Coarse Woody Debris / Lars Larson Show / Gardeners (or you)

[mdvaden]

Anybody every listen to Lars Larson on the radio?

He was covering Silviculture, logging and forestry yesterday as one topic, and I called in, mentioning "Coarse Woody Debris" or CWD, which is the big dead stuff in the woods. Logs, stumps, dead trees.

Anyhow, best I can tell, many decisions and negotiations between factions will involve something that CWD is related to - say, that some shrubs in the forest can't reproduce without it, needing the protective bulk as a barrier against browsing deer.

Anyway, Lars kept trying to shift from that aspect, as I tried to talk about it. He made a comment similar to that most people who garden would know about CWD.

So here's the deal. To avoid speculation, I figured that gardening forums would be one extra way to find out if gardeners really know what Coarse Woody Debris is. The forestry term, not bark mulch. I posted this on garden forums, and so far, no average gardener has an inkling what "coarse woody debris" refers too. My guess, is that this forum, if any, would have some people familiar with CWD.

How many of you are comfortably familiar with "Coarse Woody Debris" and its role in the forest?

How many gardeners do you think really know about it?

I plan to email Lars Larson in a week, to let him know the forum responses and whether "gardeners" really understand that aspect of Forestry or Silviculture.

Thanks.

[Don_Papenburg]

I have -heard Lars a few times .    If you would have asked me what is CWD I 'd of had a look of a deer caught in the warm glow of headlites.  My "garden" is about 500 acres.

[Sprucegum]

I have never heard of Lars , or of CWD in gardening. I have browsed through a few gardening forums myself and never seen any reference to CWD.

"People who garden" turn coarse woody debris into mulch or burn it and scatter the ashes 

[Ron Wenrich]

I'm thinking its more of a west coast thing.  We don't worry too much about woodlot debris, since fire isn't a big issue here in the east.  Mulch from wood is usually dyed and is simply called red mulch in my area.

Before I got onto forums I never heard of stuff like pine straw.  That's a regional thing, as well.

From a logging aspect, most times tops are left in the woods to help with the regeneration by keeping making it difficult for deer to get to seedlings. 

[thecfarm]

I never heard CWD either.Ron,I've heard of living tops like the way you stated on here.That's a regional thing too.If I see that done around here I call that slack logging.Most times the tops are run over with the skidders to smash them down.I myself prefer to see no slash sticking up in the air.In fact I think most of the logger's contract state that no slash wiil be left up in the air 2-3 feet.But we don't have the deer problem that you do.My lot is growing back with alot of white pine.I hope the rabbits will move back in.

[Onthesauk]

Believe most of the contracts here in Washington on State owned land require that you leave all the slash.  Can mean thousands of cords of nice maple firewood left on the ground to rot but apparently is a water quality issue.

[brdmkr]

I HAVE heard of coarse woody debris.  I am also familiar with its ecological role.

[Pilot]

Yes, I am familiar with CWD & it's role, but I was a district silviculturist for many years.

Lars & several other talk show hosts are way out of their area of expertise, it they have any, when they start to talk about forestry.

For those of you who are not familiar with it, CWD refers to the large pieces, not tops.  There is some thinking that CWD has a role in maintaining the productivity of the site, that it is habitat for many critters and has an important role in streams for fish habitat.

Personally, I never bought into the notion that a few logs scattered around (I think it was 2 per acre that they required) would have any impact on productivity except in the vicinity of the log.  I can buy the habitat role and the importance of logs in streams.  However, in Oregon, in 1964 there was a severe flood event.  Logs in streams contributed to bridges being washed out, so the policy for quite awhile after that was to clean all logs out of streams when logging an area.  Then the pendulum swung back to protect all existing logs in streams and to add logs where they were deficient. 

I am waiting to see what happens after the next 100 year flood.

[mdvaden]

Not sure if I'll send Lars what I found on the internet about gardeners knowing this stuff.

Lars is an okay guy, but I noticed that he asks questions to steer the conversation to an area that he want to, or is comfortable talking about.

As for CWD, barely anybody on the gardening forums knew about it. The few that did, were either quite a bit older, or were working for BLM, etc..

One thing not really related, that I've always been interested in, was the benefits that the beavers provided before they were all trapped, like in Beaverton, where I grew up.

It occurred to me, that their dams would have slowed the velocity of stream flow, enabling far more soil and sediment to settle inland, rather than washing into big rivers and the ocean.

Its remarkable the effects to the land, when something natural is eliminated or highly reduced.

[Ron Wenrich]

So is the CWD supposed to act like a nurse log? 

[mdvaden]

So is the CWD supposed to act like a nurse log? 

That's one thing.

When I called the radio show, I mentiioned that people could look it up on the internet and read, because there's more than could be said about it in a few breaths or paragraphs.

When I searched, with and without quotes, there was a lot of reading material to choose from.

One article, mentioned that some shrubs can't reproduce without the protective cover of CWD - due to deer eating flowers.

[Nudgewood]

Interesting topic. The role CWD plays in different vegetation regimes, or even biomes, varies widely. In African savannas for instance it's a pulsed event; eland, buffalo and giraffe make inroads into thickets and over time they open it up enough so zebra, impala, kudu and gerenuk can browse to the point that trees, especially seedlings and young plants, are significantly impacted. Then, usually during a drought or when episodic locust or catepillar infestations reduce available forrage, the elephant move in and trash what's left. The remaining CWD acts as an effective animal barrier and the cycle begins again. This is nothing like continuous drop of dead branches and blowdowns in American woodlands though beaver activity and tornadoes would probably have similar pulses.

Also, seral stages utilize nutrients differently. Pioneer species, apart from their need for sunlight, can utilize molecules 'in the raw'. Subclimax species need the availability of synthesized molecules, especially bound nitrogen. Same for Climax species except that they rely on rhizobia and bacteria that are initially associated with the root systems of the subclimax and detritus to synthesize nutrients into suitable molecules and even enzymes that are shared symbiotically between host plants and their associated rhizobia. CWD in this instance is like a slow-release nutrient source that relies on a soil biota that can only exist if the prior seral stages have evolved. That's the difference between old-growth and what we harvest today; a significant proportion of that slow-release mechanism was removed from the system as lumber.

In rainforrests this is the only role of CWD and it has no shelter or barrier function.

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