Table of ContentsIntroductionInvasive SpeciesAsian CarpMountain Pine BeetleEarthwormsMusselsCane ToadsConclusionIntroductionAn invasive species is any type of organism that enters a new ecosystem and begins to negatively alter the area. These negative consequences of invasive species include damage to the surrounding ecosystem and alteration of the habitat of organisms already living there. Native species are generally well-armed to defend themselves against other native species; However, when an invasive species appears, native organisms are not prepared to face unknown competitors. Even worse than the damage to the environment, invasive species can wreak havoc on the economy and even human health. As the National Wildlife Federation has stated, a species is considered invasive if it "grows and reproduces rapidly and spreads aggressively, with the potential to cause harm." Say no to plagiarism. Get a tailor-made essay on "Why violent video games should not be banned"? Get an original essay Immediate threats following the arrival of an invasive species include predators and competition with native animals, provoking or transmit diseases and prevent native species from reproducing. . Indirectly, invasive species can also alter the food web by destroying or replacing original sources and therefore providing little or no food source for wildlife. Invasive SpeciesAsian CarpSome invasive species are introduced to new places to serve a purpose, like Asian carp, but ultimately become an invasive species. Asian carp is a common term for a group of fish including bighead carp, silver carp, grass carp, and black carp. These fish were originally introduced to the southern United States in the 1960s to clean algae and vegetation from aquaculture ponds and sewage lagoons. Environmental causes such as flooding allowed these fish to escape into the wild where they began eating plankton that many other fish needed for food. As noted on the New York Invasive Species website, "Asian carp can consume 5 to 20 percent of their body weight per day...and can reach 110 pounds...dominating native fisheries in abundance and biomass." Having a significant impact on the food web, these carp easily outcompete native fish. Additionally, the removal of plankton-feeding fish removes important prey for predatory fish in these waters. Today, the Mississippi and Illinois river systems account for more than 95% of the biomass in some areas of the Mississippi Basin. Unlike the accidental release of Asian carp into the wild, most invasive species spread accidentally through human activity. . The goods we use travel very quickly around the world and often carry cash from other places to new regions. Typically, aquatic organisms travel in the ballast tanks of ships and on the propellers of small boats. Insects can travel in the wood of pallets and shipping crates, and some invasive species start out as pets released intentionally or accidentally. Higher than average temperatures and changes in rain and snow patterns will allowalso prevents some invasive plant species and the mountain pine beetle from moving to new areas. Mountain Pine BeetlesThe mountain pine beetle is a small insect that only grows to a size of about 4 to 7 millimeters . in diameter and spreads through the movement of firewood and other wood products. The key to mountain pine beetle survival in parts of North America is warm summers and mild winters. this not only ensures the survival of the insect, but also the continuation of infestations that lead to epidemics. These beetles primarily affect lodgepole and ponderosa pines, but are not afraid of other pine species either. The mountain pine beetle affects pine trees by laying eggs under the tree's bark. With the entry of the beetles under the bark, they also introduce blue stain fungi into the sapwood which prevent the tree from growing back killing the attacking beetles with the flow of pitch from the tree. Tree pitch flow occurs in infected trees; “They convert a large amount of starch into sugar, which causes water to flow from the soil into the tree by osmosis” (Kimmerer, 2014). The blue stain fungus also blocks the transport of water and nutrients throughout the tree. On the outside of the tree, large masses of resin, called “pitch tubes,” form where the beetles have entered. Between mountain pine beetle larvae feeding on the tree and fungal colonization, the host tree dies a few weeks after the attack. Earthworms Another example of an invasive species is earthworms. “All earthworms…of the Great Lakes region are exotic; "most are European" and were brought here by settlers in the mid-1800s. Today, earthworms are continually transported by the dumping of unused fish bait, the movement of compost and mulch, and other ground movement. Recently, research has collected data on the dramatic changes occurring in native deciduous forest ecosystems invaded by exotic earthworms. These changes include the loss of native understory plant species and tree seedlings, changes in soil structure, and a decrease in the availability of the nutrients it offers. Due to soil mixing and fragmentation, earthworms are able to directly change the soil chemistry. In areas previously free of earthworms, fallen leaves and other forest waste have been processed by fungi and bacteria, a much slower process than that of earthworms. This accumulation on the forest floor is home to “thousands of microorganisms, spiders, insects, and fungi that all support the unique plant communities of these forests” (Hale, 2013, p. 5). Equally important, this layer serves as an ideal breeding ground for the seeds of plant species, most of which take up to two years to fully germinate. However, when earthworms are introduced, they eat away at this layer, removing this spongy forest floor and making it more difficult for plants to take root. As a result, the diversity and population of native forest plant communities can decline significantly. Animals are also affected by earthworms: loss of forest floor takes away habitats and food sources from animals such as “breeding birds, small mammals, amphibians, reptiles, insects and spiders” . In areas with high white-tailed deer populations, plant regeneration from deer feeding is slow and earthworms only worsen the.