Photo-essay: The Rocky Mountain Juniper: A Special Breed

(all photos original except as otherwise notedshot with an iPhone camera in the foothills of the Sandia Mountains, bordering the east side of the City of Albuquerque, NM.)

A winter with almost no precipitation is more than enough reason to focus some adulation on the Western Rocky Mountain Juniper (Juniperus scopulorum), a perennial tree/bush that’s the major source of winter greenery in the high desert. Junipers are a particular blessing during drought winters like this one (2017–18), when there’s been almost no snow pack in the Southern Rockies at higher elevations (8000–11,000 ft [2440–3050 meters]). In the slightly lower-elevation foothills, where Junipers are prevalent, that means even less water. With such minimal water, Rocky Mountain Junipers can nevertheless photosynthesize all 12 months of the year; at intervals, very slowly. Slow and steady — they’re one of the tortoises of the evergreen world.

Juniperus is the ancient classical name for the old-world junipers; scopulorum refers to its usual habitat of rocky cliffs and hillsides.

Hiking in these high-desert areas in winter would be to encounter a rather grim landscape without the greenery provided by Junipers. The first photo shows a trail where in both foreground and background, most of the chlorophyll green is contained in smaller or larger plants, all of them J. scopulorum individuals, ranging from small trail-side bushes to much larger bushes and trees.

J. scopulorum trees/bushes along a trail in the foothills of the Sandia Mountains (trail elevation about 6000 ft. [1800 meters])

Range and Habitat

Junipers are ubiquitous, with 13 native species in North America (although only two species are native to Europe). With a large range, Rocky Mountain Junipers, J. scopulorum are found from the southwestern Canadian provinces, throughout the U.S. northwest and northern Rockies (Montana/Idaho/Wyoming/Western Dakotas), and south through Nevada, Utah, and Colorado, into the southwestern mountains of New Mexico and Arizona, with overlap to the east in several other states (for example the hills and mountains of West Texas).

In warmer high-desert climates like New Mexico, Rocky Mountain Junipers favor the north faces of hills and hillocks (mounds), with the hottest-in-summer southern faces of these elevations often devoid of Junipers (next two images), and instead more commonly populated by cacti and creosote.

North face of a Juniper-populated mound
Portion of south face of same mound, devoid of Junipers

Like all Junipers, but also as suggested by its common name, J. scopulorum prefers a rocky-and-sandy soil, favoring altitudes of 5000–8000 feet (1500–2400 meters).

Pinon and Lodgepole pines are predominant at higher altitudes. Unlike eastern North American mountains, where the limiting parameter for plant growth at higher altitudes is low temperature, more-limiting as one goes to higher altitudes (Mt. Washington in New Hampshire is exemplary), it’s quite obviously, water that limits what plants can grow in the western high desert, with water becoming more available (less limiting) as one goes to higher altitudes, so that less-drought-tolerant non-Juniper conifers (pines and some spruce) predominate at higher altitudes. The next photo shows a hillside with J. scopulorum populating the foreground and the adjacent hillside (red arrows), with a taller pine-covered (green arrow) mountain behind and one of the high peaks of the Sandias (dark blue arrow) in the background, This winter, the high peaks (above 9000 ft. [2700 m] altitude have been the only places where snowfall has accumulated in large enough amounts to persist for more than a few days. For several years, the mountain southwest has experienced higher-than-average winter temperatures, undoubtedly at least in part a manifestation of climate change. The ultimate threat, as always in the American Southwest, is drought.

Comparison of evergreens at different high-desert altitudes

Old Souls: Slow-growth

This Juniper bush, about 1.5 meters tall by 1.5 meter broad (5 ft. x 5 ft. — the hiking pole at its base is about a meter in length) has likely already lived numerous decades. It’s probably as old or perhaps even slightly older than my geriatric self, but it’s still a relatively young bush by Juniper standards. Although they’re capable of photosynthesis, and therefore growth for 365 days per year, growth is nonetheless quite slow because of the limited availability of water and some nutrients in sandy-rocky-clay desert soil. Water scarcity limits the plant’s ability to conduct all aspects of its metabolism, including the synthesis of the light-harvesting pigment chlorophyll and the construction of its molecularly elaborate enclosure, the biological solar collector used by the cells of all higher plants, the chloroplast. Chloroplast solar collectors have been designed by evolution to maximize the number of photons of light whose energy can be transformed to so-called excitons of chemical energy (whose more detailed discussion is beyond our scope).

