Vince Taylor Notes on JAG Landscape Meeting of March 13, 2009 Related to Overall Landscape Allocations
The following are not comprehensive notes on the meeting but focus on the (major) part of the meeting that was related to developing principles for silvicultural allocations across the landscape. Much of the content consists of reasonably literal transcription from a recording of the meeting.
This was a very good meeting that considered in depth development of principles for managing Jackson State Forest based on emulating natural forest processes. The notes are quite long, but if you are interested in this subject, you will find much of interest herein.
An Addendum contains maps that were displayed at the meeting, including one showing preliminary allocations to late seral and older forest and one showing ownership of surrounding lands.
Here is a link to the audio recording of the discussion summarized here [click link once to open a simple player or to download; click again to close]. Be aware, the file is 32 MB in size and several hours long. There is much detail in the discussion that is of value that is not fully captured here. You may wish to listen to selected portions of the recording, which can best be done by clicking the download link. This will either open the browser default player or allow you to download it to listen to in a more advance player.
Natural Landscape Emulation Silviculture
Prior to the meeting Mike Jani and Linwood Gill developed a proposal (a “straw man”) for managing the portion of Jackson Forest “devoted primarily to commercial timber production,” the portions on the JDSF Management Plan Map Figure 5 (see Addendum) other than those designated as preserves, late-seral, older forest, or special concern areas. This probably amounts to about 2/3 of the area of the forest. The discussion recognized that the JAG might recommend that this portion might be different than in the management plan.
The basic idea of the proposal was to use silvicultural methods in a given area of the forest that would emulate the natural processes in that area.
On the West Side of the forest, where redwoods dominate, use single-tree selection generally or small cluster selection (1/5 acre). On
On some portion of the West Side, on north-facing slopes, which would have naturally a higher proportion of fir, use openings up to ½ acre to encourage regeneration of Douglas Fir.
John Helms commented that the openings should relate to tree height, rather than being fixed. There was agreement that this seemed preferable.
The question was raised about whether the silvicultural method should relate to current composition mix or the historical, pre-European mix. It was agreed that pre-European was appropriate.
Marc Jameson said that the West Side was historically dominated by redwoods, even on north facing slopes. The redwood component is currently suppressed by the Douglas Fir that grew up following clearcuts.
On the East Side, where it is heavy to Douglas Fir and hardwoods, with scattered redwoods, employ ½ to 2-1/2 acre group selection as the dominant prescription (some thinning in the matrix), with structural retention in the clearcuts. No more that 25% of the canopy would be retained in the openings, and this would generally be clustered.
[No more that 20% of acreage can be in group openings with less than minimum stocking (what is level?). It generally takes between 10 and 20 years for restocking to occur. The regrowth time would be a constraint on reentry times.]
South and southwestern exposure would have historically had more crown fires. The incidence of fire in such exposures argues for applying (Max)10-acre clearcuts with variable retention (later stated by Linwood as minimum 25% retention, but Mike did not recall a specific number).
Dan Porter doesn’t think there is data to support any particular opening size. We should be cautious in framing recommendations. It is “obviously a mix of emulation forestry and silviculture,” and we should communicate it that way. Actual data shows some instances of much smaller openings and greater overstory retention.
Linwood: On south facing slopes could have higher retention and still get regeneration.
Porter: Western Side proposal is reasonably underpinned by data. On the East Side, much less certain, especially about higher end of fire intensity. Could frame the recommendation in terms of research on different burn prescriptions and wildlife responses.
Brad Valentine said he liked tying the silvicultural recommendations to biological reasoning about the conditions we are trying to emulate.
Mike emphasized that their proposal was tying back into the natural dynamic processes in redwood forests. “When Linwood and I have been expressing our support for Natural Forestry, this is what we have had in mind.”
John Helms:
This would differentiate in my view practices in Jackson and the Redwood Region that differ from what we used to do in the past. In the bad old days, silviculture dogma was that there were these 4 or 5 methods of silviculture … and foresters expected we would try one of those things. In fact, these are just theoretical models. You’ve got this continuum. I would say that the tendency in forestry was to apply one of these standard methodologies. The innovation in the future is to start at the other end. What is the structure you are trying to create… You back away from that and end up with the opening of this size. .. This is the way I would like to see the choice of silviculture expressed. .. In the past, silviculture was process based, rather than outcome based.
