Some species of plants brought to North America from other locations become invasive. Invasive species not only establish, but displace many of the native species of plants. Invasive plants can create shade and prevent native plants from getting the sunlight they need to grow. One example is Chinese privet, Ligustrum sinense. In parts of Northern Georgia, Chinese privet is the dominant shrub that excludes many species of flowering plants.
Butterflies use flowering plants as sources of nectar as adults. Butterfly larvae (caterpillars) often depend on one or only a few species of plants for food. How much do invasive plant species such as Chinese privet affect butterflies?
In a recent paper, James Hanula and Scott Horn describe several methods of Chinese privet removal and the affects in following years on butterfly numbers and species composition. They found that privet removal by all means enhanced butterfly abundance, diversity and evenness. The greatest affect was achieved when the privet was mulched after it was cut. Privet removal had noticeable affects on plant species composition.Invasive species that cause large economic harm attract much attention and effort to either eradicate the species or at least slow their spread. Invasive species that do not have clear economic effects may have ecological effects on other species that are not apparent without detailed investigation. The large increase in global trade over the past several decades has increased the numbers and rates of invasive species introductions. These invasive species are changing our ecosystems in many ways. Efforts to stop or at least slow the rate of exotic species importation are necessary to prevent rapid and undesirable environmental changes.