Category: Trees

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Lodgepole Pines

Lodgepole Pine
Pinus contorta
Courtesy & Copyright Michael Kuhns
https://forestry.usu.edu/

Lodgepole pine cone – open
Copyright © 2005 Steven J. Baskauf
https://bioimages.vanderbilt.edu/

P. contorta subsp. latifoliaforest
23 years before (above) and
10 years after (below) the
Yellowstone fires of 1988
Courtesy US NPS and Wikimedia
1998 Photographer: Jim Peaco

Autumn in Utah’s semi-arid climate typically means the end of a long, dry summer. While reports of forest fires popping up across the state may make us cringe, fire remains an important and natural part of our landscape. And no plant demonstrates that better than the lodgepole pine.

In Utah, these trees are found growing above 6,000 feet – mostly in the northern part of the state. Their tall, straight trunks have been important to humans for centuries as teepee poles, railroad ties and telephone poles.

Lodgepole pines have a number of adaptations that help them thrive in an ecosystem occasionally ravaged by fire. For starters, these trees produce two types of cones. Open, or non-serotinous cones, are fairly typical pine cones. Pollinated in early spring, they mature and the seeds fall during their second autumn. However, these seeds are rarely successful unless they fall in canopy openings. Lodgepole pines grow in very dense stands but their seedlings require copious amounts of sunshine to survive.

In order to combat this conundrum, lodgepole pines also produce another type of cone; called closed or serotinous cones. These cones, and their viable seed, stay on the parent tree for up to 20 years. The scales, which encapsulate the seeds, are sealed shut by a special resin that will only melt when exposed to temperatures between 113 – 140 degrees (F). In nature, the only way those temperatures are reached in the canopy, where cones are produced, is through forest fires.

A fire intense enough to emit that much heat will also kill many adult trees – especially lodgepole pines, which have very thin bark when compared to other evergreen species. However, when many adult trees are killed by fire, the canopy opens and sunlight can easily reach the forest floor where now-available seeds from serotinous cones are ready to germinate and renew the landscape.

Lodgepole pines also produce an enormous quantity of seeds – hundreds of thousands per hectare each year. The trees grow so dense that it can be hard to pick a path through them. As they age, saplings compete fiercely with their neighbors for survival, and many succumb to the pressure. Amazingly, however, this ensures that once a stand is mature, the many dry trunks and branches of the fallen provide adequate fuel to support another blaze, encouraging the next generation to rise and shine.

For sources and pictures of lodgepole pines, please visit our website at www.wildaboututah.org. Thank you to Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:

Photos: Courtesy & © Michael Kuhns, https://forestry.usu.edu/ and
             Courtesy and copyright © 2005 Steven J. Baskauf, https://bioimages.vanderbilt.edu/
             Yellowstone images courtesy USDA Forest Service and Wikimedia.
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Additional Reading:

Preston, Richard J. Jr. 1968. Rocky Mountain Trees. Dover Publications Inc. NY, NY.

Lotan, James E. and Critchfield, William B. Lodgepole Pine. U.S. Forest Service manual. Found online at: https://www.na.fs.fed.us/pubs/silvics_manual/volume_1/pinus/contorta.htm

USU Extension (2002) Range Plants of Utah: Lodgepole Pine.
Found online at: https://extension.usu.edu/range/woody/lodgepolepine.htm

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

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Seed Dispersal

Maple Seeds
Courtesy & Copyright © 2011
Linda Kervin

Milkweed Seeds
Courtesy & Copyright © 2011
Jim Cane

Burdock Flower
Courtesy & Copyright 2009 Jim Cane

Burdock Hooks
Courtesy & Copyright 2009 Jim Cane

Autumn is a season of travelers. Birds migrate south. Deer, elk and antelope move to their wintering grounds. Many plants finish maturing seeds designed for transport to favorable new habitats. Seeds come in a kaleidoscope of shapes and sizes: their structure reveals their means of dispersal.

Many plants rely on the wind to loft their seed to fertile ground. Due to wind’s fickle nature, few of these seeds actually make it to a suitable site, so to compensate they are produced in abundance. Some seeds, like those of dandelion and milkweed, have a downy fluff which floats aloft with the slightest breeze. Others utilize wing-like appendages on the seed capsule, as in maple, ash and pines. The seed is heavier than the blade shaped wing, causing a spiraling motion which propels seeds farther than mere drifting.

Another strategy for seed dispersal is to entice animals to ingest the seed. Some plants like cherries, junipers and grapes do this by imbedding their seeds in a nutritious and tasty pulp. Others, like many grasses, achieve the same end by the placement of the seeds. As grazers consume the foliage, they inadvertently ingest seeds at the same time. Hopefully the seeds end up some distance from the parent plant, deposited in their own dollop of manure to aid seedling growth. Some seeds require a trip through the digestive tract, where the impervious seed coat is eroded away so that the seed can absorb water and germinate. Ants disperse seeds that have a patch of nutritious tissue, the aril, that they gnaw off before discarding the seed.