I commented that Mike and Linwood’s proposal was far away from the concept of Natural Forestry, which uses as it basic tenant emulating natural forest processes. The reentry rates associated with managing the forest for commercial production would create large openings much more frequently than occurred historically.
Forest commented that we were talking about the areas that were designated for production.
I responded that my idea has been that we would aim to integrate production with emulation of natural forest processes; so that there would not be a conflict between production, ecology, and restoration. “I feel like we are falling back into dividing the forest into two sections — one for ecological values and one for production values. I’d like to see a much hazier distinction between these two categories.” I don’t see clearcuts occurring on the scale and rate proposed.
Mike Jani responded that I was jumping to conclusions. It depends upon the rate of reentry and the scale of the clearcuts. We need to inform this discussion by doing analysis to look at what would production look like if we did the entries at the ends of the possibilities of entry intensity.
“I am agreed that we need to produce enough revenue on a sustainable basis to support the legislative and board mandate to support the state forest system.” I don’t have a problem with this. This is a big forest. We can definitely do this once economic conditions are normal. But, I don’t want to lose sight of the biological underpinnings of strategy and moving too far over to commercial considerations.
Linwood asks for other’s thoughts.
Dan Porter says it is premature to reach judgment at this time, because it really is a time interval thing, and we don’t know what the end revenue stream looks like under differing assumption. Proposal of Mike and Linwood is just preliminary, and we need to do more exploration before adopting anything. Could explore different opening sizes. Keep aspects open.
Mike agrees that need to model it and grow it forward using Cryptos.
Marc says that models the currently exist can’t project growth within openings by opening size. Would need to model using clearcuts and selection harvests and average results. Would be approximate. Cryptos not designed for group openings.
Vince points out that the East Side of the forest is a small part of the forest and we shouldn’t get caught up to much in an ideological battle over something small. Marc says it is about a third of the forest.
Mike: Would use appropriate approach depending upon micro-climate and terrain, not just east or west.
John Helms would like it that in the future when someone comes into the forest, he or she wouldn’t know what silviculture was being applied. “What we really want to do is enhance the growth of the biggest and best trees,” and move it into a different kind of a silviculture where you are trying to upgrade the quality and the redwood growth potential.
Vince: What John stated as a goal, using silvicultural methods that enhance the best trees … [interruption, but I wanted tow support the goal of enhancing the biggest and best trees.]
Mike says that what he is proposing all it does is give the forest manager a spectrum to manage within. The only downside is that it makes life very difficult for modelers and predicting outputs using models, because you are managing at a micro-site level. Over time, averaging will occur over larger area and will become predictable.
John: This is the innovation we are looking for, impact on a larger scale.
Mike: If you think about it, this lends itself much better to the existing inventory. John: Need more plots. Marc: Wanted 2 to 4 times more plots, but reduced due to budget considerations
Vince: It seems like what you (Linwood) in your general approach is what John is talking about, except that you set limits on size. You always go into stands with the idea of improving what is left.
Mike: At some point, you always figure on regeneration. How do you do it?
Linwood: Very small openings. We take the trees on the south side of the clump and maybe the nearby firs. If it is fir, we make opening of less than 1/5 acre, leaving a couple of trees. Mostly on the West Side.
Craig Blencoe used the same approach on a site pretty far to the east. Had
Mike: Sidebar note that on East Side, hardwoods would be treated (not necessarily with herbicides).
Brad: Would like to see some retention of hardwoods, including hardwoods in stands that are primarily conifers. This represents a natural seral stage.
[Interesting discussion on regeneration. Linwood happy to have repressed regeneration for 15-20 years, and will release it at a future time. Linwood says he has had “surprising” release of firs that are older.]
Vince: We are thinking about the long term. It is good we have a different time scale than commercial foresters who need a high rate of return. A public forest doesn’t need such a high rate of return. The forest is going to be here in hundred of years. We can afford to wait for 30 years for a return.
Mike: Agrees intuitively, but not prepared to make judgments until do modeling and analysis.
Kathy: Needs a clear description. When say, 10 acres, historically the maximum is what happens. Need a very clear description to ensure that smaller acreage is used when appropriate. Also, what will happen to the retained trees in opening?
Mike: Sometime retain and sometimes not at MRC.
Dan: If we adopt thematic approach, along with allocation recommendations, also JAG suggest as part of implementation, there be appropriate staffing allocations to communicate to the local and broader community the underlying rationale. All operations are part of research. Not a 100 year plan, not even a 50 year plan, but ongoing research and monitoring. Also believes strongly in the value of outside vetting.
