Forest Management: “For a Warming World, A New Strategy for Protecting Watersheds”

This article was prepared by Yale Environment 360. Although its focus is primarily on protecting watersheds, most of the well validated scientific principles that Sound Forest Management is based on are clearly demonstrated in a way that easily shows the value of human intervention in our federal forests for other site/situational specific prescribed purposes as well. Here are some highlights which have been the subject of many previous posts on this site.

1. water managers are learning that careful management and restoration of watershed ecosystems, including thinning trees and conducting prescribed burns, are important tools in coping with a hotter, drier climate.
2. New Mexico’s forests … areas that supported 40 trees per acre in the pre-European era now were blanketed with up to a hundred times as many. This profusion of trees — as many as one per square yard — weakened all of them, and rendered them defenseless against megafires.
3. the Las Conchas Fire … consumed nearly an acre of forest per second … and left behind nearly 100 square miles so severely burned that even seeds to regenerate the forest were destroyed …
   two months later, when a thunderstorm in the Jemez Mountains washed tons of ash and debris into the Rio Grande River, the water source for half of New Mexico’s population and for a major agricultural area. Only an inch of rain fell, but the debris flows the storm generated turned the river black and dumped ash, sediment, and tree and shrub remnants into a major reservoir^⁠, requiring a costly cleanup … a heavy rainstorm two years later generated enough sediment to entirely plug the Rio Grande
4. In the last two decades, megafires in similarly dry and overgrown watersheds have ended up contaminating downstream water supplies in numerous areas throughout the western United States, including Phoenix; Denver; Flagstaff, Arizona; and Fort Collins, Colorado. Downstream water managers serving millions of urban residents have learned that the security of their water supplies is tied to the health of upland watersheds that may be hundreds of miles away.
5. In the Western U.S., watershed restoration chiefly consists of two steps: thinning of trees and shrubs, and prescribed burns. In the Eastern U.S., it involves a bigger set of tools, including planting native trees, reducing the area of impervious surfaces, and slowing the speed of stormwater so that more water percolates into soil and aquifers. All these measures are designed to improve water quality.
6. numerous pilot projects have shown the efficacy of restoration, agencies rarely have enough money to treat entire watersheds
7. after the Las Conchas fire, residents in the Rio Grande watershed … in 2014 they launched a public-private partnership, the Rio Grande Water Fund, whose 73 contributing members^⁠ include government agencies at all levels, foundations and other NGOs, local water utilities, and local businesses and residents. Together they raised enough money for a 20-year program to restore 600,000 forest acres — enough to support the resilience of the entire central and northern New Mexico portion of the Rio Grande watershed. They have already restored 108,000 acres, and are racing to complete the job before another megafire occurs.
8. The Rio Grande Water Fund’s public-private partnership model has become official federal policy. Last August, the U.S. Forest Service published a landmark report called “Toward Shared Stewardship Across Landscapes” that outlined the agency’s intention to convene watershed stakeholders of all kinds to plan and fund watershed restoration. “Because fire crosses back and forth across land ownership boundaries, the risk is shared,” the report said. “Accordingly, land managers cannot achieve the fire-related outcomes people want… without shared stewardship of the wildland fire environment.”

• The benefits of watershed restoration extend far beyond water security. Most obviously, healthy forests deter megafires. Laura McCarthy, the Rio Grande Water Fund’s executive director, says that in three instances since restoration work began in New Mexico, wildfires that ran up against restored zones immediately died down. Healthy forests can tolerate low-intensity fires: they possess diverse understories of grasses, sedges, and forbs and rich, microbe-laden soil, all of which supports wildlife, from insects to mammals. Watershed restoration can double the amount of carbon stored in the soil, which means that it’s a vital tool in fighting climate change. And watershed restoration creates jobs: In the case of the Rio Grande Water Fund, many of those jobs go to youths in traditional Hispanic and Native American communities where unemployment rates are 30 percent or higher.
• In some regions, forest restoration even increases water supplies. Roger Bales, a hydrologist at the University of California, Merced, has shown that because watershed restoration requires the removal of vast numbers of young trees, loss of water into the atmosphere through evapotranspiration in those trees is eliminated. The water instead flows downward, into the soil, often on its way to the watershed’s rivers and reservoirs. Bales’ experiments in California’s Sierra Nevada show that restoration can increase water supplies in downstream reservoirs by 9 to 16 percent. That makes restoration a more cost effective (and vastly less destructive) water supply method in California than building dams. Restoration is also cheaper than fighting the megafires that are otherwise inevitable in the overgrown forests: last year’s Camp Fire in northern California alone caused $11 billion to $13 billion in damage.
• unless it is followed by prescribed burns, undesirable trees and shrubs grow back. In that case, said Don Falk, a leading fire researcher at the University of Arizona, “You’re either committed to a perpetual Sisyphean cycle of thinning” every 10 or 15 years “or you’ve got to let fire back into the system.” Fire is an integral part of the functioning of many ecosystems: Blazes of less-than-megafire scale germinate seeds, keep native species in balance while warding off invasive species, and stimulate microbial activity that produces soil nutrients.