Monday, May 25, 2009

5-25-09 Spring arrives slowly to the higher ridges and summits

A painted trillim (T. undulatum) beside the Mt. Hale Trail. It's one of the first flowers of spring in the White Mountains. This one was at 2300 feet but they accompanied me, hundreds of them, all the way up to above 3000 feet.

Spring has flooded well up above the valley floor to at least to the 2500 foot elevation but hiking above that yesterday was like turning around and heading back towards winter. There were even patches of rotting snow in the woods off the trail.

This is one of my favorites. It's indian cucumber and grows extensively in the better soils of the deciduous woods. When I was in my mid-teens and just starting out as a guide and naturalist in the White Mountains one of my teachers was this character, Harry Levy, who was a wiz at birds and plants. I've already told the story in the blog about the eagle incident on top of Zeacliff. Well, this is another funny story. Harry had been showing me a number of plants one day including indian cucumber which is a lily (Medeola virginiana) with a beautiful six pointed white flower. The next day I was guiding and I wanted to show off my new knowledge so I showed my hiking group what I thought was an indian cucumber. It gets it's name from the thick root, or tuber, that the stalk of the plant grows from and tastes like cucumber. I had my charges taste one and they looked at me blankly, totally unimpressed. I did this on a few other hikes until Harry pointed out to me that I was feeding everyone the roots of the "star flower", actually a primrose and not a lily, that looks sort of like indian cucumber. So, it's a good thing for me the root of the star flower isn't deadly poisonous.

At 3000 feet spring has been held back by cold nights. The leaves are only half out and when the sun is out more than half of the sunlight penetrates down to the forest floor which is a good thing for the lower level shubs and flowers growing close to or on the ground.

This is a striped maple leaf just emerging. These leaves will get to be almost a foot across.

This is my old friend witch hobble, or hobble bush (Vibernum alnifolium), flowering at just about 3000 feet at the transition to the spruce-fir-paper birch zone. At 2300 feet, about 1000 feet lower, witch hobble has flowered and the flowers have already gone from the leaf axils. It is sometime quoted that when you go 1000 feet up in elevation in the White Mountains it is the same as going 500 miles north. In other words climatic variations are severe enough even within the range of 1000 feet to set back spring a week or two. Working on Mt. Washington during college summers I often left my college campus in mid-May when it was summer-like there. I would arrive at Pinkham Notch and spring would just be getting there at the 2000 foot elevation. The leaves would just be coming out and there was still snow in the woods. Then, heading up onto the mountain itself, I'd turn back the calender and outstrip spring by almost a month as it often snowed at 5000 feet into June and there would be days of near-blizzard conditions.

This is close up of the witch hobble's flowers. The showy flowers around the outside of the inflorescence are sterile and there only to attract pollinating insects. The inside flowers will contain the seeds which begin to appear in late June as clusters of red fruit, also quite showy.

This is a red spruce and a half. It's 60 feet tall and on a south facing shoulder at about 3500 feet. Mt. Hale was burned over in a forest fire in the 1880s (1886 or 1887) but there was sparse description of the extent of the fire or what portions of the mountain it burned except that it reached the summit. Presumably, then, this spruce is about 100 years old. If you enlarge the photo you'll notice that the limbs of the birches are still without leaves at this altitude and will probably take one or two days of warm weather to get them to come out.

This balsam forest is much younger. It is about 60-80 years old. The picture was taken at about the 4,000 foot elevation just below the summit and shows the damage done by snow and wind at this elevation. The other phenomenon it shows is the nursey stock of young balsam seedling that grow in profusion on this ridge. It's really amazing how thick they grow here and at other sites in the Whites. I checked to see how many of the seedlings had reproduced by "layering" and could find none meaning these trees came from the actual seeds. Layering as a means of plant propagation is explained more in Bob Monahan's paper down below.

For comparison this photo (above) taken yesterday and the one below it taken fifty years ago illustrate the extent to which the balsams have retaken the summit of Mt. Hale. The photo above shows the the anchoring pins and the concrete block that was the bottom of the stairs that went up the forest fire look-out tower that stood on the summit of Mt. Hale from 1930 until 1959.

