# A massive mess of old tree data

I’m going to start focusing more on science topics here, as time allows. I’ll start by focusing for a while on some forest ecology topics that I’ve been working on, and/or which are closely related to them.

I’m working on some forest dynamics questions involving historical, landscape scale forest conditions and associated fire patterns. I just got done assembling a tree demography database of about 130,000 trees collected in about 1700 plots, in the early 20th century, on the Eldorado and Stanislaus National Forests (ENF, SNF), the two National Forests that occupy the mid- to upper-elevations on the relatively gradual western slope of the central Sierra Nevada. The data were collected primarily between 1911 and 1923 as censuses of large plots (by today’s standards, each ~2 or 4 acres) as part of the first USFS timber inventories, when it was still trying to figure out just what it had on its hands, and how it would manage it over time. An enormous amount of work was involved in this effort, but only a small part of these data has apparently survived.

The data are “demographic” in that the diameter and taxon were recorded for most trees, making them useful for a number of analytical purposes in landscape, community and population ecology. They come from two datasets that I discovered between 1997 and 2001, one in the ENF headquarters building, and the other in the National Archives facility in San Bruno CA. For each, I photocopied the data at that time, and had some of it entered into a database, hoping that I would eventually get time to analyze them. For the ENF data, this was a fortunate decision, because the ENF, as I later learned, has managed in the mean time to lose the entire data set, most likely along with a bunch of other valuable stuff that was in the office housing it. I thus now have the only known backup. Anyway, that time finally came, but the data were in such a mess that I first had to spend about three months checking and cleaning them before they could be analyzed. The data will soon be submitted as a data paper to the journal Ecology, it being one of the very few journals that has adopted this new paper format. In a data paper, one simply presents and describes a data set deemed to be of value to the general scientific community. There is in fact a further mountain of data and other information beyond these, but whether they’ll ever see the light of publication is uncertain.

An example first page of one of many old field reports and data summaries involved

We, and others, are interested in these data for estimating landscape scale forest conditions before they were heavily altered by humans via changed natural fire regimes, logging, and grazing (primarily). These changes began in earnest after about 1850, and have generally increased with time. This knowledge can help inform some important current questions involving forest restoration and general ecosystem stability, including fire and hydrologic regimes, timber production potential, biological diversity, and some spin off topics like carbon dynamics. They can directly address some claims that have been made recently regarding the pre-settlement fire regimes in California and elsewhere, in certain papers.

The data assembly was much slower and more aggravating than expected–I won’t go into it but I’ll never do it again–but the analysis is, and will be, very interesting for quite some time, as much can be done with it. Some of the summary or explanatory documentation associated with the data is entirely fascinating, as is some of the other old literature and data that I’ve been reading over as part of the project. In fact I’m easily distracted into reading more of it than is often strictly necessary, but so doing has reminded me that a qualitative, verbal description can be of much greater value than actual data, scientific situation depending. Possibly the most interesting and important aspect to this is the degree to which really important information has been either lost, completely forgotten about, or never discovered to begin with. This is not trivial–I’m talking about a really large amount of detailed data and extensive, detailed summary documentation. Early views and discussions regarding fire and forest management, and the course these should take in CA, are extensive and very revealing, as we now look back 100 years later on the effects of important decisions made then. There are also lessons in federal archiving and record keeping.

I’ll be posting various things as time allows, including discussions of methods and approaches in this type of research. I’m also applying for a grant to cover the cost of free pizza at the end, although to be honest I’ve not had great success on same in the past. You might be surprised at the application numbers and success rates on that kind of thing.

# The Indian system

Just about as prescient, and early, of a description of the California wildland fire and forest development problem as you will find:

As regards the growth of young timber—save only among the heavy redwood forests—the number of young trees which within the last decade or two has sprung up, is very great. All the open pine forests, back of the coast, are becoming rapidly stocked with young trees, and much of the open grazing land is rapidly being converted into brush or becoming covered with young saplings—generally Douglas spruce [Douglas-fir] or yellow [ponderosa] pine.