Mike: If applying “thematic” approach on many acres, Marc, what tools do you have to compare alternative scenarios?
Marc: Option A had many yield runs. Can draw on those. Run every silvicultural system on every veg polygon.
Vince: Based on various discussions I’ve been having with people via emails, I’ve found strong support for the kind of “thinning from below” that Linwood does. From my point of view, growing it back to old growth while doing this is, in some sense, just a variation of this approach. If you are going to grow it all the way back, or just grow it to some point and then harvest it, it starts out the same way. I wonder if there is some reason not to adopt this as the basic silvicultural model for the forest, other than for research?
Dan: I think it really depends. You need to weigh the effects on forest structure of a certain minimum revenue need; then in parallel the effects on structure of the replacement rates in ancient presettlement forests. At the end of that analysis, with all the caveats, you might conclude that the answer to Vince’s question is, “No.”
Vince: Where might there be a problem?
Dan: If the economic revenue requirements is such that with the interval included that the openings foreclose opportunities to achieve the long-term forest structure.
Marc: It is already the predominant method used on Jackson. What has been proposed by Mike and Linwood is similar.
There are probably lots of reasons not to accept it as the default, but particularly, it might not pattern anything natural. It doesn’t demonstrate much to the region, other than a single form of silviculture. Everybody doesn’t want to do that.
Mike: I’ve been party to these emails. I think what is being proposed is exactly what we are going to propose for more than one-third of the forest, which is a big allocation for a demonstration forest.
Brad: What I think it is emulating is a forest with frequent understory burns, harvesting from below. What it is not providing compared to a natural situation is that the trees retained are not the trees that would naturally be retained. Usually, in this approach, take out the ugly trees, and these are often the ones that provide the best habitat. I’ve seen some of the stands managed as in the emails, and they are not very good for wildlife habitat.
Mike: How do you get structural complexity introduced?
Vince: My thought is that thinning from below is a starting point. What we did for late seral was, in my mind, a variation on that approach, but providing more complexity. The kind of silviculture that we had for late seral could by a starting point and vary from that to provide both the needed revenue stream and the historical patterning that we want.
Dan: I still think the entry interval is the key. Perhaps even with the maximum implementation, you don’t foreclose any opportunities to achieve the structural goals you want on a time scale that is generous.
Put more directly, if we run the thematic models with different entry intervals and select the most aggressive internals, and look at the effects on the structure across the landscape, you may find that you haven’t taken away enough of the structure in fifty years to foreclose the long-term development that you want. I don’t know if that is true or not, but it might be. But, if what we can put forward is an approach that moves the forest in that direction without taking away any opportunities for the next set of managers to take on that challenge with more information, I would support that.
Vince: So would I be.
Dan: In my mind, the client base is very important, too. If management reflects one silvicultural system, it won’t be appropriate to many clients.
[Lunch Break]
Mike: “Does anyone in the room have a major objection to the thematic theme we outlined here, keeping in mind that the temporal element will drive whether you manage to a very old forest or back to a commercial forest? Opening sizes change depending upon where you are in the forest.
Marc: I abstain.
Brad: I agree with what you are trying to do.
Vince: I agree with trying to tie silviculture to some biological, historical rationale.
[General assent.]
John: I would like to see variability in the temporal element as well as a spatial variability. We need to be looking at R & D with a variety of temporal approaches, always with a ? rationale.
Kathy: Vince has one outcome he brings up regularly, the forest with older and older trees.
John: A diversity of stand structures – early, mid, late seral. Kathy – still so broad as to get a direction from. John: It would be distinct from an approach of moving singularly toward older trees. I would like variability. Different tree sizes. Variability in the largest tree being planned for.
Mike: How does what you are suggesting differ from another way to look at it -– variability in the carrying capacity over time. So, one scheme would be to start with this inventory on this block and you aim to maintain that inventory. Another, start with it and aim to build inventory at this rate, i.e,, double in 50 years. Another, double in 100 years. Do the same thing you are talking about, but don’t think the public will tolerate reducing inventory and then maintain it.
John: I wouldn’t warm to the last either. But, could have same volume on a few large trees or more smaller trees. Think what should be prominent is moving toward larger older trees. How large and how old can be discussed. There could be other levels backed off from that. Would need help in terms of size classes.
Vince: Old timers up in Humboldt used to talk about 500K bf/acre on site 2.
