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Reynolds, J. W.

Publications and source records attributed to Reynolds, J. W..

3 recordsLinked to original sources

Systematic evidence map of research on life-history traits in native and introduced earthworms

Invasive species constitute one of the most significant threats to biodiversity worldwide, and are responsible for more than $400 billion in losses each year. An organism's life-history strategy, defined by how it allocates resources among growth, survival, and reproduction, plays a central role in determining whether it becomes invasive. While the life-history profiles of aboveground invaders are increasingly well characterised, those of invasive species below ground remain poorly understood. Earthworms are a diverse group of soil invertebrates that can help fill this knowledge gap. Of the ~5,800 earthworm species described to date, nearly 2% are cosmopolitan, meaning they have achieved wide geographic distributions despite limited ability for active dispersal. While life-history traits are likely to contribute to their worldwide distribution, the existing research on earthworm trait variation has not been systematically reviewed. To address this gap, we assessed the taxonomic scope, geographic coverage, and methodologies of studies on earthworm life history traits for species occurring in the US and Brazil, spanning a broad latitudinal range. Our literature search yielded over 8,000 articles across 180 species and revealed that introduced species have received considerably more research attention than native species. Research was concentrated on a few model species, most studies were experimental, and variation in life history traits was most commonly assessed in response to chemical compounds, vermicompost feed type, and environmental factors such as temperature, moisture and soil composition. Variation in adult survival was reported most frequently, followed by adult growth and cocoon production, with the bulk of life history research conducted in India (20%) and China (9%). To better understand the effect invasive earthworm species might have on native fauna, future research on life histories should address taxonomic biases and prioritise detailed study of the life cycles of native species in their natural habitat.

ecology↗

The applicability of Regional Red List assessments for soil invertebrates: First assessment of five native earthworm species in Canada

Earthworms (Annelida: Clitellata: Crassiclitellata) are prominent members of the soil community, important to many ecosystem functions. Despite this, and like many other soil invertebrates, they are rarely considered in conservation assessments, including the IUCN Red List assessments used to assess species extinction risk. To investigate the applicability of the IUCN Regional Red Listing protocol to soil invertebrates, we assessed the conservation status of five earthworm species known to be native to Canada using this protocol and all available occurrence records. In Canada, no earthworm species have yet been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Due to the lack of data on population sizes and their trends, all five species were assessed using their Extent of Occurrence (EOO) (Criterion B). One species was assessed as Vulnerable, two were assessed in non-threatened categories, and two were assessed as Data Deficient. For the majority, the main threats identified were the continuing loss of potential habitat due to land conversion and resource exploitation, as well as the effects of climate change. Increasing the amount of data, including but not limited to distribution and habitat preferences, would make the assessment process easier and status decisions better supported. By undertaking regional assessments for five native earthworm species in Canada, we show that Regional Red List assessments are feasible for soil invertebrates.

ecology↗

Global worming: massive invasion of North America by earthworms revealed

Human activities cause major ecological changes by reshuffling the spatial distribution of species. The extent to which this process affects belowground biota is a critical issue because soil organisms play a key role in ecosystem functioning and maintenance. However, the magnitude of the reshuffling of soil species remains unknown so far because of the lack of a historic baseline. Here, we begin to fill this gap with the largest spatiotemporal database of native and alien earthworms in North America. Our results reveal that the entire continent is being invaded by non-native earthworms through a variety of pathways. We show that these aliens bring novel ecological functions in most regions and thus represent a major threat to native ecosystems. Our findings demonstrate that earthworms, and most likely other soil organisms, represent a major but overlooked pool of invasive species with strong ecological impact. They need to be better integrated in control and mitigation strategies.

ecology↗