Utah’s Conifer Trees

Juniper Leaves & Cones
Copyright © 2009 Linda Kervin

Two-needle Pinion Pine
Copyright © 2009 Linda Kervin

Norway Spruce Cones
Copyright © 2009 Linda Kervin

True Fir Needles
Copyright © 2009 Linda Kervin

Douglas Fir Cones
Copyright © 2009 Linda Kervin

Now that the leaves have fallen from the deciduous trees, we can fully appreciate Utah’s evergreen trees. Conifers are trees that bear their seeds in cones instead of producing flowers and fruits. Utah has five kinds of conifers; all with stiff, needle-like leaves that remain green throughout the winter. Traits of their needles and cones allow you to distinguish between our different types of conifers. Cones can be found still attached or scattered on the ground.

I will start with the junipers. These conifers have scaly, slightly fleshly leaves. Juniper seeds are embedded in a cone that resembles a green berry. The cones are round and densely fleshy. Junipers are widely adaptable here, from arid foothills to rocky alpine slopes.

Our pines collectively span this same elevation range. They are the only conifers that have cylindrical needles bundled in clusters of 2 to 5. The one exception to this is Single Leaf Pinon, which as you might guess has single, round needles. The count of pine needles is often diagnostic of their species. Pinons mix with junipers at low elevations; their oily, wingless seeds are the edible pinon nut. Bristlecone pines, found in southern Utah, can live for over 1000 years.

Spruces are conifers that many recognize from their own yards. The spruce needle leaves a peg on the stem when it drops, which gives their twigs a rough, nubbly surface. Spruces grow in a classic pyramidal shape.

Another montane group is the true firs. Their flat needle attaches smoothly to the twig. True firs have uniquely upright cones that gradually disintegrate without dropping to the ground. Crushed fir needles are wonderfully fragrant, redolent of tangerines or grapefruit. Perhaps that is why true firs are a favorite Christmas tree.

Douglas fir, despite its common name, is in a different genus than the true firs. Its cones are distinctive; having long, three-pointed, papery bracts that project out from amid the cone’s scales. Douglas fir is one of the west’s most valuable timber tress. Like the spruces and firs, it is a montane species.

Conifer trees are a great resource for Utah wildlife, providing food and shelter, especially in the icy cold of winter.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:
Pictures: Copyright © 2009 Linda Kervin
Text: Linda Kervin and Jim Cane

Additional Reading:

Sibley, David Allen. 2009. The Sibley Guide to Trees. New York: Alfred A. Knopf.

Johnson, Carl M. 1991. Common Native Trees of Utah. Utah State University Extension Service. Logan, UT. 109 p

Kuhns, Michael R., Utah Forest Facts, Conifers for Utah, http://extension.usu.edu/forestry/Reading/Assets/PDFDocs/NR_FF/NRFF015.pdf, USU Extension

Utah’s Recent Pinyon Migrations and the Prospects for Climate Change

Utah’s Recent Pinyon Migrations and the Prospects for Climate Change
Packrat Fossil Midden
City of Rocks
Copyright © 2009 Julio Betancourt

In the late 1970’s, springtime in the American West warmed abruptly by 2 degrees Fahrenheit in the valleys, double that higher up. Our average onset of Spring now comes a week earlier across the West. If these are the first signs of climate change, even longer growing seasons will trigger not just earlier blooms but also northward plant migrations.

The past provides us with lessons about plant migrations. A thousand years ago, one-needle pinyon hopped from the Raft River Mountains in Utah to City of Rocks, Idaho. Across Utah, two-needle pinyon leaped over the Uintas to Flaming Gorge. We know this from radiocarbon dates on pinyon pine needles taken from ancient nest heaps of packrats preserved in caves. According to Dr. Julio Betancourt of the U.S. Geological Survey, who uses these packrat middens and tree rings to reveal past plant migrations, these recent advances by Utah’s two pinyon pines followed the Medieval Climate Anomaly, a period from 900 to 1300 AD marked by warming in Europe and severe drought in Utah.

Utah’s Recent Pinyon Migrations and the Prospects for Climate Change
Packrat 7000 year old Midden
Joshua Tree Natl Park
Copyright © 2009 Julio Betancourt

Droughts figure prominently in Dr. Betancourt’s view of tree migrations. Droughts trigger bark beetle infestations, wildfires, and tree dieoffs, opening up niches for regeneration. When the drought abates, the resident tree species typically return. With long-term warming, however, other species can move in from lower elevations or further south. Dead trees now abound on Utah’s landscape, and Dr. Betancourt thinks that we are on the verge of a new spate of tree migrations.

This go around, which species retreat or advance will depend on new factors, including human fragmentation of the landscape and accelerated dispersal of native and non-native species that hitch rides with us. To conserve ecological goods and services associated with some species, Dr. Betancourt argues, we will have to manage for these plant migrations.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Photo: Courtesy and © Copyright 2009 Julio Betancourt

Text: Julio Betancourt USGS NRP Tucson: Biotic Response to Climate Variability
Faculty and Staff > Julio Betancourt

Additional Reading:

USGS National Research Program: Tucson AZ
http://wwwpaztcn.wr.usgs.gov/home.html

Climate Change and the Great Basin, Jeanne C. Chambers, USDA Forest Service, Rocky Mountain Research Station, Reno, NV, 2008,

A Database of Paleoecological Records from Neotoma Middens in Western North America, USGS/NOAA North American Packrat Midden Database, http://esp.cr.usgs.gov/data/midden/ (Accessed 27 August 2009)