The Friends of the Florissant Fossil Beds

February 12, 2008

Species Spotlight: Ponderosa Pine

Filed under: Biology, Ecology, Science, Species Spotlight — The Friends of the Florissant Fossil Beds, Inc. @ 12:00 pm

Read former Florissant Fossil Beds National Monument intern J.J. Huie’s full article in the Spring 2008 Friends newsletter!

Ponderosa pine cones, photographer Walter Siegmund

With Deep Roots in Colorado: The Ponderosa Pine

by J.J. Huie

I like running in Colorado when the sound of my breathing is drowned out by a wind so violent it causes the arms of the ponderosa pines (Pinus ponderosa) to thrash about wildly. Hundreds of miles from the Pacific, in the foothills next to Rampart Range near Colorado Springs, I feel like I’m sailing through an ocean storm. In crossing this ocean, however, there is no salty scent or giant, looming swells; instead, I have the waving motion of the ponderosas and the rich aroma they exude.

In Colorado, the ponderosa pine ecosystem can be found at an elevation range of 5,600 feet to 9,000 feet on both sides of the Continental Divide, with ponderosas dominating on sunny, south-facing slopes. Throughout much of the elevation range of the ponderosa, Douglas-firs predominate on the shadier, north-facing slopes. Direct solar radiation is critical to the ponderosa, which germinates best on soils with unobstructed sunlight. Standing close to a mature tree, I enjoy the scent of vanilla that the orange-brown bark gives off as it’s warmed by the sun.

A distinctive feature of ponderosas is their long needles (up to 7 inches in length), which come in bundles of two or three needles. The needles of ponderosas are the longest among conifers in Colorado. Some ponderosas are among the largest trees in the Southern Rockies (the area from southern Wyoming through Colorado to northern New Mexico), growing up to 150 feet in height and more than 3 feet in diameter.

Mature trees usually have rounded crowns, while the oldest trees can have flat-topped crowns, unlike most other conifer species. Mature cones are globe shaped and can be up to 6 inches long; each of the cone’s thick scales is tipped with a sharp bristle.

(more…)

October 9, 2007

Species Spotlight: Wapiti or American Elk

Filed under: Biology, Ecology, Species Spotlight — The Friends of the Florissant Fossil Beds, Inc. @ 12:00 pm

Photo of American elk at Yellowstone National Park

It’s hard to forget the eerie sound of an American bull elk bugling–the sound is almost completely unlike a bugle, but rather a high, unearthly wail. Elk bugling is a common sound at Florissant Fossil Beds National Monument in the fall, when elk rut (seek mates).

American elk (Cervus canadensis*), which once numbered 10 million in North America and which lived in grasslands from coast to coast, today are mostly confined to last remaining wild spaces in the mountains. In Colorado, according to seasonal park ranger Harv Burman, wildland is developed at a rate of 4 acres per hour. That doesn’t leave much space for the elk, but in September and early October you still have a good chance of hearing or seeing elk at the park, particularly at the south end and along Lower Twin Rock Road.

Elk use tree saplings to rub the velvet from their antlersDuring the rut, or mating season, cow elk focus on eating. They need the fuel to carry calves through the winter. The bulls, however, are often too busy to eat–the successful are busy gathering and keeping harems of 10-15 cows. They shed the velvet from their antlers in August, and polish them on trees. Struggles between males usually involve only pushing and shoving, and the antlers are more for display than combat. The bugling is also a warning to other males.

The Rocky Mountain elk (C. canadensis nelsoni) is the largest of the North American elk and the largest of the red deer species worldwide. In Europe, “elk” refers to the American moose (Alces alces), and “red deer” to C. elaphus, although European and Asian red deer are much smaller than American elk. There has been a largely unsuccessful push in North America to call C. canadensis by its Shawnee name, “wapiti,” meaning “white rump.” Like “buffalo” for the American bison (Bison bison), the name “elk” has centuries of inertia behind it.

Park Ranger Harv Burman giving an elk talkSigns of elk–tracks, scat, scarred aspens, and broken ponderosa saplings–are common sights in the Front Range, but elk themselves are more elusive. Hundreds of elk graze and mate in the park in fall. In September and early October, park rangers at Florissant Fossil Beds National Monument lead evening programs to listen and look for elk. The chances of hearing the elk are very good, but elk sightings occur less often.

