As disastrous as wildfires can be, such phenomena remain an integral part of the planet’s natural ecology – especially when it come to the health of our soil, streams, grasslands, forests, and wildlife resources. Many people consider all wildfire negative, whereas the opposite is true.
Long before humans reached the North American continent, wildfires raged whenever conditions were favorable. As part of nature’s plan, smaller fires resulted in age-structured mosaics that controlled understory competition and allowed surviving trees to mature faster. Perhaps more importantly, this process lowered the odds of widespread destruction from larger, hotter forest fires.
Although times have changed, and America’s human population has surpassed 325 million, nature still adheres to a strict discipline of natural law. In certain cases, even hot canopy fires are beneficial; in the West, lodgepole pines and sequoias require extreme temperatures to melt away protective resins from their cones, which initiates seed release and dispersal. Other trees, like the Ponderosa pine, have thicker bark, which protects the cambium layer from heat. Several species employ an adaptation to lose their lower limbs for preventing fire from climbing up the trunk to the canopy. The shortleaf pine, of Southern latitudes, is fire resistant, but not fireproof. Whenever the trees succumb to fire, they generate new sprouts from these basal buds.
To truly understand the importance of wildfire in America, it is imperative to flip the pages of history back several hundred years. Prior to European colonization and settlement of the American West, the country’s topography between the Mississippi River and the Rocky Mountains was primarily grasslands – the likes of shoulder-high big bluestem, Indian grass, and switchgrass. Not only was fire a part of America’s historical tall-grass prairies, without it they did not exist. Leafy debris from the plant-life growing in these highly fertile, wide open spaces resulted in thick ground cover that choked out sunlight vital to the growth of new shoots of grasses and forbs. Also, minerals in the biomass mats were locked up until the lengthy decay process was completed. However, when conditions were right, lightning from summer thunderstorms ignited the grasslands. Driven by high winds, wildfire storms scorched large expanses of the open country, thus removing the residual material and invading shrubs. Not only did wildfires eliminate the debris, it released a vast amount of life-sustaining nutrients back into the soil – thus spurting new plant growth to support a diverse population of wildlife. Today, the majority of America’s historical grasslands have been converted into croplands and pastures; all that remains are remnant areas protected to remind us of the past.
Wildfires can have both positive and negative effects on stream water quality – a complicated issue with no shortage of opposing theories. As expected, intense fires are the most destructive. The loss of protective vegetation from surrounding landscapes and excessive rainfall results in sediment and minerals washing into the streams; not to mention the loss of tree canopies that serve to keep water temperatures in a healthy range for temperature-sensitive aquatic life. Erosion is a natural part of nature’s scheme, but heavy deposits of sediment and minerals drastically affects a stream’s ability to provide quality habitat. Under normal conditions, meaning smaller and less intensive wildfires, streams recover quickly; in some cases, they are even revitalized. The bad news, because of climate change that is affecting the world’s weather patterns, wildfire occurrence and intensity is increasing in parts of our country.
As related to wildlife, fire is instrumental in restructuring plant succession – nature’s tool to establish unique habitats for its diverse community of animals. When grasslands become inundated with shrubs, populations of ground-nesting birds and small mammals are reduced. Fire, however, removes invasive woody shrubs and recycles nutrients to reenergize the soil for promoting growth of new grasses. Some creatures require plant succession that includes a mixture of grasses, forbs, and a younger generation of woody plants; a lack of fire assures such. In growing forests, fast-burning fires remove the understory to reduce plant competition and release nutrients back to the soil, thus enhancing tree growth rates. Mature hardwoods are necessary for a wide range of animals, but provide little in the way of food and protection for others. Here, intense fires open up the tree canopy and permit sunlight and rain to reach the forest floor. These breached areas generate a wealth of new plant growth essential to certain species. In areas where fire is suppressed, plant succession maps out nature’s long-term course of action.
When it comes to managing wildlife populations, today’s natural resource conservationists often utilize prescribed burns as a means of either generating or maintaining distinct types of habitats to satisfy the needs of specific animals. The key is establishing and implementing a management plan that provides different levels of plant succession – including grassy fields, old-field habitat, early successional woody habitats, and mature hardwood and conifer forests. These control burns eliminate the buildup of woody debris that fuels larger, hotter, and more destructive wildfires. And just like wildfires, intentional burns recycle nutrients back into the soil, enhance wildlife habitat, slow infestations of insect pests and noxious weeds and, by eliminating competitive vascular plants, increase the growth rate of trees vital to the forest product industry. In order to accomplish the plan’s objectives, persons in charge of the fire have to consider variable conditions, such as temperature, humidity level, and wind direction and speed. As the largest group of landowners, the private sector must accept its inherent responsibility of natural resource stewardship, which often begins with lighting a drip-torch. Native Americas not only understood the concept, their lives depended on its success.