Premium
Earthworm invasion causes declines across soil fauna size classes and biodiversity facets in northern North American forests
Author(s) -
Jochum Malte,
Ferlian Olga,
Thakur Madhav P.,
Ciobanu Marcel,
Klarner Bernhard,
Salamon JörgAlfred,
Frelich Lee E.,
Johnson Edward A.,
Eisenhauer Nico
Publication year - 2021
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1111/oik.07867
Subject(s) - earthworm , biodiversity , ecology , species richness , soil biology , microfauna , fauna , biomass (ecology) , lumbricidae , biology , ecosystem engineer , abundance (ecology) , ecosystem , soil water
Anthropogenic pressures alter the biodiversity, structure and organization of biological communities with severe consequences for ecosystem processes. Species invasion is such a human‐induced ecosystem change with pronounced impacts on recipient ecosystems. Around the globe, earthworms invade habitats and impact abiotic soil conditions and a wide range of above‐ and belowground organisms. In northern North America, where earthworms have been largely absent since the last glaciation period and most earthworm species present today have only been (re‐)introduced a few hundred years ago, invasion impacts have been intensively studied. However, despite several studies assessing impacts of invasive earthworms on soil fauna, studies have rarely investigated the simultaneous responses of different soil‐fauna size groups and biodiversity facets which might respond differently to earthworm invasion and independently affect ecosystem processes. Our study goes beyond previously‐established knowledge on earthworm‐invasion effects by simultaneously assessing differences in four biodiversity facets, namely the abundance, biomass, richness and Shannon index of soil invertebrate macro‐, meso‐ and microfauna communities between high‐ and low‐invasion status plots (n = 80) and in relation to invasion intensity measured as earthworm biomass across four northern North American forests sampled between 2016 and 2017. Across forests and soil‐fauna groups, we found reduced abundance (−33 to −45%) and richness (−18 to −25%) in high compared to low‐invasion status areas. Additionally, meso‐ (−14%) and microfauna biomass (−38%) and macro‐ (−7%) and microfauna Shannon index (−8%) were reduced. Higher invasion intensity (earthworm biomass) was additionally related to reduced soil‐fauna biodiversity. While the studied biodiversity facet was important for the soil fauna response, soil‐fauna size group was comparably unimportant. Given the global ubiquity of earthworm invasion and the importance of soil fauna for key ecosystem processes, our observational results help to assess future impacts of this invasion and the consequences for anthropogenically‐altered ecosystem functioning.