This photo was taken in July 1959 when some of the fire tower super structure was still intact. The upper portion of the lookout, the cabin and deck, had been removed. The view to the west of North (right hand peak) and South Twin is unobstructed by trees. There is just grass resembling a pasture that extended quite a ways down from the summit. There are still remnants of this habitat to be found if you walk a ways down from the summit into the woods on the west side of the moutain.
This photo was taken facing southeast from the summit with the pins that held down the northeast corner of the steel superstructure of the fire tower in the foreground. Below are two picture taken 50 years ago looking in the same direction from the same spot.

This photo was taken from the same exact place on the summit of Mt. Hale where the large pile of stones now sits (as in the photo above) and is looking almost due south into Zealand Notch towards Mt. Carrigain seen in the haze. The picture was taken in July 1959. Look at the knee-high grass that extends down to the mass of balsams (kind of like an army approaching, or pirates!).

This photo was taken from the summit of Mt. Hale looking due east to the Willey Range in the summer of 1960. In this direction you can see the tops of some balsams appearing just below the summit but in that direction only. The extent that the balsams have circled the summit as of today and continue to invade the open area that existed here for decades is astonishing. The same phenomenon is occuring on Carter Dome which was burned over by a fire in 1903, and Zeacliff that I've already mentioned. There is a good article by a past AMC naturalist, Kimme Beal, in a recent issue of Appalachia titled "Climate change at the Top". She addresses somewhat similar issues on other summits in New England as the balsams on Hale, Carter Dome and Zeacliff. As Allan Savory points out, "nature is a coiled spring" that's waiting to explode and the nature of the forest is to grow aggressively unless impeded by humans or major perturbations like fire or storms, or insect infestations. What is happening on Hale and the other summits I've mentioned is most likely the natural course of the forest succession following a fire. One other note about the photo from 1960: in the foreground of that photo there's a soil profile exposed that shows a thick, rich layer of soil on the summit which from the inspection I made yesterday (5-24-09) no longer exists so I wonder why it's no longer there, if it merely blew away because the grass holding it died off, or something else. Another mystery!

It was a treat to find this beauty along the trail as I came out of Zealand Notch late in the afternoon yesterday a few hours after the rain ended and the sun had come out. It's Rhodora (Rhododendron canadense) and an early flowering plant found extensively in the Whites particularly in bogs.

Saturday, May 23, 2009

5-23-09 Stress and stressors; introducing two perspectives on stress in ecolgoical systems

First, I want to thank my friend Rebecca Oreskes, Public Service Staff Officer for the White Mountain National Forest, and Thomas Wagner, Forest Supervisor for the WMNF, for giving me permission to conduct research on “soil development and plant succession” at the 1954 Mt. Garfield landslide site on the Gale River Trail this summer. That’s very cool and I'm appreciative of their time and consideration.

The next couple of entries focus on stress or stressors in plant communities. The stressor is significantly different in each entry. The first paper is titled “Timberline” and was written 75 years ago by Bob Monahan who was, some of you may remember, one of the founders of the Mt. Washington Observatory and who we’ve introduced earlier in the blog. He is also the author of “Mt. Washington Reoccupied”, published by Stephen Daye Press (Brattleboro, VT) in 1933; in which he describes in detail the first year of the "new" Obs and accompanies the narrative with outstanding photos.

The second entry is on Beech Bark Disease (BBD) that’s killing American beech (Fagus grandifolia Erlh.) throughout the White Mountain National Forest and in a broad swath extending from Nova Scotia, and Quebec southwards to West Virginia. BBD is a major stressor in the eastern Boreal forests as it is slowly eliminating one of the defining tree species of this extensive forest ecosystem. BBD was introduced to North America from Europe coming ashore in a shipload of European Beech seedlings destined for a city park in Halifax, Nova Scotia in the late 1800s. It’s actually two stressors in one: a tiny insect called Beech Scale, or Cryptococus fagisuga that bores into the bark of the beech trees. Then, along comes a parasitic fungus called Nectria cocina var. faginata that moves into the tiny hole made by the scale. A second closely related and less prevalent fungus, Nectira galligena, also infects Beech in the same range as the Nectria cocina.

Monahan was affectionately known as “Gramps” by those who knew him. I took this photo of him (he's on the right) with George Hamilton at a party celebrating George’s retirement as AMC huts manager way back in August 1966. Bob was the Dartmouth College Forester at that time.

