Now it’s time to shed some light on the family of conifers found in our neck of the woods, namely species in the Pinacea, or pine family. Even those poor in botanical skills can recognize this family in Arizona, owing to the needle-shaped, evergreen leaves present on all of our Sky Island species—quite unlike the scale-like foliage found in the cypress family.
Despite this similarity in foliage, not all members of the pine family are actually pines. Also included are true firs, spruces, and Douglas firs.
Each of these species plays a crucial role in furnishing critical habitat for a wide range of wildlife. In addition to bolstering our local ecologies, they all add greatly to the beauty of a region that is, after all, largely treeless.
Pines (Pinus spp.) outnumber all other members of the pine family in Arizona combined. As a state we host ten species of pine, two spruces, two true firs, and one species of Douglas fir. Narrowing our scope to the Sky Islands, we encounter seven pines, one spruce, two true firs, and the Douglas fir. This is an impressive lineup in a part of the state far more renowned for its cacti than its conifers.
Among all of the tree species present in our region one would be hard pressed to point to a genus more important to wildlife. Perhaps the oaks with their acorns might put up a fight in this regard. Still, it’s hard to beat the combination of evergreen foliage, diversity of growth forms and high-quality food furnished by pine nuts.
Our shortest pine is the Mexican pinyon. Despite topping out at about 40 feet tall—relatively dwarfed by our taller local pines—this species produces the largest pine nuts. These are highly prized by Woodhouse’s scrub jay, Mexican jay, other birds, mice, cliff chipmunks, various tree squirrel species, black bears and humans, among others. Pinyon nut crops vary tremendously from year to year—a boom-and-bust cycle familiar to many aspects of our local ecologies. Pinyons rely mostly upon animals to disseminate their nuts.
Among the taller pine species residing in our higher elevations (where they benefit from greater amounts of precipitation) are widespread ponderosa pine, Apache pine, Chihuahuan pine, with its burnt bark countenance, and stately southwestern white pine, housing elongated cones. All produce pine nuts, albeit far smaller ones than those of pinyon species. These taller pines lean heavily on wind rather than wildlife to disperse their seeds. Nevertheless, the nuts of these species are also relished by a broad spectrum of wildlife.
Our Douglas firs (Psuedotsuga) are easy enough to distinguish from the pines, given that their smallish cones look as if a snake’s tongue is emanating from between its overlapping scales. Some specimens of this widespread western tree can attain behemoth proportions.
In our region that means perhaps 130 feet tall with a trunk diameter over five feet. In the Pacific Northwest, the same species rivals even redwoods in size. Here they grow only high up on mountains, as well as in some deep, cool canyons. The Cave Creek drainage in the Chiricahuas has Douglas firs and mesquite trees growing nearly cheek by jowl.
While cones persist on Douglas firs, they fall apart upon maturing on true firs (Abies), making the two difficult to confuse. Accentuating the differences of true fir cones from those of other local conifers is the fact that they stand upright upon their branches rather than hang down from them. Both white fir and, less commonly, subalpine fir grow on select taller mountains in our area.
Finally, we add our lone spruce species to the local conifer mix. The Sky Islands house the southernmost population of Engelmann spruce in the entire U.S.
All our larger conifers provide excellent nesting habitat to a wide range of bird species. Many others find food among the foliage of the trees. Vital habitat indeed.
Coming as no great surprise to most people will be the stark realities being imposed by climate change, both here and throughout our beleaguered planet. A warming/drying trend over recent decades has led to seemingly countless wildfires that have locally decimated our conifers. Perhaps many of the older/larger specimens we once had ,and still enjoy, germinated a few hundred years ago during the Little Ice Age, a period of cooler, wetter climate far more conducive to their reproduction.
We would do well to protect the good handful of tree species still clinging precariously to existence here, as they can easily vanish in a startlingly short period of time. “Evergreen” no more.
Vincent Pinto and his wife, Claudia, run RAVENS-WAY WILD JOURNEYS, their Nature Adventure & Conservation organization devoted to protecting and promoting the unique biodiversity of the Sky Islands region. RWWJ offers a wide variety of private, custom-made courses, birding & biodiversity tours. Visit ravensnatureschool.org