The following large quite beautiful tree, perhaps 5 meters (16.5 ft.) tall by 7 or 8 meters (25 ft.) wide would easily be several hundred years old. (Blue arrow points to hiking pole of about one meter in length, orange arrow to moist soil at the tree’s base, subsequent to a rare precipitation event.) Junipers are known to live 800 years, perhaps even longer.

Large Juniper tree, easily several centuries in age (blue arrow indicates 1-m [3.3-ft.] hiking pole)

Intelligent Organisms: Large and small adaptations

Scaled Leaves Limit Water Loss A close look at Juniper needles (leaves) reveals that they are composed of small overlapping triangular scales or tiny plates a couple of millimeters in size. The scales are sutured together with lipid waxy substances (whitish lines between the scales), which significantly limit the loss of water vapor (transpiration). This is a key factor for all plant leaves, but is especially critical for desert plants. This is one of many adaptations for stringently limiting water-vapor loss. Small yellow arrows point to individual scales on various needles. Each scale (yellow arrows) is composed of thousands of individual photosynthetic (chloroplast solar-collector-containing) plant cells.

Tiny green scales (yellow arrows) of which Juniper needles are constructed

Cycling solar collectors

Each of the thousands of plant cells within a triangular scale will behave intelligently with respect to collecting sunlight for photosynthesis. In the photo above, taken after moderate precipitation evidenced by the next photo of a melting snow patch yielding soil moisture, the needles are mostly vivid green, indicating that the pigment chlorophyll is plentiful and therefore that the chloroplast solar collectors are likewise probably plentiful in leaf cells, allowing the tree to optimally use sunlight to photosynthesize. In low-water conditions, the needles turn a mix of green and brown, the latter color likely a mix of carotenoid pigments that are always present as auxiliary solar collectors, but which are shielded by green chlorophyll in a tree that’s healthy and happily water supplied.

Since chloroplast solar collectors are energetically expensive to create and maintain, think about each leaf cell controlling the number and density of its solar collectors at any time, based upon its water and nutrient status. Availability of sunlight is not much of a factor influencing the Juniper’s regulation of its solar collectors because in the high New Mexican desert, the sun is virtually ubiquitous, shining brightly over 300 days per year. But low or no water generally means less-vivid green, higher water generally more-vivid green, indicating, at the level of single plant cells, a cycling of chlorophyll and solar collectors depending on water conditions.

One good rain or snowfall can do the trick, leaving patches of gradually melting snow that slowly soak into the soil and evidenced by trails that show damp soil beneath their sandy surfaces.

Juniper Berries: Gin, Skin, and Aboriginals

Junipers are diecious (separate male and female plants), and the bluish berries on female plants are actually the fully mature cones. The following two images show maturing female cones that have not yet become fully mature berries; semi-transparent cone scales can be discerned (of a size similar to leaf scales) in the second image.

Branch of female J. scopulorum showing purplish maturing cones
Closeup of maturing female cones (eventual Juniper berries) Note that the cone scales are structurally similar to leaf scales, but are no longer photosynthetic (green)

J. californicus and a few other species, including J. scopulorum offer edible berries, but the berries of a few species are poisonous. Interested readers are advised to check the species in their area before harvesting berries. Juniper-berry teas are available mostly through specialty and online retailers.

Health Benefits of Juniper Berries

Benefits of Juniper berries include anti-oxidant activity, important for overall metabolic health, usefulness as an antiseptic (anti-bacterial), as well as demonstrating effects on promoting healthier skin, possibly connected to their antiseptic and anti-oxidant actions. Juniper tea is also a diuretic and in that action may have even had a role in controlling high blood pressure among aboriginal peoples.