The cause of this increase is unquestionably the cessation of the old Indian practice (formerly general) of running fires through the country to keep it open to facilitate hunting, or in driving game before the flames into enclosures set with snares. Under this system about half the ground was burned over each year, in alternate halves; thereby the open lands were kept free of brush and all growth of young trees was checked in the forests. The older, well matured trees, however, suffered very little, as so little undergrowth could mature between one fire and another, that sufficient heat was not developed to hurt older trees, fairly covered with bark and with limbs some distance above the ground. In fact, the Indian system became in some sense a method of forest preservation, and to it we undoubtedly owe the noble forests which were transmitted to our hands.

We may acknowledge this debt to the red man, although his methods may no longer be available in a growing country studded if only sparsely with improvements. The Indian’s method may not have been an ideal one, but it was a better one in his day and generation than our lack of all method is in ours.

The very growth of young trees, left uncared for as at present, must be to those with the good of the forest at heart, a source of concern rather than of satisfaction. With forest fires running—often twenty in a county at one time—and public sentiment dormant to the extent that, save where individual property is at stake, few take the trouble to put out even such incipient fires as might be killed with little effort, there can be no question but that in the growth of young trees lies the certain guarantee of total extermination of much of our best forest land, within a few years, unless some effectual methods of protection are inaugurated.

Thirty years ago fires ran yearly through the woods, but forest conflagrations were unknown; the large trees standing sparsely scattered, say five to ten to the acre, were unable to transmit fire, and there was little on the ground to burn. Now thousands of young trees fill the open spaces, and a fire started not only destroys the young trees but the patriarchs of the forest also.

As yet the evil has attained no very serious proportions; but so surely as the young growth is permitted and fires not kept out entirely (which will be found a simply impossible matter) fires will occur, which will sweep everything in their path out of existence.

The longer the matter is left to find its own solution the more difficult and expensive of application remedial measures will become. As a means of protection against fires, one effectual method, and only one, suggests itself—the isolation of such forests as it may be deemed essential to preserve, into blocks of moderate area, separated by strips of waste land, wide enough to insure no spread of fire from one belt to another. This done, the forests may be left to grow up densely, if desired, without fear of extensive damage.

Topographical conditions would generally suggest the location of these waste strips. Ridge summits and canon bottoms (especially the former) are natural barriers to fire, being only crossed with difficulty by flames, when free of brush and litter. The lines of watershed on spurs are generally sparsely timbered, and could be easily maintained free of undergrowth, even if not denuded of their trees. As regards the strips which have been designated as waste, they might in many cases be capable of sodding or being maintained in grass, producing range and pasture, and for the rest, the authorized use of fire by duly commissioned persons, duly provided with adequate means of checking the spread of flames, might suggest itself as the simplest, cheapest, and most efficient method.

Of course these proposals only have reference to the public lands, private holdings must remain subject to private management, and such forests as now are held in private hands must survive or perish, as the owner elects. In any event, private holdings, when lying within the lines of districts which it might be wished to treat on the basis proposed, will always cause complication. If anything is to be done at all, it is time to do it now, while the Government owns whole districts free from settlers, and consequently, in this respect, at least, need have nothing but the public interest to consider.

First Biennial Report of the California State Board of Forestry, 1886-1888

# “A systematic record of great biological value”

Paul Sears was an early plant ecologist who did a lot of good work at the University of Nebraska and previously at Ohio State, Nebraska being the nexus of American plant ecology in the early 20th century. He was I believe, the first president of the Ecological Society of America. He was also one of the very first ecologists–of what is now a legion–to estimate landscape scale forest taxonomic composition at pre-settlement time, using the bearing/witness tree record contained within the early federal land survey. Here he takes a humorous swipe at the geometric wisdom inherent in the survey design. Ya can’t put a rectangular grid on a round planet fer cryin’ out loud, but hey, thanks for recording all those trees! 🙂

Surveying of Ohio was begun in July, 1786, under The Geographer of the United States, Thomas Hutchins, employing for the first time his device of sections one mile square. This empirical device was hailed as a great American invention, although the State of Ohio has since been found to possess a curved surface in common with the rest of the earth. All corners which lay within the forest were located with reference to nearby trees, the species of which were noted. These corners becoming permanent, the net result of Hutchins’ plan has been the preservation of a systematic record of such great biological value as to redeem its geometrical shortcomings.