Monahan’s paper was actually his thesis at Yale Forestry School in 1930. A few years later he helped re-established the Mt. Washington Observatory (MWO) on the summit of Mt. Washington. The thesis was shortened so it could be published in “Appalachia”, the journal of the Appalachian Mountain Club. The paper appeared in Volume 19 of “Appalachia” in 1933 (it begins on page 401). I want to particularly thank Becky Fullerton, librarian at the AMC prestigious library at 5 Joy Street in Boston, for helping me retrieve this article.

It’s tempting to scan the entire paper because it’s excellence in a couple of areas. First, it’s well written. It’s clear and concise (in comparison to mine). Second, it’s as a model ecological monograph of the phenomenon we refer to as Timberline, or sometimes “tree line”, it’s pure science and for that reason alone it is a good read from cover to cover. The paper covers the ground well, literally and figuratively, as an excursion along the timberline but also across the area above timberline we refer to as the alpine zone of the Presidential Range. He analyzes the role of each of the stressors that impact plant communities at their highest elevations on mountain slopes.

“Timberline” is a perfect follow up to Andrew Riely’s paper that appears earlier in the blog and talks about the world record wind of 231 miles per hour measured at the Mt. Washington Observatory in April 1934, and also explores the impact (stress) wind has on the White Mountains and mountains in general.

Looking at stressors in biological systems is fascinating because stressors usually define boundaries, the edges of things (like the timberline). Stress tests the equilibrium in all systems. Ecology is, generally speaking, the study of stress in living systems over time. It is, in some ways, similar to medicine as the study of stress in the human body. Humans have a good idea what stress is and how it impacts us. As a psychotherapist most of my work is studying stress in humans and creating strategies for mitigating it. I try to use an ecological perspective in which I separate stressors the way an ecologist does. The illustration above is a clinical tool I use to help my clients recognize and deal with the impact of their stress.

I’m using the term “stressor” as a way of introducing the concept of “tension” within ecological systems. In Bob Monahan’s paper the stressors are an interweaving of variables, all which have the potential to cause stress in diverse plant communities trying to grow at the limt; at high altitudes. The evidence that stress is occurring is the “timberline”. It represents a boundary, or edge, or limit. Stressors run the gamut. They can be ephemeral like an early or late freeze, a temporary drought, an insect infestation, or something large like a continental glacier and possibly permanent like Global Warming. A stressor is pretty much anything that disrupts the dynamic within the status quo or equilibrium (or homeostasis).

In Darwinian terms either you die or adapt to certain stressors. Plants have adaptive strategies for stress. Several years ago a number of experiments conducted by plant physiologists became newsworthy because they provided dramatic evidence that some trees can communicate with each other. The research showed that trees are sensitive to stress and as an adaptation to a stressor have developed a mechanism to communicate information about the stressor to neighboring trees as a kind of warning. One study involved trees responding to an infestation of Gypsy Moth caterpillars and demonstrated that trees could communicate with other, nearby, trees alerting them to the approach of the insects. The communication was in the form of an aerosol that the stressed trees dispersed to neighboring trees. It was described as a stress related response.

Jack Schultz was one of the researchers and he made observations in a large grove of red oaks (Quercus rubra) growing over several acres on the Pennsylvania State University campus. By wrapping some tree limbs with huge plastic bags he was able to isolate the aerosol the oaks were using to “warn” the other trees of a gypsy moth caterpillar infestation. The question, or one of them, is whether the warning is an adaptive response by one tree to the stressor, or is it an altruistic attempt by one tree to warn others of the impending threat.

After conversing with Schultz I did my own research of this mechanism because the idea that plants could “talk” to each other was exciting. I remembered those 8th and 9th grade science fair projects where three tomato plants or geranium are placed in separate rooms for a few months and each is subjected to different sounds. One sound was an awful scrreeching noise. The other plant listened to rock music constantly and in the third room the plant listened to Beethoven’s late string quartets. At the science fair we got to see the results and of course the plant that enjoyed Beethoven was thriving while the others were at near-fatal stages of stress. This experiment was supposed to prove that plants have feelings. We know plants are highly sensitive to a number of stimuli primarily light including the absence of light. Maple sugar producers know that sugar maples trees can be very sensitive to both sunlight and temperature in late winter. For instance, on a good sugaring day with the temperature around freezing the sap stops dripping instantly when the sun is behind a cloud and then commences again when the sun comes back out. This is really a thermal effect but it feels as though the tree is waiting for the sun to come back out from behind the cloud.

