In autumn, our days shorten noticeably and frosty dawns become the norm across most of Utah. Now leafy plants must be preparing for winter. Their summer of intense metabolic activities must gradually give way to winter’s dormancy. Photosynthesis and respiration are gradually shut down as nutrients and sugars are withdrawn from leaves, to be shunted to the stem and roots for storage.
The brilliant autumn yellows of our aspens, ash trees and cottonwoods, as well as the crimsons of our maples and sumacs, are all indicative of leafy plants frugality with their valuable nutrient stores. The foliar pigment phytochrome first registers the lengthening nights, initiating the cascade of physiological events that prepare a tree for the icy blasts of winter. Before discarding their leaves, deciduous trees and shrubs rescue and store what they can of sugars and nutrients found in their leaves.
The key photosynthetic green pigment, chlorophyll, and its attendant enzymes are all broken down, their components moved to storage for recycling next spring. Essential nutrients, such as nitrogen and phosphorus, are likewise extracted from foliage for later reuse. With chlorophyll gone, the other colorful leaf pigments are revealed in all their glory. These accessory pigments have been there all along, they just have been masked by the dominant green of chlorophyll.
These accessory pigments serve several functional purposes for the leaf. Some pigments protect the leaf from sunburn, some scavenge free radicals, but most capture energy from wavelengths of light missed by chlorophyll. The multi-hued spectrum of sunlight, as revealed by a prism or a rainbow, not only allows us to see splashy fall foliage colors, it is the reason for their existence.
For the plant physiologist and chemist, then, the palette of colorful leaf pigments have complex functional explanations. More mysterious psychological stirrings accompany the aching beauty of our autumn foliage, but it gives an undeniable tug at my heart. Standing before a blazing yellow stand of aspens, I smile to think that recycling can be so beautiful.
Photo: Courtesy www.bridgerlandaudubon.org
Text: Bridgerland Audubon Society – Jim Cane, Linda Kervin
A little over a week ago, I saw my first kokanee salmon run up Little Bear River just east of Porcupine Reservoir. This year, researchers counted over 10,000 fish within a mile of the reservoir. That’s a record number. My friends and I marveled at these wriggling flashes of color as they struggled upstream. It inspired me to spend the week reading about salmon. Here’s what I learned.
First of all it surprised me that salmon and trout are so close genetically. Along with whitefish and grayling, they form the family Salmonidae, but salmon and trout are the most similar. The main difference between them is that salmon generally migrate from their freshwater birthplace to the sea to get more and better food. And then they return to spawn in freshwater rivers and streams where there are fewer predators. And generally – although it’s not true for all – salmon spawn once and die while trout go through a number of spawning cycles.
The Pacific Sockeye salmon resembles a silvery rainbow trout during most of its life. But when it spawns, the male especially undergoes a miraculous transformation. His head turns green, his body turns a bright red, and his back grows a bump. And his jaw begins to hook until he’s got a pronounced overbite. There’s a lot of jostling over females during breeding, and the humpback and hooked jaw helps him intimidate other male fish so he can fertilize more female eggs. And the red color is considered highly attractive to the opposite sex.
The kokanee is an evolutionary branch of the sockeye. Both of them spawn in freshwater nurseries and then move to a nursery lake to grow for awhile. Then the sockeye salmon migrates to the ocean while the kokanee remain in the lake. After a few years they both return to the freshwater streams to spawn and die. The funny thing is, that if you take a sockeye and keep him in a lake, he doesn’t turn red when it’s time to spawn. That’s because red color derives from carotenoid pigments in the salmon’s diet and these pigments are much more prevalent in ocean food. So why does the kokanee turn the same red as the sockeye? It’s because the sexual preference for red was so strong that the kokanee actually evolved the ability to process carotenoid pigments with 3 times the efficiency of sockeyes.
Because it flexibly defines a lake as its ocean, the kokanee has become a popular fish for reintroduction into western lakes and reservoirs. In 1922, the kokanee was first introduced for sport fishing into Utah’s Bear Lake. Nowadays you can see them spawn in the Little Bear River out of Porcupine Reservoir, Sheep Creek near Flaming Gorge Reservoir, and tributary streams of Strawberry Reservoir.
If you hurry, you can still catch the last of the spawning kokanees, their bright red bodies an aquatic response to the flaming Utah maple on the surrounding hillsides.
Special thanks to Charles Hawkins (Watershed Sciences, College of Natural Resources, Utah State University) , Phaedra Budy (Utah Cooperative Fish and Wildlife Research Unit, College of Natural Resources, Utah State University) and Bret Roper (US Forest Service, Fish & Aquatic Ecology Unit, Logan, UT) for their comments on this piece.
Photo: Courtesy of and Copyright 2008 Mary-Ann Muffoletto
Text: Stokes Nature Center: Holly Strand
Craig, J.K., and Foote, C.J. 2001. COUNTERGRADIENT VARIATION AND SECONDARY SEXUAL COLOR: PHENOTYPIC CONVERGENCE PROMOTES GENETIC DIVERGENCE IN CAROTENOID USE BETWEEN SYMPATRIC ANADROMOUS AND NONANADROMOUS MORPHS OF SOCKEYE SALMON (ONCORHYNCHUS NERKA), Evolution 55(2), 2001, pp. 380-391.