A little background might be useful. Ohio was the first state surveyed under the federal land survey, all previous states being surveyed in all manner of ways by various entities under various authorities and quality control procedures, i.e. without a comprehensive and systematic plan. By law enacted in 1785–the very first congress–a hugely important law affecting how the public domain would be disposed of, all states added to the country from that point forward were to be surveyed under a systematic, regular survey design with very specific instructions regarding how to proceed (Thomas Jefferson being a driving force behind this). Ohio, being the first such state added, in 1803, also served as the test state, where various survey designs were tried out before deciding on the one that, with minor modifications, has been followed the last 200 years in the 30 federal land survey states.

To my knowledge no other branch of ecology has the quality of historic data sets dating to +/- pre-settlement times, i.e. before all the heavy impacts occurred, and most certainly not over such an enormous geographic extent. In fact, I don’t think it’s even close. We’re very lucky in that regard, and we have people like Thomas Jefferson, with his sense of mathematical order and intense interest in all things natural and landscape, for it.

Sears, Paul B. 1925. The Natural Vegetation of Ohio: I, A Map of the Virgin Forest

# Around Yosemite walls and through Yosemite forests

So, I’ve been entering bearing tree data collected by land surveyors inside what is now Yosemite National Park, for work on estimating historic forest conditions in the Sierra Nevada. Bearing trees were designed to “bear witness” to the location of on-the-ground survey markers, in case something should happen to them, and several pieces of information on them were recorded in the field notes (previous post here). So up comes the next Township on the list: Township 2 South, Range 21 East, Mt. Diablo Meridian, or T2SR21E MDM in surveyors’ shorthand, an area now inside YNP, surveyed under authority of the General Land Office (GLO) in 1880, 10 years before YNP came into existence.

An original (1880) YNP bearing tree, in 2005, with blaze partially exposed.

Well, damned if that isn’t a pretty good place to run into the man, Clarence King, and thereby to slow down the scientific progress on which society so utterly depends. Once I start reading King’s writings it’s all over in terms of getting things done. He’s done it to me before, and he will do it again.

# Douglas’ “Multnomah pine”

…August 19, 1825 Mr. Douglas, who had been exploring the upper country of the Columbia, started from his headquarters at Vancouver to proceed southward, ascending the Multnomah towards the mountains at the extreme (south) end of the Willamette Valley. After a perilous three days’ trip he reaches the natives of the region and finds in their tobacco pouches “seeds of a remarkably large size, which they eat as nuts”, and which he knew to be pine seeds. He learns that the tree grows on the mountains to the south—that is, down nearly to the present California line.

“No time was to be lost,” he writes, “in ascertaining the existence of the tree,” which he at once, with only a few imperfect seeds in hand, names Pinus Lambertiana, in honor of his friend, Aylmer Bourke Lambert, the distinguished Vice-President of the Linnaean Society of England. But sickness and inclement weather, also Indian hostilities, prevented further search southward for that season. However, he explores other regions eastward, discovering two new species of pine, which he names Pinus nobilis and Pinus amabilis (now well known firs, but then included in the genus of pines), making headquarters for the winter at Fort Vancouver. During the spring and summer months of the next year, 1826, he makes various extensive journeys, rewarded constantly by important discoveries, for the country was all unknown then. In February a hunter brings him a cone of his Multnomah pine. It “was 16 inches long and 10 in circuit” and he was assured that “trees were met with that were 170-220 feet high, and 20-50 feet in circumference”.