In the small experiments I conducted I used mixed species tree stands and I found that there’s definitely a connection between stress in individual plants and a rapid increase in phenolic chemicals in leaves of nearby trees that will deter predators to an extent. More recent research has broadened the discussion regarding communication between individual plants and blurred some of the earlier research with extenuating circumstances including some experiments that showed that it was not the predator stress that trees were responding to so it’s not quite as elegant as first thought. The newsworthy research helped the public become aware, however, that plants are sensitive

I refer to small local stressors “perturbations”. It might include the upheaval sometimes caused by snow avalanches, the destruction caused by a landslide, or damage from an average sized hurricane in which trees have been torn up and toppled. An exception would be a storm the size of Hurricane Katrina that caused major stress in a number of ecological systems. According to a Washington Post article published on November 7, 2007 Hurricane Katrina killed 320 million trees as it swept across Louisiana and Texas. It wasn’t the wind that killed the trees; it was the large scale flooding. The cause of death was drowning.

While plants can’t jump out of the way of an oncoming stressor, animals have that edge: mobility. Some, like humans, even have social groups for mutual aid but in a lot of cases animals do not fare well with stress. Some animals go into a nosedive when stressed beyond certain thresholds just like humans do perhaps because of psychological implications.

Beech Bark Disease represents a stressor larger than Katrina in scope. It, too, has most likely killed millions of beech trees over the past 100 years. The time dimensions of the stress increases it’s impact exponentially because it tests the resiliency of the species under attack. Time, in this case, is double edged. If there more time a number of plants might adapt and this may eventually be the case. As it is, though, the only thing favoring the survival of the beech is that some individual trees seem to have immunity, or at least a resistance, to the beech scale. This may be a prior adaptation, or not.

In the same 100 years, or a little more, in which we have seen Beech in the northeast area of North America die-off we have also witnessed the destruction of a tree closely related to Beech, the American Chestnut (Castanea dentata) from Chestnut-bark Disease as well as the American Elm (Ulmus americanus) that has been compromised by Dutch Elm Disease. Humans introduced all these diseases to North American. At the present time other tree species in North America are threatened by imported, “invasive” predators. The Asian Long Horned Beetle (Anoplophora glabripennis) (ALB) is one of the more recent introductions and was first identified in NewYork City in 1996 and is now know to be in areas of Massachusetts and southern Canada. It is a threat to all hardwood species growing in northeastern North America. The soft wood species, Eastern Hemlock (Tsuga Canadensis) is threatened by the Wooly Adelgid (Adelges tsugae), an Asian import, that was originally found in the Pacific Northwestern area of North America in the 1920s had now moved to the east coast and has infested trees in both New Hampshire and Vermont.

So that’s not very good news. And even though some of the players are new the mobility of infestations and infections within species and between species is not. Human's mobility to every corners of our beloved planet has repeatedly given invasive species a free ride to a new environment where they die, live marginally or find a place to thrive. It is provident that a lot of these “accidents” cause slight harm, but in others, as with the Asian Long Horned Beetle, there is possibility of catastrophe.

5-23-09 "Timberline" by Robert Monahan, Dartmouth College Forester and a cofounder of the Mt. Washington Observatory

This is the title page of Bob "Gramps" Monahan's master's thesis that he wrote in 1930-1931 when he was attending Yale Forestry School. I like the wood cut of the krummholz that he did himself. Reprinted in Volume 19 (old system of indexing), Appalachia, 1933; pg 402.

In defining timberline Monahan quotes Chittenden and other researchers who first observed that balsam fir (Abies balsamea) grows to altitudes of 5500 feet in the Presidential Range and that from 4900 feet to 5500 feet in elevation the fir produced few seed cones. Reproduction then, occurs mostly by the mechanical means referred to as “layering” in which the lowest branches of the fir that are closest to the ground send down roots into the soil and anchor the limb and the limb eventually becomes an autonomous tree.

Balsam fir, along with dwarf paper birch (Betula papyrifera) and black spruce, (Pices marinara) are the three most important tree species at timberline according to Monahan but he refines that by stating that “balsam fir and paper birch are the principal species at timberline”. To that he adds “balsam fir is the outstanding species.”

In terms of adaptations he notes that the roots of the fir grow to a greater length without branching giving it an advantage over black spruce on dry, exposed locations. Due to the more shallow roots of the fir, he states, it can absorb its moisture in the wetter upper layer of the soil. Lastly, germination requirements for the fir are simple as it only needs a layer of moss in which to germinate. Fir can establish itself in many habitats where other species cannot.

