{"type":"rich","version":"1.0","provider_name":"Transistor","provider_url":"https://transistor.fm","author_name":"Spatial Stack with Matt Forrest","title":"Mapping the Invisible: Soil Fungi, Satellites, and the Largest Network on Earth with Justin Stewart","html":"<iframe width=\"100%\" height=\"180\" frameborder=\"no\" scrolling=\"no\" seamless src=\"https://share.transistor.fm/e/e0197da8\"></iframe>","width":"100%","height":180,"duration":2311,"description":"What does it take to map something you have never seen?\nIn this episode, Matt Forrest sits down with Justin Stewart, quantitative ecologist at SPUN, the Society for the Protection of Underground Networks, to unpack how his team built the first global map of arbuscular mycorrhizal fungi, the soil organisms living in symbiosis with most plants on Earth.\nJustin walks through the full pipeline, from robotic microscopy of threads two and a half microns wide up to a planetary prediction at one square kilometer resolution. The team assembled 16,000 soil samples from more than 300 studies across 11 languages, trained a random forest on 34 satellite-derived layers in Google Earth Engine, and\nsummed the result: roughly 110 quadrillion kilometers of fungal thread, about 300 megatons of carbon, six times the biomass of every human alive.\nThe findings were not what anyone expected. The densest networks are under grasslands, not forests. Croplands run about 50 percent sparser. And 90 percent of the biodiversity hotspots for these fungi sit outside any protected area.\nIn this episode, we cover:\n- Why mapping a symbiosis is harder than mapping an organism\n- Robotic imaging in the Amolf biophysics lab, and tracking half a million nodes at once\n- Building a global database from literature in 11 languages\n- Random forest niche modeling and uncertainty analysis in Google Earth Engine\n- The effective radius algorithm that turns network length into biomass\n- Why grasslands, flooded wetlands, and the Tibetan plateau light up on the map\n- Tilling, fertilizer, and how a 450 million year old symbiosis gets broken\n- Rights of nature, eDNA, and why predictive maps are not yet admissible evidence\nLINKS:\nJustin Stewart\nSPUN profile: https://www.spun.earth/team-members/justin-stewart\nLinkedIn: https://www.linkedin.com/in/justin-stewart-70512645/\nGoogle Scholar: https://scholar.google.com/citations?hl=en&user=1aqTJIUAAAAJ\nSPUN\nWebsite: https://www.spun.earth\nUnderground Atlas:...","thumbnail_url":"https://img.transistorcdn.com/eQgCuZrC7zp58BwqV7sl3SCjjIPfOYXp-k4ce29LXQY/rs:fill:0:0:1/w:400/h:400/q:60/mb:500000/aHR0cHM6Ly9pbWct/dXBsb2FkLXByb2R1/Y3Rpb24udHJhbnNp/c3Rvci5mbS80ZjU3/N2JlMDJiYTFjOWY5/OWQ5NWQxYmZjMjMw/Yzg1ZC5qcGc.webp","thumbnail_width":300,"thumbnail_height":300}