Tuesday, March 10, 2015

7-11-16 is the NEW start-up date meaning that articles will begin to flow by the end of August.

Hello again. I'm afraid I've lost most of my credibility with all my fine promises to get back to work on White Mountain Sojourn. A lengthy period of time has gone by since any new articles have appeared here. I'll move forward, then, from this date, July 11, 2016 leaning backwards to November 2014 with the goal of finishing this rather complex, large article on soils and glaciers. For those of you who were steady readers I hope you find your way back and to those who might stumble on it in the coming months I'll say hello to you as well. Please, please give me feedback. I appreciate varied points of view, insights, and an, open collaborative approach in creating knowledge.

Nothing defines the Gale River Trail (GRT) more than the bottom half which is a long slog from the car park up along an old logging road used for the last time in the early 1960s. Either way, up or down, it's often referred to as a "death march." When I began working in the AMC huts in the early 1960s the pack trail to Galehead started out by Route 3 and the trip was 6.4 miles (according to the 1960 AMC guide book). The first two miles were a muddy slog along the logging roads. That part was bypassed when the road was lengthened in the mid 1960s and the trail was shortened. This photo was taken on November 1, 2014. It was a low cast, grey day, that felt like snow, fresh snow. It was quiet, as well.

 The other defining feature of the GRT is the Gale River itself that's always a welcome companion.
I was on my way up the trail to an old landslide track where I have been taking measurements for several years of the changes in the vegetation on the slide track itself. When the slide occurred on September 1, 1954, it tore out most of the vegetation along with most of the top soil and a lot of sand, gravel and rocks. At it's top on the eastern flank of Mt. Garfield, the slide reduced the mountain's flank to bare ledge. On the lowest section close to the bank of the Gale River, the track nearly level where some debris stopped and has rested since which included logs, boulders, sand and gravel. The delicate forest top soil that had once been a thin, fragile blanket covering the mountain was unceremoniously tugged down the mountain by the slide. Much of it disappeared, washed down the mountain in the flood that followed the slide.

                   It's believed that mountain trolls sheltered under this ancient bridge many years ago.

The slide was typical of dozens of slides that have left their initials on the steep sides of White Mountain peaks like Lafayette, Carter Dome, North Twin, Tripyramid, Cherry, and others. It was 300 feet wide at its widest point and about 1500 feet long. It came down during Hurricane Carol when heavy rains were sweeping the mountain slopes. It came down without warning at close to 2 pm. Luckily no one was near the site at the time of the slide. A member of the hut crew, Ben Bowditch, was below the slide carrying a pack board laden with 80-100 pounds of food and supplies for Galehead Hut. His sister, with a friend, had arrived at noon with the AMC supply truck and decided not to wait for her brother and she and her friend headed up the trail as Ben tied up his load at the pack house. Ben started up the trail around 1 pm. In those days, the distance from the pack house to the hut was 5.7 miles. The slide site is roughly 4.6 miles from the site of the old pack house. The two young women just  missed being caught in the slide and made it to the hut without knowledge of the slide. During the elapsed time between the slide ravaging the side of Mt. Garfield and Ben's packing up towards the site a debris dam caused by the slide was backing up water from the rain swollen Gale River. When Ben was about a 1/2 mile down stream the dam let go and a wall of water a few feet high started down the valley. Ben heard it coming, saw it, dropped his pack board, and climbed the closest tree as fast as he could to avoid drowning. He lost the packboard and its load of food.

Steps built in 1963 that ascended to the crown of the debris left by the slide when the site was free of vegetation.

From the top of the steps looking up the Gale River. On a clear day a shoulder of North Twin would be visible above the trees. It was within the area described by this photo that the small lake from the debris dam quickly filled, reached its threshold and burst, sending a substantial flood down the river valley.

The slide in profile. The debris dam did not last long with the river's high rate of flow. Those who have witnessed large slides like this one say they move very fast and take absolutely everything in their path down with the. A good example is the slide late in the 1800s that occurred on the north side of Owls Head in Jefferson, NH, that was similar in size and shape to the Gale River slide and witnessed by a number of people who said it came down in a matter of minutes with a swoosh.

                         Galehead Hut looked like this back in 1960. Mt. Galehead is to the right.

