WWNFF Environmental Science Institute 1997

            "He who learns from one occupied in learning, drinks from a running stream. He who learns from
              one who has learned all he is to teach, drinks 'the green mantle of the stagnant pool.'"
                                                                                                        A. J. Scott, 1852
The Role of Fire in
the New Jersey Pine Barrens & in Nebraska Prairies
 
Kirsten Smith & Steve Ferris (Team #36--Lincoln, NE)
 Image: Prairie Fire
What fire does within natural ecosystems is commonly misunderstood.  As a force in the environment, fire is neither entirely good nor entirely bad.  Our usual single-minded response to a fire in our environment is to extinguish it as quickly as possible.  Most of us look on fire as a terribly destructive force but everyone should know of its regenerative effects in natural systems.  Fire can stimulate growth, eliminate competition by invading weed species, induce seed germination, and do many other "good" things.  Fire-adapted species of the tall-grass prairies survive occasional burning by having underground buds.  The buds also enable the plants to survive close grazing by bison, elk, cattle, or sheep. Fire and/or grazing may eliminate some expendable parts of the plant but they generally do not kill the plant itself. Fire has never not been a force in nature; species and ecosystems have evolved in concert with fire for millions of years.  At critical seasons, suppressing fire can cause more undesirable change in certain biomes than would allowing fires to burn.  (Click for a brief look at some positive roles of fire.)

Among the biomes which may be said to have evolved with fire are the North American grasslands, the New Jersey sand-dwelling pine/oak forest communities (eloquently described in John McPhee's book The Pine Barrens), the South African fynbos, the chaparral and oak groves of California, the long-leaf pine association of the Gulf Coast, and the Australian eucalyptus-dominated ecosystems.  Native American peoples utilized fires for hundreds of years to manage food resources in many regions of the continent.  Prescribed fires are used proactively today to control wildfires in the Pine Barrens and to control woody weedy species in prairie grasslands.

At the beginning of the institute, we started with the hypothesis that occasional fire increases both the soil nitrate content and the diversity of soil invertebrates.  We drove several times to the Pine Barrens (near Whiting, NJ) to collect soil.  We performed nitrate analysis using a LaMotte soil nitrate test kit, and we used Berlese apparatuses to extract invertebrates from samples. Our data were inconclusive but we feel more study is warranted.  In every sample we took, tested soil nitrate levels were "less than ten pounds per acre" which may be due to the intense leaching of the sandy soil by rainfall -- no differences between burned and unburned locations were detected.  Soil invertebrates were only found in one sample (from the duff, or litter, layer), but this may have been due to the low moisture content as well as the relative infertility of the sand.

We believe that testing may be more interesting and prove more conclusive in Nebraska.  We can spend more time on more extensive research in Nebraska, and both of us plan to involve our students in the study of soil invertebrates.  We will also investigate more sensitive ways to determine amounts of nitrates (and phosphates) in grassland soil.

Since fire has played a vital ecological role in many regions around the world, it can serve middle- and high-school teachers as a motivating focus for scientific investigation as well as an opportunity for cross-disciplinary studies involving mathematics, social studies, literature, and art.  Occasional fire (either deliberately set or not) has positive roles in many ecosystems and, in many cases, actually increases the biological diversity within the system.  Understanding that by "destroying" a plant by burning it we may help it during its next season of growth will encourage students to take a "long view" of life processes.  We believe that students who develop an understanding for the dynamics of fire in the biological landscape will begin to appreciate its effect on the ecosystem.  Knowing that one's own area contains unique and fascinating natural areas having complex interaction of biotic and abiotic factors will perhaps instill a sense of pride in the local landscape.

Many comparison studies can quite readily be made between burned and unburned portions of a prairie (or a forest, a desert, etc.)  We suggest the following investigations:  growth rate comparisons, soil nitrate level and/or phosphate level comparisons, soil invertebrate diversity comparisons, soil temperature comparisons, native/alien diversity comparisons, Geographic Information System (GIS) analysis of burned and unburned plots, as well as more traditional plant/animal identification, construction of bloom-time calendars, etc.  Some investigations will be quick while others involve much more effort and time, but a fire-driven system will be useful for study throughout the seasons. [Note:  Fire has similarities to grazing as a force on vegetation because of its feedback effects; if you don't live near fire-managed natural communities, grazed land may provide similar opportunities for investigation.]

In our Web-Portfolio-To-Be we will include other suggestions for class research, outlines for possible class activities, multicultural and inter-disciplinary ideas, and hotlinks to related web sites.

Please send any comments about this page to:
            Kirsten Smith
            Steve Ferris (team contact)

A view of the Pine Barrens from our camera
Teacher activity:  National Science Teaching Standards
Information from the Northern Prairie Science Center
More information on the Tallgrass Prairie
More information on the Pine Barrens
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 image: Under Construction