Lessons from Travels: Great Basin Ecology

by Carl Strang

A November conference in 2003 gave me the opportunity to take some extra time off, rent a car, and tour central Nevada. Previous Lessons from Travels posts have highlighted the Lehman Cave and Extraterrestrial Aliens aspects of that trip. Today’s focus is on the ecology of the Great Basin. This is an area where the crust of the Earth stretched thin, as though pulled from its eastern and western edges. It occupies much of Nevada, and extends south. The stretching produced a series of north-south cracks, or faults. Alternate wide blocks dropped down to produce low basins, and the areas between them thrust upward to produce narrow mountain ranges. The spacing of these ranges and basins is rhythmic and regular.

The low areas are flat and dominated by sagebrush, but there are plenty of other plants and animals to lend diversity to this desert.

The low areas are flat and dominated by sagebrush, but there are plenty of other plants and animals to lend diversity to this desert.

Higher mountains bounding the west edge of the Great Basin draw most of the moisture from the prevailing westerlies. The little remaining rain falls mostly on the ranges and evaporates, or soaks into the ground long before it can flow to the centers of the desert plains.

Here is a typical view of one of the many ranges that divide the basins. The dominant trees are singleleaf pinyon pines and Utah junipers.

Here is a typical view of one of the many ranges that divide the basins. The dominant trees are singleleaf pinyon pines and Utah junipers.

This landscape is not monotonous. There are abundant unique features sprinkling it. Sand Mountain is one example.

This enormous isolated dune is composed of sand blown up from a source 40 miles away. It stopped traveling when it hit a bight in one of the ranges.

This enormous isolated dune is composed of sand blown up from a source 40 miles away. It stopped traveling when it hit a bight in one of the ranges.

The thinning of the crust produced volcanic activity in places.

Core of an ancient volcano, dark with basalt.

Core of an ancient volcano, dark with basalt.

There are occasional badlands areas as well, where weakly cemented stone has eroded into beautiful shapes.

Cathedral Gorge badlands

Cathedral Gorge badlands

People have lived in this region for thousands of years, and left their mark in many areas.

Grimes Point petroglyphs

Grimes Point petroglyphs

Wildlife is diverse, as well, in the region.

Mule deer in the mountains

Mule deer in the mountains

I took a hike on the Pole Creek Trail, in Big Basin National Park.

The scene from my turn-around point

The scene from my turn-around point

On the way back down I found where a bobcat had stepped in my tracks.

The feline had passed within the hour.

The feline had passed within the hour.

The mountain chickadee is one of the delightful upland birds.

The mountain chickadee is one of the delightful upland birds.

The basins have their own array of wildlife.

Pronghorns occur in scattered small groups.

Pronghorns occur in scattered small groups.

It was still warm enough for a snake and other reptiles to be active in southern Nevada.

Striped whipsnake at Kershaw State Park

Striped whipsnake at Kershaw State Park

From its geology to its distinctive ecology, the Great Basin provides no end of contrasts that, upon reflection, help to define our own home region.

P.S. This is the 1000th post of this blog.

Lessons from Travels: The Mound Builders

by Carl Strang

There was a time when I thought of the North American landscape in an ideal sense, wanting my ecological studies to delve into the interactions of organisms and their history without any messy intrusions of human influence. Certainly my experiences as a graduate student in the Alaskan wilderness supported that point of view. As I spent more time in the field and continued to observe, and think, I gradually came to the realization that this ideal vanished thousands of years ago as humans filled the continent and influenced it strongly. That understanding became more concrete as I visited earthworks created by Native American civilizations. My first such encounter was Serpent Mound in Ohio.

It is difficult to have a proper perspective from ground level. The shape is a winding narrow mound with a mouth-like extension at one end embracing a separate oval shape.

It is difficult to have a proper perspective from ground level. The shape is a winding narrow mound with a mouth-like extension at one end embracing a separate oval shape.

