A Northwood Almanac for 8/13 - 26, 2010
Tornado on the Turtle-Flambeau Flowage
As a wild storm blew through the Manitowish area during the early evening of July 27th, Mary and I knew a major problem had occurred near us when four ambulances passed our house heading north toward Mercer. We found out the next morning that a tornado had struck the Turtle-Flambeau Flowage, beginning over the western edge of the Flowage near the southern tip of Big Island, and damaging many of the smaller islands between the Turtle Dam, Springstead Landing, and Murray’s Landing. Many trees either snapped off or were uprooted in the tornado. Aerial photographs reveal trees laying cross-hatched across one another. Substantial tree damage occurred near Springstead Landing with many structures in the area damaged by falling trees up to 2 feet in diameter.
The tornado lasted only briefly, continuing eastward and uprooting or snapping trees in many campsites before the damage became much more sporadic and the tornado apparently lifted. The tornado path was embedded within a 1 to 3 mile swath of intense thunderstorm wind gusts that also caused damage and stretched across the Flowage such that bulk of Flowage campsites received at least some sort of tree damage. Ten campsites will likely be permanently closed, while four others will be further evaluated when the leaves drop in the fall.
Rescuers needed three hours to cut through downed trees to get to Murray’s Landing and two hours to get to Springstead Landing. DNR personnel began a campsite by campsite boat search in the dark for people at the 60 campsites on the Flowage and found three people seriously injured– two with broken vertebrae – who were eventually taken by ambulance to Howard Young. Since all campsites on the Flowage are non-reservable and first-come-first-serve, no one knew which sites were occupied and which weren’t. Trees had fallen on many tents, and those who had wisely huddled under picnic tables were least injured.
The Master Plan for the Flowage states that, “In event of natural disaster, the trees [within 300 feet of the shoreline] will be left lying and salvaged or cut.” Flowage manager Chris Niehaus told me that the trees on the islands will be left as is except those directly around the camping areas which will be cut into firewood. The accessible trees felled beyond the 300-foot zone were in a number of established timber sales already, and other sales will be set up to take out the rest.
The good news is that the downed trees in the water will provide woody habitat for fish and other aquatic species, further improving an already exceptional fishery. The fallen trees on the uplands will provide habitat for a host of amphibians, salamanders, ground-nesting birds, and other animals that utilize dead and dying wood for food, cover, and nesting/denning.
On many of the islands, Niehaus noted that as a forester in 1992, she helped plant thousands of white pines under existing stands of aging white birch in anticipation of the white birch dying. The white birch had held on longer than anyone thought they would, but most came down in this storm, revealing the 10-foot-tall white pines that had been planted 18 years ago. These pines are now reveling in the full sun and will grow quickly to replace the birch.
Many of the largest super-canopy white pines were also snapped off in the storm, a number of which supported eagle nests for decades. But many large white pines survived just off the edge of the storm path, and the eagles will very likely build anew in these trees. Callie and I paddled out from Springstead Landing on 8/6 to observe the storm damage, and while we were taken aback by the damage, we were also encouraged by how much was still standing overall.
Windstorms, like fires, floods, and other major disturbance events, have always been part of biological change in northern forests. The forests are remarkably resilient and have responded with rapid regrowth again and again over the centuries. The species change, but over time, barring other major distubances, the species that were lost usually return.
Researchers (Loucks 1993) looking at presettlement survey records found blowdowns in 25 percent of the 1,600 Wisconsin townships, covering 213,084 acres in 535 separate blowdowns. The largest blowdown observed by the surveyors was 15,000 acres with four others just under 10,000 acres. The researchers calculated that windstorms blew down nearly 11,000 acres of trees every year in Wisconsin.
Those blowdowns were nothing compared to the 1999 storm that hit the Superior National Forest in Minnesota, leveling 477,000 acres, so the TFF storm was relatively little in the larger scheme of things.
When will the next big storm return to the TFF? Researchers (Shulte and Mladenoff, 2005) estimate that the return time (the expected number of years between a disturbance of comparable area at a particular location) for heavy wind events in the Northern Highlands area is 636 years. So, while that’s a long time in between major storms, wind still has always been THE major disturbance event for most of the Northwoods. The damage wrought is emotionally very difficult to see, but needs to be accepted as part of the natural dynamics of northern forests. Mother Nature has always been the CEO of this ship, and always will be.
