected by climate, rainfall, management factors, acidity, etc. Soil food webs are found in both terrestrial and freshwater/marine sediment soils. The interactions carried out in the soil food web is highly important in both systems.

Terrestrial

Terrestrial soil food webs can consist of but are not limited to many soil microbe/plant interactions. Terrestrial soil food webs are more adaptive to having many plant exudates and very rich organic matter coming from mainly alive primary producers. Given that the primary producers do their role's; terrestrial soils will have a more diverse community of soil microorganisms that can contribute to each different trophic levels in the soil.

Freshwater & Marine Sediment

In more aquatic habitats different composition of soil microorganisms are found. Organic matter and other materials are introduced in a different way and in different concentrations when looking at deep marine sediment and shallow marine sediment.

Interactions

Interactions among soil microorganisms with each other and also their interactions with primary producers can be very different. Host type and diversity of microbial populations can differentiate these activities.

Positive

Some interactions found in the soil food web that are both positive to the host plant/microorganism and another microorganism can include mutualism, symbiosis, commensalism, and synergism. An example of this would be how the plant gives soil microorganisms nutrients to survive through root exudates, in return the microorganism fix and respire vital nutrients that the plant needs in order to survive.

Negative

Interactions can also have a negative effect on either plant/microorganism or a negative effect on both. These would include predation, competition, parasitism, or ammensalism. An example of an interaction having both a negative and positive effect would be parasitism. A microorganism could be attached to a plant's roots and be taking nutrients that are vital to the plants health and the plant could be dying which would be having a positive effect for the microorganism, but a negative one for the plant.

Niche

Describe the physical, chemical, or spatial characteristics of the niche where we might find this interaction, using as many sections/subsections as you require. Look at other topics available in MicrobeWiki. Create links where relevant.

Microbial processes

What microbial processes are important for this microbial interaction? Does this microbial interaction have some ecosystem-level effects? Does this interaction affect the environment in any way? Describe critical microbial processes or activities that are important in this interaction, adding sections/subsections as needed. Look at other topics in MicrobeWiki. Are some of these processes already described? Create links where relevant.

Key Microorganisms

What specific kinds of microbes are typically involved in this interaction? Or associated with important processes? Describe key groups (genera, species) of microbes that we find in this environment, and any special adaptations they may have evolved to survive in this environment. List examples of specific microbes that represent key groups or are associated with important processes found in this environment. Add sections/subsections as needed. Look at other microbe listings in MicrobeWiki. Are some of the groups of microbes from your environment already described? Create links to other MicrobeWiki pages where possible.

Current Research

Enter summaries of recent research here--at least three required

References

Edited by Brian Kirk, a student of Angela Kent at the University of Illinois at Urbana-Champaign.