allows this invasive species to utilize less of its energy in root biomass to absorb necessary nutrients. This may be crucial in allowing Oriental bittersweet to act as an effective invasive species as it is able to allocate more energy to its aboveground biomass instead of its belowground biomass; a significant point regarding this plant's invasiveness relies on photosynthetic ability and reproductive capacity. The symbiotic relationship established with fungi only occurs with arbuscular mycorrhizal fungi, while no such relationship has been observed with ectomycorrhizal fungi. These studies have shown that suitable mycorrhizae are a strong determining factor regarding whether a plant can survive in its environment. Studies have also shown evidence that “introduced plant species can modify microbial communities in the soil surrounding not only their own roots, but also the roots of neighboring plants, thereby altering competitive interactions among the plant species”. This may be a key invasive trait for Oriental bittersweet, as it allows the plant to negatively affect surrounding plant life by altering their underground symbiotic microbial relationships. However, further experimentation is necessary to determine whether this organism employs this trait as an invasive strategy. Competitive interactions One of Oriental bittersweet's invasive characteristics is its effective utilization of energy to increase plant height, thus giving it a competitive advantage over similar plants. A study conducted in 2006 showed that, in comparison to its congener American bittersweet, Oriental bittersweet had increased height, increased aboveground biomass, and increased total leaf mass. This is not to say that Oriental bittersweet outperformed American bittersweet in all criteria: in comparison to Oriental bittersweet, “American bittersweet had increased stem diameter, single leaf area, and leaf mass to stem mass ratio,” suggestive that American bittersweet focused growth on ulterior portions of the plant rather than plant characteristics emphasized by Oriental bittersweet such as stem length. This is significant as height plays a major role in allowing Oriental bittersweet to outcompete surrounding vegetation. Focusing growth on stem length allows it to be in a strong position to absorb light, while also negatively impacting surrounding plant life by creating shade-like conditions. The species' vine-like morphology has also been shown to have negative effects on surrounding plant life. For example, evidence suggests that this morphological characteristic facilitates its ability to girdle nearby trees, creating an overall negative effect on the trees such as making them more susceptible to ice damage or damaging branches due to the weight