Environmental DNA research has skyrocketed in the past decade, with publications exploring spatiotemporal presence of biodiversity in all kingdoms of life, addressing questions in many different scientific disciplines. Few programs simultaneously inventory biodiversity in multiple kingdoms, and few programs coordinate distributed sampling in narrow temporal windows. Our program, CALeDNA, aims to use six metabarcoding loci simultaneously to track the presence of taxa in different kingdoms from soil and sediment samples collected en mass, by volunteers as a citizen and community science initiative. Launched in 2017, CALeDNA has facilitated collections of 15,000 samples from across California. Examples include coordinated beach sampling across the state in the same weekend, and seasonal sampling of the same vernal pools over three years. Researchers and the public use the open-access collections and datasets to ask many questions about community ecology and beyond.
Here, we use SpIEC-EASI software to determine ecological co-occurrence networks for groups of eDNA samples collected across California and test the stability of these network degrees.
Results/Conclusions
The thousands of relationships identified among the 17,000+ organisms are uncovering holobiomes and other biotic interactions such as possible food webs. However, because samples are an instance of space-time, how much can isolated collections and the ecological networks we generate from sample collections be useful to probe changes through time? We explore spatiotemporal network stability as well as alpha, beta, and zeta biodiversity patterns across the state in this presentation, and suggest new algorithms and modelling frameworks needed for appropriately using eDNA in temporal analyses. We also suggest new applications of eDNA-derived community patterns for a variety of environmental management applications.