Philip Abiolu is an IMAE student from Nigeria. He's part of the 2021-2023 cohort and he and decided to travel to Canada, and enrol at the University of Saskatchewan (USask) to work on his dissertation project: Responses of macro-invertebrates in agricultural prairie soils to inorganic fertilizer application.
"Prairie soils are soils found in regions that are too dry to be a forest but also too wet to be a desert and are very fertile soils, due to high soil organic matter and macro-invertebrate activities, however, due to human population pressure and commercial agriculture, the use of inorganic fertilizers are at an all time high, which has placed direct stress on soil macro-invertebrates, so for my research, I aim to investigate and report the effect of varying concentrations of the active ingredients of these fertilizers on the survival, growth, feeding, and reproduction of Folsomia candida (Collembola or Springtails) and Enchytraeus crypticus (Pot worms)."
Luísa Fraga is an IMAE student from Portugal. She's part of the 2021-2023 cohort and chose to stay and develop her Master's dissertation at the University of Coimbra:
Evaluating soil macrofauna using morphological and DNA approaches along a gradient of farming intensification.
"For my second year I chose to come back to the University of Coimbra. It has been definitely the right choice for me. I am focusing on biodiversity assessment tools of soil macroinvertebrate (traditional and molecular methods) with Dr. Luis Cunha. I was able to develop several abilities in all the parts that make an ecologist. I went to the field to collect data and then I processed it in the lab using several different tools, regarding computational capabilities, I have been working on bioinformatics and also statistics in R. It has been a great experience that I highly encourage everyone to follow!"
The concept of One Health underscores the interconnections between human, animal, and environmental health, necessitating multidisciplinary collaboration for a sustainable future. Soil health is a critical foundation of terrestrial ecosystems, supporting essential functions for life. Soil biodiversity, comprising diverse species, plays a vital role in nutrient cycles, decomposition, and soil structure maintenance. However, agroecosystems' intensive practices threaten soil biodiversity, while extensive and traditional methods promote biodiversity, food security, climate change mitigation, and ecosystem services. Research on soil biodiversity remains limited compared to above-ground organisms, posing challenges for conservation. Soil biodiversity comprises a vast array of species and these are vital for ecosystem functions, including nutrient cycles, decomposition, and soil structure maintenance. Regarding agroecosystems, intensive practices are the major threats soil biodiversity is under. While extensive and traditional ones, such as agroforestry, might promote biodiversity, contribute to food security, climate change mitigation, and ecosystem services, thus being an ally towards a more secure and sustainable world. However, research of soil biodiversity remains limited when compared to above ground organisms, creating challenges for conservation. Advanced molecular methods, like barcoding and metabarcoding, offer promising results in assessing soil biodiversity more efficiently.
This study aims to evaluate and compare morphotaxonomy, barcoding, and metabarcoding approaches to assess soil macrofauna diversity in agroecosystems with varying management intensity levels and explore the validation of the methods used. Using an integrative approach I have combined morphotaxonomy and molecular techniques to assess soil invertebrate fauna in different agroecosystems. The analysis of 192 samples revealed a total of 9418 individuals from 13 different taxonomic groups. Out of the sequenced samples, 716 operational taxonomic units (OTUs) belonging to soil macrofauna were identified. Primer pairs, such as Folmer, BF3/BR2, were employed for DNA barcoding and metabarcoding, with both methods recovering carabid species level OTUs with high similarity percentages. However, discrepancies between the two methods were observed, indicating potential primer bias and the need for further exploration. However, metabarcoding indicated the necessity of intensifying sampling efforts to reveal the true biodiversity of the systems, while barcoding showed higher sampling completeness. The integrated dataset was congruent in revealing that higher biodiversity levels in traditional and organic agroecosystems was found when compared to improved pastures.
The study emphasizes the need for highly integrative approaches to overcome pitfalls inherent in each method and improve species identification accuracy. Further analysis should assess the impact of specific taxonomic groups on agroecosystem dynamics and evaluate the influence of environmental and management practices on biodiversity richness and community composition. Additionally, concentration effects in mock communities and comparisons with similar studies are essential for refining the metabarcoding pipeline and increasing genetic references. However, the data collected has the potential for further development and more in-depth conclusions in the future. This study sheds light on the challenges and opportunities of using molecular-based approaches, highlighting the importance of integrating morphotaxonomy knowledge with molecular data to curate existing databases and enhance reliability. Biodiversity conservation requires reliable methods to understand biodiversity loss and identify areas at risk. This research demonstrates how an integrative strategy utilizing both morphotaxonomy and molecular techniques can provide comprehensive insights into species richness and composition. Molecular methods, such as DNA barcoding and metabarcoding, can offer precise species identification, especially when morphological identification is difficult or ambiguous. However, there are pitfalls associated with molecular approaches, including primer bias and mismatches between morphological and molecular methods. To address these challenges, collaboration between researchers and taxonomy experts is vital to ensure accurate species assignments and reveal hidden diversity.