Many quaking aspen (Populus tremuloides) trunks in the park are scarred from elk eating the bark. Aspen bark is photosynthetic and a favorite of elk, especially in winter when nutritious grazing is hard to come by. Unfortunately for the aspens, elk chew makes them vulnerable to infection. Canker-invading fungi such as sooty-bark canker (Encoelia pruinosa) attack the trees, often killing them. Because aspens stands are “clones” with a common root system, fungus spreads rapidly from tree to tree. Sometimes a combination of overgrazing and fungus can kill an entire aspen clone.

The last elk walk this year will be on October 13, but you can always visit the park to listen and look for elk yourself. Nearby Mueller State Park is also a good place to spot elk.

ELK-SPOTTING TIPS

  • Early morning and late evening in fall are the best times to see elk in the Front Range.
  • Elk are color-blind, so it doesn’t matter what you wear, but try to stay in the cover of the trees.
  • If you spot a herd, approach quietly and slowly from downwind. Elk have excellent senses of hearing and smell.
  • Stop and listen frequently for the distinctive wailing bugles of the bulls. Elk herds can travel and change direction quickly.
  • If you want a virtual guarantee of seeing elk and don’t mind them being practically tame, visit Rocky Mountain National Park. In this area, elk are so used to humans they have become pests.

-Melissa Barton

Photo Credits: PDPhoto.org/Jon Sullivan (elk at Yellowstone), Melissa Barton (broken sapling and Ranger Burman giving a talk)

*Some biologists classify American elk as belonging to the same species as European and Asian red deer, C. elaphus. Recent genetic studies suggest that American elk belong to a different species from red deer. Further studies will clarify the relationship of different species and subspecies of red deer and American elk (return to article).

August 31, 2007

Driving the Gold Belt Byway: Indian Springs Trace Fossil Site and Phantom Canyon (Stops 19-21)

Filed under: Activities, Biology, Geology, Gold Belt Byway, History, Paleontology, Science, Travel — The Friends of the Florissant Fossil Beds, Inc. @ 12:00 pm

Our last major stop for the day on the Gold Belt Byway was Indian Springs Ranch, a ranch and campsite owned by the Thorson Family. The Indian Springs Trace Fossil Site is a National Natural Landmark (NNL) protected by the federal government, but it is owned by the Thorson Family and you must have permission and be accompanied by a family member to visit the site. Tours may be arranged by calling ahead.

Photo of chinchweed flowersCarly Thorson, who led our tour, is very knowledgable about the many plants of the ranch, as well as its history. The flower to the left is chinchweed (Pectis papposa), a lemony-scented plant with several medicinal uses. We also saw a petroglyph and some historical sites, including the cabin used by Wild Bill McKinney of Quantrill’s Raiders.

Photo of National Natural Landmark markerThe Middle Ordovician (c. 450 million years old) trace fossils were found by Thorson’s father, Bennie C. Thorson, who worked the site for five field seasons with now-retired Colorado College professor William A. Fischer. The site was designated as an NNL in 1979. The voluntary NNL program, administered by the National Park Service, provides a way to recognize and protect important natural resources on any type of land, including private, local, municipal, state, and federal. Not all NNLs are open to the public, and many others require landowner permission to visit.

Photo of Indian Springs Trace Fossil SiteThe Indian Springs Trace Fossil Site consists of a shallow excavation exposing a single bed of the Harding Sandstone, representing an “instant” in geologic time. The quarry is 16-18 feet above the base of the Harding. Much of the overlying sandstone has been eroded at this locality. The Thorsons keep the site covered to protect the exposed trace fossils, which remain in situ according to family policy.

Photo of sea scorpion trackBody fossils are rare in the Harding, including at Indian Springs, but trace fossils are abundant. Bony plates from ostracoderms (armored fish) and conodont elements are found there, but the site’s primary significance lies in its spectacular trace fossils from various animals moving across the Ordovician seafloor. At right, you can see a track left by a sea scorpion (eurypterid).

Photo of ostracoderm feeding traceOstracoderms were some of the earliest vertebrates. They lacked jaws, but were covered with bony plates, and were also the first organisms to use gills exclusively for respiration. Ostracoderms were bottom-feeders and probably relatively slow-moving. Here you can see a feeding trail of an ostracoderm. The close spacing of the feeding marks indicates that food was abundant on the Ordovician seafloor.