The whole has been compared to a snake, with the oval either representing its head or perhaps an egg the snake is about to swallow. My own interpretation is much different. It reminds me of an ovary and oviduct with its expanded, embracing end, and thus has fertility symbology.

In 2005 I made a couple trips that included a number of stops at other mound-builder sites. Mound City in Ohio was the first stop.

This site has been studied and preserved, as part of the Hopewell Culture National Historic Park, with interpretive amenities for the public.

This site has been studied and preserved, as part of the Hopewell Culture National Historic Park, with interpretive amenities for the public.

The Hopewell culture flourished around the first 400 years A.D. during the Woodland Period, a transitional time when people with a hunting gathering culture increasingly were including agriculture in their economy.

A defining boundary ring a few feet high contains various sizes and shapes of mounds.

A defining boundary ring a few feet high contains various sizes and shapes of mounds.

Sophisticated works of art, many of them based on animal forms, have been found in Hopewell sites.

Excavation of a mound revealed that it had been constructed over a charnel house (the walls indicated by the posts), which had been burned along with the accumulated human remains it had housed.

Excavation of a mound revealed that it had been constructed over a charnel house (the walls indicated by the posts), which had been burned along with the accumulated human remains it had housed.

Already it becomes clear that mounds had more than one function in these societies. The greatest mounds are in Illinois, at Cahokia.

This photo does not do justice to the largest mound at Cahokia, though the car, telephone poles and human figure silhouettes give some sense of its size.

This photo does not do justice to the largest mound at Cahokia, though the car, telephone poles and human figure silhouettes give some sense of its size.

Cahokia was the greatest center of the Mississippian Culture, which followed the Hopewell times and lasted until drought forced a decline beginning around 1400 A.D.

The view from the top of that high mound shows that its lesser neighbors were themselves substantial.

The view from the top of that high mound shows that its lesser neighbors were themselves substantial.

The Mississippian economy was strongly dependent upon agriculture.

This reconstructed ring of poles, nicknamed Woodhenge, apparently was a ceremonial observatory.

This reconstructed ring of poles, nicknamed Woodhenge, apparently was a ceremonial observatory.

The population around Cahokia was huge, a city by any definition, and it all was built and collapsed before Europeans or Americans arrived on the scene. The huge mounds were built basketload by basketload of excavated earth.

These mounds were of a third type, having buildings constructed on top of them. Moundville, in Alabama, is a site where one of the mounds has a reconstructed building on top.

Moundville was part of the Mississippian culture, and so was connected to Cahokia.

Moundville was part of the Mississippian culture, and so was connected to Cahokia.

Continuing south, I made a stop at Poverty Point in Louisiana. This Archaic Period town was much earlier than the sites described above, and in 1500 B.C. was the largest settlement in North America.

The trees give some sense of scale to this Poverty Point mound.

The trees give some sense of scale to this Poverty Point mound.

Emerald Mound is an impressive single construct in Mississippi. It was active later than Cahokia, but was still an expression of the Mississippian culture.

The climbing people show this moundlet was of good size.

The climbing people show this moundlet was of good size.

Here is that moundlet from the other end of a plain.

Here is that moundlet from the other end of a plain.

That plain is revealed to be the top of Emerald Mound, which qualifies as “enormous.” It is second in size only to the largest of the Cahokia mounds.

That plain is revealed to be the top of Emerald Mound, which qualifies as “enormous.” It is second in size only to the largest of the Cahokia mounds.

By the time Europeans came along, there was only a diminished remnant of the Mississippian culture, the Natchez people. Their mounds were much less impressive.

This is Temple Mound, at the Natchez Grand Village.

This is Temple Mound, at the Natchez Grand Village.

All of this serves as a cautionary reminder that the North American continent cannot be regarded as undisturbed in its ecology. It has a human history, beginning with the killing off of the megafauna, which began influencing things long before the landscape settled out of its glacial disturbance.