Wednesdays and Saturdays were "truck trip" days for the AMC hut system. Hurricane Carol "slammed" into New England on Tuesday, August 31st and headed north-northeast into Maine and New Hampshire. It's probable that the slide occurred September 1st as the soil on the mountain sides became saturated from the 4.5 inches of rain that was dumped on the White Mountains by the storm. Ben's sister and her friend passed the slide area in a narrow corridor of time just before the slide occurred. They did not hear a rumble or feel the ground shake. When Ben did not show up at the hut, Art Prentiss, the hut master, and two others descended the trail looking for him. Art. later and in a private phone conversation, exclaimed that "it was a pretty wild night" when they were out looking for Ben. They were shocked by the size of the slide and feared Ben may have been killed or injured. They kept going downhill shouting his name and finally hailed Ben who was descending on the opposite side of the river. Art and the hut guests who had some along to help walked on the west side of the swollen river and Ben walked down the east side back down to Route 3. They then drove and hiked to Zealand Hut and had breakfast. Ben rested before going back up to Ghoul (the nickname for Galehead Hut).

The bottom of the slide track in November 1967 thirteen years after the slide. Note returning vegetation in the form of alders and balsam firs. It's still possible to see the damage done by the flood from the slide on the opposite bank and downstream, too, where all the alders are growing.

The top soil that came down in the slide was swept downstream when the dam burst. Medium sized boulders, rocks, gravel, sand were also swept downstream. What was left on the side track did not fit was silt, gravel and these boulders. There was top soil but only in pockets.

The slide track as it looked in November 1974, twenty years after the slide. Note the vegetation at the edges of the slide which is mostly alder and some poplar (Aspen), two pioneering species. The top most section is still bare ledge. In 1974 there were a few woody plants growing in soil-catching cracks in the upper ledges. In the middle section, on a wide shelf traversing the slide track, there were clumps of alder and poplar, beginning to colonize the slide track. There is a mix of exposed bed rock, gravelly soil

By November 2014, jumping ahead 40 years, the biomass has increased dramatically. This photo shows the southeast corner of research Plot #1 (in the northeastern corner of the research area) and the accumulated organic debris that's a mainstay of forest plants and soils. What you also see is  evidence of "succession. That is the process in which plants colonizes a favorable site and continue to grow there until there's and upheaval and other pants take over the site. Succession occurs in stages,  and might happen quickly (a few growing seasons) or slowly involving decades or longer.

There are two goals of this informal research where the 1954 Gale River landslide occurred. The first is to better understand the stages of repair by plants that begins after a landslide (or a vast continental ice sheet). This includes, as in this case, a slide that has scoured the mountain side down to the basement rock. This goal involves measuring the amount of time that passes between the event, the landslide in this case, and the advent of vegetation. In the1968 color photos above there is spotty vegetation and in the black and white photo six years later, the vegetation is still spotty. It has taken decades for the site to support growth. Accurate measurement might offer a realistic idea of how long it took vegetation to re-colonize this region after the Wisconsinan Glacier eventually melted away from the mountains.  Many disturbances, large and small, can destroy large tracts of vegetation in the mountains, but few can fully clean the rock of all vegetation and the soil itself, even a forest fire. Only large landslides and the grinding of glaciers like the vast ice sheets that passed by here thousands of years ago can scrape away all soil and plant life.  

I've simplified my tools and methods so that I am sure I leave no trace of my presence here. I measure soil depth with heavy duty knitting needles.

In the past 7 years of studying soil development in the track of the1954 slide I've found that soil development takes place incrementally. In some plots it is barely negligible year to year like one plot that is host to a thick population of small balsam fir. In other plots it grows quickly, a 1/4 to 3/8 of an inch a year. The "plots" that I have randomly selected are 10 meter square and the pace of soil development (growth) varies from meter to meter. Gravity is an important factors in soil development, as you can imagine. In mountain areas with steep slopes it makes sense that soils would have a difficult time developing where soil building material is transported down slope during heavy rains, avalanches, snow melt, spring runoff, and small and large land slides, etc. That is what has happened here and probably dozens of times. Old timers, older than I, recall the presence of landslide tracks from several slides similar to the 1954 slide that ran parallel to it, but much earlier. It is a safe conclusion that the mountains are always moving and in some place more dramatically than others.