Photo of horseshoe crab feeding traceTracks of several species of horseshoe crabs are quite common. The feeding traces typically curve either left or right according to the species. Horseshoe crabs are not actually crabs–they are more closely related to sea scorpions, and distantly related to the spiders–and they have evolved little since they first appeared in the fossil record. They are tolerant of harsh environments and protected by their sturdy shell.

Photo of ostracoderm feeding and predator attack tracesThis trace fossil shows an abruptly ended ostracoderm feeding trail, as the fish became a meal for a predator. The preservation of interactions like these is one reason the Indian Springs fossil site is so important. Other trace fossils at this site include tracks from trilobites, merostomes, and polychaete worms.

After Indian Springs, we drove back through Phantom Canyon (Stops 19-20), the location of several historical railroad sites, as well as more outcrops of Precambrian granodioriate and metamorphic schist and quartzite. We didn’t manage all of the stops on the Gold Belt Byway–that would take at least two days–but we had a great field trip.

-Melissa Barton

Photo Credits: Melissa Barton

Geologic Guidebook to the Gold Belt Byway, Colorado, by Thomas W. Henry, Emmett Evanoff, Daniel A. Grenard, Herbert W. Meyer, and David M. Vardiman (Gold Belt Tour Scenic and Historic Byway Association, 2004), is available at the Florissant Fossil Beds National Monument Visitor Center for $19.95 plus tax.

More Gold Belt Byway Posts:

August 21, 2007

Species Spotlight: Mountain Mahogany

Filed under: Biology, Paleontology, Species Spotlight — The Friends of the Florissant Fossil Beds, Inc. @ 12:00 pm

Photo of modern mountain mahogany seed cluster

Seed clusters of living mountain mahogany, Indian Springs Ranch, Colorado.

Mountain mahogany (Cercocarpus) is a small genus of deciduous shrubs or small trees, currently placed in the rose family (not closely related to true mahoganies, in the Meliaceae family). In addition to growing throughout the Rocky Mountain region today, mountain mahogany is a relatively common Tertiary (65 to 1.8 million years ago, the time between the extinction of the dinosaurs and the first Ice Age) fossil found in the Florissant and Antero Formations, as well as at Creede, Webber Lake in the Sierra Nevada of California, the Desert Peak Formation of Nevada, Oligocene sediments in Mexico, and many other localities.

Photo of mountain mahogany fossil from the Antero FormationMountain mahogany seeds are more common than leaves in the Florissant Formation (34.07 million years old), although the numerous hairs of the modern seeds (above) are not evident–seeds are generally preserved as a small oval seed with a long curling tail. In certain localities in the nearby Antero Formation (~33.76 million years old), mountain mahogany leaves are the most abundant fossil. At left you can see the well-preserved part and counterpart of a mountain mahogany leaf from the Antero.

Photo of fossil mountain mahogany and pine from the Antero FormationWe haven’t found any mountain mahogany seeds like the ones from Florissant in the Antero yet, only leaves. Further study will show whether the Antero mountain mahogany more closely resembles the species from Florissant or the species from the Oligocene Creede flora, which grew in a much colder climate than that of ancient Lake Florissant.

-Melissa Barton

Photo Credits: Melissa Barton

August 15, 2007

Summer Seminar Series ends with aspen ecology

Filed under: Biology, Conservation, Ecology, Education, Seminars — The Friends of the Florissant Fossil Beds, Inc. @ 4:13 pm

Aspen grove

Dr. Wayne Shepperd’s aspen ecology seminar on August 11th finished the summer seminar series. The seminar was well-attended by local teachers, who had a chance to go out in the field to see different aspects of aspen ecology and discuss possible conservation methods for encouraging growth in different types of stands.

Looking for aspen suckersAt left, students look for aspen suckers in the meadow by the Fowler Education Center. Aspen send out root suckers in an area that extends up to 150 feet from the main grove. This is their primary means of propagation. If the park wished to encourage the spread of this aspen grove, fencing the meadow to protect it from elk and deer would be a logical first step.

Aspen suckerAspen grows rapidly and, in Colorado, can reach ages of up to 300. The average age of an aspen tree in Colorado is about 120.  Healthy clones produce numerous suckers.  There are a variety of ways to encourage aspen clones to sucker, including controlled burns or trenching to cut suckers off from the mother tree.

-Melissa Barton

Photo Credits: Melissa Barton

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