Literature Review: The Aleut Story

by Carl Strang

As mentioned in yesterday’s post, I got to spend some time in the Aleutian Islands as a graduate student. I heard a few things about the Aleut people at the time, but a news review in Science last year provided the opportunity to learn more about this interesting chapter in the human story of our continent.

Balter, Michael. 2012. The peopling of the Aleutians. Science 335:158-161. This article reviewed recent and current research into Aleut archeology. Archeologists have found that the Aleuts spread into the islands from the Alaska Peninsula rather than from Siberia, and they did so in two waves. The Paleo-Aleuts had skeletal features with some European influence, a simpler social structure (for instance, houses had only one room), and a simpler economy (they ate mainly fish, seabirds and sea otters). They reached Adak Island in the middle of the chain by 7000 years ago (glacial remnants made living in the Aleutians impossible until 9000 years ago), and the western islands around 3500 years ago.

The Aleutian Islands have some dramatic scenery.

The Neo-Aleuts began to arrive 1000 years ago, and blended with rather than replaced the Paleo-Aleuts, with today’s people showing a ratio of about 2/3 to 1/3 Neo-Aleut to Paleo-Aleut genetics. The Neo-Aleuts brought innovations of multi-room houses, and preyed on larger sea mammals including seals, sea lions and Steller’s sea cows. The population was estimated at 16,000 in 1740, but Russian enslavement for fur harvesting knocked them down to about 1600. They increased after American acquisition of Alaska, but were removed from the Aleutians during WWII as it appeared that the war would endanger them. The naval base on Adak closed in the late 1990’s, some Aleuts have moved back there and to other islands in the chain, and culturally they have conserved some of the distinctions of different island populations despite the mixing imposed by the Russians.

The returning people found a mix of resources and wreckage left behind from the military chapter of Aleutian history.

Aleuts are closer to Siberians than to Yupiks (the nearest “Eskimos”) genetically, apparently having crossed the Bering Sea independently and remaining culturally distinct through their spread into the Aleutians. Though their facility with sea travel has been cited by some as evidence for a coastal spread southward of Native Americans in glacial times, others point out that the Aleuts came along much later.

Literature Review: Pleistocene

by Carl Strang

The following notes complete my review of last year’s scientific literature. These studies looked at the most recent epoch, the Pleistocene, and focus on the megafauna, the large mammals.

Mastodon fossil, an iconic megafaunal species

Edwards, Ceiridwen J., et al. Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline. Current Biology, 07 July 2011 DOI: 10.1016/j.cub.2011.05.058     As described in a ScienceDaily article. This new mitochondrial DNA study places the female ancestor of all current polar bears in Ireland 50,000 years ago, at the peak of the last ice age. Brown and polar bears once were both circumpolar, or nearly so, and the ebb and flow of the glaciers brought them in and out of contact, providing hybridization opportunities. The authors mention that this continues today, with the retreat of polar ice bringing the two species more into contact, and several recent hybrid individuals are known. The researchers indicate that this process needs to be taken into consideration both in understanding the nature of these species and in conservation planning.

Long, Charles A., and Christopher J. Yahnke. 2011. End of the Pleistocene: elk-moose (Cervalces) and caribou (Rangifer) in Wisconsin. J. Mammal. 92:1127-1135. They describe the northernmost caribou fossils found to date in Wisconsin, from Marathon County. The Cervalces (also known as stag moose) from the same site is the first for the state, and northernmost for the species. The study location was at the boundary between the glacier’s Green Bay Lobe and the driftless area. The age of the caribou antler is placed at 11,260-11,170 years ago. The elk-moose was from 12,920-12,790 years ago. The caribou probably was of the more southern woodland caribou species. The older elk-moose fossil was found in a sediment layer suggesting it lived close to the edge of the glacier, in more of a tundra environment.