In June, while at the junction of the Lewis and Clarke Rivers, he planned a long trip southward to the Umpqua River, in search of “the gigantic pine”, but could not get off in that direction until October. On the eighteenth Douglas, with a companion, “set off due south through the dominions of the Chief, Center-Nose, and having climbed wearily a high divide, we were cheered by the sight of the broad Umpqua River in the valley far below”. A raft was necessary for crossing it, and in its construction Douglas “grievous blistered his fingers”..October 23rd they reach the headwaters Of the Umpqua, guided by the son of old Center-Nose, and still “intent upon finding the Grand Pine so frequently mentioned in my journal”.

…Early in the morning of the same day (October 25th) Douglas quitted camp, and “after an hour’s walk met an Indian, who, on perceiving me, instantly strung his bow, then slung his raccoon skin of arrows upon his left arm, and stood on the defensive. Being quite sure that he was not hostile, but prompted by fear only, I laid my gun at my feet and beckoned him to approach me, which he did slowly and with many precautions. I then made him place his bow and quiver beside my gun, and, striking a light, gave him a smoke out of my pipe. Then with pencil and paper I drew a rough sketch of the cone and tree which I desired to find, and exhibited the sketch to him, when he quickly pointed towards the hills, fifteen or twenty miles distant, and southward.”

Hastening on, at midday Douglas “reached the locality of my longwished-for pines, and lost no time in examining them, and endeavoring to collect twigs, specimens, and seeds. “New and strange things,” Douglas pauses here to remark, sententiously, “seldom fail to make strong impressions, and are, therefore, often faulty or overrated; so, lest I should never again see my friends in England, to inform them verbally of this most beautiful and grand tree”.

“I shall here state the dimensions of the largest found among several that had been felled by the wind. At three feet from the ground its circuit was fifty-seven feet nine inches (that is, nearly nineteen feet in diameter). At one hundred and thirty-four feet it was seventeen feet five inches. Extreme length, two hundred and forty-five feet. The trunks are uncommonly straight, the bark smooth, the tallest stems unbranched for two thirds of their height, the branches outreaching or pendulous, with long cones hanging from the points like sugar loaves in a grocer shop. The cones are borne only by the largest trees, high suspended in air, and the putting myself into possession of three of them, all I could procure, nearly brought my life to a close.”

“As it was impossible either to climb the trees or to hew one down I resorted to knocking them off by firing at them with ball. The report of my gun almost instantly brought into view eight Indians, all armed with bows, bone-tipped spears, and flint knives. I endeavored to explain to them what I was doing there and what I wanted, and they seemed satisfied, sitting down to smoke with me; but presently I perceived one of them to string his bow, and another to whet his knife with a pair of wooden pincers. Further testimony of their intention was unnecessary.

“To save myself by flight was impossible, so without hesitation I sprang backwards about five paces, cocked my gun, drew one of the pistols from my belt, and showed myself determined to fight for my life. As much as possible I endeavored to preserve coolness, and thus we stood facing each other without the slightest movement or uttering a word for full ten minutes. At last the leader dropped his hand and made signs for tobacco and pipe. I signified that they should have a smoke if they would fetch me a quantity of cones. They went off immediately, and no sooner were the out of sight than I picked up my precious cones and made the quickest possible retreat.”

Poor Douglas never saw his “Grand Pine” again, and upon his second tour of western exploration the next season, after visiting Monterey Bay and vicinity, where he discovers Pinus insignia and P. sabiniana, he sailed for the Hawaiian Islands, and while exploring there he fell into a pit prepared for capturing wild cattle, and was trampled to death by an entrapped steer.

Source

# Analytical problems in science; an example

In this post I’m going to give an example from the work I’m doing at the moment, of the kinds of problems that scientists often have to deal with (i.e. confront and resolve) in order to advance the state of knowledge in a given field. The topic under investigation involves statistical and mathematical issues that are fundamental to what scientific research is all about at its crux. I’ll give the briefest of introductions of the subject so as to quickly get to these important, general issues.

