NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/695082
36 NEBRASKAland • JULY 2016 shaded forests to thin trees creating open, sunny woodlands with lush grass, wildflower, and fruit-bearing shrub understories, providing food for themselves and the game they hunted. Plains grasslands were also set ablaze as bison were attracted to the fresh regrowth, these fires sweeping through woodlands in their path. The frequent presettlement fires limited Nebraska's ponderosa pines to the somewhat fire-protected escarpments and river bluffs, with the trees forming mostly open woodlands and savannas (grasslands with widely scattered trees). Dense pine forests were found only in deep, cool and moist canyons and north-facing slopes where fires burned sporadically and with low intensity. The Loess Hill pine stands "were usually in deep rifts in the hills, running more or less at right angles to the river plain [North, Middle and South Loup], with sides so steep and broken as to form an adequate protection against the annually recurring prairie fires," wrote H.W. Foght in his 1906 book The Trail of the Loup. Pine seedlings that sprouted in the thick grass of adjacent prairie survived only until the next fire. The fires that burned through the pine forests and woods were mostly ground fires, consuming only grass and fallen pine needles and branches. Such blazes killed many small ponderosa pines, but a few large trees whose thick, flaky bark protected the vulnerable cambium layer – where new growth is initiated and found just below the bark – from the fire's heat, survived. Self- pruning lower branches and thick bud scales added further protection. Occasionally, during drought years, the fires burned hotter and flaming nearby small pines or burning pitch runs on a tree's trunk carried the fires into the crowns of large pines. In dense stands, the crown fires easily leaped from tree to tree, especially when windy, killing or damaging large numbers of them. These severely burned forests were ecologically valuable, providing early successional habitats for many plant species, and the dead and dying trees supporting specialized insect and bird species. In the central Niobrara valley, the pine woods, bordered by Sandhills prairie on the uplands, burned on average every 3.5 years between 1830 and 1900, and every 8.5 years between 1901 and 1950 after active fire suppression by residents. Whereas, the pinelands on our drier western escarpments, surrounded by lighter- fueled shortgrass prairie, burned on average every 10 years between 1650 and 1900, but every five years between 1830 and 1900 after fire- sloppy Euroamericans entered the region, but before fire suppression. A region's fire frequency is determined by examination of fire scars within the growth rings of both living and dead trees. The scars form when the cambium layer is damaged by a fire's heat; this usually occurs on the upslope side of a tree where litter gathers and fires burn hot. In 1876, Colonel Richard I. Dodge, a member of an 1875 scientific expedition to the Black Hills, wrote of the region's fire-shaped ponderosa pine woods: "Large and fine saw-logs are to be found, and in very considerable numbers, but rarely in large bodies." Old and large trees, which by some means escaped the fires were "scattered through the young forests." Dodge estimated that 40 percent of the Black Hills was young forest, 10 percent was "wind-shaken, or injured by lightning or fire," 10 percent was "good lumber," and grassy openings comprised the remaining 40 percent. Nebraska's presettlement pinelands likely had a similar structure. The Sawyer's Blade In 1874, A.A. Sloan, a member of a survey party that followed the central Niobrara River for over 100 miles, wrote in a northeastern Nebraska An 1875 photo of Crow Butte in the Pine Ridge of Dawes County. Frequent wildfires kept the pines from venturing down from the rocky, fire-protected Butte onto adjacent prairie. When mature, the bark of ponderosa pine turns orange to yellow in color. NSHS RG5895-8 PHOTO BY GERRY STEINAUER When mature the bark of ponderosa pine