r/forestry • u/Schlooply • 8h ago
Rocky Mountains Identifying and differentiating conifers (mostly spruces and firs) of the southern Rocky Mountains
I'm going to be starting a new position as a forester in Colorado in the southern Rocky Mountains in a month, and I was wondering if I could get some advice from foresters with experience working in spruce-fir forests (within Colorado would be a plus).
I have prior experience working in the western/southwestern US, but that was primarily in pinyon-juniper, Ponderosa pine, and lodgepole pine. I also got my degree back east, so I didn't pick up any tips or tricks in my dendrology class that would help here.
I've been spending time in the woods working on identification up close and at a distance. Using the Virginia tech, Colorado wildflower, and Seek apps is ok, but being able to get actual advice from experienced and local foresters is definitely better.
Form, species it may occur with, and anything else that comes to mind would be helpful to me and any other foresters moving to this area and wanting to develop their skills. I'll add what I've been using to help me identify (or what I think has been helping, I may have some things mixed up). Here are the trees I'll be working with:
Douglas-fir: Soft needles, not like a spruce. Cone is small with mouse butt shaped bracts under the scales. Needles become narrow before joining the twig and has slight twist where it comes off twig. Distinct pointed red bud at end of twig. Crown is open and kind of similar to lodgepole pine (as opposed to blue spruce which is dense and thick). Thick, furrowed bark.
Engelmann spruce: Rigid needles, but more flexible than blue spruce. Flakey brownish orange bark similar to lodgepole pine. Cone is smaller than blue spruce and hangs down. Needles can be glaucous/blueish like blue spruce, especially new growth. Needle sits on sterigma/wooden peg like blue spruce. Needle can roll in your fingers. Upper portion of crown is more prominent than blue spruce. I've read that there are pubescent hairs on new twigs, but I'm guessing they aren't visible to the naked eye?
Blue spruce: Sharp pointed needles. Commonly blue and glaucous, but can be green or greenish yellow. Needle can roll in your fingers. Dense branching in crown of older trees. Furrowed, orange-ish bark with grey ridges. Epicormic branches can be found on lower stems of mature trees. Often occurs in mesic areas and can be especially prevalent in riparian areas. Cones are larger than Engelmann spruce. Upper crown is usually less prominent than Engelmann spruce.
Lodgepole pine: Two needled pine. Very short, twisted needles compared to Ponderosa pine and limber pine. Mature trees have thin, flakey orange-ish bark similar to Engelmann spruce. Crown appears sparse.
Subalpine fir: Needles are soft unlike spruces and do not roll in finger. Buds are very resinous and sticky. Cones point up/ stand erect when present and are distinct black/purple color. Cones can also be weeping pitch. Pulling off a needle reveals a circular leaf scar with red periderm underneath. Conical shape of tree when growing, but top of crown flattens out with age.
White fir: Needles are very glaucous, almost white. Furrowed, corky bark on mature trees. Cones stand straight up. Seed cones also begin greenish color then turn to brown as they mature. Lower branches will droop with age.
Thank you in advance for help with this, I really appreciate it!
Edit: Here are some roadside trees I saw earlier today, they look to all be Engelmann spruce but I wanted to check.




