Kudzu, wildfires and bark beetles

How healthy are our forests? How vulnerable are they to fires, erosion and invasive flora and fauna?  

Well, consider that it’s early June and Western wildfires are already burning forests to a crisp.

Just down the road from my house, in east Arkansas’ St. Francis National Forest, invasive kudzu has overtaken huge swaths of towering trees. On some hillsides, tree carcasses still stand, swallowed up by a choking tide of the vines.

But kudzu is a slow killer compared to bark beetles that have, in recent years, been responsible for the destruction of literally millions of U.S. forestland acres.

The United States isn’t alone in having to battle massive blazes. Last January, wildfires tore through much of Australia’s forestland.

Don’t believe climate change is caused by man? Don’t want to jump to conclusions?

That’s fine say the authors of a USDA report by U.S. Forestry Service scientists. But whatever the reason, they paint a frightening – even dystopic, in some cases -- picture of what’s in store for coming generations.By 2050, they predict wildfire damage will be double the current 10 million-some acres burned annually.

“It is difficult to conclude whether recently observed trends or changes in ecological phenomena are the result ofhuman-caused climate change, climatic variability, or other factors,” they write. “Regardless of the cause, forest ecosystems in the United States at the end of the twenty-first century will differ from those of today as a result of changing climate.”

Read the report here [3].

They continue: “Although increases in temperature, changes in precipitation, higher atmospheric concentrations of carbon dioxide and higher nitrogen deposition may change ecosystem structure and function, the most rapidly visible and most significant short-term effects on forest ecosystems will be caused by altered disturbance regimes. For example, wildfires, insect infestations, pulses of erosion and flooding, and drought-induced tree mortality are all expected to increase” this century.

Temperature increases will alter the growing environment of many tree species throughout the UnitedStates, “reducing the growth of some species (especially in dry forests) and increasing the growth of others (especially in high-elevation forests). Mortality may increase in older forests stressed by low soil moisture, and regeneration may decrease for species affected by low soil moisture and competition with other species during the seedling stage.”

The consequences will differ regionally “and will pose significant challenges for resource managers to mitigate and reduce damage to resource values.”

Among their predictions for the Southeast, where a majority of the U.S. pulp and timber supply is produced:

• Red spruce and eastern hemlock, already declining in some areas, are projected to be extirpated from the Southeast by 2100 as a result of the combined stresses of warming, air pollution, and insects.

• Conditions for pine growth may begin to deteriorate.Even if regional forest productivity remains high, the center of forest productivity could shift northward into North Carolina and Virginia, causing significanteconomic and social impacts.

• Increasing demand for water from a rapidly growing urban population, combined with increased drought frequency could result in water shortages in some areas of the Southeast.

• Warmer temperature may increase decomposition of soil organic matter and emissions of CO2, reducing thepotential for carbon sequestration.

• Increased fire hazard and insect outbreaks will provide significant challenges for sustainable management of forests for timber and other uses, but may also motivaterestoration of fire-tolerant longleaf pine forests.