Some terminology needed for understanding some of the prominent features of the timberline. The first is the word “Krummholz” that’s German for “twisted or gnarled wood”. Trees growing in the severe conditions at timberline are often twisted and form thick mats close to the ground and are called krummholz. Fell-field defines a “rocky flat or plateau in arctic, or subarctic regions or on alpine summits of mountains” according to one of Monahan’s sources. Fell-fields shouldn’t be confused with “feldsmeer”, the large areas of weathered and broken rocks that are common on or near the summits of the Presidential Range.

The Climatic Conditions and Their Effect on Timberline

The following are direct quotes from Monahan’s paper:

“Climatic conditions must be recognized as the principal cause of limitations in the altitudinal distribution of trees on high mountains and for the peculiarities of tree growth at and near timberline; in particular, conditions of air temperature, solar radiation, atmospheric humidity, precipitation, and air movement.

“There are local physiographic conditions which explain a deviation in the altitude reached by tree growth but in general this vegetation continues upwards until the climatic complex becomes too acute and equilibrium between growth requirements and climatic factors is destroyed.

“It should be understood that no one of these factors, per se, can limit tree growth; for example the adverse effect of lower temperatures may be offset by the increasing precipitation. The series operates in a complex to such an extent that the individual effect of each factor is very difficult, if not impossible, to measure.

“As might be expected, the actual altitude of timberline varies with latitude. In general, in traveling northward, it occurs at increasingly lower elevations, and toward the northern limit it is but little above sea level. It is further influenced by other general climatic relations: whether for instance, the range is located in a region of continental climate marked by lack of uniformity, high and low temperature extremes, irregularly distributed and moderate precipitation, strong insolation, great loss of heat by radiation at night and in the winter, and relatively slight humidity; or whether, on the other hand it is located in a region near the sea-coast where the maritime climate is more moderate and the annual precipitation higher.

“ The climate of the Presidential Range is neither continental nor maritime, but a variation between the two. The Presidential Range has been described by several writers as “an arctic island in the temperate zone,” having the same climate as Labrador at 60 degrees north latitude. It is hoped that the current records of the Mt. Washington Observatory may provide a more complete definition. (Ed. note. Here’s a plug for the MWO. Apparently Monahan either wrote this paper while working at the Obs or at one of the AMC huts during a summer off from grad school.)

“It should be readily appreciated that the climatic conditions found on high mountains are far different from those that prevail in the lowlands. This change is accounted for directly by the diminution in the atmospheric pressure as the altitude increases, which indirectly influences the other climatic factors of heat, light, and precipitation.

“The climate plays a leading part in affecting the variations in the forest cover ahs been established by numerous ecologists. This paper will indicate the result of the operation of these various climatic influences at timberline and will attempt to emphasize those which may be considered the determining factors.” (end of quotes.)

Monahan, from this point on, analyzes the primary influences he feels play a role in creating the timberline beginning with Air Temperature. This he explains was long-thought to be the direct cause of timberline and there was a lot of direct evidence that timberline more or less paralleled certain isotherms.

Air temperature certainly has a major role in the life process of trees directly and indirectly, he points out, as temperature effects evaporation, transpiration, and might counteract the effects of lower barometric pressure and accelerated air movement. A lengthy discussion of the effect of altitude on temperature and the effect of temperature on tree growth with the following observation of note:

“As tree growth occurs chiefly during the night, it is logical to suppose that the low nocturnal temperature greatly inhibits growth and this relation may be an explanation of the prostrate form characteristic of trees growing the zone of cold nights.”


“In the true alpine zone the growing season, in which the plant must complete all its vegetative and reproductive processes, is reduced from five months to three weeks. This short season is responsible for the rarity of annual plants. Even when annual plants are transplanted from the lowlands they will frequently develop a perennial habit. The brief period of growth is also one cause of the prevalence of evergreen trees among the timberline species, because the evergreens are ready to assimilate at the first opportunity where as the assimilation of the deciduous trees cannot begin until the leaves have developed.”

