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Ecosystem Overview Consider for a moment prehistoric people. Think about how they made their shelters, hunted for food, wore animal skins, were warmed by the heat of a fire. Now consider the difference in our modern lifestyle from that of prehistoric people. We have isolated ourselves from nature behind an increasingly complex technology. Today we are dependent upon grocery stores for food, stoves and microwave ovens for cooking, building contractor for our homes, natural gas for heat, electricity for light, and a faucet for water. Behind it all is a complicated economic system of resource extractors and producers, manufacturers, advertisers, sales people, shippers, and retailers who supply these needs. Today you don't have to sneak up on a bison and kill it so you can eat, but the fact remains that we are as dependent upon nature as our prehistoric ancestors. There is nothing you have or use that did not have its origins in nature. Think about this. I've tried to come up with something I have that does not originate in nature, but I can't. You won't either. This is just one reason ecosystems are important for our survival. The Dinosaur ecosystem contains a landscape of great beauty and variety. The variety grew out of the past geologic events and current geological processes of weathering and erosion by ice, running water, and wind. Uplift and erosion of the Uinta Mountains during the past 65 million years has exposed 26 rock formations within the monument. Each rock formation weathers into its own soil type (sand or clay) with varying chemical characteristics. The variety in soils results in a variety of plants adapted to those soils. Erosion by the Green and Yampa rivers and several creeks in the monument have carved deep canyons with side-draws and parks. The varying elevations (4,900 to 9,000 feet) of the landscape and exposures of slopes to the sun result in varying accumulations of precipitation and niches for plants. Environmental variety due to the landscape results in a variety of plants and animals. Variety also springs from the abundance of water from the aforementioned rivers and creeks. In Utah, communities associated with rivers and wetlands are the most productive of all the communities for plants and animals. The Green River is a natural thoroughfare for migratory birds, aquatic animals, pollen, seeds, plant cuttings, and overland colonizers seeking new habitat. Thus, we have some residents whose natural home is in the Sonora Desert in Arizona and the Wind River Range in Wyoming. Dinosaur's location also adds to its variety. The monument is situated where four physiographic provinces meet and overlap. Thus, the monument is home for plants and animals from the Wyoming Basin, Rocky Mountains, Colorado Plateau, and Great Basin. By now it should not be surprising for you to read that Dinosaur National Monument is blessed with great biological diversity. There are over 600 species of plants, over 3,000 species of insects, 21 reptiles, 219 birds, 68 species of mammals, and the lists can go on and on. The more we look, the more we find. So, what is an ecosystem? Let's take care of some definitions. Organism = An individual plant or animal. The communities comprising the Dinosaur ecosystem are the aquatic riparian, desert shrub, pinon pine and juniper forest, mountain shrub, and montane coniferous. The principle living and nonliving environment of communities in an ecosystem consist of the physical environment, the chemical environment, the living environment, and energy (sun). These four categories comprise all the nonliving and living parts in an ecosystem, as well as the interactions that occur within the system.
The physical environment consists of such things as: Light, Elements (oxygen, carbon, hydrogen, etc.), Food chains are just one of the many interactions between plants and animals and their nonliving environment. Organisms in a food chain can be grouped by their function. The diagram below illustrates a simple food chain that can be found in the desert shrub community.
Another way to understand the interactions within a community is to construct a food web. A food web is a complex of feeding relationships (food chains) in a community. The diagram below is derived from the desert shrub food chains just mentioned.
Yes, this is a confusing diagram; there are a lot of connection lines going in a lot of different directions. This is similar to real life, but in an actual community the number of connections are even greater and far more complex. A rule to keep in mind is this: All things, including you and me, are interconnected. If you hurt one thing in the web of life, you will affect everything connected to it. That could be you!
Communities Within the Dinosaur National Monument Ecosystem Dinosaur National Monument, and the country surrounding the park, is mountainous. The variations in elevation caused by these mountains produce significant variations in precipitation, temperature, the exposed geologic substrate and resulting soil, and the orientation of slopes to the sun (aspect). These variations, brought together by topography, allow different communities to co-exist in a relatively small area, such as the monument. As one goes up in elevation, the communities sort out into bands along the mountainside (figure17). In turn , each community provides habitat for particular organisms. The greater the number of communities that are present, the greater the diversity. The greater the diversity, the greater the ecosystem stability. The greater the ecosystem stability the greater our material, aesthetic, and recreational wealth. The greater the natural wealth, the greater is our responsibility to maintain ecosystem integrity and to be ever watchful for threats.
Figure 17: Uinta Basin Communities.
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