Dr. Erin Cameron, a researcher in the department of Environmental Science, has published a paper in the prestigious Science Magazine on her work studying the global diversity and biogeography of earthworms.
The study had two main findings: that local species richness (the number of earthworm species at a site) was higher in temperate regions of the world compared to tropical areas, and that climate is the strongest driver of earthworm diversity. This suggests that future climate change could significantly alter earthworm communities worldwide, threatening the many functions they provide.
“Having her research recognized by such a prestigious scientific publication is a testament to Dr. Cameron’s innovative work in the field of environmental science,” said Dr. Lori Francis, acting Dean of Science at Saint Mary’s University. “The huge scope of her collaboration with such a large international group of scientists is impressive, and this work will allow further collaborations with other leaders in this field and answer important questions about effects of global climate change on earthworm communities.”
“Having her research recognized by such a prestigious scientific publication is a testament to Dr. Cameron’s innovative work in the field of environmental science.”
Dr. Cameron and her German collaborator Prof. Nico Eisenhauer were the senior authors on the paper, with their postdoc Dr. Helen Phillips as the lead author. The research, based at the German Centre for Integrative Biodiversity Research (iDiv) and Leipzig University in Germany, used research compiled from 140 researchers from across the globe to create the largest earthworm dataset worldwide, encompassing 6928 sites in 57 countries.
First conceived in 2014 at a global earthworm conference after a workshop discussing questions concerning diversity patterns of earthworms, this report has been years in the making. The researchers looked at questions about what factors drive global patterns of earthworm diversity: soil properties such as pH and the organic carbon content of soil, or habitat cover, or climate: i.e. temperature and precipitation. Dr. Cameron had previously looked at earthworm distributions in the boreal forest of northern Alberta, and was intrigued by earthworms found further north than expected.
Earthworms substantially shape the way ecosystems function: their burrowing creates holes, mixes soil components and they eat organic debris. By doing so, they drive a wide range of ecosystem services, including nutrient provision, water infiltration and run-off, carbon storage, climate mitigation and seed dispersal.
“Earthworms are ecosystem engineers; they are species with a large impact on the structure of ecosystems,” said Dr. Cameron. “While the impact of earthworms on their local ecosystems is fairly well known, until now there has been no research or data on the distribution of earthworms at a global scale.”
“A surprising result of this study was that the biodiversity patterns in above-ground organisms do not match those of soil organisms, with a greater local diversity found in more temperate climates compared with tropical locations,” Dr. Cameron explained. “As typically the highest number of species in a local area is found in the tropics, this result was not expected, however we suspect that the total number of earthworms across the tropics is still higher than other regions due to dissimilarity among sites.”
“This is a seminal accomplishment in climate change research which Dr. Cameron has achieved so early in her professional career, with this being the first time Saint Mary’s research has been featured on the cover of Science Magazine,” said Dr. Adam Sarty, Saint Mary’s University’s Associate Vice-President Research. “Her ability to lead this large international collaborative project, and provide a truly global perspective, makes us excited to see where her next projects will lead as she joins the growing team of Saint Mary’s University researchers focusing attention on the impacts of, and responses to, the effects of climate change.”
The research also found that the biggest driver of diversity in earthworm communities was climate, namely precipitation and temperature. “These organisms are an important part of our ecosystem, and below-ground biodiversity must be considered when considering the effects of climate change on our ecosystems,” said Dr. Cameron.
The study and its resulting comprehensive global map used as much data on earthworm diversity, abundance and biomass as possible. Future stages of this work will project earthworm diversity levels in the future.
Dr. Erin Cameron is an assistant professor in the Environmental Science department at Saint Mary’s University. Her research examines effects of global change on species distributions, community composition, and ecosystem functioning. She uses a combination of field observations, experiments, citizen science, molecular approaches, data synthesis, and modelling to assess global change impacts across spatial and temporal scales. Dr. Cameron was recently awarded an NSERC Discovery Grant with a Northern Research Supplement.