The RoVing Naturalist: Climate change and succession

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By Dennis Prichard

I attended a meeting of forest ecologists some 20 years ago wherein the scientists presented speeches on what might happen in the future in respect to forests in the Southwestern U.S. Their predictions were rather dire.

Fire was a major topic as is usual with foresters. The effects of fires had been studied extensively, and new technology made predicting natural phenomena much easier with more precision. A computer program is fed information as to the conditions at hand on any given parcel of forest. Info including how dry different types and sizes of wood were, height and species of each type of plant in the area, wind speed, direction and estimated duration were all plugged in and gave practical information for a fire crew. If a fire did start, they could predict how fast a fire could spread, how large it may get, and even the flame heights. With this in mind, the fire bosses sent crews far enough in front of the fire to have time to build lines to contain it.

Fire ecologists, though, predicted that as the planet warms, even a few degrees, certain things were going to happen. First, there would be more fires, or the number of incidences would rise. Second, these fires would be bigger in acreage – more trees would be burned than ever before. Third, the fires would be worse in that they would totally destroy the vegetation of a given area, not just singe the bottoms of the trees.


Others and I could see the logical progression of their thinking, but never thought it would come about in our time. This was just a little too much change in too little time. Lo and behold, they were proven right over the next two decades. There were more fires and more acreage burned, and the fires were hotter, causing losses of all mature trees in an area.

There was one other prediction those scientists and field foresters had made that eclipsed all the others. After a fire, burned areas usually regenerate plant species, and over generations, would return the forest to its original state just before the fire, something called the “climax community.” Now that the climate was changing and temperatures were rising, the burned area would not return to climax community status. Forests would become shrublands, shrublands would become grasslands, and grasslands would turn to deserts. From tree ring records the experts could read the histories of the trees and learn of the frequency of fires in the past, and their relative destructiveness. The future looked like it would be hotter than ever both in temperatures and fire effects.

Another prediction caused a lot of biologists to worry about species extinctions. The so-called “Sky Islands” on the peaks of the tallest mountains held species that had slowly retreated to the summits as the Ice Ages warmed. These creatures could no longer survive in hot, dry climates and were trapped by the “sea of desert” that lay between them and the next higher mountaintop sanctuary. Thus, like the proverbial ice cube, these islands would start to warm and “melt,” and with each came a loss of another species. Soon, those species which had survived for thousands of years now have their habitats change so quickly that they cannot continue and cannot migrate. They are lost forever.

Sadly, the scientists were right. More serious fires and more acres have burned, as has been evident from the news. I hope we were wrong about the plant succession and the demise of our precious forests. But I won’t be around to prove it or not. That we leave to our children to determine.

[Editor: This is not a political statement. Please do not comment on it as such.]

Dennis Prichard is a retired park ranger. He’s worked and studied wildlife at many National Parks and Wildlife Refuges including Carlsbad Caverns, Mammoth Caves, the Everglades, Sequoyah NWR in Oklahoma, Sevilleta NWR in New Mexico, and Isle Royale National Park, to name a few. He and his wife travel in a fifth wheel.

Read previous RoVing Naturalist articles here.

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4 COMMENTS

  1. The information is flawed. Historically to present day, less acreage of forests have been destroyed by fire. Look the data up. There is a trend line showing a decrease in overall acreage loss due to forest fires. The information is provided by the US government. Sadly it is just another article that doesn’t present the facts.

  2. Yet in another section of this “RV Travel”
    “Trivia
    In 2018, 89% of wildfires were caused by humans. (Happy Birthday, Smokey Bear!)

    • The cause of a fire and how extensively it burns are two different things. Yes, people cause fires, but the fires are now more serious and burn more acres.

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