Ecological Modeling as a Tool for Conservation

Abstract

In a time when undeveloped habitats are shrinking it is very important to instill a understanding for conservation and biodiversity in the general public. Ignorance of basic ecological principles such as the effects of disturbance or the requirements for maintaining an area's biodiversity leads to a misunderstanding of conservation practices. As a result, visitors at times unintentionally misuse areas set aside for conservation or fail to fully experience the benefits such areas offer (Hammitt and Cole 1987). Even some landowners who have set aside their land for conservation mismanage due to a lack of basic ecological knowledge. For example, a landowner once asked me to clear off 25 acres of dead wood and leaves because he thought the material made it harder to see wildflowers. He was completely unaware of litter's value in soil development, moisture retention, and providing cover.

Teaching something as basic as the relationship between environmental variation and community composition could enhance experiences in natural areas and improve management by private landowners. This goal can be advanced by developing user-friendly materials that reflect results from predictive ecological models. Such models have been effectively applied to a variety of questions about impacts associated with development of biologically sensitive areas (Chiarucci 2001), as well as questions about distributions and requirements of threatened species (McGraw 2003). An education program that utilizes ecological modeling could convey ecological principles in an easily understood fashion. Linking ecological modeling and education can instill basic understanding of scientific principles that provide the biological support for conservation.

Ecological models used to predict plant community types are based on the relationships between plants and environmental factors that vary across habitats and through time. Environmental variation affects plant communities by regulating which species coexist in particular locations. Variations in factors such as light, nutrients, and water-variables that directly affect plant growth-are characterized as direct environmental gradients. Environmental factors like elevation, aspect, and slope do not directly affect plant growth, but they do influence direct gradients, and changes in these factors are described as indirect environmental gradients. Predictive models based on indirect gradients are well suited for educational purposes because the environmental variables and their biological associations are easy for even the most casual observer to see. Although models based on indirect gradients are less generalizable than models based on direct gradients, their use is appropriate if not preferable when designed for a specific region (Austin 2002).

Community prediction from ecological gradients has a variety of conservation applications. Whittaker's (1956) work with moisture gradients accurately predicted species composition in the Great Smoky Mountain National Park (GSMNP). Lehmann et. al (2002) describe the power of regression models to predict the sustainability and suitability of tracts for conservation (Margules and Pressy 2000), and to determine the diversity or potential diversity of a region. Chiarucci et. al. (2001) determined from canonical correspondence analysis of environmental gradients in Tuscany Italy that soil texture and nutrients and elevation have greater influence than presence of heavy metals on plant community composition. The locations of heath balds in the GSMNP have been modeled with moisture, aspect, and light factors (White et. al. 2001). Elevation and aspect have also been used to predict the locations of the species of concern Panax quniquifolius (McGraw 2003). These studies show the potential of ecological modeling to provide basic information necessary to conservation.

Expanding more environmental education programs beyond human ecology to include concepts about biodiversity and biological communities could provide an opportunity for increased understanding for the needs of conservation areas. Educational programs that use simplified scientific techniques can be easily understood, while conveying deeper biological meaning. For example a description of the correspondence between local plant communities and indirect environmental variables can be written as a branching key (Table 1) for easy identification of plant communities. Environmental gradients can be arranged according to the strength of the correlations between the gradient and differences in community types. Following the key, the individual chooses values of environmental factors based upon their own observations. After evaluating several environmental factors the user will come to the resulting plant community type for the location. If the key is properly used the individual will identify the community and have a list of species characterizing. The process could be done in a group or individually, with or without the help of an educator once the technique is learned. By learning about differences in environmental gradients and their effect on plant communities, a user can learn why plant community composition is so closely related to habitat.

This type of model has broad applications important to conservation efforts. For example these models can be used to identify key areas for conservation by land managers and conservation groups. They can also be used to identify specific management needs. A plant community key built from an ecological model can be used to identify areas where a species or community may be located. Restoration ecology can also benefit from this tool as a guide for revegetation efforts in disturbed areas. Encouraging individuals to identify these areas at the education centers can initiate similar exploration on private lands and the creation of stepping stones between conservation areas. Modeling herbaceous community reactions to disturbance can indicate areas that should be avoided/utilized during logging practices or other land manipulations. A model that is accurate over a region could provide a resource for many education centers and even local state and federal park systems such as the Great Smoky Mountains National Park's education center. This type of model can be used by science teachers in the state school systems allowing for hands on activity for middle school, high school, and college students.

In conclusion, an understanding of basic ecological principles can be taught by incorporating ecological modeling into environmental education. Helping individuals observe their natural surroundings with simple scientific techniques will help reveal the connection between habitat and diversity. Providing a simple tool to describe ecological characters and properties could increase efforts at conservation. This type of environmental education will cultivate support for conservation efforts through increased understanding and respect. This increased respect will allow for more effective conservation on both state and local levels.

Literature Cited

Chiarucci, A., D. Rocchini, C. Leonzio, and V. De Domingicis. 2001. A test of vegetation-environment relationships in serpentine soils of Tuscany, Italy. Ecological Research 16: 627-639.

Hammitt, W.E. and D.N. Cole. 1987. Wildland recreation: ecology and management. John Wiley and Sons, New York. 341 p.

Margules, C.R. and R.L Pressy. 2000. Systematic conservation planning. Nature 405: 243-253.

Mc Graw, J.B., S.M. Sanders, and M. Van Der Voort. 2003. Distribution and abundance of Hydrastis Canadensis L. (Ranunculaceae) and Panax quinquifoleous L. (Araliaceae) in the central Appalachian region. Journal of the Torrey Botanical Society 130(2): 62-69.

Lehmann, A., J.M, Overton, and M.P. Austin. 2002. Regression models for spatial prediction: their role for biodiversity and conservation. Biodiversity and Conservation 11: 2085-2092.

White, Peter, S.P. Wilds, and D.A. Stratton. 2001. The distribution of heath balds in the Great Smoky Mountains, North Carolina and Tennessee. Journal of Vegetation Science 12: 453-466.

Whittaker, R.H. 1956. Vegetation of the Smoky Mountains. Ecological Monographs 26: 1-80.

Table 1. Branching key based on hypothetical environmental gradients. An individual on a south-facing nose with 45% slope at 2,450 feet could follow these steps to identify Plant Community B. The branching key will consist of a page for each of the major environmental gradients (in this case aspect) used in the model. The packet will include a description of each community type with a list of dominant species.

ASPECT ELEVATION (ft.) SLOPE (%) RELATIVE LOCATION COMMUNITY TYPE SOUTH 2000-3000 0-30 SLOPE Community A NOSE Community B HOLLOW Community C 30-60 SLOPE Community A NOSE Community B HOLLOW Community D 60-90 SLOPE Community B NOSE Community E HOLLOW Community F 3000-2000 0-30 SLOPE … NOSE … HOLLOW … 30-60 SLOPE … NOSE … HOLLOW … 60-90 SLOPE … NOSE … HOLLOW …