Literature review Alien invasive species In today’s world, many areas have become urbanized and natural areas have become fragmented due to human interference (Alston and Richardson 2006). This in turn has caused many interfaces between the urbanized world and the natural landscape (Alston and Richardson 2006) which most of the time have negative impacts on the natural environments (Alston and Richardson 2006) such as pollution and invasion of exotic species. A species has to pass a few criteria before it can be considered an alien invasive species, not just for the reasoning that the species was not originally from that area (Richardson et al. 2000). A species is considered to be an exotic species once it has been brought into an area that it was not established in previously by humans, either by accident or intentionally (Richardson et al.
Partly through lack of focus, but also due to the fact that herpetofauna are hard to study in their natural environments, and that changes brought by these aliens can be too subtle to detect (Kraus 2009). Following a risk assessment, action can be undertaken to prevent or stop an invasion. If a species has established, the alternatives are to eradicate or accept and control the invasive species. Prevention is by far the most preferable as it is the most cost-effective (Jarrad et al. 2011b), least detrimental to native flora and fauna and most likely to succeed (Genovesi 2005;2007, Bogich et al.
Invasive species are the second largest threat to biodiversity after habitat loss. An invasive species is a species that is not native to a particular area, but arrives (usually with human help), establishes a population, and spreads on its own. Not all species that come to a new location become invasive in fact most of them do not. A lot of the garden plants are imported from other places, and they sometimes grow wild, they do not achieve big populations and do not make a huge splash on native species survival. These are just called non-native or introduced species.
Invasive Species Invasive, alien species, those which colonise, expand and out compete native species (Smith & Smith, 2009), are a major threat to our habitats, terrestrial and aquatic species, and biodiversity. Agricultural and leisure industries are affected as well as conservation welfare and the continued wellbeing of man, flora and fauna. Whole ecosystems can be distorted and the economic cost of awareness, prevention and eradication systems is substantial. Most invasive species have been introduced by mandeliberately or otherwise. As an island, Ireland has been subjected to less invasive species than larger nearby land masses e.g.
Invasive species can have harmful effects to the environment such as, affecting the ecosystem; limiting biodiversity; and using resources available to the existing habitats. Invasive species are also recognized in forest and open forest habitats. An example of
This proves that evolution may cause new species but, it isn’t always good. Natural selection is also a factor in the changing of organisms population. Natural selection cause overpopulation where we have to many species in one area. Then, there is variation which is the difference between individuals. Last is competition which occurs when resources are limited.
Ecological impacts, Genetic pollution, agricultural damage are some negative effects caused by invasive species. Biological species invasions altered ecological systems in multiple ways. “Worldwide an estimated 80% of endangered species could suffer losses due to competition with or predation by invasive species (panda.org, 2014) ”Some native species may be put at a disadvantage to survive while other species survival is enhanced in physical power due to the change in environment. Genetic pollution might also occur, naturally evolved region specific wild species can be threatened with extinction through the process of genetic pollution. Including, uncontrolled hybridization, introgression (gene flow from one species into the gene pool of another, by the repeated backcrossing of a hybrid with one of its parent species) and genetic aggression and take over, which leads to the replacement of local species as a result in an enchanted advantage of foreign species.
The cause for the bottleneck in the orca population was too old and widespread to be credited to human disturbance so it must have been caused by the last glacial maximum. The populations of orcas that recovered after the glacial period evolved to change. Some remained predators to fish and birds, others evolved to a different niche of marine mammals and sharks. These populations diverged due to geographic differentiation and this also could have affected the intraspecific evolution of these orcas. However even though the killer whales at different locations have similar genetic variation this variation is enough to separate them, partially because the kinship genetic variation within a specific population is even smaller.
They have caused endangered species at risk due to them. The threats of invasive species are that they carry diseases and are cable of changing ecosystems. In this essay I will argue that humans need to take action to solve this problem we created before its brings danger to our environment, ecosystem, and human health as the cause of killer bees. As you know invasive species have caused low food supply The armyworm is an example. “The fall armyworms eat corn.
What is an invasive species? Invasive species is any animal or plant that comes from a different ecosystem and causes harm to the environment. They are called “invasive” because they reproduce quickly and spread rapidly, causing destruction on people’s health and the ecosystem. Human activities are one of the biggest contributing factors in spreading invasive species from one location to another. People can purchase these invasive plants for their beauty, low maintenance, and fast growing nature.