Conservation Matters: Forest Service reports on droughts' effects on forests and rangelands

Forest Service reports on droughts’ effects on forests and rangelands

Forest Service reports on droughts' effects on forests and rangelandsMortality of Ashe juniper at Colorado Bend State Park, TX, after the 2011 drought. (Photo by Rob Jackson, Stanford University. Courtesy of U.S. Forest Service.)

The U.S. Forest Service has released a new report, Effects of Drought on Forests and Rangelands in the United States: A Comprehensive Science Synthesis, which provides a national assessment of peer-reviewed scientific research on the impacts of drought on U.S. forests and rangelands. This report will help the Forest Service better manage forests and grasslands impacted by climate change.

“Our forests and rangelands are national treasures, and because they are threatened, we are threatened,” said Agriculture Secretary Tom Vilsack. “This report confirms what we are seeing, that every region of the country is impacted by the direct and indirect effects of drought conditions and volatile weather patterns. Sixty million Americans rely on drinking water that originates on our 193 million acres of national forest and grasslands. They support 200,000 jobs and contribute over $13 billion to local economies every year.”

The report establishes a comprehensive baseline of available data that land managers can use to test how well their efforts to improve drought resilience and adaptation practices are working nationwide. Major findings from the report include:

  • Drought projections suggest that some regions of the U.S. will become drier and that most will have more extreme variations in precipitation.
  • Even if current drought patterns remained unchanged, warmer temperatures will amplify drought effects.
  • Drought and warmer temperatures may increase risks of large-scale insect outbreaks and larger wildfires, especially in the western U.S.
  • Drought and warmer temperature may accelerate tree and shrub death, changing habitats and ecosystems in favor of drought-tolerant species.
  • Forest-based products and values – such as timber, water, habitat and recreation opportunities – may be negatively impacted.
  • Forest and rangeland managers can mitigate some of these impacts and build resiliency in forests through appropriate management actions.

“Since 2000, fire seasons have grown longer and the frequency, size and severity of wildland fires have increased,” Vilsack said. “Among the many benefits of having this solid baseline data is the improved ability to identify where restoration work can help forests adapt and prosper while minimizing the threat and impact of future wildfires.”

The assessment, a broad review of existing drought research, provides input to the reauthorized National Integrated Drought Information System (NIDIS), established by Congress in 2006, and the National Climate Assessment (NCA), produced every four years to project major trends and evaluate the effects of global climate change on forests, agriculture, rangelands, land and water resources, human health and welfare, and biological diversity. Together these serve as key, science-based, resources for anyone working to maintain or improve public and private lands in the face of a changing environment.

For more information, read the full U.S. Forest Service news release and report.

Stocked fish ponds more susceptible to oxygen depletion during summer months

Stocked fish ponds more susceptible to oxygen depletion during summer months

Texas A&M AgriLife Extension Service photo by Adam Russell.

Summer is beginning to heat up in Texas, and a Texas A&M AgriLife Extension Service expert advises landowners to start monitoring stocked ponds for oxygen depletion.

Landowners with stocked fish ponds should be aware of possible problems with oxygen depletion as hot, still days become more prevalent, said Dr. Billy Higginbotham, AgriLife Extension Service wildlife specialist.

From June to September, when the outside air is increasingly hot and pond water temperatures climb, are the time of year when oxygen depletions occur most for a variety of reasons, he said. Improper aquatic weed control, too many pounds of fish and the weather all contribute.

Higginbotham said typical ponds can sustain 1,000 pounds of fish per surface acre through summer months. When the environment is optimized and the pond owner stocks heavily, especially with channel and blue catfish, and feeds heavily with floating fish rations, that density level can be easily met and exceeded.

Oxygen production via photosynthesis can slow or stop after several hot, still, cloudy days, while fish can continue to use oxygen until it falls below 3 parts per million gallons, which stresses fish, Higginbotham said. Fish will then begin swimming to the surface to try to obtain enough oxygen to survive at the air-water interface.

Higginbotham recommends checking the pond at daybreak when oxygen levels are at their lowest daily levels. The pond owner should act quickly if fish are surfacing for air.

Larger fish are affected by low oxygen levels more than smaller fish, he said.

“It’s almost as if they are gasping for air at the air-water interface,” Higginbotham said. “That’s a clear sign of oxygen depletion, and the pond owner should act quickly to avoid a complete die-off of their fish.”

Pond owners can produce more oxygen for fish in various ways.

Backing a boat engine into the pond and circulating the water is one way to create more oxygen, Higginbotham said. Pond owners can also place a water pump in a shallow portion of the pond and spray water along the surface to circulate water along the air-water interface.

Once oxygen levels are restored, Higginbotham said pond owners should investigate the pond conditions that contributed to the depletion. He recommends thinning fish populations to reduce the pounds of fish the pond supports going into the mid-summer months.

Controlling aquatic vegetation can also contribute to oxygen depletion, Higginbotham said. Oxygen is removed from water as plant tissue decomposes, which can create a scenario where a die-off might occur.

Weed control efforts should be done gradually, about 15-20 percent of the vegetation at a time and with a week break between treatments, he said.

An aeration system is also a good investment for landowners to avoid problems or prevent future problems, Higginbotham said.

“Watch very carefully as we enter these still, cloudy days, the dog days of summer,” Higginbotham said. “Be mindful of oxygen depletion and the possibility of losing fish populations.”

Read the full AgriLife TODAY article for more information.

Flood recovery resources are available through AgriLife Extension

As many Texans recover from recent flood damage, the Texas A&M AgriLife Extension Service has resources that can help.

The Texas Extension Disaster Education Network, or Texas EDEN, has science-based materials related to floods, and other emergencies and disasters at texashelp.tamu.edu. View the Texas EDEN Floods page for expert advice on flood recovery, and see these specific resources for additional information and for experts to contact:

Read this AgriLife TODAY article for more information about Texas EDEN and flood safety.

The National Forest Service Flooding and Its Effects on Trees page also has helpful information for landowners assessing and monitoring damaged trees. And, for resources on maintaining and protecting healthy riparian areas along streams and rivers, visit the Texas Water Resources Institute’s Texas Riparian and Stream Ecosystem Education Program at texasriparian.org.

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