28 May 2018

Canyon de Chelly


Sculpted sandstone at Canyon de Chelly
National Monument, Arizona.
Canyon de Chelly, a moderate-sized national monument in the northeast corner of Arizona, was not one of my planned destinations through the Southwest this spring, but it made sense to stop given my route from New Mexico to southern Utah. It was a brief stop, but a treat!

The monument is within the Navajo Nation, a large Native American reservation that stretches from the Grand Canyon to the Four Corners region. The Tribe and the Park Service have joint management responsibility for the monument, and that specific arrangement is manifest in some of the not-so-ordinary arrangements for an NPS site (more on that in a bit).

The monument is accessible from the small town of Chinle on US route 191 and this is essentially where the canyon begins. It deepens to the east, branching into several canyons. There are north and south rim drives but I only had time to observe the canyon from the south rim and make a few stops before heading to southern Utah.


Maps of Canyon de Chelly National Monument. At left: Map of Canyon de Chelly's location in northeast Arizona in the Four Corners region by Shannon1, cropped and arrow added to original map, CC BY-SA 4.0 license. At right: General map of the monument by the National Park Service, public domain.

At the end of the south rim road is a viewpoint of Spider Rock, a picturesque pair of red rock spires that tower hundreds of feet above the canyon floor. At the lookout point there are some wonderful panoramas of the winding canyon and vegetation growing below.

Spider Rock, Canyon de Chelly National Monument.

At only one location in the monument are visitors allowed to walk unguided into the canyon, and that is the short trail to White House. The trail begins on the mesa and then descends pretty steeply into the canyon. Several plots of land are visible on the canyon floor – these farmed areas are privately owned by members of the Navajo Nation.

Once one has descended several hundred feet into the canyon, it is only a short distance more to the White House, which are ancient ruins set in the base of a towering rock cliff. The ruins are similar to those found at Mesa Verde and Bandelier and were constructed centuries before the Navajo people entered the area. In fact, the Canyon has apparently been inhabited by humans for some 5000 years.

Two views of the White House at Canyon de Chelly. The upper level has original remains of Ancient Puebloan dwellings while the structures on the canyon floor below have apparently been restored recently.

Near the White House, several Navajo artisans had set up tables on the dusty canyon floor and were selling jewelry and pottery. This vending was apparently one of the unique arrangements between the Park Service and the Tribe. The other is that guided tours throughout other areas of the canyon are offered by Navajo Nation members. I spoke with one artisan for a bit and purchased a small seed pot from her which was engraved with her name on the bottom and “CDC”, the abbreviation for the monument. She resided in Chinle but her family owned a plot of land in the canyon.    

Some petroglyphs near the White House.


19 May 2018

Carlsbad Caverns backcountry


One of the best ways to experience the National Parks is in the backcountry, off the beaten path. There is a time and place for the more curated nature experience, the “park” component of the National Park System, and frankly is the only way of engaging with some of the most iconic geologic features of the parks. At Carlsbad Caverns for example, it seems unlikely one could ever tour the caverns without running into a fair number of people. Similarly, if the grandeur of Yosemite Valley is to be experienced, it usually has to be shared with the crowds that assemble beneath its most iconic features.

Rattlesnake Canyon, Carlsbad Caverns National Park, April 2018.

Yet the backcountry of many national parks offers another treasure: solitude. It is a commodity in increasingly short supply in today’s noisy and hyperactive world, and one that seems to be vastly underappreciated given how few park visitors are willing to get off the paved trails and away from the visitor centers.

During my spring trip through the Southwest I was fortunate to backcountry camp at White Sands and Carlsbad Caverns in New Mexico, and later on, at Bryce Canyon in southern Utah. The latter two parks offered an opportunity for a night of complete solitude where I was likely the only person out in the wilderness within miles. At Carlsbad Cavers I hiked into Rattlesnake Canyon from a dirt loop road winds through Chihuahuan Desert habitat west of the entrance to the caverns.

Unopened flowers of ocotillo, Carlsbad Caverns National Park, April 2018.


Texas walnut growing in a dry wash.
The region around Rattlesnake Canyon is a collection of rounded mesas dissected by winding canyons, not unlike the topography I remember from the southern part of Mesa Verde National Park. Ocotillo, prickly pear cacti, and shrubs grew throughout the dry slopes. It wasn’t as colorful as the Sonoran Desert vegetation I observed just days before in Saguaro National Park, but the blooming ocotillo added some vibrant color to the desert scrub.