# Hardy-Weinberg genetic equilibrium and species composition of the American pre-settlement forest landscape

This post is about how binomial probability models can, and cannot, be applied for inference in a couple of very unrelated biological contexts. The issue has (once again) made popular media headlines recently, been the focus of talk shows, etc., and so I thought it would be a good time to join in the discussions. We should, after all, always focus our attention wherever other large masses of people have focused theirs, particularly on the internet. No need to depart from the herd.

Binomial models give the coefficients/probabilities for all possible outcomes when repeated trials are performed of an event that has two possible outcomes that occur with known probabilities. The classic example is flipping a coin; each flip has two possible outcomes of h = t = 0.5, and if you flip it, say twice (two trials), you get 1:2:1 as binomial coefficients for the three possible outcomes of (1) hh = two heads, (2) ht = one head and one tail, or (3) tt = two tails, which gives corresponding probabilities of {hh, ht, tt} = {0.25, 0.50, 0.25}. These probabilities are given by the three terms of (h + t)^2, where the exponent 2 gives the number of trials. The number of possible outcomes after all trials is always one greater than the number of trials, with the order of the outcomes being irrelevant. Simple and easy to understand. The direct extension of this concept is found in multinomial models, in which more than two possible outcomes for each trial exist; the concept is identical, there are just more total probabilities to compute. Throwing a pair of dice would be a classic example.

The most well-known application of binomial probability in biology is probably Hardy-Weinberg equilibrium (HWeq) analysis in population genetics, due to the fact that chromosome segregation (in diploids) always gives a dichotomous result, each chromosome of each pair having an equal probability of occurrence in the haploid gametes. The binomial coefficients then apply to the expected gamete combinations (i.e. genotypes) in the diploid offspring, under conditions of random mating, no selection acting on the gene (and on closely linked genes), and no migration in or out of the defined population.

# Tree growth analysis issues, again, part five

Continuing in this series, the point of which is to explore issues in tree growth analysis and their relationship to claims made by Stephenson et al. (2014)

Previously, I derived a function relating tree above-ground biomass (AGB) to time, given an apriori equation from the literature (Chave et al., 2005) relating biomass to diameter that is similar to the one used by Stephenson et al. [I used this similar equation, rather than the one actually used by Stephenson et al. (2014), because doing so allowed for an easier derivation of the function relating diameter to time that would produce a constant mass growth rate.] The point of that exercise was to establish a reference frame of constant mass growth rate, from which I could then investigate what increasing and decreasing mass growth rates would imply for radial growth rates. The analysis showed me that models of that basic structure could only produce continuously increasing or decreasing mass (and radial) growth rates.

But continuously decreasing rates are biologically unreasonable, because they require impossible growth rates when trees are very young, and although continuously increasing rates do support what Stephenson et al. claim, they too are untenable. This is simply because, of course, nothing in nature can grow at an ever-accelerating rate; there has to be a deceleration at some point, at the very least to an asymptote, but more likely to an actual decline. The universe is not over-run by tree mass after all. In fact, one of the things that worries me about their paper is that their data shows very little rate deceleration at all, including in species that reach very large size. So…given the rate accelerations at the maximum tree sizes they report–the main point of their paper–then where are all the trees that are > 1.0X the mass of the largest they report? Shouldn’t they also exist? Did all their tree sizes just happen to fall short of the size threshold where growth rates start to decline? Or do they imagine that tree growth rates never slow down and maximum size is limited by various other forces? If so, what are they? Some things just don’t add up here.

# Tree growth analysis issues, again, part four

Continuing….

Last time, I derived an equation that gives constant tree mass growth rates with time, given an apriori, defined relationship between biomass and diameter. Varying two parameters thereof (q and s) produced continuously increasing or decreasing mass and radial (diameter) growth rates, but only the continuously increasing mass growth rates also had reasonable radial growth rates over the full range of small and large trees. I now want to investigate whether there are radial growth models that can give more complex relationships of mass to time, unimodal responses in particular. But before I get to that I’ll show some graphs illustrating these dynamics, and provide the R code as well (at the end).

