In the article, the author mentions that ‘leaf litter’ is critical to the survival of many of the deciduous forest’s local species. This means that it could serve as a habitat or food source, as it is nutritious and decomposing. This duff, often referred to as the “O Horizon”, is also home to many plant species, which emerge from its leafy soil, such as the bluebell. Abiotic changes are those that arise among non-living environmental components. If the forest’s leaf litter was totally consumed by the Asian worms, the gasses given off by the duff would lessen dramatically. Another abiotic change is that the soil would become more moist, or even muddy, and there would be a lack of nutrients on the forest floor. A plant which thrives in muddier, barer soil could easily take root here, after all of the leaf litter is consumed. This may be the ideal condition for an invasive species, such as Japanese stiltgrass. If I were to do a controlled experiment to determine whether the worms, in fact, do change the forest ecosystem, I would test the duff levels in the forest which contains the Asian worms and compare it to a similar forest nearby that does not have an abundant Asian worm population. The average height for the O Horizon is about 2cm, so I would measure the leaf litter levels over the course of the year. If it is much lower in the forest with the Asian worm, we may conclude that it could pose as a threat to the local species and changes the forest ecosystem.