First of all, let me say that there are probably people in the Forest Service who have thought all this through. I’m hoping that they will help out with their explanations in the comments.
If old growth is old growth, and mature forests are on their way to old growth, and young forests are on their way to mature forests.. then it seems like there is no ceiling on the amount of old-growth needed, and no reason to ever have openings other than “natural” ones. This can be problematic, conceptually, as some groups believe that today’s wildfires and wind events are all unnatural or caused or “supercharged by” the anthropogenic part of climate change.
And if you believe that, then does any ecosystem have “integrity”? Or is the key thing to promote resilience (including biodiversity) in the face of climate change and protect key values of ecosystems and people from these and other dangers? To keep diverse living trees alive on the landscape, and to protect water, wildlife and other values? Perhaps some will say “it’s the same thing” and if it is, then perhaps the use of plain English would save time and misunderstanding.
Let’s go back to the 2012 Planning Rule Handbook:
Assessing the status of ecosystems—their level of ecological integrity—is difficult. There is no guide that provides a comprehensive protocol, and each ecosystem has a unique body of scientific information relevant to the ecological assessment. The planning rule and supporting handbook identify departure from the natural range of variation as a criterion to assess ecological integrity. The natural range of variation refers to the variation in key ecosystem characteristics produced by dominant natural disturbance regimes, usually in a pre-European influenced reference period. This method works well for ecosystems that are relatively well-studied and their natural range of variation can be estimated through ecological modeling or other methodology.
(my bold). Now, as most readers know, I wasn’t a fan of this approach at the time. At that time, my thinking went along these lines… (1) there’s a great deal of pre-European time and yet a certain time has to be selected, humans have been around since glaciation; (2) animals and plants move around and hybridize- and evolution is part of Nature, after all; (3) time’s arrow only goes one way, at least genetically; and (4) if climate is changing faster than usual, then there is no reason to think that the past is well adapted to the future. And don’t we want forests that are adapted to the future? As described in the Handbook, it unintentionally downplays the role of Indigenous fire management and the idea “natural= pre-European” only fits if Indigenous folks are part of Nature, which some now consider to be racist. It would perhaps be clearer and more accurate to say “we want to go back to Indigenous ways of managing the landscape,” if that’s really the case, but again we’d need more Indigenous people and give them authority over federal forests plus make them do not what they think best but what they think their ancestors did. And the importance of Indigenous management and climate have only become clearer or perhaps “supercharged” in more recent discourse.
Many forests have done vegetation modeling and historic research, and came up with desired conditions of say, certain amounts of habitat with certain characteristics. For example, x acres of early successional habitat, or y acres of western white pine or oaks, or even the historic densities of some species. So logically, to recreate these conditions, we may need to thin trees for density reduction and create openings for some pine and oak species to regenerate. There are different ways of getting openings. Depending on where you are, openings could occur due to wildfire, wind events, volcanoes, floods, trees dying from old age and/or native or introduced diseases and pests, and so on. With or without attribution to anthropogenic factors of climate change, some of these are more natural than others (fire suppression and non-native species obviously not).
Generally, the only other way is to manage is via prescribed fire or some combo of mechanical treatments (aka “logging” or “tree-cutting”) and prescribed fire. So do we still want those carefully arrived at NRV distributions or not? According to some, if the opening-treatments would occur in currently mature or old-growth forests, then not. So that leaves “natural” disturbances (affected by AGW, so then unnatural, except for volcanos?) and hoping that they get to the desired ratios; or alternatively, doing openings over and over in younger forests but not mature ones, so that they don’t go through their successional stages, which seems also unnatural. Look who wrote about the importance of early successional ecosystems in this 2011 paper (abstract)
Different disturbances contrast markedly in terms of biological legacies, and this will influence the resultant physical and biological conditions, thus affecting successional pathways. Management activities, such as post-disturbance logging and dense tree planting, can reduce the richness within and the duration of early-successional ecosystems . Where maintenance of biodiversity is an objective, the importance and value of these natural early-successional ecosystems are underappreciated.
So will the new OG amendment effectively replace the concept of “pre-European conditions” with “creating as much old growth as possible”? Because we can imagine quite a possible tension between “maximizing old growth” and “ensuring diversity of tree species”, and the latter would be important to fulfill certain requirements of NFMA, specifically.
“provide for diversity of plant and animal communities based on the suitability and capability of the specific land area in order to meet overall multiple-use objectives, and within the multiple-use objectives of a land management plan adopted pursuant to this section, provide, where appropriate, to the degree practicable, for steps to be taken to preserve the diversity of tree species similar to that existing in the region controlled by the plan;”
My bold, Of course, trees and bark beetles, do their own things, unbothered by humans’ desire for shade or carbon credits, or even plan amendments, forest-specific or national. From the Fire Effects website:
The average lifespan of Rocky Mountain lodgepole pine is 150 to 200 years [37,170], though some Rocky Mountain lodgepole pine trees live more than 400 years