John: I would like to see, where we are headed, managing for bigger, older trees and probably more volume. But because R&D forest, not aiming for a single optimum, but managing for R&D, which implies variability.
Mike: Vince, in analyzing model, does tree diameter go up as volume grows.
Vince: Yes, in the very simple model.
Mike: Marc, what is your experience? If you set volume per acre targets, would high targets drive large tree sizes?
Marc: Yes, but would address productivity.
Mike: One way to do allocation would be to set up “terminal” volume per acre targets. Just throwing this out.
John: Alternative would be to set terminal size classes.
Mike: Volume per acre has advantage of regional growth curves. Lindquist and Palley, for example. Whatever we propose needs to be within the realm of reality. A goal of 300K bf/acre needs to tie back to data. Would have different goals depending on site class. Plays into “bands” across the forest. From standpoint of demonstration, landowners would relate to those targets, because they think in those terms. There are tradeoffs. Higher goals, lower annual volumes. So if landowners could look at these alternatives, it would be true demonstration.
John: This involves the time dimension. The more volume the target, the longer time it will take to get there.
Mike: The forest manager can look at the stand he is looking at, when he is looking at an older stand, then from a demonstration point, he can move that out to an higher-volume stand sooner.
John: If you give me a given target, I can reach that faster by not cutting anything. It is going to force management to no cutting.
Marc: What landowners want to do on the private side is to reach a high level of productivity, which is going to be a marriage between the rate at which things grow and the amount you carry. I stands are even age and it is probably going to take some time to get that point. You want, not culminating mean annual increment, but culminating periodic annual increment. [1]
John: You give me a size you want to get to, I can get their quicker by releasing the trees.
John: Unentered plots ALWAYS have the higher volume. I repeat that, ALWAYS.
Is it true over long periods?
John: It depends on mortality and whether you capture mortality. That is the idea behind forest management, that you can capture the mortality. The biomass productivity is always higher in an uncut stand, if you include the mortality.
Dan: Cutting trials show a great elasticity of response; so total volume, including harvests, are very close over time, unless you go to very heavy removal rates.
John: Nervous about goals based on volumes.
Vince: We need to keep in mind that we are making recommendations that have a perhaps 20-year lifetime; but not much difference will show up for fifty years. So, what we need to do is set things on the right path and not foreclose options in the future. Kathy & Dan: Need to characterize things for a long time frame while recognizing the practical things. Vince: We are here to set out a long-term landscape plan and to provide the underpinning the most we can, but in our silvicultural recommendations, unless we do something really bad, we will probably set it on a time path that is consistent with a lot of different futures. I’d like to collect a lot information over the next 20 years, in the hope we can extend it to fifty years; so that our collection of information tells us can we be moving up the scale of productivity and older forest simultaneously. We haven’t been doing this objective for long enough to have reached a steady state in terms of these people who have in mind a 100-year rotation, and can we do better than that?
Dan: Going back – John offered a mix of seral stages as a goal; then had volume and size goals offered as alternatives. Think it is a good idea to put side bars on the ideas that have been offered.
Mike: When I proposed terminal volume targets, could set up 3 to 5 goal levels. This is what we would want to manage toward, based on what was biologically possible. Then, it avoids drawing any hard lines on the map, but causes the forest manager to say, “I’m in this site class potential, and this is where I demonstrating this facet of the possibilities.” This has huge ramifications, because if in this management unit has a goal of high volumes per acre, it will drive entries and marking. Again, John’s idea of tree size might work, too.
John: When I’m looking at tree size, I’m looking at value. I don’t want to be forced into managing for a dense forest with lower value. Can be constraining for wildlife values. Volume might work, but I’d like to have a better understanding.
Kathy: What about height?
John: Within normal ranges of stocking, the density is not related much to height. Site is the determining factor.
Dan: The problem in melding the volume and tree-size standard is that there is a huge variation in tree sizes. I think that site productivity standard has the most merit. I think site quality, if you want to create a biological basis for end points, site class productivity has a lot of merit, but it is constrained by forest quality and what it looks like in the interim while reaching the target. The site classes describe the what, the goal, and the emulation practices describe the how. Describing the what, that is what we are focused. What is the future condition? Can describe it purely biologically or a mix of biology plus an aesthetic that reflects the operational realities and goals inherent in managing a forest, but seems more a communication issue than an operational issue.
