PART TWO: Tree mortality in the Sierra continues to rise

 

This is the second installment in a multi-part feature on tree health in the Sierra and throughout California. The first part of the series may be read online here. Part Three is here.

 

When I was seven years old, I was witness to an event that forever changed the way I look at a forest. Dead or diseased trees can be lethal, I learned one picture-perfect sunny day.

The summer of 1966 was the third year that my family traveled to Yellowstone National Park to live at Lewis Lake Campground, about 20 miles from the park’s South Entrance. My dad, Jim Barton of Three Rivers, was the seasonal campground ranger; we arrived for the 1966 summer season on July 1. 

The next day — Saturday, July 2, just after 5:30 p.m. — while my dad was away from the campground on patrol, frantic campers reported to my mom that there was an injured man in the campground. With her two young children in tow, my mom ran to site W-9 in the campground.

What we discovered at this walk-in site was that a family — a husband, wife, and their three-year-old daughter — had recently arrived and were setting up camp. The man had just finished erecting the tent and was standing inside it when a large lodgepole pine that was about 50 feet away from the campsite toppled and landed on him. 

There was no wind. No rain. Just a clear, cloudless sky.

What is forever seared into my memory is when the emergency responders arrived at the scene and eventually extricated the victim to place him on a stretcher, he was bent over at the waist, but backwards. His spine had obviously snapped in two.

He died in the Park Service ambulance en route to the park’s Lake Hospital.

What was determined later when my dad and others inspected the lodgepole pine, which was estimated to be about 300 years old, was that it was in an advanced state of decay due to a pine rust canker, a type of parasitic fungus. In the winter of 1966, we were back home in California when my dad was subpoenaed to a Casper, Wyo., courtroom to testify in the case of Middaugh v. United States.

The wife of the decedent, Stephen Athan, 39, of California was suing the National Park Service for wrongful death.

Based upon the evidence, the court ruled in favor of the plaintiff that negligence on the part of the defendant, the United States, had caused the death of Stephen Athan:

The United States of America failed to provide a safe place for the decedent to camp in that the opening near the base of the tree was clearly visible to the officials of the National Park Service had they looked, and a further examination of the tree would have disclosed that the trunk of the tree was in an advanced state of decay…

“Stephen Athan, was an invitee in Yellowstone National Park to whom the United States owed the duty to use ordinary and reasonable care to keep the premises reasonably safe for his visit and to warn him of any hidden danger. The Government, as landowner, is required to have a superior knowledge of dangers which would not be obvious to the invitee if such dangers are discoverable in the exercise of due care…

“The collapse of the tree which killed the decedent was not due to an Act of God, which is an injury due directly and exclusively to natural causes without human intervention which could not have been prevented by exercise of reasonable care and foresight. The Government, as owner and proprietor of Yellowstone National Park, was charged with the duty to inspect and to guard against injury to invitees drawn thereto since the tree was under the exclusive custody, control and management of the proprietor.

Stephen Athan’s estate was awarded $43,750 in damages. And this case greatly influenced the future of the National Park Service’s hazard tree policy.

* * *

Currently, the west side of the Sierra Nevada Mountain Range is in the midst of a die-off of conifers in the mid-elevation zone while lower in the foothills the oaks are dying. Taking personal responsibility for the safety of one’s self and loved ones in this situation means that when camping or recreating to be aware of and stay clear of dying or dead trees.

The National Park Service checks campgrounds, roadsides, picnic areas, and other visitor-use locales and removes hazard trees as necessary. But as in the case of Stephen Athan, where the tree was obviously decayed yet undetected, accidents can and will happen.

Dead trees around homes are health and safety hazards as well as fire hazards. They should be removed, especially those within the 100-feet defensible-space perimeter of the dwelling.

 

Park Service and tree research

 

When posing the question of what the local Park Service’s policy is on the massive die-off of trees in Sequoia and Kings Canyon, the following response was received by Dana Dierkes, public affairs specialist:

Droughts have occurred with some frequency in California for millennia and are a natural cause of tree mortality. The insects killing the trees are also native and have a long history of episodic outbreaks.

However, climate change and fire suppression may be playing roles in this current mortality event that may be increasing the intensity and scale of the die-off.

Sequoia and Kings Canyon National Parks has been removing dead trees that are at risk for falling where they could damage life or property in developed areas. In undeveloped areas, staff and partners are investigating the extent, severity, and anticipated ecological changes due to tree mortality. The Park Service is also testing management tools to improve forest resiliency, such as prescribed burning and/or stand-level thinning. 

Sequoia-Kings Canyon currently has ongoing cooperative research studies:

—With the U.S. Forest Service to study treatments that may improve forest resiliency.

—With the U.S. Geological Survey and academic partners to study drought stress detection and variation in drought stress at a landscape scale in giant sequoias (Leaf to Landscape Project).

—With USGS and academic partners to look at impacts of prescribed fire and mechanical thinning on tree mortality.

—With USGS to look at what sizes and species of trees are dying in some areas of high tree mortality.

 

Attack of the bark beetles

 

The past winter of normal rainfall was not enough to counteract four years of drought. Bark beetles, which are native to California and about the size of a grain of rice, have taken up residence in the pine trees of the Sierra.

Bark beetles are opportunists that survive in trees that are stressed or diseased. Bark beetles are currently prolific, taking advantage en masse of weakened, overcrowded stands of pines that can’t produce enough sap, the trees’ natural defense, to fight off the insects.

In other words, nature will thin the forests, one way or another.

According to a U.S. Forest Service publication, “Bark Beetles in California Conifers,” there are 220 species of bark beetles, about a dozen of which feed on California pines.