Plot #1 is close to the river and is one of two plots that are fairly level. Soil development on these plots out performs other plots that are, on average, steeper even if they have dense vegetation. The mix here is some evergreen fern, some red spruce, balsam fir, with a lot of organic debris across the forest floor. Measuring the biomass of each of the plots is time consuming but fascinating. The presence of a large amount of particulate organic matter (POM) is intrinsic to the preservation of productive soil.

Plots #1 and #2 have the most organic matter. This is the northwest corner of Plot #2 and, like plot #1 the soil here is productive, drains extremely well, and has a surplus of organic matter to provide more than enough nutrient. The vegetation in this plot includes some large white and yellow birch that donate tons of organic nutrients to the soil here. The pattern suggests that some areas are much richer in nutrient than others in the same plot. Overall, Plot #2 is the best drained.

A large yellow birch in Plot #2, twenty-one inches in diameter, that's getting sprinkled with snow as snow showers pass through the mountains..

The other goal of this research is to better understand the forest as it stands now which means studying the track of succession that has occurred here since the that period between 18,000 and 7,000 years ago when the Wisconsinan ice sheet melted down and faded away..

You have probably heard the expression, "the forest took back the land' as when an abandoned pasture or corn field gives way to white pine seedlings that soon evolve into a forest. "Succession" in its ecological context means the process by which species of plants live, move, grow, and die. It refers to the stages by which plant communities develop over time and effect environments. Succession is often guided by the presence of a limiting factor. There are many synonyms for this process. It is often spoken of as competition as in the dominance of one plant, or group of plants, over others. From the human perspective it  could certainly mean a successful fight by one species over another, but it is better defined as "opportunity". Charles Darwin said it well: "Those who have learned to collaborate and improvise most effectively have prevailed."

W. D. Billings, one of my early teacher, gives a good definition of Succession in his classic Plants, Man, and the Ecosystem, published in 1965 and again in 1970.

“We all know what happens when we fail to cultivate or weed the garden; weeds soon replace the tomatoes or marigolds. On a small scale, this replacement is similar to the change that takes place in the vegetation of any ecosystem where a limiting factor is removed. Moreover, the dominant plants of an ecosystem may so change the environment that their reproduction fails, where as that of another species with different tolerances will succeed. (cont.)

The southwest corner of Plot #2 has a gentle slope and a lot of debris from the 1954 slide that is still visible. The organic matter on the ground, the dead wood and leaves all represent reserves of stored nutrient and soil building material. The yearly cycle of material is not democratic particularly with respect to distribution so a good supply from a variety of sources is an asset for the existing plants.

(Billings cont.) "In the case of the garden the limiting factor is selective cultivation. When this is removed, the weeds’ ever abundant seedlings survive and soon overtop the cultivated plants. If we should decide to abandon this garden completely, would the weeds remain there year after year? In most cases there will be a change from the weeds to something else. The change may be either gradual or fast, and will continue until the vegetation is made up of species in complete equilibrium both with the general environment and with the microenvironment that determines the success or failure of reproduction. The series of vegetational changes on a single site is called plant or vegetational  succession. The early changes can be relatively rapid, but eventual stabilization of the vegetation may take centuries.(cont.)

The area in the photo above looking uphill in Plot #2 in the early fall.
(Billings cont.) Succession on new areas is called Primary Succession. Such succession must perforce, always be accompanied by the development of a soil. Vegetational succession  and soil development go hand in hand—slowly at first, then more rapidly, and then slowly again—but they cannot be separated nor can one reach stability without the other

The same ares of Plot #2 in the early summer.

 (Billings cont.) Primary succession starting on bare rock is particularly slow. No matter what the climate, there is no drier micro-environment than that of a rock surface from which water escapes by runoff and by evaporation. The first plants are likely to be crustose, intricately patterned lichens. These lichens, however, contribute very little to the breakdown of the rock into elementary soil. The big contribution to vegetational establishment and soil initiation are usually made by moss mats or by herbaceous vascular plants, which get started along deep cracks in the rock. Since these cracks vary in abundance with the type of rock, the speed of succession and soil formation depend to some extent on these rock characteristics.

Plot #4 which is mostly, if not all, thin balsam fir that grow very slowly due to lack of light and very poor soil, a thin, talc-like sand with little nutrient.

(Billings cont.) Succession starting in open water is relatively fast. The northern part of the American Midwest is dotted with forested bogs that were open water glacial lakes less than 10,000 years ago. Conversely, the bare glacially polished rocks of the Canadian Shield not far to the north still have little soil or vegetational  development.