Monahan then concludes:

“I believe that, rigorous as the temperature conditions on Mt, Washington may be shown to be, cold alone will not directly limit tree growth. The greatest importance of this factor rests in its keeping the soil frozen during the long periods throughout the year. During this time the moisture in the soil is literally locked up and non-available, with the result that the trees are growing on a physiologically dry site. To make the conditions more adverse for the trees, strong desiccating winds are blowing much of the time, which tend to ‘lick up’ whatever moisture may be available in the tree. Timber growth at treeline must therefore be very conservative in its water relations. At such times, when the transpiration loss, augmented by the constant air movement, cannot be offset by the supply of water in the soil, the tree is persisting under conditions that my ultimately result in death”

In a short sequence of other factors solar radiation, atmospheric humidity, precipitation, and air movement, Monahan discusses the contributions of each and its effect on the timberline. Solar radiation and humidity in the White Mountains do not limit tree growth at higher altitude in the Presidential Range as they might in mountains in more arid regions, he observes. Precipitation is important and he remarks that the highest level of precipitation is achieved during the summer months in the White Mountains including the Presidential Range which is advantageous for the trees as this is their growing season. Otherwise, he says, the total annual rainfall on Mt. Washington averages a little more than 80 inches so one could not conclude that precipitation is a limiting factor on tree growth.

Air Movement, “the daily alternation of winds descending to the valleys and ascending to the mountains, coupled with the normal increasing air passage with greater altitude, produces a constant movement of the air at high altitudes. This behavior of air currents represents a factor of considerable importance in limiting tree growth. The crux of the wind relations depends upon the ability of the individual trees to develop enough foliage, despite the adverse wind conditions, to carry on photosynthesis,” he states.

In addition wind increases rates of transpiration loss and the evaporation of soil moisture which are important factors in the success of failure of the timberline trees. Wind plays an important role in the morphology, the shape and structure of the trees, and wind also plays a role in the dispersal of seeds. Wind, also, may be responsible for “dry killing” trees at timberline because the winds are so severe and there is no moisture available, Monahan observes.

He goes on to say that trees adapt to the wind, along the “tension belt” by growing in areas protected from the wind making use of topography and physiographic features like rock outcroppings, boulders, and the sides of ravines. He notes that, “Not only the height but also the spread of these more fortunate pioneers is measured in terms of the dimensions of the sheltering boulder or ledge.”

He observes “the side of the rock around which the winds sweep with the greater velocity is readily indicated by cross-section of the trunk, for the growth rings against the direction the greater velocity are compressed many times closer than those in more favorable quadrants.

It should be borne in mind that it is the dryness rather the high velocity of the wind, which causes such a marked effect at, treelike. The combination of dry winds blowing across the mountain slopes at great speed forms and exceedingly critical condition.”

The list of factors in Monahan’s discussion that impact timberline includes Soil composition, soil moisture, surface and depth of soil, and soil temperature. Of these, pertaining to the Presidential Range, he remarks that “inadequate soil moisture, especially in the winter, may well become the limiting factor in the upward extension of tree vegetation.” He also puts importance on the affect of soil temperature on the distribution of trees at timberline altitude because of the effect on the length of the growing season as it “does not allow the seeds adequate time to ripen.”

“The frozen condition of the soil for long periods may explain the success of the balsam fir on Mt. Washington, “ he writes” for the zone with the most constant temperature is at the surface of the soil, this favoring the shallow-rooted balsam, the roots of which feed in the upper horizon.”

Monahan goes on to discuss slope and exposure, air drainage, snow deposits, altitude, and forest fires and their impact on timberline saying that in the order of importance individual or as a group they do not have more than a negligible impact on the formation of timberline in the White Mountains. Instead he concludes:

“The several factors influencing timberline have been discussed in detail and the most important conditions emphasized. I have attempted to stress the necessity of considering each factor not only from the view of its individual effect on tree growth but also in its relation to the complex of factors whose combine influence governs the altitudinal extension of timberline.
I do not claim to have solved this problem, which numerous investigators have failed to explain fully. I do, however, take this opportunity to emphasize one set of condition which must be considered in the case of the Presidential Range. It has been pointed out that snow cover on the upper slopes is surprisingly thin and therefore provides no protection to the soil beneath. Whatever moisture may be in the soil is frozen and consequently not available to the trees during long periods. Simultaneously strong dry winds are sweeping across and promoting a high transpiration loss that the tree is unable to sustain through further absorption of soil moisture. The result is that the tree literally dies of thirst. The leader may be killed, or the entire tree may die, if the period during which these conditions prevail is prolonged.
There are other factors which produce a marked effect, but I believe that the chain of circumstances offered in the preceding paragraph is the most logical explanation for the formation of timberline on the Presidential Range.”

