It’s a vast living web beneath our feet – a tangled underground web of microscopic tubes weaving through the soil, pulsating with nutrients, tying the roots of trees and other plants into networks that extend over square kilometers.

Mycorrhizal fungi, they’re called. Most land plants rely on them entirely.

In exchange for sugars and fats from plant roots, the fungi provide a steady flow of phosphorus and nitrogen. Nutrient flows along fungal hyphal networks are both complex and dynamic. Here’s a video of nutrients flowing, in real time, captured by a team of researchers and microscopists at the Free University of Amsterdam (credit: Loreto Oyarte Galvez, AMOLF + VU, Amsterdam)

But, mycorrhizal fungi do more than just feed plants. They cycle carbon from atmosphere to soil, contributing to the storage of vast quantities of carbon below ground. In so doing, they help regulate Earth’s climate.

Not surprisingly, underground fungal networks face a host of threats from above, including deforestation, industrial agriculture and the associated use of herbicides, pesticides and nitrogen-based fertilizers.

In response, soil scientists are calling for the protection of fungal networks, and are inviting citizens to do the same (e.g., by not leaving garden soils bare, and avoiding fertilizers that help plants — but leave mycorrhizal fungi out in the cold).

Toby Kiers is a professor in the Faculty of Science, Ecology & Evolution at the Free University of Amsterdam. She’s also the founder of a group called SPUN – the Society for the Protection of Underground Networks.

In early June, Toby was awarded the Netherlands’ highest scientific distinction, the Spinoza Prize.

Not resting on her laurels, she’s just published an article, together with colleagues, on the crucial role of mycorrhizal fungi in addressing the climate crisis. The paper has received major media attention.

Listen to my conversation with Toby Kiers in today’s podcast. Click on the link above, or go here.

Toby Kiers (Credit: David Meulenbeld)

The cedar is Lebanon’s national symbol.

Cedrus libani stands tall on Lebanon’s flag and banknotes — a source of identity and pride.

But Lebanon’s renowned cedars — and the natural forest ecosystems they’re a part of — are not what they used to be.

Once a continuous carpet running up and down Lebanon’s mountainous spine, these splendid stands of cedar, pine and spruce have been exploited since the days of the ancient Phoenicians, who built ships out of them. The Egyptians used cedar in their mummies.

The Ottomans, British and French took their turn, exploiting Lebanon’s forest wealth.

Jouzour Loubnan’s Tony Shaheen tends after Cedrus libani saplings on a Lebanese hillside (David Kattenburg)

Today, all that remains of Lebanon’s cedar forests are a dozen fragmented islands, threatened by livestock grazing and climate change. The key to restoring them is their genetic diversity. That’s precisely what a Lebanese NGO called Jouzour Loubnan – ‘Lebanon Roots’ — has in mind. In partnership with a team of researchers at the Université Saint Joseph, on the edge of Beirut, Lebanon’s strongest cedars are being rescued and replanted.

Here’s a story about that. Listen to my conversation with Magda Bou Dagher Kharrat, Director of Biodiversity & Functional Genomics at the Université Saint Joseph (now a principal scientist at the Mediterranean Facility of the European Forest Institute), and with several of her colleagues.

Click on the podcast link above, or go here.

Back in 2017, astronomers feasted their eyes and focused their instruments on something Albert Einstein predicted a hundred years ago, but that no one had every actually observed.

A hundred and thirty million light years away (back when dinosaurs were roaming the Earth), a pair of super dense neutron stars had collided with each other, sending out pulses of electromagnetic signals and gravitational waves on a 130 million-year journey to Planet Earth — rippling the fabric of space-time.

That’s not all. Within an instant of that cataclysmic binary neutron star collision, a host of heavy elements (heavier than iron) were forged and ejected outwards. Armed with sophisticated spectrophotometers pointed at the neutron star collision, Earth-based astronomer observed these elements: gold, platinum, titanium and more — in quantities sufficient to explain their presence in the universe today. (supernovae, and neutron star collisions like this one — named after the date it was observed — GW170817).

The Big Question: what emerged from this monumental collision, 130 million years ago — a huge neutron star or a black hole? I spoke about this with Samar Safi-Harb. Safi-Harb is a Professor of Physics and Astronomy, and a Canada Research Chair on Extreme Astrophysics at the University of Manitoba.

Listen to our conversation in today’s podcast. Click on the link above, or go here.

Thanks to Dan Weisenberger for his wonderful guitar instrumentals.