At the bottom of the valleys were water would be more frequently available (no water was to be seen at all during my visit) small trees – Texas walnut (Juglans microcarpa) grew. One of the more interesting plants to catch my attention, growing throughout the park, was “sotol”, an interesting yet forbidding plant that grows in basal rosettes of pointed leaves like some species of Yucca. The long slender leaves bear sharp hooks which are very adept at catching clothes.

Sotol is formally Dasilirion wheeleri, and a member of the Asparagaceae family. Yucca, which it resembles in overall growth form is actually in a different plant family, the Agavaceae. Interestingly sotol has been used to produce both beer-like and distilled alcoholic drinks. Fibers of the plant were also useful to the Ancient Puebloan people of the Chihuahuan Desert.

Sotol, Carlsbad Caverns NP, April 2018.
Barbary sheep near the entrance to Carlsbad Caverns National Park. This species is non-native
and was introduced into the area from northern Africa.


03 May 2018

Carlsbad Caverns

I’ve been in two very spectacular caves before in the western US: Lehman Cave at Great Basin National Park, and Oregon Caves National Monument. Both had ornate features of various shapes such as stalactites and drapery, precipitated inside the caves slowly over countless years. However Carlsbad Caverns, by its palatial size and seemingly endless collection of geological treasures, is in a league of its own. 

The extensive caverns hundreds of feet below the surface are the main attraction of this smaller national park in southern New Mexico. The park rests on the rim of an ancient limestone reef from the Permian Era (251-299 mya) that once encircled a shallow sea in southern New Mexico and northern Texas. (Guadalupe Mountains National Park in northwest Texas is part of this same reef system.) That limestone setting provided the geologic and chemical ingredients for cave formation.


Map of the ancient Permian limestone reef system that includes present day Carlsbad Caverns at left (source) and the natural entrance to the caverns at right.

I took the self-guided tour to view the publicly-accessible caverns, entering at the “natural entrance” and spent over three hours underground, amazed at the size, variety, and sheer number of formations. These formations included stalactites, stalagmites, columns, drapery, and other features, each given different names. 

Stalactites and stalagmites.

The “Big Room” is immense and itself can take well over an hour to view at a leisurely pace. There were several pools underground too and I was particularly drawn to these including one called “Mirror Lake”. Drops of water falling from above kept sending ripples through the pool. Of course naturally all of these features would be hidden to the human eye in complete darkness, but the Park Service carefully uses dim lights throughout the cave system to highlight features.

Features in the Big Room.

The main caverns are apparently only one of over a hundred caves that have been discovered so far in Carlsbad Caverns National Park. Discovery and mapping of caves continues. There is more to the park than the caverns themselves – as amazing as they are – and in the next blog post I’ll feature some of what I observed while backpacking into the park’s wilderness.


This large column has been named "Rock of Ages".

Other types of formations in the caverns. At right is a formation termed "popcorn", although this type more reminds me of a coral reef.

Formations reflected in the water at "Mirror Lake".
Another pool with formations. The faint green color is due to algae, which apparently will grow eventually hundreds of feet below ground if a dim light source is available.
An area termed the "Boneyard" by earlier explorers.

A ladder from earlier exploration in the 1920s (left) and a view of Lower Cave from the main caverns (right).
More stalactites.


Perhaps some 800 feet directly below the Visitor's Center there is almost an underground city where there are bathrooms, vendors and this mail drop. Elevators lead to the surface. Though I walked in via the natural entrance gradually descending into the caves, I took an elevator up (here photographed at 250 ft below ground).

29 April 2018

Brilliant White Sands

White Sands National Monument, New Mexico.

White Sands National Monument in southern New Mexico was stunning and exceeded my expectations. It will undoubtedly be one of the highlights of my trip through the Southwest this spring, made so in large measure because I was able to camp in the backcountry overnight.

The dunes are a brilliant white color due to being composed of gypsum (selenite) sand. They are remarkably cool to the touch, which is counter-intuitive for anyone who has spent time on a sandy beach in the warm sun. Because the sand was so cool and soft I was able to do some hiking in bare feet. The mineral composition of the sand (selenite is a hydrated mineral) and the relatively high water table in the dunes apparently help keep it cool.

The dunes are extensive, covering close to 300 square miles in a valley east of the San Andreas Mountains in southern New Mexico. A US military missile testing range is the Monument’s neighbor on three of its four sides, and sometimes the Monument closes because of missile activity.

