Terrestrial biodiversity from soil samples

eDNA analysis for assessing terrestrial mammal biodiversity from soil samples

Let’s move on to looking at the terrestrial biodiversity using soil samples. For this we have selected a published research work that compared eDNA analysis of soil samples with a 9-year camera-trapping study to address knowledge gaps regarding eDNA’s nature, spread, and persistence in terrestrial environments. The researchers tested various experimental parameters, including sampling designs, DNA extraction kits, and metabarcodes of varying lengths. All mammals regularly detected by cameras were also identified through eDNA, along with additional small mammals not captured by cameras but known to inhabit the area (Leempoel et al. 2020). 

Upon comparing different approaches, the study discovered that a long metabarcode (≈220 bp) from mitochondrial rRNA genes 12S and 16S was as effective as a shorter one (≈70 bp), and that a cost-effective phosphate buffer-based extraction method performed similarly to a commercial kit based DNA extraction method. The findings suggest that eDNA-based monitoring is a valuable tool for ecosystem surveys, and recommend further improvements to mitochondrial reference databases for better analysis (Leempoel et al. 2020).

DNA barcode/s used for this study: Mitochondrial rRNA genes, 12S and 16S

Sequencing technology:  Illumina MiSeq

To find further details about this study, you can refer the full article: A comparison of eDNA to camera trapping for assessment of terrestrial mammal diversity.