Biome Archives - Page 27 of 40

November 17, 2014January 24, 2021

Water Properties

In our winter wonderland, water is all around. It piles upon the landscape in great white drifts. It is a substance life is completely dependent upon and as ordinary as it seems, this tasteless, odorless substance is actually quite amazing. Up to 60% of our body mass is due to water, and life as we know it would not exist if not for water’s unique physical properties.

Properties of Water

When most known liquids get colder they contract – shrinking around 10 percent in total volume. Water contracts too, but only until it reaches its freezing point, at which time it reverses course and begins to expand. This molecular marvel does wonderful things for life on earth. As water freezes and expands, the resulting ice becomes lighter than its liquid form, causing it to float. If ice contracted as other liquids do, it would sink, and lakes would freeze from the bottom up – and freeze quickly, meaning big changes for aquatic life. Water in all forms happens to be a very good insulator, meaning that it doesn’t change temperature very quickly. Ice floating on top of a pond insulates the water underneath, keeping it warmer, and therefore liquid, longer than it normally would. Obviously, this is beneficial for local creatures like fish and beavers not to mention the penguins, whales and seals that thrive in the colder parts of our planet.

Another critical property of water is its stickiness. Individual molecules are generally more attracted to each other than to other substances such as air or soil. This ‘stickiness’, or cohesion, creates surface tension, which allow puddles, rivers, and raindrops to form, and also enables water striders to glide on the water’s surface and rocks to skip across a lake. Water tension is also responsible for a tree’s ability to siphon water from the soil and transport it to the very topmost leaf. However, water’s bonds aren’t so strong as to be unable to break when a fish swims through or when you cannonball into the deep end. You can observe surface tension at home by dripping water onto the head of a coin, and watching it ball up into a surprisingly large mound.

Water is also one of the only known substances that naturally occurs in three phases – solid, liquid, and gas. This is important to many facets of life including the proper functioning of the weather system as we know it. Thankfully, there is a lot of water here on earth – about 320 million cubic miles of it. However, only four tenths of a percent of that comes in the form of freshwater lakes & rivers. Most of the rest is locked up in glaciers and oceans. It’s also important to realize that this is all of the water that Earth has ever had, and all the water we’re ever going to get, which can lead to some interesting thoughts about where that water you are about to drink has previously been. Perhaps it was once part of Lake Bonneville, in the snow that fell on the back of a wooly mammoth, or in a puddle slurped up by a brachiosaurus. If only water could talk…

For more sources and to calculate your water-use footprint, visit our website at www.wildaboututah.org.

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

Credits:
Images: Andrea Liberatore, Stokes Nature Center in Logan Canyon.
Text: Andrea Liberatore, Stokes Nature Center in Logan Canyon.

Additional Reading:

Bryson, Bill (2004) A Short History of Nearly Everything. Broadway (Random House): New York.

U.S. Geological Survey (2013) The USGS Water Science School. Accessible online at: https://ga.water.usgs.gov/edu/

United Nations: Water. Accessible online at https://www.unwater.org/

Calculate your water footprint:
https://www.waterfootprint.org/?page=files/YourWaterFootprint

September 25, 2014September 11, 2023

Encountering Cheatgrass

Click to view an article about cheatgrass, Photo Courtesy NPS, Neal Herbert, Photographer — Cheatgrass
Photo Courtesy NPS, Photographer:
Tom Heutte, USDA Forest Service,
Bugwood.org

A grassland inundated by cheatgrass
Photo Courtesy NPS
Neal Herbert, Photographer

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

It’s difficult to visit a landscape in the West without encountering cheatgrass. While cheatgrass’ small stature might make it hard to notice, it’s impossible to forget its sharp, spiny seeds. One hike through a cheatgrass meadow can render a good pair of socks unsalvageable.Encountering Cheatgrass

Although cheatgrass, a nonnative grass scientifically known as Bromus tectorum, is an annual grass- germinating, growing, producing seeds, and dying each year- it is particularly effective at colonizing disturbed areas because it grows and produces seeds much earlier in the spring than many perennial native grasses. Cheatgrass monopolizes water and nutrients by germinating and establishing itself during the previous fall and winter, when many native plants have become dormant. Over time, cheatgrass has become the dominant ground cover in many of Utah’s sagebrush ecosystems.