Native Americans used the berry juice for skin inflammation and ate berries or perhaps brewed a tea for infectious-disease amelioration. Berry juice has been shown to be effective against Staph bacteria a major provocateur of skin inflammation such as acne. It’s also been shown that Junipers contain deoxypodophylllotoxin (DPT), an anti-viral compound effective against Influenza (Flu) and Herpes viruses, and that may have helped limit other infectious diseases among Native Americans in collaboration with their immune system responses; except, of course, those such as Smallpox to which North Americans had no prior exposure and hence no innate immune memory.

With 13 Juniper species native to North America it’s not surprising that different native tribes found a diversity of uses for Junipers. For example, Florida’s Seminoles used eastern Junipers (incorrectly called the Eastern Red Cedar) to treat colds, inflamed joints, fever, headache, and diarrhea. In addition to anti-oxidants, and anti-virals, the berries also contain vitamin C. A bird called the Cedar Waxwing is named for its habitat, the Eastern Red Cedar, which is actually a Juniper, Juniperus virginiana, formerly mis-construed as a cedar. A major part of the bird’s diet is Juniper berries.

Cedar Waxwing, © Kent Mason

Juniper Berries in Today’s Foods

Modern foodies make a balsamic vinegar from the berries, which is not surprising given that berries of the common juniper, J. communis is used as part of the piney flavoring in gin. Juniper berries are also quite important in German cultural cuisine, with sauerbraten and sauerkraut including berry juice as usual constituents.

Male cones (red arrows in the next photo) are smaller and although also encased in tiny scales, lack the blue-purple color of female cones. When mature, they will readily yield scads of yellowish pollen, the nasal-irritation-provoking nemesis of many desert dwellers. Contrary to common belief, this isn’t a classic allergy like a peanut or bee sting-allergy, which require only a tiny exposure to provoke symptoms, but rather another type that’s dependent on exposure to high doses of the allergen, in this case, massive quantities of Juniper pollen in the air.

Male cones (red arrows)

Habitat for Other Species

Beyond simply their potential dietary benefits to humans, birds, and other animals, Junipers also benefit their immediate ecology J.scopulorum roots bind the easily dislodged sandy soil in their habitat. And their branches, particularly the network of dead branches often found in the tree’s interior accommodate birds and small mammals offering both nesting sites and predator shielding. The next image shows a portion of a Juniper’s inner branching (“inner” meaning closer to its main trunk at the photo’s far left [red star *). Some branches bear needles, others, bare of needles may be dead but retained unless an external event breaks them off. A branch with even one needle cluster is alive because it’s receiving water from the trunk and roots and returning sugars (sap) to them.

Bird and small mammal habitat in a Juniper’s interior branches (red star indicates tree’s main trunk)

Limited Death: Older Half Dies-back So Newer Half Can Survive

One of the ways that some Junipers may achieve increased longevity is to die-back part of themselves in order to nurture a newer or healthier part. The Juniper in the next photo appears to exhibit this strategy, the approximately half at the left side of the image far less well-endowed with needles and enduring more bare and some deceased branches. In contrast, the half at the right side of the image is far more well-endowed with needles and is therefore doing the lion’s share of the photosynthesis for the tree. It’s my intention to follow this Juniper over the next few years, as climate change is likely to give us even less of a genuine winter in Albuquerque and the Sandia Mountains.

Left half of this old J. scopulorum is possibly dying-back, while portion at right is fully-needled

Biology and Geology Cooperate

I’m going to close with a favorite image — of this same half-diminishing/half-thriving Juniper, showing how it initially grew hugging an adjacent giant boulder.

Boulder-hugging Juniper , front view of previous image

It’s a rather symbolic image — Mother Earth, Mother GAIA integrates all things: biological, geological, atmospheric chemistry, and otherwise into its remarkably complex system. It’s an astonishingly beautiful system, a natural cathedral surely worth preserving, not only for ourselves, but for other noble, intelligent species like the Junipers.

Ideas about bio-medicine and environmentalism. Vin holds a PhD from Columbia U. in Cell and Molecular Biology & worked as a college prof. & science writer.