Eline D. Lorenzen, et al. Species-specific responses of Late Quaternary megafauna to climate and humans. Nature, 2011; DOI: 10.1038/nature10574     As described in a ScienceDaily article. They looked at a range of genetic, archeological and other evidence, and found that the megafauna that went extinct and those that survived in the northern hemisphere represent a complex picture. All had survived previous glacial cycles by finding refugia in warm periods, with populations just large enough to continue. Some were able to do so again after the most recent glacial retreat, for instance caribou and musk oxen in the far north and bison in the North American plains, and survive to this day. Others did not, and in at least most of these cases humans are implicated, either by preventing retreat to refugia or by decimating the reduced populations.

Waters, Michael R., et al. 2011. Pre-Clovis mastodon hunting 13,800 years ago at the Manis site, Washington. Science 334:351-353. (also interpreted in a news article on p. 302 of the same issue). They found a spear point made of mastodon bone, imbedded in the rib of an adult male mastodon. It is dated to several hundred years before the Clovis culture. The location near the coast in Washington State is consistent with a coastal spread of people from Beringia, where bone spear points also were used. This also supports an extended period of megafauna hunting, further pointing toward human hunting as a factor in extinctions (a long period of hunting, even if it only removes animals slightly faster than they can reproduce, increases the importance of that mortality factor).

Lessons from Travels: Mayan Civilization

by Carl Strang

As I recall from elementary school history class many decades ago, we were given the impression that Europeans brought civilization to the New World. That may be true if “civilization” is equated with European culture (i.e., circular reasoning). Today I look at such things biologically, and long have regarded civilization as the evolution of any culture that creates the illusion of division between people and nature. In general that means the construction of an architecturally elaborated space in a part of the landscape that has been cleared of its wild vegetation. It also depends upon the previous establishment of agriculture (artificial selection of certain wild plants and animals to the point where they are domesticated), which allows people so to concentrate their populations. By that definition, there were many civilizations in North, Central and South America prior to the arrival of Europeans. Today I want to focus on vestiges of ancient Mayan civilization I saw in Central America.

This is the view from a tall Mayan building at Tikal, in Guatemala. Today the surrounding space is filled with forest. If it looks familiar, it may be because this spectacular scene was included in one of the Star Wars movies.

Over the years, many Mayan towns and cities have been discovered buried in the vegetation.

This building was uncovered at a smaller site in Belize.

By measures of architecture, agriculture, the technology required to shape and move masses of stone, and the social organization needed to accomplish these things, Mayans were thoroughly civilized.

This building alone, one of several enormous structures at Tikal, is a wonder. The climb those people are making is very steep and up huge steps clearly designed to inspire awe.

They had written language and mathematics as well.

Mayan writing, designed to last.

Recent research suggests that the drought which ended this civilization may not have been extreme. All it took was a reduction in summer rainstorms so that the reservoirs dried out. The intensive agriculture needed to support so many people in cities collapsed. Over time, a vast region that had been cleared for civilization was reclaimed by the forest. At least there were remnants of forest sufficient to do the reclaiming.

Do I need to state the lesson plainly? These people did not have an inferior or faulty civilization. In every significant respect it was the equivalent of ours. They no doubt assumed, as we do, that the Universe supported them and their way of living, and it would go on forever (or at least until 2012, small joke there). Their huge concentrated population was balanced upon the climatic conditions that supported their technology. As we can see, that balance was easily upset. They had removed their forests, which in part set up the drought, the climate change, which defeated them. Their descendants survived because they could fall back on an earlier, more dispersed way of living, and they had not completely trashed their soil and landscape. Their population was in the tens of thousands, rather than billions.

Some of the Lessons from Travels are chilling.

Similar Seedcases

by Carl Strang

Both the well-known common milkweed and the less familiar dogbane develop their seeds in similar pods. Most botanists place them in separate, if closely related plant families. In winter, with its parachute-bearing seeds scattered to the winds, common milkweed looks like this:

When flowering, it had the following appearance.

Dogbane’s flowers look a little different.

The flowers produce similar pods with similar seeds, but the pods are very long and narrow, resembling handlebar mustaches.

