Competition between species occurs all the time
The natural species are placed in constant danger by threats such as wildfire, hurricanes, and other pollutants. Because of this, the ecological systems are put in lots of stress and pressure. Most of the experts believed that in these circumstances the thing that changes is the competition which usually occurs between the species. They believed the fact that in such conditions where the life of the species is affected by conditions such as the ones mentioned before; they do not care as much about competing against each other, because each species is focused on saving their own skin.A controlled experiment was conducted on the microscopic organisms. They were influenced by exterior disturbances and factors and the scientists analyzed the way in which they reacted. The results were surprising for everyone, and made them change their thoughts about the way in which the organism behave in times of high pressure. Lin Jiang, who is an assistant professor in the Georgia Tech School of Biology said that this allowed the scientists to observe the way in which the organism behave in the case of pressure as a result of external disturbances.
What they wanted to see was they way in which these organisms interact with each other when such disturbances occur. They wanted to observe the interactions and to see the consequences that these interactions bring. The research was introduced in the online edition of the Proceedings of the National Academy of Science, on June 28, 2010. The experiment was sponsored by the National Science Foundation. In the article they mentioned the fact that the life of the organisms depends a lot on the way in which they interact with each other during times of high pressure, and when external factors are introduced in the equation. They revealed the fact that the survival of organisms depends a lot on this interaction. They managed to demonstrate that in a slight manner the regulation of the ecological communities depends a lot on the competition.
Jiang conducted the experiment together with his team which was composed of the following members: Zhichao Pu, who is a Georgia Tech biology graduate student and Cyrille Violle who is a formerly postdoctoral fellow at Georgia Tech, who currently works at the University of Arizona. The organisms which they used in their experiment were freshwater bacterivorous protists. They introduced these organisms in microcosms, which in other words are simplified ecosystems.
The experiment lasted a few weeks but thanks to the microcosm, the team was able to observe lots of things. Jiang mentioned that the microcosm system allowed the organisms to reproduce at a higher rate than they would usually reproduce. Because of this, the team was able to “…examine multigenerational community dynamics, including competitive exclusion and stable coexistence, in a period of a few weeks.”
The team used protozoa in their experiments. The protozoa belong to the species single-celled eukaryotes. They wanted to see the way in which the protozoa behaves in situations where they have no competition, the way in which they react when they have competition but when no external disturbances occur, and they way in which they react when they have competition and when the external disturbances occur.
They used sound energy as disturbance; and they used 11 levels of disturbances. The weak disturbances did not influence most of the species, whereas the strongest one caused the extinction of most of them. The next thing the team did was to separate each group of organisms and to observe the way in which they acted when the external disturbances occurred. They observed the change in population, behavior, and other factors as well. Then they put together two different types of species and let them battle for resources for a period of ten weeks.
During the final phase of the experiment the team placed the organisms together in order to let them fight for survival while they were subjected to the external factors. In the end most of the 11 species of organism died as the disturbances increased. However the interesting fact is that most of these 11 species managed to survive when they were contained in their own microcosm, even when the disturbances were at their highest levels.
This can only mean that the main reason for the disappearance of certain species was the competition. The disturbances could not have killed them when all of the species were together if they managed to survive it while they were alone. Previous hypothesis suggested the fact that when the disturbances are low, the species which survive are the ones which have the highest competitive factor whereas in the case of high disturbances the species which survive are the ones which can resist only to the disturbances.
The results showed a different thing, as some of the species which have a high competitive factor were not too much affected by the disturbances, which means that they still prayed on the other species even when they were influenced by those external events. However the experiment is not too conclusive since its events can not be applied to other factors. In the case of this experiment, the species had to fight only for the resources, as they did not attack each other. The one which got the most food had the highest chances of surviving. However Jiang admits the fact that in the case of the organisms which attack each other the situation might be completely different, as in that case the competitive factor could prove decisive as long as both of the organisms would be able to survive the external factors.
Another important factor is the one of the microcosm. The microcosm acted as a world, which meant that all the events were global, and that does not happen in real life, where the disturbances and the other factors occur at a local level.11
