Devin Lavign wrote:Here is a good article on Doug Fir ecology that is well worth reading http://and.lternet.edu/lter/pubs/pdf/pub34.pdf especially worth noting is how it discusses a diverse and well rounded ecosystem in old growth Doug Fir forests. In fact this diversity is being put forward as needed to be clasified as a legit old growth Doug Fir forest.
I think the issues of diversity deserts in Doug Fir and other conifer forests have a lot to do with human intervention rather than the true nature of these trees.
#1 issue likely is wild fire suppression. A lot of these forests evolved with regular fires running through them. We humans have really messed up much of the conifer forests due to trying to prevent and stop wild fires from doing what many of these forests actually need to happen.
#2 the devastation of massive logging in the past. A lot of the conifer forests were completely stripped. This utterly changed how the forests regrew. Fire does not strip entire mountain ranges of all it's forests typically. But we humans did exactly that, removing entire forests from all hills and mountains in our greed to take the lumber. The regrowth since then has been nature trying to bounce back from a massive disaster. This alone could be a big part of what knocked out a big part of the diversity that is cited as a problem with conifers. The under story would have been wiped out as collateral damage by the initial logging. While those loggers might have thought to replant some conifers, did they think to also plant in the understory plants? Modern logging you don't see understory planting along side of the tree replanting, so it is doubtful the old loggers thought to replant the understory either.
#3 human replanting. When humans replant they tend not to replant diversely. They also tend not to replant with succession in mind. They just plant the trees they want to log in the future.
The whole "natives burned out Doug Firs to favor oaks" seems like our culture killing off dandelions to preserve lawns. The natives valued a specific plant and so inhibited other plants from replacing them. But is this Doug Firs being invasive or natives artificially selecting what should grow in an area? To me this sounds like human intervention in succession rather than a problem with an invasive.
From what I understand (I harvested these commercially for a few seasons), it is not the fact that the forest is a second growth plantation that it produces chantrelles; it's because all of that forest is of the right age (70 to 150 years) to have the symbiotic relationship with the chantrelle fungi. After the forest passes this age spectrum, then other mychorizal fungi slowly take over the niche, and there will be no chantrelles at all. In your naturally regenerated forest, which is more advanced in diversity of ages and species, you will find a more diverse selection of mychorizal partners in the system, and though you might not have chantrelles in quantity, there might be a few hidden here and there, and a whole bunch of other fungi as well.
One day I got up the gumption to learn how to harvest chantrelles. It occurred to me that I'd never seen any on my property - they didn't grow there! My neighbors, however, found massive patches in their previously clearcut, doug fir replant. And I learned that's where you find the most chantrelles typically, anyways.
This is not just a boreal occurrence, but is relatively common in many forest ecosystems outside of true old growth systems, and even within them. It is only the ancient old growth systems (which are in patches of old growth) that are fire free. The vast majority of forest fires are not complete burns, even in the boreal. The pattern of a regular fire is called a mosaic for the uneven distribution of heat and totality of burn. Some fires are so intense that there are few dead standing trees in a large area, and everything is reduced to ash, but this is rare. Sometimes even the massive fires leave all kinds of islands of intact forest.
This generally only happens up in boreal forests where entire forests go through fire regrowth death cycles in big patches.