Issues of concern to people who live in the west: property rights, water rights, endangered species, livestock grazing, energy production, wilderness and western agriculture. Plus a few items on western history, western literature and the sport of rodeo... Frank DuBois served as the NM Secretary of Agriculture from 1988 to 2003. DuBois is a former legislative assistant to a U.S. Senator, a Deputy Assistant Secretary of Interior, and is the founder of the DuBois Rodeo Scholarship.
Thursday, February 13, 2020
Cancel Earthworms: The “crazy worms” remaking forests aren’t your friendly neighborhood garden worms
...Until about 10,000 years ago, a vast ice sheet covered the northern third of the North American continent. Its belly rose over what is now Hudson Bay, and its toes dangled down into Iowa and Ohio. Scientists think it killed off the earthworms that may have inhabited the area before the last glaciation. And worms—with their limited powers of dispersal—weren’t able to recolonize on their own. For someone like me, who grew up in the Midwest seeing earthworms stranded on the sidewalk after every rain, this was a shocking revelation. With the exception of a few native species that live in rotting logs and around wetlands, there are not supposed to be any earthworms east of the Great Plains and north of the Mason-Dixon Line.
But there are, thanks to humans. We’ve been moving worms for centuries, in dirt used for ship ballast, in horticultural plants, in mulch. Worms from South America now tunnel through the global tropics. And European earthworms live on every continent except Antarctica. Dobson, a forest ecologist at Yale University, calls it “global worming.”
But of all the earthworms people have shuttled around the world, the ones Dobson shows me at Seton Falls have scientists most concerned. Originally from Korea and Japan, they are known as jumping worms, snake worms, or crazy worms. And they have the potential to remake the once wormless forests of North America...Common species like Lumbricus terrestris,
better known as the night crawler, arrived hundreds of years ago with
European settlers, and have long been welcomed in gardens and farmland.
In the 1980s, however, researchers began to find European worms in the
forests of Minnesota and other northern states. One hypothesis is that
people spread them when they throw away extra fishing bait next to lakes
and streams. The
discovery alarmed scientists. In the absence of worms, North American
hardwood forests develop a thick blanket of duff—a mille-feuille of
slowly decomposing leaves deposited over the course of years, if not
decades. That layer creates a home for insects, amphibians, birds, and
native flowers. But when worms show up, they devour the litter within
the space of a few years. All the nutrients that have been stored up
over time are released in one giant burst, too quickly for most plants
to capture. And without cover, the invertebrate population in the soil