Microbiology Lab for Biology Majors (BIOL 3221)
Soil Module: Isolation and Characterization of Soil Microorganisms from a Long-term Fertilization and Disturbance Study
Microorganisms are responsible for a range of ecosystem functions, and microbial diversity and composition must be maintained. Environmental changes and species interactions influence belowground microbial communities just as they influence the aboveground plant communities. Abiotic factors such as available soil nutrients, pH, moisture, and temperature impact the diversity and composition of soil microbial communities. In addition, biotic factors, specifically microbial interactions with plants, strongly influence microbial community composition and diversity. Microbial communities can also significantly impact plant community composition, abundance, productivity, diversity, and plant evolutionary processes. In previous studies, plant diversity loss has been linked to decreased microbial abundance and richness. Disturbance can also have negative impacts on microbial community diversity, whereby more disturbed soils exhibit lower levels of microbial diversity compared to undisturbed soils. For example, disturbance has been seen to negatively impact microorganisms through the removal of large amounts of the plant biomass. Plants are responsible for supplying microbial communities with carbon, the main energy source for heterotrophic microorganisms. Reduced carbon availability (in terms of amount of carbon and types of carbon resources) is expected to support a smaller microbial population and in turn decrease microbial diversity and impact metabolic functions. Over time, fertilization and mowing reduced plant species richness (i.e., number of species) and diversity at the WRC. Also, disturbance by mowing maintained the highest plant species richness compared to other treatments.
Given this long-term pattern in plant community composition, Microbiology students are asked to address the following questions based on soil bacteria cultured from the plant & microbes RULE project:
(1) How do you expect soil microorganisms to respond and adapt to these long-term nutrient additions and disturbance by mowing treatments?
(2) How do you expect long-term nutrient additions and disturbance to impact soil microbial function?
Microorganisms are responsible for a range of ecosystem functions, and microbial diversity and composition must be maintained. Environmental changes and species interactions influence belowground microbial communities just as they influence the aboveground plant communities. Abiotic factors such as available soil nutrients, pH, moisture, and temperature impact the diversity and composition of soil microbial communities. In addition, biotic factors, specifically microbial interactions with plants, strongly influence microbial community composition and diversity. Microbial communities can also significantly impact plant community composition, abundance, productivity, diversity, and plant evolutionary processes. In previous studies, plant diversity loss has been linked to decreased microbial abundance and richness. Disturbance can also have negative impacts on microbial community diversity, whereby more disturbed soils exhibit lower levels of microbial diversity compared to undisturbed soils. For example, disturbance has been seen to negatively impact microorganisms through the removal of large amounts of the plant biomass. Plants are responsible for supplying microbial communities with carbon, the main energy source for heterotrophic microorganisms. Reduced carbon availability (in terms of amount of carbon and types of carbon resources) is expected to support a smaller microbial population and in turn decrease microbial diversity and impact metabolic functions. Over time, fertilization and mowing reduced plant species richness (i.e., number of species) and diversity at the WRC. Also, disturbance by mowing maintained the highest plant species richness compared to other treatments.
Given this long-term pattern in plant community composition, Microbiology students are asked to address the following questions based on soil bacteria cultured from the plant & microbes RULE project:
(1) How do you expect soil microorganisms to respond and adapt to these long-term nutrient additions and disturbance by mowing treatments?
(2) How do you expect long-term nutrient additions and disturbance to impact soil microbial function?