National Data Buoy Center
Water temperatures measured at a buoy stationed in the middle of Lake Michigan recorded 80°F temperatures on August 1, the first time temperatures have reached 80 since 2001. The highest temperature ever recorded at the buoy on the southern end of the lake, 40 miles offshore from Racine, was 81°F on 8/18/1995.
The National Oceanic and Atmospheric Administration (NOAA) operates a number or moored buoys on the Great Lakes that record current water temperature, air temperature, wind speed, wave height, and a number of other measures.
To view current daily data for the western Great Lakes, go to the following website and simply click on the buoy: www.ndbc.noaa.gov/maps/WestGL.shtml
Wood Turtles
Ferdy Goode sent me a photo of a wood turtle he saw on the Bear River in late July, a rather rare observation. Wood turtles are a threatened species in Wisconsin, and Mary and I have only seen a few over the 27 years we’ve lived in the Northwoods.
Fortunately, wood turtles are easy to identify due to the patterns on their shells that look like the cross-sectioned woodgrain of a tree branch.
Wood turtles prefer to live in lowland hardwood forests, and typically dig their
nests into south-facing sandy river banks. They are semi-terrestrial, often wandering into uplands a few hundred yards away from rivers and wetlands. The hatchlings and juveniles appear to particularly utilize alder thickets along shorelines, habitat that is considered critical for them.
Once found statewide, wood turtles now exist only in small scattered populations primarily in the northern and western two-thirds of Wisconsin. They do best in clear rivers with moderate to fast flows and uneroded shorelines. Because they nest communally, they are particularly vulnerable to predators like raccoons, skunks, and humans. Females don’t reach sexual maturity until 10 to 14 years of age, but can live as long as 58 years. If you see a wood turtle, by all means snap a picture, but otherwise give it a wide berth out of respect for its threatened status.
Sightings
Various migration events appear to be commencing a bit earlier than normal this year. Nighthawks, which usually migrate in later August, have been seen in migration as of 8/8. Warblers have been observed in migration since the beginning of August, and numerous reports have recently been posted on the Wisconsin BirdNet of large migrations of common green darner dragonflies. Thousands are being seen in Cudahy,
along Lake Michigan in Milwaukee, and in Menominee Park in Oshkosh. “The air has been full of green darners,” say the observers.
If you’re not familiar with green darners, the adults average about 3 inches long. Both genders have a green thorax, while the male has a slender, bright blue abdomen and the female a brick red to gray abdomen. Their huge eyes meet across the top of their head, so they look a bit like they’re wearing a helmet.
The darners are voracious predators, eating insects of all sizes including other dragonflies and damselflies. In turn, they are highly desired by avian predators from songbirds like Eastern kingbirds and nighthawks to raptors like kestrels, peregrine falcons, merlins, and even broad-winged hawks. During autumn migration, researchers have observed merlins, kestrels, and peregrines eating them on the wing. One researcher has even theorized that kestrel and merlin migration is correlated with green darner movements at Hawk Ridge in Duluth.
Two different populations of green darners are thought to live in Canada and the U.S: a resident population that overwinters under the ice as larvae, and another population that migrates. It’s the offspring of these migrants that return to the Northwoods very early each spring to breed in the north, their young emerging in late summer, and then as juveniles migrating south by the thousands during August and September.
Celestial Events
The peak night for the Perseid meteor shower occurred last night, 8/12, but many should still be viewable tonight, 8/13. The complete Perseid meteor shower lasts from July 13 to August 26, so, if you missed the chance to see them last night, be sure to go out tonight. The best meteor observing hours occur after midnight, but you should still see many meteors earlier if the late night is not your cup of tea.
If the predictions are correct, meteor observers in a clear, dark location away from city lights should see from 60 to possibly as many as 100 meteors per hour. Look to the northeast where the constellation Perseus is located.
On 8/23, look for Venus just below Mars at dusk. On 8/24, the full moon occurs, the year’s most distant and smallest full moon.
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