By Josh Pike
Pagosa Wetland Partners
When you think about the Pagosa Springs Riverwalk wetlands that lie between the Ross Aragon Community Center and the San Juan River, you likely think of birds. The 183 recorded bird species in the wetlands are a sign of exceptional species diversity, and a major draw for birders and other observers who frequent the area. Several of these birds, such as the great blue heron, frequently seen along the Riverwalk wetlands, may be termed “charismatic species” because of their reputation and popularity to residents of Pagosa Springs.
A charismatic species is an animal with symbolic significance, or widespread popular appeal. Such species are often the nexus of conservation movements, bringing a recognizable face and appeal to efforts to preserve the environment. An excellent example of a charismatic species is the polar bear, which has become a central symbol in the struggle against global warming. However, successful conservation and environmental efforts of either birds or bears must go beyond simply protecting these symbolic species from death by starvation or hunting, and work to support the broad range of species that directly and indirectly allow these charismatic animals to thrive.
The relationship between charismatic species and the broader environmental systems is often conceptualized in terms of food webs, a system of interlocking food chains. Food webs have four main elements: 1) the solar and mineral resources that support the system, 2) the primary producers, 3) the various kinds of consumers and 4) the decomposers.
All of these elements are active in our local wetlands and work to support the communities of birds and other animals that we so enjoy. In the context of the Riverwalk wetlands, environmental resources are represented by the ample sunlight and the unique minerals that constantly flow into the wetlands, fed by geothermal seeps. These resources are consumed by the primary producers, including waterside plants like cattails, reeds and a variety of algae, which convert these largely inorganic resources into a biomass of nutritious organic material. Plants and algae are then, in turn, consumed by a wide variety of insects, invertebrates, birds and mammals who constitute the consumer class of the wetland.
Animals, like mice, that directly eat primary producers (plants) are referred to as “primary consumers,” while animals, like hawks, that eat these primary consumers are referred to as “secondary consumers.” This system continues upward through the range of consumers who are increasingly distant from directly eating plant biomass or other products of primary producers.
Many species, however, do not cleanly fit into a single level of consumer behavior. Hawks, for example, eat both primary consumers (mice) and secondary consumers (smaller birds), while the smaller birds feed on insects (either a primary or secondary consumer) and fruits/seeds (a primary producer). Thus, a simple food chain becomes a complex food web of interrelated parts.
Finally, all organisms die, and the decomposers, including insects and bacteria, bring the cycle of the food web to its conclusion by breaking down and returning the organic elements that were initially absorbed into the web by the primary producers to the soil and water, thus allowing the cycle to begin anew.
The immense complexity and interweaving structure of food webs, even in small environments like the Riverwalk wetlands, means that protecting charismatic species is considerably more complex than it might appear. If one key element of the food web is diminished or damaged, the entire web suffers and begins to collapse due to the close interlinkage of the organisms in the web. Examples of damaging impacts may include: the flow of mineral water being reduced or contaminated from commercial runoff, a specific insect or amphibian species succumbing to disease or environmental degradation, or algae blooms being reduced due to increased levels of pollution and toxins. Thus, a conservation approach that protects the entire ecosystem is crucial.
Food webs do have a degree of plasticity. Organisms adapt and find new food sources to substitute for missing ones, or new species move in to occupy the niches left by declining ones; however, this plasticity only extends so far. Because of this, our efforts to protect charismatic species must extend beyond direct protection into ensuring that the web of supporting environmental conditions and organisms remains intact.
As the Pagosa Wetland Partners work to protect the beautiful Riverwalk environment, enjoyed by both tourists and locals alike, a whole-ecosystem approach to protection will be critical to ensuring their preservation for future generations. If you want to learn more or get involved in protecting our wetlands, please contact Pagosa Wetland Partners, an affiliate of the Weminuche Audubon Society, at Pagosawetlands@gmail.com or visit us on Facebook at www.facebook.com/pagosawetands.