I’ve altered two things from the previous post, for convenience. First, I re-defined q so as to make the connection between M = f(D), and D = f(t), easier to follow. Specifically,

$M = de^{-1.864 + 2.608\ln(D)}$ and
$ln(D) = \frac{\ln(st)}{2.608q}$ and therefore
$M = de^{-1.864 + \frac{\ln(st)}{q}}$

where M is tree mass, D is diameter, d is wood density, e is the base of natural logs, t is time in years and s and q are computed parameters that jointly give equal mean growth rates at year t = 200 (as explained in the previous post). In this formulation, any model having q < 1.0 will result in continuously increasing mass growth rates as functions of either time or diameter. Second, I changed the target diameter from 156 cm to 120 cm, at 200 years (i.e. slower mean growth rate). This slower mean growth rate just allows me to extend growth beyond 200 years and not get unrealistically sized trees as quickly, at say 300 years.

But before going on, below are four graphs, each showing the growth dynamics of six models, given what I’ve done so far. All produce increasing mass growth rates as a function of time, result from varying q and s in the above equation, and have q < 1.0. The graphs show: (1) diameter and (2) mass, as functions of time, and then mass growth rates as functions of (3) time and (4) diameter. The values of q and s listed in the legends are for the third equation above $M = de^{-1.864 + \frac{\ln(st)}{q}}$

# Tree growth analysis issues, again, part three

To re-state, the specific issues I have with Stephenson et al. can be placed into three categories:
(1) Sampling issues
(2) Biological implications of stat/math issues
(3) Results presentation issues

I’m actually going to start with issue (2) since it’s the crux of the issue, and try to work issue (1) into the discussion, since the two are intertwined. Issue (3) is a bit of a separate matter and if I get time I’ll address it separately.

I take a theoretical or “bottom up” approach to the issue, examining the authors’ main conclusion(s) in light of the implications of applying their allometry equations to certain tree growth models, to evaluate the degree to which their findings might be artifacts of their methods. There’s math involved, but just algebra and natural log transforms, and I’ll try to explain exactly what I’m doing, and why. This general approach is greatly simplified by the fact that many (56%) of the 403 species they analyzed were tropical “moist” forest species (by their definition), whose above-ground biomass (AGB) is modeled as f(diameter) by a single biomass equation taken from Chave et al. (2005). I’ll therefore concentrate on them, at least for now. A close look at Chave et al. (2005) is required.

# Tree growth analysis issues, again, part two

This picks up from the previous post on Stephenson et al (2014).  Hoping that you’ve looked at the paper, I’ll try to explain why I have concerns about it. It presents a good opportunity to discuss some important analytical issues, biological and mathematical.

I’ll begin with a criticism that relates more to a general concern with scientific publications: the way statements/claims are made in titles and abstracts.  Many scientists will only ever read the abstract of a given article, or even just the title, so it’s extra important to word things carefully there so as not to create the wrong impression.  And since scientific protocol strongly trains for accuracy and brevity in writing, there’s little room for excuses when failing to do so. Their title reads: “Rate of tree carbon accumulation increases continuously with tree size“. That’s an unambiguous, general statement; they’re basically claiming a new, general finding (law?) regarding tree growth rates, world-wide.  Hmmmm. All I will say to that is, better be able to back something like that up, because a lot of people have been looking at tree growth rates for a long time, and some of them are probably going to look pretty closely at it. Or very closely.

# Tree growth analysis issues, again

Is there something particularly difficult about tree growth analysis that I’m missing?

I’ve already discussed at length (some of) the serious analytical problems involved in dendroclimatology. [Even with 14 posts, I only got < 1/2 way through all the issues, but am still hoping to finish it, eventually]. Now comes a paper from Nature heralding the major breakthrough that the “rate of tree carbon accumulation increases continuously with tree size“. This message was quickly–within a day or two–megaphoned to the public by the media, which precludes any any critical scientific commentary beforehand. Amidst the numerous Twitter “wow-cool”s, I was able to find exactly one comment questioning the study in any way, out of dozens. Here is the typical sort of reaction, involving the individual that wrote the USGS summary article (link below).

