We know that biodiversity – is good, but often it is only the result of purely theoretical considerations. Obtain experimental evidence of the positive impact of biodiversity on ecosystem sometimes difficult. The reason for this – in the huge complexity of such research: biodiversity is best studied in large, complex ecosystems, and that means thousands and thousands of samples, and the mountain of statistical and analytical work. However, ecologists from the University of Colorado at Boulder (USA) not afraid: The species composition of amphibians almost 350 ponds, they concluded that the diversity of amphibian species prevents the spread of these infections.
|The more species in the pond frogs and salamanders, the less chance of the parasite that causes the deformation of the body of the amphibians. (Photo by Oregon State University.)|
Researchers were interested in the relationship of amphibians and fluke Ribeiroia ondatrae, which causes deformation of the body during development of the animal: the frog may appear superfluous legs, normal limb may be deformed and so intermediate host for R. ondatrae are water snails, so we had to collect more and snails. A total of 24,215 treated environmentalists amphibians and 17,516 snails. The results of this titanic work published in the journal Nature.
And they are as follows: in a pond inhabited by six species of amphibians, the chance to get the parasite from them as much as 78% less than that of a frog or newt, of which one view of the entire lake. It is worth saying that the researchers did not stop just a collection of statistics, even very large. They also put on a series of experiments with 40 artificial ponds in which to run amphibians and their parasites. Was able to observe important pattern of biodiversity: in the pond lived a kind, it is usually looked as the most sensitive to the parasite. In order not to disappear, this amphibian to reproduce extremely intense. Indeed, the species living alone, are of the highest fertility. As the population of the pond there were species new amphibians, more resistant to infection, and finally came to the last one who is least bothered parasite.
Species that reproduce rapidly, faster than all covers new territory, but for that they have to pay an increased sensitivity to infection. Later they pulled less prolific and less sensitive species, and then come to the parasite is not the best of times: biodiversity greatly dilutes the original sensitive species. The parasite is now highly likely can get a stable individual, where he did not shine. Because of this, the overall density of the parasite falls, and the ecosystem is healthy.
The authors believe that such a law is not the private affair of amphibians and R. ondatrae that it holds for all species and ecosystems. Many diseases run between humans and animals, and will not be an exaggeration to say that the biodiversity of birds, animals, fish, and so is used to shield people from a variety of pathogens. In this sense, the preservation of some of the Amur tiger is a concrete practical – epidemiology – the goal: who knows, maybe it is due to these cats in Siberia and the Far East have not manifested any parasite, which would pale before the legendary Rush Ebola.
Prepared according to the University of Colorado at Boulder.