Plot #4 receives very little moisture other than during the winter when snow is blown into the dense thickets of evergreens.

(Billings cont.) Once a soil has developed, the vegetation over it may be destroyed by fire, grazing, or cultivation. If the soil is not destroyed by erosion caused by the removal of the original vegetation, it provides a ready-made substratum for revegetation. The revegetation is called Secondary Succession. Because {secondary succession) does not need to wait for soil development, it is relatively rapid. Stability is reached in terms of few centuries as compared to the thousands or tens of thousands of years involved in most primary succession. The abandoned garden with its weeds are stages in secondary succession.”

Plants, Man, and the Ecosystem by W.D. Billings, 1964 by Wadworth Publishing Company, Berkeley, CA. Fundamentals of Botany Series. Reprinted 1970. p 89-90.

Examples of Disturbances resulting in Secondary Succession

At 5 am on October 8, 2014 a fast moving storm coming out of the northwest generated a "micro burst" when it confronted Mt. Tom, the western most peak in the Holyoke Range in west central Massachusetts, a few miles from my home. (you can google a report and photos of the damage on the day of the micro burst at Micro Burst, Mt. Tom). It lasted only a few minutes but caused extensive damage that was difficult to take in. It looked like a large bomb had been dropped. Huge areas of what had been ancient red oaks where flattened in a matter of seconds. Trees were shattered, huge stumps ripped from the ground, and a building that stood at the entrance gate of the summit road was shattered to oblivion.

It created a wild feeling of awe that this damage could have happened in just a few minutes.

                                  Trees were snapped off pretty much at similar heights, or

                                                ripped out of the ground roots and all.

                                  This is the root ball of the huge stump in the photo above.

The road to the mountain's summit that was heavily shaded by red oaks for most of its length. The shade was so dense it felt like driving through a tunnerl. The oaks were ancient. Crews came in immediately to salvage trees for lumber.

Again, this is a form of succession going on and on throughout the Earth's existence.

It was difficult to assess the loss. Members of the salvage crews spoke about finding thousands of bodies of small animals like squirrels and birds. A bald eagle found trapped under a large tree was removed successfully, taken to a veterinarian and was able to fly off within a few days.

Looking at the damage from the microburst and the damage from the tornado that hit Springfield, MA. in June 2010 shows marked similarities which we would expect as the two perturbations were so similar. They probably look similar to the aftermath of the September 1915 storm that pummeled the White Mountains and leveled huge tracts of the forest that was still recovering from the logging and devastating fires that followed the logging. It's reasonable to believe that disturbances of all kinds, large and small, have left their mark throughout what is now called the New England region including the White Mountains before and after the Wisconsinan Glacier arrived and eventually melted back where it came from. It is conceivable that micro bursts and tornadoes have plied this landscape many times in the past 7,000 to 11,000 years.

I want to get back to the Gale River slide by saying I am not suggesting that the landslide in an way duplicates the remarkable changes caused by the Wisconsinan ice sheet. What the glacier did to the forest that existed at that time is on a far different scale than this realtively small landslide and suggests very long term, primary succession in most of the glaciated areas, but certainly not in all areas covered by the ice sheet. There were many exceptions which will be explained below.

My research only is meant to perhaps glimpse the pace of soil growth in smaller models of primary succession and what similarities they have with the growth of soils following the final retreat of the Wisconsinan ice sheet and the emergence of the lovely forests that blanket the White Mountains at the current time.
Example of Primary Succession: moss and lichen growing on granite.

 And another: a snoozing glacial erratic near the Zealand Trail.

Part II: Glacial "Sheet" Mechanics.

This article, in fact this blog, came to life from a few thoughts I had standing on top of Mt. Adams on a clear, cold, February day in 2005. I was looking south at Mt. Washington admiring the shape and complexity of the Great Gulf including Jefferson Ravine and Madison Gulf and the Great Gulf, itself, which are all the remnants of small alpine glaciers that formed here 100s of thousands of years ago.

In those few moments as I gazed from the Atlantic to the Adirondacks, a sweep of nearly 150 miles, I was  looking at a large chunk of the Northern Appalachian Mountain or Highlands and wondering what this same view was like when the the Wisconsinan Ice Sheet was at its peak here just before commencement of deglaciation.