Another means of dispersal relies on a chance encounter to hitch a ride in an animal’s fur. The seed coat has clinging hooks, hairs or spines that latch onto fur or clothing. Many noxious weeds including burdock, hound’s tongue and cheatgrass use this type of dispersal, so be careful where you groom and dispose of their seed.

Grasses don’t run and pines don’t roam, but plant seeds have many tricks to gain mobility.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Images: Courtesy & Copyright Jim Cane &
            Courtesy & Copyright Linda Kervin
Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:

Seed Dispersal
https://andromeda.cavehill.uwi.edu/Dispersal.htm (archived link)

Wind Dispersal
https://www2.palomar.edu/users/warmstrong/plfeb99.htm

Seed Dispersal by Animals
https://www.cnr.uidaho.edu/range556/…

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Great Basin Bristlecone Pines Utah’s Mountain Sentinels

Bristlecone Pine
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Bristlecone Pine Grain
Compared to a Dime
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

Utah’s cold mountaintops, like its hottest deserts, are rather inhospitable to most plants. Although more precipitation falls at higher elevations, colder temperatures prevent much of the water from being used by plants, since most of it falls as snow in winter. High winds also inhibit growth and can contribute to frost or wind damage to plants. Any plants that grow here must be especially hardy.

The Great Basin bristlecone pine is a grand sentinel of our rocky, high mountain ridges. Its shorter needles are grouped in bundles of five, and grow densely at the end of the branches, creating a ‘bottlebrush’ or ‘foxtail’. However, the growth of the wood is the most interesting aspect of the Great Basin bristlecone pine. For a tree, each ring represents one year of growth. Because of the colder temperatures and shorter growing season, each growth ring of a bristlecone pine is particularly small, usually around 1/32th of an inch. The tight growth rings result in especially dense, resinous wood that is resistant to decay and insects.

At higher elevations, a bristlecone pine’s growth form becomes more twisted and contorted by the wind. Over time, much of the tree may die, and the living portion may simply be a strip of bark up the trunk and just a few branches.

These adaptations allow the Great Basin bristlecone pine to live an exceptionally long life despite such harsh conditions. It is common for a bristlecone pine to live for thousands of years, and the oldest recorded specimen was aged at approximately 5,000 years old. That means it germinated from seed a few hundred years before the first Egyptian pyramid was even built! Bristlecone pines can even remain standing for thousands of years after they die. Growth ring patterns can be compared between living and dead bristlecone pines to reveal a chronology of our climate for the past seven, eight, maybe ten thousand years!

To see bristlecone pines in Utah, hike the Bristlecone Pine Trail in Bryce Canyon National Park or the Ramparts Trail at Cedar Breaks National Monument. Be sure to take only photos, and not wood or cones. Bristlecone pines will be around a lot longer than we will, and they could use all the help they can get.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:
Images: Courtesy & Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.


Additional Reading:

Lanner, R.M. 2007. The Bristlecone Book: A Natural History of the World’s Oldest Trees. Mountain Press Publishing Company.

Cohen, M. P. 1998. A Garden Of Bristlecones: Tales Of Change In The Great Basin. University of Nevada Press.

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USA National Phenology Network

Courtesy USA National Phenology Network

The study of recurring plant and animal life cycle events is phenology. It is the calendar of nature. This includes when plants flower, when birds migrate and when crops mature. Phenology is relevant to interactions between organisms, seasonal timing and large-scale cycles of water and carbon. Phenology is important to us for many reasons. Farmers need to know when to plant and harvest crops and when to expect pests to emerge. Resource managers use it to monitor and predict drought and assess fire risk. Vacationers want to know when the best fall colors will be or when the wildflower blooms will peak. Timing varies but we can discern patterns.

The USA National Phenology Network monitors the influence of climate on the phenology of plants, animals and landscapes. They encourage people to observe phenological events such as flowering, migrations and egg laying. The Phenology Network provides a place to enter, store and share these observations, which are then compiled and analyzed nationwide. Participants range from individual observers in their own backyards to professional scientists monitoring long-term plots. My husband and I monitor leafing and flowering of lilacs, a key species in the program.

These observations support a wide range of decisions made routinely by citizens, managers, scientists and others. This includes decisions related to allergies, wildfires, pest control, and water management.

I urge you to participate. The National Phenology Network has many public, private and citizen partners. It is a great way to become involved in a nation-wide effort to better understand our environment. All this information and much more is available at the National Phenology website, to which there is a link from our Wild About Utah website.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Text: Linda Kervin, Bridgerland Audubon Society
Additional Reading:

Linda Kervin’s pieces on Wild About Utah

Phenology Tools for Community Science
USA National Phenology Network, https://www.usanpn.org/
Nature’s Notebook Education Program, US National Phenology Network, https://www.usanpn.org/nn/education

North American Bird Phenology Program, USGS Patuxent Wildlife Research Center, https://www.pwrc.usgs.gov/bpp/BecomeAParticipant.cfm

eBird, https://www.ebird.org/

iNaturalist, https://www.inaturalist.org/