Stems of both these plants are the source of excellent fibers for making string and rope. Nets and other objects made with dogbane string are so resistant to decay that they sometimes are found in archeological sites. The plants themselves are poisonous, though some parts of milkweed plants can be made edible with the proper, several-step treatment.

Primary Succession

by Carl Strang

A few days ago I shared an account of a morning spent with botanist Wayne Lampa and restoration steward Frank Keller. As we searched for lichens on the north deck of the old friary, Wayne remarked at how its bricks were becoming obscured by the plant growth.

Brick cracks succession 2b

Mosses had become established in the spaces between the bricks, and had spread over the edges. Those mosses in turn had provided a substrate in which a number of vascular plants were growing.

Brick cracks succession 1b

The most spectacular of those that day were balsam ragworts.

Senecio 2b

Curly dock was another.

Curly dock 2b

This sequence of events is close to the ecological process of primary succession, in which life becomes established in stages on a new substrate that did not have life on it before. Wayne’s and Frank’s study of lichens, particularly those on the concrete and rocks, was in part an examination of the first stage of primary succession. Whether the friary deck counts as primary succession I would have to leave for a plant ecologist to say. There was a little soil between the bricks to provide a foundation for the mosses. Given time, the deck could be covered by a deeper and deeper layer of soil, ultimately with a forest growing over it, reminiscent of lost Mayan ruins in the jungles of Central America.

Fullersburg Archeology: A Mystery

by Carl Strang

 

It’s time to conclude my series on Fullersburg Forest Preserve history and archeology. Time to put on the pith helmet one last time and check out a mystery. And if you can cast light on it, I will appreciate the assist.

 

If you take the informal dirt trail clockwise around the edge of Butler Woods from Rainbow Bridge, it will take you to the Hairpin Turn.

 

fullersburg-place-names-map-north1

 

Shortly after you go around that turn you will see a branch of the trail heading right (east) and up the hill. At the top of the hill is a trench, dug no doubt for some agricultural purpose. It’s not a glacial feature.

 

Just below that trench is a trio of concrete structures whose function at present remains a mystery. These include a 25-foot-long, arc-shaped low wall built of 2’x2’ concrete blocks, one of which is being shifted as a large white oak grows in behind it.

 

fbw-mystery-wall

 

This arc’s concave side faces south, and in the focus of that arc 30 feet further south there is a bunker-like structure 8’ wide, 7’ deep, and 3’ tall, open on the south side with some dolomite flagstones stacked in the bottom, an old decaying piece of lumber on the ground, a few red bricks scattered on top, and an iron ring set in the center of the roof piece on its south edge.

 

fbw-mystery-bunker

 

This bunker is dug into the side of the hill. Brookfield Zoo educator Jim Ritt has made the interesting suggestion that the structure was designed for dynamite storage. Its orientation away from farm clearings and buildings to the north that show on the 1939 aerial photo is consistent with this hypothesis. Back, now, to the trail. On the north side of that trail, roughly in line with the center of the arc and the bunker and 10 feet north of the wall, the third structure is a 3’ circular piece of concrete with a rectangular slot through its top that is about the length and depth of one of the wall’s elements.

 

fbw-mystery-slotted-circle

 

The axis of that slot is in line with the bunker. These objects are within a string of older trees that are visible in the 1939 photo. Incidentally, piled in a refuse heap a short distance north of there, just south of the swamp and east of the Hairpin Turn, is a rusting tank of the sort used for heating oil in a home furnace, along with two rusted crushed objects which may be identical tanks, and a wheel still bearing its tire.

 

fbw-tanks-b

 

So that’s where I’ll end this topic, at least for Fullersburg. There are some other archeological features on that preserve I haven’t mentioned, but I’ll leave them, along with the ones I never found, for your own discovery.

Fullersburg Archeology: Old Building Foundations

by Carl Strang

 

Two old building foundations are waiting your discovery in northern Butler Woods. The informal dirt peripheral trail crosses one of these,

 

fbw-structure-13-b

 

very close to a roadside sign and boulder which indicate that this was where a hunt club paused before crossing 31st Street in the old days. I wonder if this building might have been a rest shelter for hunt participants. If not, it probably was a farm outbuilding.

