GSM 2017 Nebraska Day 6
Sep 14, 2017Public
Photo: We'll start with yet another orientation within Nebraska: The area we explored on Day 6 is within the red rectangle, in the heart of the Sand Hills
Photo: After meeting back in North Platte, we roughly followed the black line.
Photo: We started with a beautiful sunrise over Lake Ogallala at Cedar Point Biological Station.
Photo: Sherry was delayed due to keys locked in her car; AAA to the rescue. She caught up with us by late morning. (photo by Sherry)
Photo: Our first stop was in the heart of the Sandhills, where Highway 83 crosses the Dismal River.
Photo: The Highway 83 bridge caught someone's eye.
Photo: I had passed this same area when returning from the GSM Colorado Front Range field trip in June, 2010. This photo was taken then,  late in the afternoon, so the shadows were longer.
Photo: (2010 photo) The Dismal River is a winding 71.9-mile-long river in Nebraska. Most of the land along the river is privately owned and used for ranching. The water comes from the Ogallala Aquifer and boils up beneath the river in places, sometimes creating areas of quicksand.
Photo: Deer, coyotes, beavers, turkey and rattlesnakes inhabit the area along the river. Much of the river's length is unpopulated.
Photo: The Sandhills is a region of mixed-grass prairie on grass-stabilized sand dunes in north-central Nebraska, covering just over one quarter of the state. The dunes were designated a National Natural Landmark in 1984. Dunes in the Sandhills may exceed 330 ft in height. The average elevation of the region gradually increases from about 1,800 ft in the east to about 3,600 ft in the west.
Photo: Paul explains the formation of the Sandhills. They are composed of sand eroded from the Rockies and blown east.
Photo: Paul's hand-drawn diagrams show three general shapes of sand dunes (top): crescent-shaped (barchan), parabolic, and linear. As shown in the bottom diagrams, most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a slack.
Photo: The Sandhills sit atop the massive Ogallala Aquifer; thus both temporary and permanent shallow lakes are common in low-lying valleys between the grass-stabilized dunes prevalent in the Sandhills. The eastern and central sections of the region are drained by tributaries of the Loup River and the Niobrara River, while the western section is largely composed of small interior drainage basins.
Photo: Junipers are coniferous plants in the cypress family. Junipers vary in size and shape from tall trees, 66–131 ft tall, to columnar or low spreading shrubs with long trailing branches. They are evergreen with needle-like and/or scale-like leaves.
Photo: The female seed cones are very distinctive, with fleshy, fruit-like coalescing scales which fuse together to form a "berry"-like structure, 0.16–1.06 in long, with 1–12 unwinged, hard-shelled seeds. In some species these "berries" are red-brown or orange but in most they are blue; they are often aromatic and can be used as a spice.
Photo: A juniper berry is the female seed cone produced by the various species of junipers. It is not a true berry but a cone with unusually fleshy and merged scales, which give it a berry-like appearance. Unlike the separated and woody scales of a typical pine cone, those in a juniper berry remain fleshy and merge into a unified covering surrounding the seeds. The berries are green when young, and mature to a purple-black colour over about 18 months in most species.
Photo: (2010 photo) The World Wide Fund for Nature designated the Sandhills as an ecoregion, distinct from other grasslands of the Great Plains. According to their assessment, as much as 85% of the ecoregion is intact natural habitat, the highest level in the Great Plains. This is chiefly due to the lack of crop production: most of the Sandhills land has never been plowed.
Photo: Paul leads Deb and Nina to our second Sandhills site, which is in a fenced cattle pasture south of Mullen, NE. (Cattle pastures featured prominently in this field trip!)
Photo: Yucca seed pods by a fence post.
Photo: Paul has scouted out this dune and featured it in previous field trips he led, since it is one of few that has an outcrop.