Like coastal beach dunes, some of the gypsum dunes at White Sands had a modest cover of vegetation, while others were barren. Plants were more apt to be found in flat interdune areas that may provide longer-term stability from the vagaries of shifting sand. The most attractive flowering plant was sand verbena, with hemispherical clusters of light purple flowers. The only animal life I really saw was two species of beetles, though the Park Service made a point to illustrate that populations of animals (mammals, reptiles) inhabiting the dunes had adapted to become lighter in color than nearby populations which live in habitats with darker substrates.

Some dune vegetation, including a Yucca (or similar species), small trees that may be cottonwoods (Populus), and purple-flowered sand verbena.

 
Dune beetles.
Sunset over the dunes.
White Sands is a photographer’s dream, at least for the style of photography I am interested in. From the macro to landscape scales there were alluring subjects, curves, and shadows all around. I found the most compelling time for photography to be perhaps an hour or two before sunset and an hour or two after sunrise. During this period when the sun was low on the horizon, it cast beautiful shadows over the dunes and seemed to provide an ideal level of contrast. The white sand in the shadows in the early morning often appeared purple to me.

One feature of the dunes that I found particularly attractive was the parallel ripples, typically no more than a few centimeters in height over the dune surface. There are analogous undulations in coastal sand caused by water, and the ripples in the middle of this desert brought to mind the fact that air (wind) is like a fluid, acting to shape the substrate below it by its direction and strength of flow.

White Sands is certainly a park I would visit again, hopefully in the same fashion as this trip: sleeping under the moon and stars in a dunefield of sublime beauty.

Animal tracks.

Different ripple patterns on the surface of the dunes.

Shadows cast at a dune crest.
An interdune area with rougher texture, I suppose composed of selenite crystals.
Looking south over the dune field with the early morning sun casting shadows to the west.

My campsite and hiking barefoot in the dunes.


26 April 2018

Quitobaquito


Along the US-Mexico border, about 15 miles west of the border crossing between Lukeville, Arizona and Sonoyta, Mexico is the small oasis of Quitobaquito in Organ Pipe Cactus National Monument. The shortest route to the site is a dirt road that, for much of its length, parallels the international border. In fact, in places it is no more than 20 meters from the metal fence on the US side, a barrier less formidable than many backyard fences. The saguaros and desert scrub take no notice of the artificial line in the sand so important to humans.

At Quitobaquito, perhaps a half kilometer north of the border, a tiny creeklet finds its origin in a spring that itself seems to just emerge from the base of a small non-descript slope of dry Sonoran Desert soil. The Park Service has lined the creeklet with concrete, no doubt to preserve the integrity of the waterway, because so minute is the flow that it seems like the desert dust could consume the trickle of water with no effort. As I walked along the creeklet, looking for its source, I could see signs of researcher presence – a short submerged PVC tube that I’m guessing houses a temperature sensor or other device, and some red plates underwater about which I cannot surmise their purpose.

Arriving at Quitobaquito (left) and some saguaro cacti near the oasis (right).

The creeklet ends in a rather large shallow pond to the south which is encircled by a narrow but dense band of sedges (just like Schoenoplectus americanus of west coast wetlands, though I’m not positive it is the same species). It looked like there was widgeon grass (Ruppia) in the water. The pond and creeklet were lined with colorful flowering species that I had not seen elsewhere in the Monument.

The pond at Quitobaquito. Sedges line the edge of the pond.

Why the effort to protect flow in the creeklet? This little oasis is home to an endangered fish species, the Quitobaquito pupfish (Cyprinodon eremus). I saw quite a few fish in the creeklet that led to the pond. The species is dimorphic in color – larger blue fish are reproductively mature males and females and immature males are smaller and light grey-brown, blending in well with the substrate. Incredibly these pupfish can tolerate high salinity, very high temperatures, and low oxygen conditions. The fish I observed were skittish and apparently territorial, chasing one another in short bursts of activity.

Quitobaquito pupfish. A arrow points to the female or immature male at left since these fish
blend in much better with the mud than the blue reproductive males.

Flowering plants near the pond: Heliotropium curassavicum (left) and Funastrum cynanchoides (right).

References

Reistad, A. 2012. Pupfish. In: National border, national park: A history of Organ Pipe Cactus National Monument, at: https://organpipehistory.com/orpi-a-z/pupfish/

Spellenberg R. 2012. Sonoran Desert Wildflowers. 2nd ed. Falcon Guides, Guiford, MT.

Flowering plants near the creeklet: Anemopsis californica (left) and unknown pink-flowered species (right).