The dense, dry, fine stalks of cheatgrass, which sets seeds and dries out by June, are particularly flammable fuel for wildfires. Fire roars through the carpet-like cover of cheatgrass, and wildfires are now at least twice as frequent as they were in the 1800’s. This has caused a loss of sagebrush habitat that is particularly important to a wide diversity of wildlife. More frequent fires create an even greater challenge for rare species such as the black-footed ferret and desert tortoise to survive. Native grasses are slower to recover from fire, and cheatgrass is particularly effective at recolonizing burned areas. Utah State University researchers Dr. Peter Adler and Aldo Compagnoni have found that reduced snowpack and warmer temperatures promote the growth of cheatgrass, which could potentially increase its distribution and fire risk into previously colder areas of Utah.

Researchers and managers are continually working to find ways to control cheatgrass in Utah. Effective control usually involves a combination of mechanical pulling or tilling, grazing, burning, spraying with a chemical herbicide, and replanting with native grasses. USU researchers Dr Eugene Schupp and his former graduate student Jan Summerhays found that applying a pre-emergent herbicide to prevent the germination of cheatgrass seeds, as well as temporarily limiting Nitrogen in the soil, gave native grasses and perennials a better chance of establishing. When faced with such a large management problem in Utah and throughout the West, we can use all of the helpful tools we can get.

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

Credits:

Images: Courtesy NPS, Neal Herbert Photographers
and NPS, USDA Forest Service, Bugwood.org, Tom Heutte Photographer
Text: Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.

Additional Reading:
Beck, George. Cheatgrass and Wildfire. Fact Sheet No. 6.310. Colorado State University Extension. https://www.ext.colostate.edu/pubs/natres/06310.html
Cheatgrass. Range Plants of Utah. https://extension.usu.edu/range/Grasses/cheatgrass.htm

Fairchild, John. Cheatgrass: threatening homes, stealing rangelands. Utah Division of Wildlife Resources. https://wildlife.utah.gov/watersheds/links/cheatgrass.php

Opsahl, Kevin. USU study: Climate shift could trigger cheatgrass. Herald Journal . October 21, 2012. https://news.hjnews.com/allaccess/article_f1436aee-1a3c-11e2-935a-0019bb2963f4.html

Forero, Leslie, Plants Surviving Cheatgrass Invasion May Improve Restoration Chances, Study Shows, UPR Utah Public Radio, Feb 26, 2018 https://www.upr.org/post/plants-surviving-cheatgrass-invasion-may-improve-restoration-chances-study-shows

Larese-Casanova, Mark, Cheatgrass, Wild About Utah, October 25, 2012 https://wildaboututah.org/cheatgrass/

August 21, 2014July 18, 2020

Wind and Sagebrush

Hi, I’m Holly Strand of the Quinney College of Natural Resources at Utah State University.

By late summer, most of Utah’s flowering plants have fizzled out for the year—those that remain are looking pretty spent. But not true for the sagebrush. It’s show time for over 20 types of sagebrush of the Intermountain West.

Like grasses and conifers, sagebrush plants are pollinated by the wind. They have no need for the specialized traits designed to attract live pollinators. Instead, they have evolved other strategies to survive and multiply.

For instance, wind-pollinated plants don’t need showy, colorful petals to attract insects or birds. The wind is going to do its job anyway regardless of visual cues. Thus sagebrush flowers are very small and nondescript. In fact, when passing by flowering sagebrush you might not even notice that it’s in bloom. Look for long spikes with clusters of tiny flower heads. The pale yellow flowers are concealed by petal-like bracts, which are the very same color as the rest of the plant.

While the flowers of sagebrush lack in beauty, they make up in quantity. A single flowering stem of the most common sagebrush—known simply as big sagebrush–can hold hundreds of flower heads that produce a massive amount of pollen. Most wind-blown pollen grains won’t end up anywhere near the female part of another plant. So to make up for this risky method of fertilization, individual plants must produce greater volumes of pollen. In contrast, plants with live pollinators get door to door service during fertilization. Far less pollen is needed to get the same job done.

Scent is another way for plants to attract live pollinators. Species pollinated by bees and flies have sweet scents, whereas those pollinated by beetles have strong musty, spicy, or fruity odors. However, the iconic western scent of the sagebrush has absolutely nothing to do with pollination. Instead, the pungent aroma of the sagebrush is a by-product of certain chemicals produced in the leaves. These chemicals evolved to repel animals and to reduce the odds of being eaten or grazed.

The chemicals—bitter terpenes, camphors and other secondary compounds–—peak in early spring. But as the late-summer flowering period approaches, the chemicals start to break down. By winter, browsers like deer and elk can nibble on the protein-rich seed heads without getting a nasty aftertaste.

Thanks to botanist Leila Shultz for sharing her knowledge of sagebrush. For a link to the online version of Leila’s book Pocket Guide to Sagebrush, go to www.wildaboututah.org
If you’d like a hard copy of this Pocket Guide, send an email to wildaboututah@gmail.com We have 5 copies to give away to listeners from across the state.

