The colors of Fall in early October- Travelling across the Rocky Mountain in Colorado, USA- XXII
photographed from our running bus.
.
It is nearly impossible to describe the beauty you will encounter while travelling across Rocky Mountain in Colorado during early October! Thick aspens (Populus tremuloides) in patches with their golden leaves stand against lush green mountains. Ice peaks over 12,000 feet rising through the forest truly enhance the beauty of its landscapes.
Rocky Mountain
Rocky Mountain National Park in northern Colorado is one of the most distinctive of America's alpine area parks. It is home to a vast collection of 72 peaks that scrape the skies at over 12,000 feet and offers diverse geography that encompasses barren alpine tundra and thick, lush forests. While summer crowds help to make the park one of the top 10 most visited in the national park system, autumn provides a quieter time to enjoy the vibrant colors of the changing seasons. September and October typically experience dry, moderate weather, making for ideal visits.
Trees
The park's fall colors are most defined by the legions of white-barked aspen trees that line the valleys and mountains. Starting in late August, aspens in the highest reaches of the park begin their annual quaking, a term to describe the aspens unique leaves changing a golden-yellow hue. As the quaking progresses the park's high country becomes striped with color, appearing on fire from a distance. These trees become yellow in mid-September and provide crisp shades of gold and red into October. The colors contrast with the deep greens of the evergreen trees that make up the majority of tree species in the park. The peak season for fall colors comes in late-September and the changing colors generally last four to five weeks. Hundreds of elk migrate down from the high country to find a mate for the winter.
Intensity of Fall Colors
Aspen (Populus tremuloides) are among the most colorful and wide-spread color-changing trees in Rocky Mountain National Park. Experience suggests to us that aspen produce more or less colorful leaves from year to year, and that these differences seem to relate to weather patterns, soil fertility, and the amount of moisture they received during the growing season.
Ecological mysteries of fall colors-
Recently scientists put forward an intriguing alternative explanation for intense fall colors in some trees (Ecol. Lett. 6, 807, 2003). Mountain birches in Norway may use intense fall colors to signal leaf-chewing insects not to infest them. The intensity of color seems to be an indicator of how much chemical defense compound the tree can produce. In the case of the mountain birches, an inchworm (geometrid) moth lays eggs on the trees in the fall. The following spring the eggs hatch, and the moth caterpillars eat the trees' leaves. Trees that can produce larger amounts of chemical defenses to make their leaves unpalatable receive less damage. The trees with the most intense leaf colors in the fall also have the least damage the following spring, suggesting a direct relationship between chemical defenses and intense colors. Over time, perhaps the moths have learned to avoid laying eggs on trees with the most highly colored leaves!
Its not know whether the same thing happens in Rocky Mountain National Park's aspen or other trees. We do know there are many different representatives of the inchworm or geometrid moth family in the park. However, whether you enjoy fall colors because they are beautiful or because they may reveal scientific secrets, Rocky Mountain National Park offers an excellent opportunity to experience a glorious autumn.
The colors of the Rockies are truly singular
The colors of the Rockies are truly singular, that is, they are all yellow. Gorgeous expanses of yellow aspen (Populus tremuloides) color the mountain sides, contrasting firmly with the dark green spruces and firs. The orange, red, and purples of the east seem absent.
The autumn colors in leaves are produced by an interestingly subtractive process. In summer, green chlorophyll masks the colors of several other pigments that exist in leaves, pigments that, like chlorophyll, assist with photosynthesis. These yellow, red, and purple pigments - carotene, xanthophyll, and anthocyanins - produce the bright fall colors, but only after the chlorophyll wanes as temperatures cool and days shorten. As autumn proceeds, even these hardier pigments ebb, and leaves become brown, gray, or black.
Sources:
traveltips.usatoday.com/fall-colors-rocky-mountain-nation...
www.myrockymountainpark.com/park/fall-in-rocky-mountain-park
www.nps.gov/romo/intensity_fall_colors.htm
www.nps.gov/romo/fall_colors.htm
The colors of Fall in early October- Travelling across the Rocky Mountain in Colorado, USA- XXII
photographed from our running bus.
