Eager Embryos for the New Year

Some of us stewards have been raking leaves in the forest. Are we crazy? 

Raking forest leaves into piles and onto tarps? Really?

Then tossing tarp-fulls on to a bonfire? What gives? 

In fact, we are restoring nature, guided by actual scientific experiment. Previously, we found that our rare, precious seed produced few or no seedlings when we broadcast it on dense woodland leaves. See photo below from 2015.

We had sowed patches of seed in circular plots a) where leaves had been raked away and b) in similar unraked plots. Only the raked plots produced bountiful seedlings, as shown here, during the second spring, following a burn. The unrated circular plots didn't make helpful photos. They were just expanses of thick dead leaves.

For more on this experiment, see Endnote 1. 

Where we cut away the dense buckthorn, there is little flora left to recover. So, as suggested by the experiment, we generally broadcast our seed after a burn removes the leaf litter. The seed then works its way into that blackened, bare ground – and seedlings thrive. But we didn’t manage to have a prescribed burn this fall. No good burn weather last fall. Perhaps next spring?  But some species need to be in the ground all winter. So, experimentally, we rake leaves off some areas for seeding. 

 

Nine bags of seed for “MW” or “mesic woods” (mesic meaning in between “wet” and “dry” woods). We gather a dozen different mixes, with tens of thousands of dollars’ worth of seed, if we were to buy it. But the local ecotype is not available commercially. In other words, this rare seed is invaluable. We don't want to waste it.

The handfuls of seeds that we carefully broadcast are the future of the ecosystem that will support butterflies, birds, salamanders, beetles, coyotes, and the whole family. 

What to do with those leaves we rake off? We sometimes make piles. But that’s not the preference in the areas that have diverse spring flora. The piles are thick enough to kill much of the existing flora that comes up underneath. (It’s the summer and fall flora that’s dramatically killed off by the excess shade.)

Although it’s more work, we sometimes toss tarp-fulls of leaves over a brush bonfire. Then we’re rid of them. They burn more like dry leaves would burn in a controlled fire, more completely and hotter. Such burning is very different from the smoking piles of leaves that drew public outcry years ago by people sensitive to smoke. This is different smoke, and convection tends to loft it happily out over Lake Michigan. 

So, raking means “Happy New Year” to the literally millions of rare embryos of the more than 200 plant species that we have gathered, prepped for planting, sorted into wetness-and-shade-level mixes, and now raked for and broadcast.

We look forward to celebrating with them their bounteous futures in years to come.

Spring: In a restored area, blooming geranium, robin plantain, yellow stargrass, and bastard toadflax share space with species that bloomed earlier, like wood betony, and which will bloom later, including cream vetchling or “wood pea.” 

In early summer this restored open woodland features blooming wild columbine, spiderwort, and beardtongue. All these and many others had been killed off by the buckthorn shade and were seeded back in.

Later in the summer, Joe-Pye-weed and woodland sunflower start to overtop the starry campion, wild coffee, and woodland brome, which bloomed earlier. 

Endnotes

Endnote 1

A caveat: leaf raking seems to be most needed in places where dense oaks leaves cover the ground. There are places in the woods where leaves blow into piles or, for whatever reason, bare soil is visible. In such places, we just scatter seed on whatever bare ground there is.

But in the photo, six of the raked circular plots are obvious here in the second year of this experiment – because of the diverse vegetation emerging. This vegetation did not emerge in the unraked circles. Indeed, the sparse emerging vegetation outside the raked plots now is almost exclusively young maple trees. Oddly, lots of maples emerged in the un-raked patches, but not in the raked patches. Perhaps the maples couldn’t compete with the restored turf from the diverse seed mix? Maple invasion is a major degradation threat in the oak woodland.

How did the grasses, sedges and wildflowers of the oak woods reproduce before we were here to rake leaves? Perhaps only after burns? Or perhaps just very slowly. We notice that in scattered small patches the ground is bare of leaves because of animal disturbance, or wind, or whatever. Perhaps most seedlings once germinated in those patches. 

Another possibility is suggested by our experience with savanna and prairie seeding, which is much different than our woods experience. While we’d prefer to seed on the year of a burn, there’s actually seedling-establishment potential in savannas and prairies during non-burn years because the structure of the previous year’s vegetation prevents the build-up of a thick mat of fallen leaves. Unlike tree leaves, much prairie vegetation is more vertical than flat. Perhaps as the years progress and diverse vegetation is restored, seeds will do a lot better in the better-vegetated woodlands without our help. 

Thanks
for photos to Eriko Kojima and Stephen Packard

Thanks
for hard work and high spirits - to scores of Somme weekend stewards
(P.S. You're invited to join in. See our schedule at Somme calendar.