Class Year


Document Type

Student Research Paper

Date of Creation

Fall 2020

Department 1



Chinese Tallow (Triadica sebifera) and Japanese Blood Grass (Imperata cylindrica) are two invasive species that wreck havoc on their invaded areas by reducing the biodiversity of their new environments. We studied the rate of dispersal of these two species in North America to determine which species spreads faster. We hypothesized that Chinese Tallow spreads faster than Japanese Blood Grass since Chinese Tallow was introduced in North America long before Japanese Blood Grass and has a greater number of seed dispersal methods (e.g. wind, water, bird, etc.) than Japanese Blood Grass. To test our hypothesis, we collected the record of Chinese Tallow and Japanese Blood Grass in North America from their year of introduction to present and determined the area covered by each species individually over time. After comparing the range covered by the two species over time, we observed that though Chinese Tallow spread faster in its early years, yet in sum, Japanese Blood Grass spreads faster than Chinese Tallow, which opposes our hypothesis. For the log transformed total range difference of Japanese Blood Grass subtracted by Chinese Tallow 70-120 years after introduction, our equation for the trendline was y= =-0.0302*x + 3.39 with an R^2 value of 0.934. This negative slope evident from the trendline refutes our initial hypothesis. For the data analysis, our t=-5.31, d.f=2, p(one-tailed)=.016842. Based on our experiment, it was clear that the rate of dispersal of the Japanese Blood Grass in North America is increasing at an alarming rate and it is necessary to control this species as it is extremely harmful for the environment and biodiversity. As our data showed that the rate of dispersal of the Chinese Tallow is decreasing, the management methods for the Chinese Tallow can be studied to find effective ways to control the Japanese Blood Grass.


Written for Bio 111: Introduction to Ecology and Evolution