Vince: When you say that stands that grow back naturally may have low value, are you talking about economic or wildlife values. Trees near the Woodlands have high volume per acre even though they are small.
John: There isn’t that much of a difference between diameter and price. It is for redwood more sapwood versus heartwood.
Dan: Define good productivity at the level of the individual tree rather than stand. If main difference for goal is between tree size or volume, throw both away. Focus instead on the individual tree, rather than the broad stand scale. Adopt a metric for individual tree: It looks good if …
Mike: That would be taking a giant step, looking at something no one has wanted to look at in second growth redwood stands: What is the optimum increment to grow a valuable redwood tree?
Kathy: Red parts of trees are still worth more. Marc: Time to produce it needs to be taken into account. Slow growth probably encourages growth of more red. Mike: Be debate raging within his organization. Marc: Had same debate. Releasing trees makes both red and white to grow faster. Kathy: Maybe this is one of the variabilities that we want to include. Marc: Don’t set too strict constraints.
Mike: We are already going to take old structure, late seral, and old growth stands and manage them to be very old and very big; so that riddle is going to be answered by that allocation we are near completing. So, what questions are you going to answer on the remainder of the forest?
Marc: How to attain a high level of growth, high level of value, create various habitats simultaneously, effects on watershed health? That is one of the reasons that management plan has fewer constraints. It is a matter of trusting the managers to do right.
Mike: That is our charge, to set a bracket of constraints with which the public will trust. Unfortunately, leaving it to Cal Fire to set those brackets has been the raging debate. I’m not in favor of bracketing you down, especially in light of the allocations we are making. I don’t think the Board will go along with too tight brackets.
Linwood: How does this discussion move us forward on the allocation topic?
Mike: To take the acres we overlaid with a management scheme and see if there was any further stratification that we could overlay on that.
Linwood: As I listen to this, there is so much it seems to complicate the issue and we shouldn’t go there.
Mike: We might have consensus minus one. Doesn’t meet Vince’s goals.
John goes to the flip chart and draws the following:
The time scale (top figure) is 500 years. Zero is where we are now. The dashed line is the gross growth curve. The solid line is net. The difference between the two is mortality. What we’ve done in the redwood region is come in, say at 150 years, and remove a large part or all (clearcut). Would come back on a line roughly parallel to the gross curve, perhaps becoming asymptotic to the net curve at some time. We’ve made varying decisions. What we want to do on Jackson is advancing this thing, perhaps even out to 500 years. From and R&D perspective, what we’d like to know is how it advances if we have different volume goals. An alternative way of looking at it (lower graph) is have number of trees as a function of size. We had something like this for Brandon Gulch and much lower numbers for old growth stands. So we could aim to lower the numbers over time up to 500 years. But we might want to have diameters only up to a certain size, or to a different size. To me this give me structure, where I can demonstrate different approaches to the management of the forest, where I’ve got diversity of structure. The allocation issue is what proportion of the forest do we want to have different diameters. When I look at the matrix area (outside of old and reserves), I would be looking for managing the forest for diversity in these distributions.
Mike: Even though you know full well, in the allocations we’ve gone through, we have the right-side allocations already in the late seral? John: Probably not. Brad: But if in short supply in our stratification. Not saying it is there. Dan: Already there in the matrix in the riparian zones.
Mike: What I hear you advocating for is how Linwood manages, with diameter targets.
John: But, I would want to have a wide variation in the diameter targets.
Mike: In the matrix, you might say we would have some proportion targeted for 30”, 50”, 70”, for example. This would inform the managers of what to do.
John: But this doesn’t illuminate the issue of volume. I want differing densities, which means I’m going to get my big trees farther in the future. I don’t want to give a goal that would lead to lower stocking levels.
Mike: The swath we are talking about today is where the managers would have latitude to try a wide variety of things.
Vince goes to board and draws the diagram below:
The line labeled “Potential” is the ceiling or upper limit of volume for the stand. Volume first grows at an increasing rate; then slows, and eventually approaches the ceiling asymptotically- a sigmoidal curve. How far out do we go before reaching the point of cumulating mean annual increment? John: Lindquist and Palley will tell you. It is relatively early.
Marc: L&P are only for even age. There are very few sites where CMAI has been observed. One is the Wonder Plot. At about 60 years. We have another on Jackson where it may have been obtained. These are for very high site class. On class 2, it will be further out, perhaps 120-130 years.
Vince: Krumland and Wensel never found CMAI out to the limits of their data, 120 years or so.
