Introduction to Organisms
The soil ecosystem in an important environment that allows both plants and animals to survive, grow and reproduce. The significance of the soil as an ecosystem is at times overlooked despite its major contributions to the environment. The soil environment is a complex and varied microbial habitat. The plants and organisms inhabiting the soil contribute to its thriving diversity. Soil life is diverse in morphology, metabolism, size, and many other characteristics. It is believed that “there is sufficient [microbial] DNA in 1 g of soil to extend 1,598km.”  Soil is a heterogeneous environment with various zones of rhizosphere, aggregates, organic matter and animal residues. Given each zone is a small component of the larger soil ecosystem, rhizosphere accounts for only 5 to 7 percent of the soil environments but contains over “70 percent of the bacterial- and fungal-feeding nematodes.” Since, all three domains of life: archaea, bacteria and eukarya, inhabit the soil environment it is difficult to observe each microbe individually within the soil ecosystem.Only a few representative groups of each domain will be discussed to provide examples of the roles these organisms play in soil. This page attempts to outline the major microbial groups within the diverse soil environment.The interactions between soil microbes amongst the soil microbial diversity. The concept of survival of the fittest is seen in the soil food web, which allows only a selective few with the correct nutrients to thrive in a soil environment. The interactions of soil microbes is not only a part of nature but it also only selects those organisms that are fit for survival, growth and reproduction. The soil food web and symbiotic relationships are used to explain the dynamic interactions between soil organisms.