A method to indicate how much of an effect humans have on neighboring communities is to utilize the abundance of the microscopic taxa in rural and urban locations. Since, specifically, tardigrades, rotifers, and nematodes can withstand adverse environmental conditions, they are ideal subjects to determine the effect of human activity.

We plan to gather lichen samples from trees in multiple locations ranging in the amount of urbanization: a forest, a campus, and a city. Once the samples are collected, they will be moistened and then filtered to observe and create a census of the taxa from each location microscopically. To keep our data as randomized as possible we will collect our samples from different trees distributed across each location. Depending on the population density of taxa in each location, a comparison will be conducted to decide if our hypothesis that human activity negatively affects surrounding ecosystems was correct.

From our results, tardigrades, rotifers, and nematodes showed a statistically significant difference of frequency in each location. More specifically, the urban locations (Lansing and East Lansing) showed a much higher frequency of taxa compared to the Holmes Hall Woods location.

Microorganism Abundance

• Since the rural location had the least amount of microorganisms present, human activity increases microorganism abundance (Figure 1).
• Tardigrades, rotifers, and nematodes undergo cryptobiosis to withstand extremely harsh conditions, which could be an explanation for their higher survival rates in an urban locations (Jönsson and Järemo 2003).

Microorganism Composition

• Human impact negatively influenced tree density in the urban location of Lansing and therefore decreased the diversity of the three microorganisms.
• Studies performed on the Amazon Rainforest proved that habitat degradation reduces biodiversity (Prist et al., 2012).

Relevance

• Although abundances may be higher in urban locations, urbanization would still have a negative impact on microscopic ecosystems by decreasing biodiversity.

Future Directions

• It is unknown why urban locations had the highest microorganism abundance. Future research can be used to identify human impacts on ecosystems (pollution, infrastructure, etc.) in urban and rural communities.
• In a future study, researchers should investigate how microorganisms disperse across an environment to clarify why urban locations have the least amount of diversity.

References

Jönsson KI, Järemo J. 2003. A model on the evolution of cryptobiosis. Annales Zoologici Fennici 40(4): 331-340.

Prist, P. R., Michalski, F., & Metzger, J. P. (2012). How deforestation pattern in the Amazon influences vertebrate richness and community composition. Landscape Ecology 27(6): 799-812.