Marc: in board feet, L&P don’t cumulate out to 100 years, except for the highest site classes.
Vince: For Brandon Gulch, the point of cumulating maximum annual increment might be at 150 years with volume of 150 K bf/acre [based on Lindquist and Palley tables, the volume would probably be significantly higher at 150 years, closer to 200K]. What might be the ceiling? [Pretty much silence. No one has experience.]
Mike: What has never been done, in uneven age stands, how much does the culmination point get pushed out? In my mind, it might never cumulate if we keep thinning.
The lower red lines were meant to approximate the effects of periodic harvesting. Only the lowest red line is accurate in its general shape: a vertical drop at harvest time, with regrowth between harvest times.
Vince: My question is, where do we reach the maximum production? How far out is that?
Mike: Need to consider both harvest volume and volume added in the stand.
Vince: We might want to weight the two differently. From a public standpoint, standing trees have value.
Mike: You could use this as a stratification technique.
Marc: Vince has gone back into late seral.
Vince: No, because I’m talking about continuing harvest. The assumption for late seral has been that we’d make a couple of entries and then leave it alone.
Mike: There is some point where you would — but you’d always want to be taking mortality.
Kathy: From a habitat standpoint, you wouldn’t want to remove mortality before occurs?
Brad: It depends upon whether you are managing for habitat or some other economic purpose.
Mike: If you think of stem exclusion, you’ll get to a point of excess stems.
Kathy: Though, only early.
Mike: Yes, you will eventually reach a point of equilibrium. Then you will leave it pretty much alone.
Dan: Plant ecologists speak to productivity issue, broadly defined. Site productivity (biomass) increases with species diversity.
Dan: All the numbers in the chart are affected by selection. We have no idea how.
Vince: One of the people in the email says that all that you cut grows back in 15 to 20 years.
John: You’ll never get back up to the line.
The slope gets reduced.
The fastest way is to live it alone.
Vince: Now we need a lot more reserves! [Laughter]
Mike: Landowners want to know what jagged line to follow.
John: I want to have lots of jagged lines as demonstrations for land owners. We want to take advantage of the biological uniqueness of redwood.
Brad: Jackson is too small to have too many alternatives.
Vince: One way to think about this is how far you go below the unmanaged line. The difference between the unmanaged line and the managed line is a measure of how much we’ve deviated from the “natural forest.”
John: We can affect the line by the proportion of cut and the interval between entries.
Marc: Ask John to write up his high medium and low tree size and combine with legal, biological, or historic needs of the forest. Then you will have moved somewhere.
Vince: I’m trying to find a metric for different approaches we take. The difference between the two lines measures the effect of management as compared to the natural forest recovery path.
[Various cases are described and discussed. Could be different stocking goals to which you go toward. Different horizontal lines at different distances from the potential line.]
John: We’ve already go the potential line set for a third of the forest. [Some back and forth about how much of the forest is going to be allocated to late seral.]
[John agrees to articulate his vision of 3 seral stages combined with the east-west thematic ideas. Brad: How these scenarios would lay out on the landscape would be a topic for a future meeting. Mike: I’m more in favor of a broader idea, and then leave it to managers to lay it out. Vince: I think we should at least some example and show. Take a watershed and show how it would play out, as for example what we did for Brandon Gulch. Mike: What that looks like, if John ends up with three seral classes, it creates nine in a matrix, laying them over our east-west continuum. Linwood: Gets even more complicated, many more possibilities. Vince: Varying entry intervals is key. [No conclusion.]
Discussion leaves silvicultural and broad allocation discussion. Kathy Bailey makes a presentation on area in Jackson Forest that abuts Jughandle staircase trail and proposes making a reserve area.
Addendum: Maps of Interest
Preliminary Late Seral and Older Forest Allocations
Ownership of Lands Surrounding JDSF
[1] I later asked Marc for a definition of “culminating periodic annual increment.” Here is his reply:
It’s not a commonly used forestry term, possibly my own invention. What I mean by this is maximizing the growth over a specified period of time, normally between harvest entries (e.g. every 10, 20, or 30 years). It would seem that this is an admirable goal, trying to maximize what can be sustainably grown and harvested.
Since it can be so variable, depending upon stand management, there really is no reference in nature, such as was available for most even-aged yield tables. In fact, there may be many ways to achieve it, varying by how the stand is managed and the time between successive harvests. Value (monetary and product) vs volume would also be a consideration.