But as for me, I have quite a number of questions on this study, both regarding the science issues themselves and their presentation. Addressing these will require time and care, backtracking through the critical references to track down the logical foundation of the stated conclusions. Checking papers closely is not quick or easy, which is why it often just doesn’t happen, including where it’s supposed to: during peer review. Not that I’m sure the investment is worth it here either, since journalists and the Twitter crowd will be long gone, scavenging for their next “wow, cool” fix. That’s what they do.

Anyway, here at least are links to the article, and it’s publicity, to date. Note that if you lack full article access, Nature wants to charge you for it, of course. What they do not tell you though, is that since the lead author is a US government employee, the article is freely available therefrom. Surely that’s just an oversight by Nature though.

# Fire: The California Rim Fire

The California Rim Fire in the Tuolumne River Canyon, Stanislaus National Forest, August 17 2013, the day it started. The fire expanded enormously over the next week, into Yosemite NP, was not contained for over two months, and finished as the 3rd largest fire in the California documentary record. Source: US Forest Service, via Tom Clark

Lately I’ve been trying to decide among several possible topical themes to focus on here, which is a challenge since my interests are all over the place.

For several reasons, I’ve decided to finally focus on the issues surrounding wildland fire, using this summer’s Rim Fire in California as the focal point. I couldn’t write about the fire when it happened, which from a news standpoint was fine since, being a national media event, everybody who was anybody (PBS, National Geographic, Time, USA Today, BBC, NY and LA Times, etc.) was busy crawling over each other to see who could dramatize it the most, and because it’s a landscape that’s near and dear to me, for several reasons, now turned to a moonscape in many places. I (and others) saw this coming long ago, and I know what awaits me when I go back in there to continue my research next year.

This event is a potential springboard for the discussion of many issues, including landscape ecology, land management practices, fire/disturbance ecology, remote sensing, climate change effects, and the media portrayal of events and the science behind them.

But for now, and by way of introduction, links to Tom Clark’s posts containing a series of photos and written commentary, here and here, to give you a sense of what happened. And here is great footage of the cockpit-level view of the terrain from a C-130 tanker as it drops a load of fire retardant along a ridge line in the Stanislaus National Forest, as the aircraft’s automatic alert system detects the terrain below. Google and YouTube searches will bring up an enormous amount of information and imagery of the fire if you’re interested.

# Early effects of fire reduction on California forests

The effects of fire suppression/reduction policies on landscapes of the western United States have been researched extensively.  It is widely known that these policies have greatly changed the nature of the vegetation, and the pre-settlement fire regimes, over very wide areas.  Vegetation in Mediterranean climates (hot and dry in the summer, i.e. California) has generally been altered the most drastically.  However, it has not always been clear how early these changes began.  This is because official government fire suppression policies at state and federal levels did not begin until the 1910-1925 time period (thus well after settlement and Indian removal), and because the magnitudes of pre-settlement Indian burning and pre-1925, non-official fire suppression work, are both pretty unclear.

The following extract from Early Days in Yosemite was written by Galen Clark in 1907, near the end of his life (its original title was: “A Plea for Yosemite“).  Clark lived in Yosemite Valley for many years, beginning in 1856, which was just three years after the Yosemite band of Miwok was driven from its long-time home after hostilities with both white settlers (the “Mariposa War”) and with the Mono Paiute on the east side.  He therefore had about a 50 year, personal perspective on the vegetation changes in the Valley, which is highly valuable.  [He was also elected the first “Guardian” of the Valley, after it was deeded to the State of California in 1864 by President Abraham Lincoln.  According to Yosemite historian Shirley Sargent, Clark was the single most important individual responsible for Yosemite becoming a National Park in 1890, above even John Muir].