Underground Networks

First image of our black hole (with wider background)

Black holes & gnarled old cedars

GPM # 59

It’s a vast, living web beneath our feet – a tangled underground network 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 plants rely on them entirely. In exchange for plant sugars, mycorrhizal fungi provide phosphorus and nitrogen.

But, mycorrhizal networks do more than just feed plants. They cycle carbon from atmosphere to soil, regulating Earth’s climate.

Underground fungi face a host of threats from above. Soil scientists have come together to protect fungal networks, and are calling on citizens to do the same. 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.

Toby Kiers (Credit: David Meulenbeld)

The cedar is Lebanon’s national symbol. It’s on its flag, its banknotes, a source of identity and pride.

But Lebanon’s renowned cedar forests are not what they used to be. Once a continuous carpet running up and down Lebanon’s mountainous spine, these splendid forests 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.

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. Here’s a story about that.

Jouzour Loubnan’s seed bank (David Kattenburg)

Back in 2017, astronomers feasted their eyes and focused their instruments on something Albert Einstein predicted, but no one had every actually observed. A hundred and thirty million light years away, a pair of super dense neutron stars had collided with each other (when dinosaurs roamed the Earth), sending out pulses of electromagnetic signals and gravitational waves, rippling the fabric of space-time.

The GPM spoke with Samar Safi-Harb about the event, named after the date it was observed — GW170817. Safi-Harb is a Professor of Physics and Astronomy, and a Canada Research Chair on Extreme Astrophysics at the University of Manitoba.