Variation In Estimates Of Fire Intervals

Author : Stephen F. Arno
Publisher :
ISBN 13 :
Total Pages : 12 pages
Book Rating : 4.2A/5 ( download)

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Download or read book Variation in estimates of fire intervals written by Stephen F. Arno and published by . This book was released on 1982 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors examine variation in the length of mean intervals between fires (occurring between the years 1600 and 1910) in sample units of various sizes, ranging from a point on the ground (single tree) to a large stand (200 to 800 acres; 80 to 320 hectares). Recommendations are made regarding appropriate sizes of sample units for fire history studies.

Author : Stephen F. Arno
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.54/5 ( download)

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Download or read book Variation in Estimates of Fire Intervals written by Stephen F. Arno and published by . This book was released on 1983 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors examine variation in the length of mean intervals between fires (occurring between the years 1600 and 1910) in sample units of various sizes, ranging from a point on the ground (single tree) to a large stand (200 to 800 acres; 80 to 320 hectares). Recommendations are made regarding appropriate sizes of sample units for fire history studies.

Author : STEPHEN F. ARNO
Publisher :
ISBN 13 : 9780265061565
Total Pages : 0 pages
Book Rating : 4.63/5 ( download)

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Download or read book VARIATION IN ESTIMATES OF FIRE INTERVALS written by STEPHEN F. ARNO and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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Publisher :
ISBN 13 :
Total Pages : 426 pages
Book Rating : 4.31/5 ( download)

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Download or read book Research Paper INT. written by and published by . This book was released on 1982 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Danielle Robbins
Publisher :
ISBN 13 :
Total Pages : 224 pages
Book Rating : 4.53/5 ( download)

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Download or read book Temporal and Spatial Variability of Historic Fire Frequency in the Southern Willamette Valley Foothills of Oregon written by Danielle Robbins and published by . This book was released on 2004 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: A crossdated fire history was reconstructed for a 1562 km2 area in the southern Willamette foothills of Oregon, using fire scars and tree origin years from twelve sites. The purpose of this study was to determine fire frequency for each site and to quantify temporal and spatial variability of fire frequency. Fire frequency distributions were related to climate history and the patterns of human settlement, and compared with other regional fire histories. Dendrochronological methods were used to assign calendar years to fire scars and pith dates. General Land Office maps and surveyor notes were used to determine site and study area level changes in vegetation and Euro-American land use patterns. Climatic influence on fire over time was determined using superposed epoch analysis. Forty-three fire dates were reconstructed for the 290 year period from 1700 to 1990. The minimum and maximum fire intervals were two years and 191 years; the study area mean fire return interval was 49 years. Over two-thirds of all site level fire intervals were less than 40 years, and less than one-fifth were longer than 80 years. Fire frequency differed between the east and west sides of the Willamette Valley. West side sites experienced more frequent fires on average than the east side sites: 57% of all west side site fire intervals were less than 20 years, while 68% of all east side site fire intervals were less than 40 years. Both human and vegetative factors were potentially influencing the fire regimes of each side of the valley. West side sites were within, or adjacent to, woodland forest cover types and were closer to earlier and more intensive Euro-American settlement. Fire frequency throughout the study area did not change substantially over time. Fire occurred every decade or so, with occasional longer fire intervals, until after 1905, at which time fire occurred roughly every 15 to 20 years until 1979. Unlike other regional fire history studies, this study found no statistically significant differences in the number of fires by time periods of varying land use and climate. When the rule set for defining fire events was modified, fire frequency could be shown to be weakly significantly associated with these time periods. This indicates that methodology can appreciably influence the results of fire history reconstruction. Moreover, the sample size of trees dating from the 1 700s was small, so the estimate of fire frequency for the 1 700s is uncertain. Fire frequency was not related to drought over the whole study period (1700- 1990), but fire was more likely to occur three years following a drought year over the period from 1700 to 1849, whereas after 1850, fire was significantly associated with drought years. Fire occurrence was as expected (but not significantly so) during the period 1700 to 1800, slightly higher than expected (but not significantly) for the period 1800 to 1850, higher than expected (but not significantly) after 1850, and lower than expected (but not significantly) after 1925. Several hypotheses could explain these findings: (1) the relationship between wildfire and drought is different during cooler, wetter periods than warm, dry periods; (2) Native Americans influenced fire during the 1700-1849 period, obscuring the relationship between fire and drought; (3) European settlement of the Willamette Valley in the mid to late 1 800s increased the occurrence of fire and enhanced the effects of a warming climate, and (4) fire suppression after 1920 resulted in a decrease in fire occurrence. More sampling of older stumps in the Willamette Valley foothills would likely lend credibility to the record of fire frequency before 1800 and would increase the sample depth for use in the Superposed Epoch Analysis of the fire-drought relationship. Sampling along transects extending from the foothills into the Cascades and Coast Ranges would foster a better understanding of the spatial scope to which Native American burning influenced forests adjacent to the valley floor.

