There ’s an encroacher lurking beneath our groundwork . Slimy , slender , and faceless , they ’ve colonize the soil of North America and have the potential to have hoo-ha . No , that ’s not the game of a broken - budget sci - fi motion-picture show , but instead the story of non - aboriginal earthworms , which a new study propose are an overlooked threat to aboriginal ecosystems .
Though there ’s only a small number of sketch that have describe on thisalien invasionin detail , according to the raw research , there are at least 70 imported earthworm species in North America . To determine this and track their gap , the authors aggregate record on aboriginal and non - native earthworms dating from 1891 to 2021 with reports on US edge interceptions of non - native earthworms document between 1945 to 1975 .
A helping script from automobile learnedness revealed that alien earthworms could be found in 97 per centum of the continent ’s study soils . In fact , it was estimated they represent nearly a quarter of North America ’s 308 angleworm coinage , and in the US specifically , they beat out the number of invasive Pisces , mammal , andinsectspecies by a moderately goodish margin .
Whilst they can be found throughout North America , there also appear to be a pattern to alien nightcrawler ’ dispersion . The symmetry of alien earthworms to aboriginal species was found to be at its highest in the northerly regions of the continent and depleted in the due south and Occident .
“ These ratio are probable to increase because human activities facilitate the evolution of alien mintage that threaten native earthworm species , a phenomenon still largely overlooked , ” said sketch lead author Jérôme Mathieu in astatement .
But what are the potential threats the authors are concerned about ? After all , according to some , encroaching species are “ one of the five horsemen of thebiodiversity apocalypse ” .
Non - native earthworm specie have historically been introduced to enhance agriculture – though they ’ve also been import for fishing bait – as they aeratesoiland , through their waste , provide it with nutrient - rich plant food .
According to the research worker , however , alien fishworm can cause problems by outcompeting aboriginal coinage . Their presentation can also inadvertently bear upon the ecosystem as a whole ; where foreign wiggler have been introduced near sugar maple trees , it ’s causeddiebackand impacted the food for thought mountain chain .
“ This is most potential the crown of the iceberg , ” said study co - author John Warren Reynolds . “ Many other soil organisms may have been introduced , but we know very little about their encroachment . ”
With limited previous research , it ’s hard to know the true extent of invasive red worm ' impact thus far , but the researchers believe that their significant numbers and distribution across a wide range of home ground mean we should be pay them much closer attention .
“ Earthworms tell the story of the Anthropocene , the age we experience in , ” said study elderly writer Elizabeth Hadly . “ It is a narration of world homogenization of biodiversity by humans , which often leads to the decline of unique local species and the disruption of aboriginal ecosystem processes . ”
The study is published inNature Ecology & Evolution .