25 April 2018

Arizona cacti


Heading east from San Diego I descended into the hot Imperial Valley and the Sonoran Desert. Ocotillos appeared signaling entry into this desert province. After a relatively cool spring in northern California, I wasn’t quite ready to be thrust into summer temperatures. My first major destination was Organ Pipe Cactus National Monument, just north of the Arizona-Mexico border. It lies right in the heart of the Sonoran Desert.

Organ Pipe and other cacti at Alamo Canyon.


Night sky at Organ Pipe Cactus National Monument.
I first visited Organ Pipe 20 years ago, when with a class of UC Santa Cruz students we descended on northern Mexico to study the ecology of the Gulf of California. The road to Sonoyta, Mexico passes bisects the monument. I arrived after dark, and turned up a dirt road to a small campsite at the head of Alamo Canyon. It was a warm evening. I stayed up for some time photographing landscapes dominated by Saguaro cacti. A half moon shone brightly in the sky above but was gone by 4 AM when I awoke again to photograph stars and the Milky Way.

With the new day, the diversity of cacti was evident from the start. Saguaros were very common, and organ pipe cacti became more common as I made my way up the valley for a morning hike. There were menacing cholla cacti, with their beautiful golden spines covering plants like a blanket. I also recognized the prickly pear cactus, Opuntia.

The organ pipe cactus (Stenocereus thurberi) is a collection of rather large stems, emerging from a common base. The namesake of the monument, the species is more common in Mexico than in the US and has a limited presence here due to its intolerance of frost. Flowers apparently only open during the night and are primary pollinated by bats.

Saguaros (Carnegiea gigantea) were actually very common at Organ Pipe Cactus NM, growing in most regions of the monument that I observed. However, there is a whole national park named in honor of this species, and that was my next destination. Bisected by the city of Tuscon, Saguaro National Park comprises two units east and west of the city. I briefly visited some of both, catching the sunset at the west unit and doing some morning hiking at the east unit.

Saguaro cacti. Left: spines (which are actually modified leaves on cacti) on a plant at Saguaro NP. Right: An open flower on a plant at Organ Pipe Cactus NM.


The morning of my hike started off warm. I began at a trailhead at Loma Verde and hiked about 2 miles into the Saguaro Wilderness along the Squeeze Pen and Carillo trails. Saguaro, barrel cacti, and Opuntia were common. Mesquite, palo verde (literally, “green stick”), and other trees and shrubs were also abundant in the area. At Wildhorse Canyon I found pools of water remaining in a wash.

Flowering cholla cacti at Saguaro NP. At left is the pencil cholla, Cylindropuntia arbuscula.


Though not a cactus, ocotillos were common at both Organ Pipe Cactus and Saguaro NP and were frequently in bloom, their bright red flowers adding color to the landscape. At Saguaro I saw many ocotillos with leaves (some green, some senescing), a sight that may not be particularly common since these plants readily shed their leaves during times when water is scarce. It is a true deciduous desert species.

Ocotillos. Left: With leaves at Saguaro NP. Right: Hummingbird visiting flowers at Organ Pipe Cactus NM.

Wildlife was fairly common at both of these desert parks. I saw coyotes (Organ Pipe), a Gila Monster (Saguaro), a hummingbird (Organ Pipe) and other birds, a deer (Saguaro), Desert pupfish (Organ Pipe), and lots of lizards (both parks).

Barrel cactus, Ferrocactus, at Organ Pipe Cactus NM.

Chainfruit cholla cactus, Cylindropuntia fulgida, at Organ Pipe Cactus NM.

An organ pipe cactus near the US/Mexico border that is half skeleton at this point.

Prickly pear, barrel cactus, and saguaros at Saguaro NP.

Sunset with Saguaro cacti and ocotillo at Saguaro NP.




21 April 2018

California's marine biogeographic break

Felimeda macfarlandi, a chromodorid nudibranch at Cambria.

This month I’m repeating my spring road trip through the southwest, but oppostite of my general course last year, I’m first heading down the California coast. My focus is on marine life for a few days and then I head to the deserts and mountain ranges inland. Cambria was my first stop on Thursday morning on the central coast just south of Big Sur.

At Cambria, fleshy red seaweeds, surfgrass, kelps, and invertebrates filled out the rocky sandstone boulders and bedrock. I again saw a healthy population of the rockweed Pelvetiopsis hybrida, a seaweed I first encountered and wrote about last year. There were adorable small sporophytes of bull kelp in a handful of small patches in the low intertidal. One new find was a beautiful purple chromodorid nudibranch, gliding among leafy red algae.

Young sporophytes of Nereocystis luetkeana (bull kelp)
in the low intertidal at Cambria. Egregia menziesii is in
the background.