Hi, I’m Dick Hurren from Bridgerland Audubon Society.
If you’ve spent much time in the forests and wetlands of northern Utah, you may have been lucky enough to see one of North America’s most magnificent animals, the Moose.
The Moose is the largest member of the deer family, and one of the largest mammals to survive the last Ice Age. Utah’s subspecies of Moose is known as the Shiras,
or Wyoming Moose. Although the smallest subspecies of Moose in North America, it can grow to be nearly six feet tall and weigh as much as 1,000 pounds. Bull Moose
can grow a rack of antlers that reaches four feet across.
One might assume such an ancient and enormous animal has long existed in Utah, but in fact the Moose is one of Utah’s newer immigrants.
The first Moose in Utah were seen about 100 years ago, and the total population may have been less than 100 animals as late as the 1950s. Today, there are about 4,500
Moose throughout northern Utah. So how did the Moose become so plentiful in such a short time?
The Moose’s immigration to Utah looks like a case of perfect timing. Many of the Moose’s predators like Grizzly Bears, Wolves and Mountain Lions had been largely
exterminated. At the same time, logging was replacing mature forests with new meadows and scrub that Moose prefer. The combination of young growth and wetlands provided
the ideal habitat for Moose to thrive.
On top of these favorable conditions, human management has helped the Moose expand. Overwhelming demand for Moose hunting
has fostered strategies to encourage population growth.
More recently, there have been attempts to speed up the expansion of Moose by transplanting them to new mountain ranges.
Despite success in the last hundred years, Moose face many challenges in the next hundred. Maturing woodlands will be able to support fewer Moose.
Old predators are rebounding slightly and will take their toll. But the most difficult challenge the Moose may face is that of climate change.
The Moose evolved to survive in extreme cold climates. If temperatures continue to rise, the Moose will retreat
higher into the mountains and further north until one day this recent visitor returns to Wyoming or even further north.
The next time you visit the mountains, pay close attention to the streams and lakes particularly those surrounded by willows.
And you too may be lucky enough to see the moose.
For Wild About Utah I’m Dick Hurren.
Photo: Courtesy and Copyright Jason Pietrzak www.ptrzk.com
Text: Bridgerland Audubon Society – Jason Pietrzak, Dick Hurren
Hi, I’m Holly Strand for Stokes Nature Center in beautiful Logan Canyon.
Mongolia, China, and United States have produced far more dinosaur fossils than any other countries in the world. And Utah is a prime dinosaur site within the United States. Scattered around Utah are several active quarries, including the world famous Carnegie Quarry in Dinosaur National Monument and the Cleveland-Lloyd Dinosaur Quarry outside of Price. Paleontologists are beginning to find that the Grand Staircase Escalante Area is another prolific boneyard. In their day, dinosaurs roamed almost all parts ofthe known world, so what makes Utah so exceptional for dinosaur discoveries?
First of all, it’s important to understand that the vast majority of dinosaurs lived and died without leaving any fossil traces. Thus, what we find today is an extremely small percentage of the total of all dinosaur matter. In order to be preserved a creature needs to be buried or frozen almost immediately upon death, Given that the world was pretty warm in the age of the dinosaurs, most of today’s fossils come from individuals that died in or near a sand dune, lake or sea and were then quickly covered by sand or mud. Dinosaurs lived in the late-Triassic, Jurassic and Cretaceous periods of the Mesozoic era –that is 225-65 million years ago. At that time, what-would-be-become Utah featured both a shallow inland sea and dunes.. So dinosaurs who lived and died here had a much better chance of being fossilized.
Once fossils are well preserved, certain conditions will increase the probability that they will be found. First of all, you want exposed Mesozoic rock, since dinosaurs lived and died in the Mesozoic era. The Morrison and Cedar Mountain Formation are both from the Mesozoic and are extremely rich in dinosaur fossils.. In fact, Utah has one of the most detailed Mesozoic rock records in the world. Certain types of sedimentary rock –including sandstones, mudstones and limestones –are most promising for fossils and Utah has plenty of these.
Another condition for good fossil hunting is a dry environment. Desert and semi-deserts are optimal for discovery, since decomposition is slowed. With little or no vegetation on the ground, wind and water erosion increases and more ancient fossils are uncovered. In this regard also, Utah is perfect, having just the right amount of water. There’s enough to cause occasional and severe erosion to expose new rock, but not enough to encourage the amount of plant growth that will anchor soil or reduce visibility of the ground.
In the past 2 decades, dinosaur discovery and research has been enjoying a renaissance with plenty of new species being unearthed.. In an upcoming episode, I”ll talk about some exciting new discoveries in our state.
For Wild About Utah and Stokes Nature Center, I’m Holly Strand.