 

The second foundation clearly was a home.

 

fbw-structure-14a-b

 

It is located near the 31st Street Stem trail, west of Butler Prairie. The stone boundary of a foundation flowerbed still can be seen. An old trail or drive extends south from the west edge of the house. That this area was agricultural is supported by the presence of drainage tiles in the Butler Prairie area. The north edge of the forested block southwest of this house still can be seen as a straight boundary between older trees, and younger ones that have grown up post-agriculture. Many years will pass before the influence of this stage of Fullersburg’s history disappears from the forest.

Fullersburg Archeology: Butler Woods Trails

by Carl Strang

 

In a series of earlier posts  I reviewed surviving ruins as well as structures still in use that were constructed by the Civilian Conservation Corps at Fullersburg Woods Forest Preserve. Now is a great time to explore the ruins of Fullersburg, with temperatures warmer and obstructing vegetation not yet in leaf. Today I want to look at some fading signs of events at this preserve that followed the Great Depression, focusing on Butler Woods. Here is a map with place names.

 

fullersburg-place-names-map-north

 

The improvements made by the CCC, plus the limited number of other preserves available at the time, drew crowds to Fullersburg Woods. It was too much of a good thing, and by the 1960’s Fullersburg was regarded as suffering from overuse. The boat house was closed, and that building was converted to the Visitor Center, which opened on May 2, 1973. The addition of other forest preserves eased the pressure, allowing Fullersburg to recover. In 1975, Butler Woods was added via a 30-acre donation by the Butler Company, plus a 40-acre purchase. The 31st Street Stem trail was constructed to connect York Road to 31st Street through the preserve. New trails were developed through the Butler Woods addition. Except for the main trail along Salt Creek and the 31st Street Stem, these have always been dirt paths and are no longer maintained. Most of them continue to be used enough by people and deer that they still can be followed easily. Some railroad-tie steps remain in place where the trail climbs the hill at the end of the Hairpin Turn, and a few unused ties still are piled below there. Slight alterations in the trail route have accumulated over the years, possibly originating when tree falls forced detours. In addition, a new route developed after the 1970s which skirts the northern edge of the preserve along 31st Street. The old trails east of the 31st Street Stem now are almost exclusively the province of deer.

 

One approach to finding the disused trails east of the 31st Street Stem is to make your way along the south boundary of Butler Prairie. Along the way you may see the drains at each end of the prairie, both eroded over time so they seldom will be reached by flood waters.

 

fbw-structure-2-b

 

Above the westernmost of these drains are concrete pieces that appear to be a corner and other bits of wall.

 

concrete-corner-oc08-2b

 

At the east end of the prairie, in addition to scattered pieces of brick from an earlier age, is one of the old trails, which still (in 2008) is fairly easy to follow southeast from there. Eventually that trail peters out into a deer trail that bends more straight east. With some effort you may be able to find one or both of the old human trails that descended to Salt Creek. These joined the trail you are on just after it curves east, with one essentially going straight south downhill, and the other angling more southwest. Both are marked by clear worn depressions, though fortunately neither has gullied. The more distinct one goes straight down hill. If you look carefully you can see the remains of timbers installed as steps or check dams. The most intact of these timbers is at the bottom of the old trail, which joins the main trail about 20 feet east of a bench.

 

fbw-structure-22b

 

If you choose to find this trail from this bottom end, note that there is a recent unofficial path angling down from the church parking lot. This joins the main trail at the same point. The historical trail heads straighter north, straighter uphill, and is less obvious. Look for that timber step. The place where the other branch of the historical trail joins the main trail at Salt Creek is obscure. To find it, follow the east bank of the little stream that passes under the main trail a short distance west of the same bench. This is the stream that originated at the westernmost of those two stranded storm drains. 10-20 yards from the main trail, look for the shallow depression marking where the historical trail angles NE up the hill.

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