The number of virtually all insects decreased by 75-82% in all the reserves and national parks in Germany, the reason for which is not yet clear and the consequences of which can be extremely serious, say environmentalists in an article published in the journal PLoS One.
“All the corners of nature that we studied are protected areas, whose territory is protected by law and the authorities of Germany.” Despite this, in all of them the number of insects fell sharply, perhaps because all of them are surrounded by agricultural lands, where insects simply can not survive, “- said Caspar Hallmann (Caspar Hallmann) from the University of Radbud (Germany).
In recent years, environmentalists and biologists have been seriously concerned that the species diversity and numbers of many insects began to decline dramatically in recent years. For example, recent observations in Britain have shown that six species of the most common butterflies can disappear from the island in the coming years, and the abundance and abundance of many species of wild bees in South America can drastically decline by the end of the century.
Hullmann and his colleagues found that the scale of this environmental disaster is greatly underestimated today, having conducted a kind of “population census” in six dozen reserves, created in Germany over the past century.
The innumerable insects living in every corner of the Earth hinders such calculations directly, and therefore scientists conduct them, setting special traps on the territory of national parks and counting the number of insects that fall into them for a certain period of time. Comparing the mass and the number of individuals in a similar “catch”, one can understand how the species diversity and the number of insects change with time.
Such observations, as Hullmann says, draw a catastrophic picture that has developed in recent years. According to scientists, the number and biomass of insects declined by about 75% and 82% in all six reserves, despite the huge differences in climate, flora and fauna between them.
For example, in 1990, about 10 grams of insects were trapped every day, and today this figure has dropped to 2 grams per day. This sharp drop, as the researchers note, can lead to the collapse of all ecosystems – it affected not only various predatory and parasitic insects, but also pollinators.
The reasons for this are not yet clear, but German ecologists suggest that a decrease in the number of pollinators and other insects may be due to intensification of agriculture and the spread of herbicides that reduce biodiversity among plants and limit the ways in which invertebrate forest and meadow inhabitants feed on their leaves, wood and pollen.