Invasive Species

Many things can disrupt and alter ecosystems. Huge benefactors of disrupting ecosystems are invasive species. Invasive species are non-native organisms alien to the ecosystem. They are capable of mobbing aggressively into a habitat and take over the resources including sunlight, food, water, nutrients and space. Usually and most likely their invasion causes economic or environmental harm or harm to human health. Invasive species can be plants, animals or any other living organism whose introduction is primarily by the means of human actions. There are a limited amount of natural resources in an ecosystem so the invasive species and the native species compete for these resources. The native species have predators that check their population while the invasive species do not, so therefore the invasive species out competes the native species.

There are many components that make up an ecosystem. In an ecosystem there are biotic factors, living, and abiotic factors, not living aspects. There are many different species, a group of organisms that look alike and are capable of producing fertile offspring in nature. There are populations, groups of individuals that belong to the same species that live in the same area and breed within the same group. And there are communities which are many different populations of species that live together in habitats, the place where a particular population of a species lives in. The abiotic components within an ecosystem include sunlight, rain, soil, temperature, rocks, and overall climate.

A major functional aspect of an ecosystem is energy flow. A pyramid can be made of different trophic levels. A trophic level is how energy moves throughout an ecosystem depending an organism's source of energy. The producer is on the bottom of the ecological pyramid where it generates 100% of the energy. Above the producer is the 1o consumer, 2o consumer, and so on. Of the producer's energy, only 10% of the energy becomes the 1o consumers energy in which it is able to use for its own needs. Beginning with 100% energy, the producer uses a percentage of this energy for themselves for growth, heat and movement. A certain percentage is not consumed and therefore the energy from that goes to the decomposers. As a result, the remaindering 10% of the producer's energy travels on through the energy flow pyramid to the 1o consumer. Each trophic level has 10% energy of the lower trophic level. For example, the sun would provide energy for the trees (producer) which would give 10% of their energy to the caterpillars (1o consumer) which would give 10% of their energy to birds (2o consumer).

This pattern is also true with biomass and population numbers. Biomass is the combined weight of all members of a trophic level. Each trophic level has 10% biomass of the lower trophic level. For instance, if the weight of all the members of the producers is 50,000 grams, then the 1o consumer's biomass is 5,000 grams. The population numbers pyramid follows the same pattern as well. Each trophic level has 10% of the population of the lower trophic level. For example, if there are 2,000 producers, then there should be 200 1o consumers, and 20 2o consumers. All three of the pyramids are components of a healthy ecosystem. Vigor and organization are also two very important components of healthy ecosystem.

Invasive species can completely alter ecosystems food web, energy flow and certain organism's niches. When an invasive species "invades" an ecosystem, it can eat the food supply of another native organism, killing off that native organism. This messes up the food web because now the organism that usually eats that native organism that just died due to the eaten supply of their food by their food by the invasive species will not have anything to eat causing its population to drastically drop or even become extinct.

Invasive species can disrupt a habitat. An example of this is the infestation of purple loosestrife. Purple loosestrifes are tall non-native wetland plants that have invaded Tichigan Lake. It was brought over from Europe in the mid 1800's for its beauty. These plants are choking the native species and changing the habitat of the lake. The purple loosestrifes have taken over the native plans that help the wetlands. The roots of these invasive plants are huge and take up an abundance of space. There is no more room for the native amphibians, fish and other species that used to live in the lack. The purple loosestrife does not have any natural predator so they just keep on reproducing and have been a detriment to the wetlands.

Some projects have been put in place to try to contain this invasive species. A small amount of the purple loosestrife have been dug up and sent to scientist to grow colonies of European beetles that feed entirely on purple loosestrife. These beetles eat the plants' leaves which prevent the plant from further reproducing. The purple loosestrife causes the whole ecosystem to become out of balance and tainted the habitat of Tichigan Lake.

Invasive species can also spread diseases that can further harm an ecosystem and even cause economic and environmental harm. The glassy-winged sharpshooter (Homalodisca coagulate) is a large leafhopper originally from the southeastern United States that is posing a serious agricultural threat in California. The glassy-winged sharpshooter most likely came into California from Florida in the late 1980's in nursery stock, as eggs which are harder to detect. It is a vector of Pierce's disease. Pierce's disease is a bacterial pathogen that clogs a vine's water conducting vessels and doesn't allow them to craw water and other nutrients from the soil. The effect of this disease is that the vine slowly starves to death. When this pest is feeding, it transmits disease to the grapevines and other crops which poses a huge threat on grape, raisin, and wine industries. Pierce's disease kills the host. An outbreak of this disease would cause a major economic problem in California amounting to billions of dollars. It will also create a threat to the viticulture industry if it spreads to the wine producing areas of central and northern California. The glassy-winged sharpshooter is more common than the native species of sharpshooters.

There are many things that are being preformed in order to control and kill the Pierce's disease ranging from chemical treatments to the release tiny wasps that feed on the eggs of the glassy-winged sharpshooter. However, there is no way to completely annihilate the insects from the state at this time. Luckily however, this disease can not be transmitted to humans.

Another example of how invasive species alter ecosystems is with the Caulerpa Taxiflora plant. This seaweed was originally from Europe and was imported as a decoration for tropical fish tanks.