The insects bore through the pine’s bark where they lay eggs. The larvae then feed on the tree’s living tissue, which interrupts the flow of the tree’s nutrients. The beetles emit pheromones that attract other beetles, so ultimately, several thousand beetles could infest a single tree, then easily spread to nearby trees.

 

California dry spell

 

This summer is shaping up to be a hot one in Kaweah Country and, for that matter, nationwide. For the last two months, every single state has been warmer than average, including Alaska, which has had warmer than average temperatures for more than 100 consecutive days. 

No doubt about it, this region of California is still in an extreme drought. And the forecast is grim: a potentially strong La Niña could emerge later this year, bringing with it a renewed stretch of dry weather.

Although after four years of drought, California experienced an “average” rainfall year (July 1, 2015-June 30, 2016), the snowpack was still relatively disappointing because as global warming progresses, the snow collects at ever higher elevations, meaning less snowmelt reaches the key reservoirs. 

La Niñas are typically bad news for California, and this coming winter shouldn’t be any different: Climate forecasters are reluctantly predicting a below-normal start to this winter’s rainy season, and continued pressure from global warming will ensure that storing snow will be especially challenging too.

 

Managing fire

 

When the U.S. Forest Service was created in 1905, along with it came fire-suppression and fire-prevention policies. Fire suppression was necessary to protect stands of timber that had commercial value; fire prevention was to educate the public how not to start conflagrations in the first place.

It took more than a half century for public-land managers to realize that this no-fire philosophy was creating dense, unhealthy forests. It’s taken another generation to reach a tenuous consensus with the general public that fire is a necessary component of a healthy ecosystem.

Since the 1970s, the public-lands policy has been to let fires burn when and where appropriate, usually natural-caused, usually in wilderness areas. This let-burn policy encountered a setback during the 1988 Yellowstone fires, which during one of the driest summers on record burned over 30 percent of the total acreage of the park, including threatening the historic Old Faithful Inn, from June till the November snowfall. 

Since around 1990, fire suppression efforts and policy have taken into account what is now known as the wildland-urban interface, where forest meets town. California’s Rough Fire, which burned last summer on Sierra and Sequoia national forest lands and into Kings Canyon National Park, illustrated how fires are growing in size and ferocity. 

The USFS firefighting budget has grown to about 50 percent of the agency’s entire budget, which limits funds available for land-management activities such as land restoration and forest thinning that could aid in fire suppression.

“The threat of wildfire which is created by millions of dead trees cannot be significantly reduced by logging,” wrote Tom Nichols on The Kaweah Commonwealth’s website in response to the first installment of this feature. “As noted, the work to date is a drop in the bucket.” 

Tom was the NPS Chief of Fire and Aviation when he retired in 2014 after 37 years with the National Park Service. In 1977, he started his career in the fire-management division at Sequoia and Kings Canyon National Parks, where he worked for 17 years.

He offered some words of wisdom and advice for Kaweah Country:

“The careful use of prescribed fire, and perhaps of natural fire under certain conditions, are the only methods to reduce the widespread threat over time. But it has to be done on a significant scale, on the order of several thousand, and not a few hundred, acres annually. 

“To do that, the local communities and the land management agencies will have to work together to develop a consensus on where, when, how often, and how large the burns should be. And while the Rough Fire was, in fact, contained in part due to NPS fuel reduction work done in previous prescribed and natural fires in Kings Canyon NP, no such activity has occurred for years, if ever, in the North, Middle, and South Fork Kaweah drainages of adjacent Sequoia NP. 

“These drainages are greatly primed for a Rough-like fire, and the necessary wildfire hazard reduction work in these drainages will require the support and encouragement of members of the local community. Indeed, the NPS is unlikely to proceed with prescribed fire projects on a scale sufficient to significantly reduce wildfire threat in these drainages without a clear signal that it has local support for this work.”

 

Fire’s aftermath

 

Whether planned or unplanned, fire has been determined to be mostly good for the forest. That is, after the fact.

Animal species are adapted to survive wildland fires. Not all will get out alive, but studies suggest they can deal with fire. Vegetation returns, sometimes within a season. The soil is more nutrient-dense.

Cultural resources and archaeology could be impacted or destroyed. 

Viewsheds are changed with a forest of trees replaced by burned skeletons. These standing dead trees will be seen for many years to come, but grasses, shrubs, seedlings, and other vegetation will grow in their place because the canopy has been removed, allowing for sunlight to reach the forest floor.

The general consensus of the scientific research is that fire is necessary for forest ecology. Of course, it’s the agencies receiving federal funding to reintroduce fire into the wildlands that are also performing the research so they have a stake in the outcome.

According to an editorial in the Los Angeles Times on June 27, 2016, by Chad Hanson, research ecologist and coauthor of “The Ecological Importance of Mixed-Severity Fires: Nature’s Phoenix”:

Among scientists, there is an overwhelming consensus that weather (hot, dry, windy conditions) determines how wildland fires behave, not the density of dead trees or ‘snags.’ 

Trees larger than just a few inches in diameter are not consumed in fires — only the outer bark layer and the needles actually burn up — so the great majority of the dead trees in the forest do not significantly influence fire behavior, even if they are dry. Besides, once trees die, the combustible oils in the needles quickly begin to dissipate and the needles fall, making it more — not less — difficult for flames to spread through the forest canopy. 

As it happens, numerous empirical scientific studies have been conducted on this very issue. Last year, a study published in Proceedings of the National Academy of Sciences found that high snag levels had no effect on the rate of fire spread in conifer forests of the Western U.S., including California.  In 2016, another group of researchers found that forests with high snag levels actually tend to burn less intensely than other forests.

According to Hanson, the massive amount of dead trees in the Sierra aren’t a fire hazard after all. 

But what this theory actually proves is that more research is needed. After all, that’s how science works.

Coming up: Drought and the giant sequoias.

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