My thoughts took me back 20,000 years when the ice sheet was in position here and was all the eye could see. I tried to imagine what it would look like if I chiseled a shaft straight through the ice up to the surface directly over what is now the summit of Mt. Adams. Would it be a vast flat surface or would it undulate much like the White Mountains do today with their varied topography. Twenty thousand years ago most of the White Mountains were several hundred feet below the surface of the ice sheet. Mt. Washington, itself, is more than likely to have been below the ice sheet. So, I was dreaming of a frozen surface stretching from the realms of Hudson Bay east and west south to what is now the south coast of New England its surface undulating in a pattern  of "domes and saddles" with
 nunataks, those islands of rock and soil sticking up through the ice sheet. The nunataks are fascinating features in the glacial panorama. If I was around then I would have summited one to see what, if anything, was growing on them. Imagine the summit of Mt. Washington 17,000 (17,000K BP) years ago as a nunatak or, 7,000 years when it may have been possible to put on skis to take a run down to Mt. Munroe.

A bibliography by Canadian Ecologist E. C. Pielou that she published with her excellent book After The Ice Age, The Return of Life to Glaciated North America, (University of Chicago Press,  Chicago, 1991).Throughout the discussion where I cite facts from her book l will  notate them by  her last name, "Pielous", with the page number.

During the entire Glacial Period there were some times vast variations in temperatures as well as ice depths and coverage, of the ice. There were, according to E. C. Pielou, long periods when the weather on and around the ice sheet would have been frigid; similar to Arctic and Antarctic conditions in the mid-20th century. She notes that "katabatic" winds like those measured descending the fronts of the Greenland and Antarctic ice caps, would have descended from the higher points of the Wiscosinan ice sheet, some 3,500 meters (11,000 feet) in altitude, at speeds of up to 156 kilometers per hour (100 miles per hour). Glacial Periods  have come and gone several times, the last one reportedly was 250k BP (or 250,000 years ago) each time followed by an Intergalcial Period. The Wisconsinan was the last ice age and having just ended fairly recently we're now in the interglacial period of time which, according to Pielou, will end relatively soon

The beginning and end of an ice age is brought on by climate change which is brought about by several things including drifting continents, rising and lowering sea levels, and solar cycles; specifically the 100,000 year-long Milankovitch Cycle that's made up of three smaller cycles plus the Hypsithermal Cycle. There have been 19 to 20 intensely cold glaciations in the last billion years followed by interglacial periods of 10,00 to 40, 000 years. It's important to note that glacial ages or interglacial periods are not uniformly cold. They alternate constantly from very cold to moderate or mild periods that each might last several thousand years.The climate change goes on constantly.

Pielou writes that it appears that the climate "has a 100,000 year cycle in which glaciations lasting  60,000 to 90,000 years alternate with interglacial periods lasting 10,000 to 40,000 years, respectively. What must be explained is the reason for the 100,000 year climate cycle." Pielou says the 100,000 year cycle is based on the Earth's orbit around the sun in what is called the Milankovich Cycle. The Milakovich is made up of three other cycles including a 105,000 year cycle in the shape of the Earth's orbit from a more elongated to a less elongated ellipse. Second is the 41,000 year cycle in the tilt of the earth's axis and, third, a "21,000year cycle which begins at the point that the Earth is closest to the sun, as it traverses its elliptical orbit, shifts forward from January through February and with in the yearly seasons' cycle, Pielou explains.

The role played by the drifting continents over vast periods of time has interfered with warm water from the tropics being cut off from the northern and southern polar regions. Warm water from the equator, billions of years ago, was free to flow around the globe including around and over the poles. The continents have gone through a number of changes over long period of time including major changes in location where they tend to slow the flow of warm equatorial water that has been all but shut off at both poles allowing those areas to become colder in the winter. The  climatic effect of these cycles is a variation in the degree of contrast between summer and winter temperatures, she wrote. (p. 8.). This contrast between the seasons is the climatic factor that, more than any ohter, accounts for the fomration and disappearance of ice sheets over the land during a "Glacial Age".

"Throughout most of the glacial age (that is during the glaciations) when the contrast  between seasons is comparatively slight, summer temperatures are not high enough for the previous winter's snow and ice to melt. They accumulate year after year, inexorably building up huge contintal ice sheets in temperate latitudes even though the winters are relatively mild." (p. 9)

to be continued