Tardigrades are microorganisms that can survive extreme conditions and have been around for thousands of years. We are studying if urbanization and human colonization impacts the tardigrades ability to colonize new areas and trees.
To do this, we are sampling 12 trees each from rural and urban areas. Of those 12 trees, six will have a diameter greater than 1 foot, and six will have a diameter less than 1 foot. We will scrape lichen samples off and preserve them in a dry area to initiate anhydrobiosis or dehydration of the tardigrades. Once in the lab, we will rehydrate them and soak them to bring them out of their dehydrated state. After soaking the samples, we will observe them under the microscope and count how many tardigrades are in each sample. From these observations, we will be able to determine if humans and urbanization impacts the colonization of the tardigrades.
Upon collecting data from 24 trees, we found that small trees in urban areas were colonized most by tardigrades. This was opposite of our hypothesis, which claimed that large, rural trees would be colonized most. It is unclear why this result was achieved however, it is possible that on urban trees there are less microbiota for tardigrades to compete with. Because tardigrades can survive in harsher conditions than nematodes and rotifers, it is probable that other microbiota did not survived the harsh conditions, leaving tardigrades with more resources in urban areas than rural. Our Chi Square goodness of fit test demonstrated strong findings to confirm that there was more colonization on small trees than large trees(X2=42.08; p<.0001). More testing could be done to determine why small trees colonized more than large trees and to confirm the new hypothesis about urban tree colonization. Overall, the results of our experiment showed that urbanization has no effect on tardigrade colonization.
Figure 1. Graphical comparison of tardigrade abundance in samples taken from Urban and Rural locations. The green bar represents small (diameter<1ft) trees while the yellow bar represents large (diameter>1ft) trees