For Wild About Utah and the Quinney College of Natural Resources, I’m Holly Strand.

NOTE: The copies are gone. You can view the book as a .pdf here or check here for the next printing from https://www.sagestep.org/pubs/brushguide.html.

Credits:

Photo Courtesy & Copyright 2007 Dr. Leila Shultz
Text: Holly Strand, Quinney College of Natural Resources at Utah State University

Additional Reading:

Dudareva, Natalia. 2005. Why do flowers have scents? Scientific American April 18. https://www.scientificamerican.com/article/why-do-flowers-have-scent/

Shultz, Leila. 2012. Pocket Guide to Sagebrush. PRBO Conservation Science. https://digitalcommons.usu.edu/sagestep_reports/20/
As pdf: https://rdjzr2agvvkijm6n3b66365n-wpengine.netdna-ssl.com/wp-content/uploads/2018/06/sagebrush_pock_guide_reduced.pdf

Shultz, L. M. 2006. The Genus Artemisia (Asteraceae: Anthemideae). In The Flora of North America north of Mexico, vol. 19: Asterales, pp. 503–534. Flora of North America Editorial Committee, eds. Oxford University Press. New York and Oxford.

USDA, NRCS. 2012. The PLANTS Database, National Plant Data Team, United States Department of Agriculture (USDA), Natural Resource Conservation Service (NRCS): https://www.plants.usda.gov

VanBuren, R., J. C. Cooper, L. M. Shultz and K. T. Harper. 2011. Woody Plants of Utah. Utah State University Press & Univ. Colorado. 513 pp. https://upcolorado.com/utah-state-university-press/item/2323-woody-plants-of-utah

July 24, 2014June 26, 2016

Cryptobiotic Soil Crusts

Click to view larger image of Cryptobiotic Soil Crust, Photo Courtesy and Copyright Mark Larese-Casanova — Cryptobiotic Soil Crust
Photo Courtesy & Copyright 2009
Mark Larese-Casanova

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

Looking out over a Utah desert, we might see relatively few plants- perhaps some sagebrush, maybe a few junipers or Joshua trees, or even some small wildflowers or cacti. What is less noticeable, though, is the living soil crust that holds this entire landscape together. It’s not just sand, but rather an important and vast partnership between bacteria, lichens, algae, and fungi. These soil crusts are often referred to as ‘cryptobiotic’, which means ‘living in suspended animation’. This is a fitting description, considering that water can be so rare in Utah’s deserts.

Cyanobacteria, which is often called blue-green algae, is the backbone of cryptobiotic soil crust. Vast networks of long, microscopic filaments of cyanobacteria and fungi grow in length when they are wet, and leave behind a casing that literally binds the soil together. So, what might otherwise be loose sand not only is less likely to be washed away by water or blown away by wind, but also is able to hold much more water for plants.

Cyanobacteria is also extremely useful to desert landscapes for its ability to take Nitrogen out of the air and make it available to plant roots in the soil. Desert soils typically have relatively low nutrients, so this is especially important to desert plants.

In many Utah deserts, cryptobiotic soil crusts can cover up to 70% of the ground surface. Old soil crust can often look like small mountain ranges with black or white peaks inhabited by lichens or mosses. The little valleys in between the tiny mountains of crust are perfect spots for the seeds of desert plants to grow. Over time, the above ground crust can grow up to ten centimeters, or four inches, thick!

However, cryptobiotic soil crust grows at an alarmingly slow rate of about one millimeter per year. So, any soil crust that is disturbed can take a very long time to recover. Depending on the amount of moisture a desert receives, it can take anywhere between 20 and 250 years for soil crust to grow back.

Next time you’re out in the desert, kneel down and have a close look at the telltale peaks and valleys of cryptobiotic soil crust. If you bring a magnifying glass, you just might be able to see some of the lichens and mosses. Be sure to stay on trail, though, and whatever you do, don’t bust that crust!

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

Credits:

Images: Courtesy and copyright Mark Larese-Casanova
Text: Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.
Additional Reading:

US Department of Interior. 2001. Biological Soil Crusts: Ecology and Management. Bureau of Land Management Technical Reference 1730-2., https://www.blm.gov/nstc/library/pdf/CrustManual.pdf
Rosentreter, R., M. Bowker, and J. Belnap. 2007. A Field Guide to Biological Soil Crusts of Western U.S. Drylands. U.S. Government Printing Office, Denver, Colorado., https://www.soilcrust.org/