Does Rotting Wood Hurt Prairie Plantings?

Many years ago, restoration pioneer Ray Schulenberg of the Morton Arboretum told me that rotting wood acidifies the soil, that our kind of prairie likes limey soil, and thus rotting wood chips and branches would hurt a prairie or prairie planting.

But I have seen projects where fairly deep wood mulch is left after a brush clearing operation, and the  people in charge assured me that the prairie would grow fine from seed planted in the wood.

I've never tried a side-by-side comparison of seeding diverse prairie on woodless soil compared to wood-mulched soil. I wonder if others have.

I've seen a fallen tree in a savanna or prairie kill many of the species under the branches, even when the branches seem far enough apart to let plenty of light through. Is that "death by acid?" Indeed, the prairie there will often be replaced by a thistle patch.

We cut dense brush off a prairie wetland. Will thick beds of downed wood damage the planted prairie?

Last winter in deep snow we cleared dense buckthorn from a long-neglected area of Somme Prairie Grove. The area seemed like an opportunity, since an overstory of green ash had just died. As always, we burned as much of the brush as we could, but we didn't realize that some areas had dense rotting wood on the ground under the snow.

The area still has trees, but most of them are dead ash.

We had broadcast our seed in the fall, before we even cut the buckthorn, but I returned this spring to put out some extra seed. Now I noticed the dense wood. I suppose last fall I'd expected we'd clean it up and throw it on the bonfires over the winter.

Much of the ground had more wood than bare soil.

Now, standing there with our "prized" seed, I doubted the wisdom of investing our full diversity of  seed here. Our "wet prairie" and "wet-mesic prairie" mixes were rich with rare sedges, turtlehead, swamp betony, cardinal flower, prairie Indian plantain, gentians, gerardias, etc. etc. The warnings of Ray Schulenburg haunted me.

We hauled tarp-load after tarp-load of wood to last winter's bonfire scars. 

I suppose it might have been a valuable contribution to science for us to have left the wood in some plots and picked it up in other plots (after choosing which plot got what treatment by a truly random process). But - as is so often the case - we sacrificed the science because we didn't want to risk wasting the rare local seed. Perhaps someone else has done that science?

Brush piles of dead wood scavenged from the ground.

If anyone has experience with this kind of decision (or dare I ask for actual scientific data?), I'd certainly be interested.

This sort of thing is a long term problem for us who are trying to develop biodiversity restoration for conservation results. We sometimes do some science. But mostly we hope that other people would do it.

The problem is that a good academic scientist might want to control all the variables. Perhaps forty plots of each type - perhaps replicating the experiment on different soil types - and in different years under different weather conditions. And with those challenges, there probably wouldn't be resources to use the the very diverse mix of rare species that we seem to have such good results with. So perhaps that science wouldn't help me much? Instead, I talk with people who have a lot of experience.

That's kind of sad. "The discipline of restoration" is developing well. But "the science of restoration" - perhaps - not so much? I used to check the journal "Restoration Ecology" for data or conclusions that would help me in my on-the-ground conservation work. I never found much.

Have others had better experience?