Friday morning I was at the Palos Verdes Peninsula in Los Angeles. Remarkably I have never been tidepooling in LA County despite growing up in the region and attending graduate school in San Diego. Pt. Fermin was my planned destination, but when I arrived there in the morning, all access was officially blocked off. Skirting around a barrier would have been no problem, but it didn’t seem advisable. Instead I drove a little farther north to White Pt.

Relatively strong surf pounded some high relief rocks in the intertidal just off the southern parking lot. I explored a section of coastline south of there, almost to White Pt. itself. The site was comprised of sandstone benches, boulders, and cobbles, a drab yellow color.

The changed character of the biota between central California and Los Angeles was immediately evident. I was struck with the incredible abundance of barnacles in the upper intertidal at White Pt. – a desert as far as macroalgae were concerned. Red fleshy seaweeds were essentially non-existent, and the large seaweeds (a few species of kelps and large brown algae) were generally limited to the low intertidal zone.

I had crossed a well-known biogeographic barrier by entering southern California, and the marine flora in particular indicated this dramatic change in biotic composition. Point Conception north of Santa Barbara is often regarded as the break; this is where the mainly north-south coastline of northern and central California bends toward the east to form the southern California Bight. North of Point Conception, water temperatures are cooler and there are pockets of coastal upwelling that bring nutrient-rich cool water to shallow depths for photosynthetic organisms to enjoy. The north-to-south California Current dominates the near-shore. South of the point, waters are warmer and the south-to-north Davidson Current is present. Hot and dry Santa Ana winds that blow from the northeast can bake the southern California coast.

A wave crashing into sandstone benches just north of White Pt., Los Angeles Co.


A cowrie at White Pt.
Desiccation stress, always a concern for aquatic organisms which are periodically exposed to air, may be more intense in southern California than in more northerly parts of the state. More intense sun, less rainfall, and warmer temperatures in southern California probably exacerbate desiccation stress in southern California.

I found the abundance of small barnacles in the high intertidal curious. These organisms must be hardy against desiccation – they are exposed to air most of the time after all – but I wonder how being clamped tightly shut most of the time affects their ability to capture food. They must open up and sweep the water in order to catch food particles.

Except for the low intertidal which is submerged often, tidepools were the other microhabitat at White Pt. where larger seaweeds were likely to be seen. Relative to the central coast, however, these were not particularly large, consisting of branching coralline algae, Gelidiales, and others. Small fish darted to hiding spots when they sensed me nearby.

Common low intertidal kelps north and south of Pt. Conception. Left: Laminaria setchellii at Cambria. Right: Eisenia arborea at White Pt.

One of the interesting kelps of southern California that is not seen farther north is Eisenia arborea. Its species name suggests “tree”, and that is not an inaccurate moniker. Eisenia is a small kelp species, born on a stiff stipe from which two sets of blades droop down in a sort of disheveled brown mess. At White Pt. it was almost exclusively in the low intertidal, with some stragglers a little higher up where pools were present. Eisenia also occurs in Japan. In central and northern California Laminaria setchellii takes its place in both overall form (though it is not such a mess) and in ecological niche. I’m curious to know if these species overlap in distribution at all, or where one begins exactly and the other ends. Some exploration of Santa Barbara and the northern Channel Islands holds the answer to that question I think.

Juvenile spiny lobster (Panulirus interruptus) in a tide
pool at La Jolla. It's carapace was about 3-4 cm long.
Today I was in La Jolla. The flora was different yet again, but more similar in overall growth form to White Pt. than Cambria. Eisenia was present, but so too was a small kelp, Laminaria farlowii, that I didn’t see in Los Angeles. These plants are simple ruffled blades, aggregating or growing as singlets in the low intertidal. La Jolla also had a remarkable contingent of brown seaweeds of the order Dictyotales. This group tends to favor tropical and subtropical regions globally.

At La Jolla I explored the area around Nicholson Pt., a series of sandstone benches between the posh homes and the Pacific. Ravines, and even an arch, were cut into the sandstone. In the mid and high intertidal were also pools of various depth and diameter – all providing a variety of microhabitats for marine organisms. The beautiful marine plants notwithstanding, today’s best find was probably a tiny lobster in the warm water of a pool in the mid-intertidal! I’m tempted to tidepool once more tomorrow morning, though I originally planned to leave early for Arizona. We shall see!


Zonaria farlowii (Dictyotales) was very common in low elevation
sandy tide pools at Nicholson Pt., La Jolla. This species grows in
elegant rosettes.