Author : Gregory K. Dillon
Publisher :
ISBN 13 :
Total Pages : 85 pages
Book Rating : 4.63/5 ( download)

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Download or read book Historic Range of Variability for Upland Vegetation in the Medicine Bow National Forest, Wyoming written by Gregory K. Dillon and published by . This book was released on 2005 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approach for synthesizing the results of ecological research pertinent to land management is the analysis of the historic range of variability (HRV) for key ecosystem variables that are affected by management activities. This report provides an HRV analysis for the upland vegetation of the Medicine Bow National Forest in southeastern Wyoming. The variables include live tree density, dead tree (snag) density, canopy cover, abundance of coarse woody debris, species diversity, fire return intervals, the abundance of various diseases, the proportion of the landscape in different land cover types, and the degree of patchiness in the landscape. The variables were examined at the stand and landscape scales, using information available in the literature and USFS databases. High-elevation landscapes were considered separately from low-elevation landscapes. Much of the report pertains to forests dominated by lodgepole pine, subalpine fir, and Engelmann spruce at high elevations, and by ponderosa pine and aspen at lower elevations. We defined the HRV reference period for the MBNF as approximately 1600 to 1860.

Author : Wulfram Gerstner
Publisher : Cambridge University Press
ISBN 13 : 1107060834
Total Pages : 591 pages
Book Rating : 4.38/5 ( download)

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Download or read book Neuronal Dynamics written by Wulfram Gerstner and published by Cambridge University Press. This book was released on 2014-07-24 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: This solid introduction uses the principles of physics and the tools of mathematics to approach fundamental questions of neuroscience.

Author : Thomas T. Veblen
Publisher : Springer Science & Business Media
ISBN 13 : 038721710X
Total Pages : 456 pages
Book Rating : 4.09/5 ( download)

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Download or read book Fire and Climatic Change in Temperate Ecosystems of the Western Americas written by Thomas T. Veblen and published by Springer Science & Business Media. This book was released on 2006-05-10 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both fire and climatic variability have monumental impacts on the dynamics of temperate ecosystems. These impacts can sometimes be extreme or devastating as seen in recent El Nino/La Nina cycles and in uncontrolled fire occurrences. This volume brings together research conducted in western North and South America, areas of a great deal of collaborative work on the influence of people and climate change on fire regimes. In order to give perspective to patterns of change over time, it emphasizes the integration of paleoecological studies with studies of modern ecosystems. Data from a range of spatial scales, from individual plants to communities and ecosystems to landscape and regional levels, are included. Contributions come from fire ecology, paleoecology, biogeography, paleoclimatology, landscape and ecosystem ecology, ecological modeling, forest management, plant community ecology and plant morphology. The book gives a synthetic overview of methods, data and simulation models for evaluating fire regime processes in forests, shrublands and woodlands and assembles case studies of fire, climate and land use histories. The unique approach of this book gives researchers the benefits of a north-south comparison as well as the integration of paleoecological histories, current ecosystem dynamics and modeling of future changes.

Author :
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ISBN 13 :
Total Pages : 124 pages
Book Rating : 4.1V/5 ( download)

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Download or read book Fire Ecology and Management of the Major Ecosystems of Southern Utah written by and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document provides managers with a literature synthesis of the historical conditions, current conditions, fire regime condition classes (FRCC), and recommended treatments for the major ecosystems in southern Utah. Sections are by ecosystems and include: 1) coniferous forests (ponderosa pine, mixed conifer, and Engelmann spruce-subalpine fir), 2) aspen, 3) pinyon-juniper, 4) big and black sagebrush, and 5) desert shrubs (creosotebush, blackbrush, and interior chaparral). Southern Utah is at the ecological crossroads for much of the western United States. It contains steep environmental gradients and a broad range of fuels and fire regimes associated with vegetation types representative of the Rocky Mountains, the Great Basin, Northern Arizona and New Mexico, and the Mohave Desert. The Southern Utah Demonstration Area consists of contiguous state and federal lands within the administrative boundaries of the Bureau of Land Management (BLM), Fishlake and Dixie National Forests, National Park Sevice, and State of Utah, roughly encompassing the southern 15 percent of Utah (3.24 million ha). The vegetation types described are similar in species composition, stand structure, and ecologic function, including fire regime to vegetation types found on hundreds of millions of hectares in the 11 western states.

Author :
Publisher :
ISBN 13 :
Total Pages : 488 pages
Book Rating : 4.9E/5 ( download)

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Download or read book Fire, Fuel Treatments and Ecological Restoration written by and published by . This book was released on 2003 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: