2 resultados para Hilly gullied Loess Plateau

em DigitalCommons@University of Nebraska - Lincoln


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The purpose of this paper is to provide quantitative fire history information for a geographically unique region, the Loess Hills of northwest Missouri. We sampled 33 bur oak (Quercus macrocarpa Michx.), chinkapin oak (Q. muehlenbergii Engelm.), and black oak (Q. velutina Lam.) trees from the Brickyard Hill Conservation Area in northwest Missouri. The period of tree-ring record ranged in calendar years from 1671 to 2004 and fire-scar dates (n = 97) ranged from 1672 to 1980. Fire intervals for individual trees ranged from 1 to 87 years. The mean fire interval was 6.6 years for the pre-Euro-American settlement period (1672-1820), and 5.2 years for the entire record (1672-1980). A period of more frequent fire (mean fire interval = 1.6 for 1825 to 1850) coincided with Euro-American settlement of the area. The average percentage of trees scarred at the site was 16.8%, or about 1 in 7 trees sampled per fire. No significant relationship between fire years and drought conditions was found; however, events prior to 1820 may have been associated with wet to dry mode transitions.

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After several years of successively rising land values and cash rents, Nebraska’s farmland markets throttled back during 2008. Preliminary results from the University of Nebraska-Lincoln’s 2009 Nebraska Farm Real Estate Market Survey show a clear picture of the market mood turning very cautious in response to the U.S. and global economic downturns. As of February 1, 2009, the weighted average value of Nebraska farmland was $1,424 per acre, identical to the year-earlier level (Figure 1 and Table 1 at end of article). Likewise, estimated 2009 cash rents are stable to slightly down from 2008 levels throughout most of the state.