The End

(Ed. Note: I’m enclosing several photos of my own to help illustrate Monahan’s thesis points. The black and white photos contained in his Appalachia article did not photocopy well.)

A photo taken from Jefferson's Knee of Mt. Adams showing the irregularities in the timberline that is often interrupted by the feldsmeer (areas of broken, weathered rock), slide tracks, and also where the balsam has taken advantage of a protected slope to advance higher in a few areas.

This photo is towards the summit of Mt. Jefferson, also from Jefferson's Knee, and in the foreground shows a "fell field", or rocky plateau, characteristic of the arctic. The large "fan" of balsam extending to the left and below the area of bare rock on the slope above the fell-field can partially be explained by the snow patch shown in the next photo which each year fills the "bowl" created by the area of bare rock .

This is a photo of the famous Mt. Jefferson snow patch that sometimes lingers until late June and early July. The snow patch is sitting in the middle of the rocky opening shown in the previous photo. This photo was taken from the summit of Mt. Adams on July 17, 1969, the year of the heaviest snowfall ever recorded in the White Mountains. But the idea is that the balsam growing on the eastern side of Mt. Jefferson at 5100 feet are benefited by the extra moisture provided by the lingering snow even if it doesn't always linger until July.

This is krummholz growing on Franconia Ridge at 5063 feet and establishing the higher advance of tree growth in that location. The photo was meant to show how snow packs in around the trees and protects them from the wind and provides added moisture to the soil around the trees' roots in the spring.

This is another example of a fell-field. It's called Bigelow's Lawn and is located on the southeast side of Mt. Washington. The kummholz in the foreground in balsam fir. The large, distinct green patch of krummhoz on the lower part of the summit cone is growing in an area where large amounts of snow, the "upper snow field", accumulates and remain well into May and sometimes June providing moisture for the trees and alpine plants.

This photo shows the approximate timberline across the western flank of Mt. Washington. It is roughly at the 5,000 foot elevation. This is an area of high winds throughout the year.

This photo is looking acrosss the timberline on the Franconia Ridge with Mt. Lincoln (5,106 ')
in the background. Here you can see trees, black spruce and balsams thinning out but advancing up the slope and creating an irregular line. This is an area of high winds through out the year as well.

This is a photo of the timberline on Mt. Adam's north slope. It also thins out gradually and balsams seem to advance up slope in an irregular line at just below 5000 feet. Again, this is an area of very high winds.

A hiker below the summit of Mt. Adams navigating the feldsmeer with crampons on. Generally speaking, the feldsmeer is only a feature of the northern summits of the Presidential Range; Mts Madison, Adams, Jefferson, Clay and Washington. It is most visible above timberline and therefore a feature of the alpine zone of the summits just named. It most likely exists below timberline in some areas and is obscured by the forest growing there.

If you look back up to the photo of Bigelow Lawn and the summit Mt. Washington you can see that most of the cone of is covered by feldsmeer and there is a funny story about this prominent and defining feature of the mountain. The story involves a man by the name of Russell Hodgson who was actually called "Casey" because his father had been an engineer on the Boston and Maine Rail Road and somehow Casey got that nickname from his father's profession. Casey had many jobs around the mountains. He worked for the US Forest Service, for the AMC, and for a number of years was an observer at the Mount Washington Weather Observatory (the Obs). In fact, he and Bob Monahan were good chums. Anyway, one afternoon in July 1961, Casey was out in front of the observatory taking the 2 pm weather observation when a man came running up to him. "Mister!, Mister!," he yelled at Casey and then with some urgency in his voice asked, "can you tell me where all these rocks come from?" Casey looked around calmly as if surveying all the rocks (the feldsmeer) individually and he looked back at the guy and replied, "The glacier brought 'em." Then the guy looked around a little more at all the rocks while Casey finished the 2 pm observation. "Well," the guy then asked Casey, "where's the glacier now?" Without missing a beat Casey, with a slight air of impatience, replied, "Gone back for another load." That's a true story.

A lovely photo of Mt. Adams from the cone of Mt. Madison taken in early April. In the lower center of the photo you can see Star Lake and just to the right of that you can see the advanced line of balsam that has managed to invade this col as the trees receive direct protection from the wind from Mt. Adams. The area in the col is moist, if not wet, most of the summer. The elevation of timberline here is also 5,000 feet, roughly.