.
It is nearly impossible to describe the beauty you will encounter while travelling across Rocky Mountain in Colorado during early October! Thick aspens (Populus tremuloides) in patches with their golden leaves stand against lush green mountains. Ice peaks over 12,000 feet rising through the forest truly enhance the beauty of its landscapes.
Rocky Mountain
Rocky Mountain National Park in northern Colorado is one of the most distinctive of America's alpine area parks. It is home to a vast collection of 72 peaks that scrape the skies at over 12,000 feet and offers diverse geography that encompasses barren alpine tundra and thick, lush forests. While summer crowds help to make the park one of the top 10 most visited in the national park system, autumn provides a quieter time to enjoy the vibrant colors of the changing seasons. September and October typically experience dry, moderate weather, making for ideal visits.
Trees
The park's fall colors are most defined by the legions of white-barked aspen trees that line the valleys and mountains. Starting in late August, aspens in the highest reaches of the park begin their annual quaking, a term to describe the aspens unique leaves changing a golden-yellow hue. As the quaking progresses the park's high country becomes striped with color, appearing on fire from a distance. These trees become yellow in mid-September and provide crisp shades of gold and red into October. The colors contrast with the deep greens of the evergreen trees that make up the majority of tree species in the park. The peak season for fall colors comes in late-September and the changing colors generally last four to five weeks. Hundreds of elk migrate down from the high country to find a mate for the winter.
Intensity of Fall Colors
Aspen (Populus tremuloides) are among the most colorful and wide-spread color-changing trees in Rocky Mountain National Park. Experience suggests to us that aspen produce more or less colorful leaves from year to year, and that these differences seem to relate to weather patterns, soil fertility, and the amount of moisture they received during the growing season.
Ecological mysteries of fall colors-
Recently scientists put forward an intriguing alternative explanation for intense fall colors in some trees (Ecol. Lett. 6, 807, 2003). Mountain birches in Norway may use intense fall colors to signal leaf-chewing insects not to infest them. The intensity of color seems to be an indicator of how much chemical defense compound the tree can produce. In the case of the mountain birches, an inchworm (geometrid) moth lays eggs on the trees in the fall. The following spring the eggs hatch, and the moth caterpillars eat the trees' leaves. Trees that can produce larger amounts of chemical defenses to make their leaves unpalatable receive less damage. The trees with the most intense leaf colors in the fall also have the least damage the following spring, suggesting a direct relationship between chemical defenses and intense colors. Over time, perhaps the moths have learned to avoid laying eggs on trees with the most highly colored leaves!
Its not know whether the same thing happens in Rocky Mountain National Park's aspen or other trees. We do know there are many different representatives of the inchworm or geometrid moth family in the park. However, whether you enjoy fall colors because they are beautiful or because they may reveal scientific secrets, Rocky Mountain National Park offers an excellent opportunity to experience a glorious autumn.
The colors of the Rockies are truly singular
The colors of the Rockies are truly singular, that is, they are all yellow. Gorgeous expanses of yellow aspen (Populus tremuloides) color the mountain sides, contrasting firmly with the dark green spruces and firs. The orange, red, and purples of the east seem absent.
The autumn colors in leaves are produced by an interestingly subtractive process. In summer, green chlorophyll masks the colors of several other pigments that exist in leaves, pigments that, like chlorophyll, assist with photosynthesis. These yellow, red, and purple pigments - carotene, xanthophyll, and anthocyanins - produce the bright fall colors, but only after the chlorophyll wanes as temperatures cool and days shorten. As autumn proceeds, even these hardier pigments ebb, and leaves become brown, gray, or black.
Sources:
traveltips.usatoday.com/fall-colors-rocky-mountain-nation...
www.myrockymountainpark.com/park/fall-in-rocky-mountain-park
www.nps.gov/romo/intensity_fall_colors.htm
www.nps.gov/romo/fall_colors.htm