TY - THES T1 - A comparative study of soil disturbance from uprooted trees, and mound and pit decay in Puerto Rico and Colorado T2 - Institute for the Study of Planet Earth Y1 - 2003 A1 - Melanie Lenart KW - colorado KW - Mound and pit KW - Puerto Rico KW - Soil disturbance KW - Uprooted AB - The toppling of trees forms mounds of disturbed sediment and pits from which the mound removes sediment, rocks, and organic matter. Sites of uprooted trees in Puerto Rico and Colorado were examined (1) to compare areas and volumes of mounds and pits relative to tree size, (2) to compare areas and volumes of mounds and pits formed during catastrophic events at the landscape scale, and (3) to consider decay of mounds and pits after formation. For a given basal area, the analyses found no difference among sites in area and volume of freshly formed individual mounds and pits. For landscape-level catastrophic uprooting, the percent of toppled trees in a plot can explain 85% and 87% of the areas and volumes, respectively, of the quantity of soil uplifted. Exponential decay coefficients developed by monitoring mound/pit complexes indicate that mounds and pits at the humid tropical site in Puerto Rico decay in about 74% and 57% of the time, respectively, of mounds and pits at a temperate Colorado site. Decay coefficients developed for the Colorado site indicate that mounds and pits are reduced to 10% of their original volume within 30 and 78 years, respectively. Coefficients for Puerto Rico suggest that a similar reduction in volume requires 17 years, whereas pits generally fill within a decade. JF - Institute for the Study of Planet Earth PB - University of Arizona VL - PhD UR - http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=765017541&sid=9&Fmt=2&clientId=43922&RQT=309&VName=PQD ER - TY - THES T1 - Stand Replacing Fire History and Aspen Ecology in the Upper Rio Grande Basin T2 - Department of Renewable Natural Resources Y1 - 2003 A1 - Margolis, Ellis Quinn KW - aspen KW - basin KW - colorado KW - conifer KW - dendrochronology KW - dendroecology KW - Ecology KW - fire KW - fire history KW - new mexico KW - rio grande KW - spruce fir KW - stand replacing KW - tree ring AB -

Dendroecological techniques were applied to reconstruct stand-replacing fire history in mixed conifer and spruce-fir forests in northern New Mexico and southern Colorado. Stand-replacing fire dates with annual accuracy and precision were determined using four lines of evidence for each of twelve sites within a 75,000 square kilometer area. The four lines of evidence were: (1) aspen inner-ring dates, (2) conifer death dates, (3) tree-ring width changes, or other morphological indicators of injury, and (4) fire scars. The annual precision of dating allowed the identification of significant synchrony of stand replacing fires among the 12 sites and regional surface fire events previously reconstructed from the large network of fire scar collections in the Southwest. Nearly all of these synchronous stand-replacing and surface fire years coincided with extreme droughts. This suggests that stand-replacing fire activity occurred primarily when drought conditions allowed fires to ignite and spread within these high elevation forests and/or for the spread of surface fires between lower and upper elevations. Fifty percent of reconstructed stand-replacing fires pre-dated large-scale Euro-American settlement in this region. This may suggest that land use practices (such as logging and mining) were not as important in promoting stand-replacing fires in these study sites, as compared with other areas in Colorado.

JF - Department of Renewable Natural Resources PB - University of Arizona CY - Tucson VL - Master of Science ER - TY - THES T1 - Tree-Ring Reconstruction of Western Spruce Budworm Outbreaks in the Rio Grande National Forest, Colorado T2 - School of Renewable Natural Resources Y1 - 1999 A1 - Ryerson, Daniel E. KW - colorado KW - dendrochronology KW - department of agriculture KW - forest service KW - national forest KW - outbreak KW - palmer drought severity index KW - RGNF KW - rio grande KW - tree ring KW - western spruce budworm AB -

 

Tree-ring records were used to reconstruct the spatial and temporal patterns of western spruce budworm (Choristoneura occidentalis Freeman) outbreaks in the Rio Grande National Forest (RGNF) of southern Colorado. Reconstructions at 11 host stands showed a synchronous pattern of outbreaks with a peak in the number of trees recording outbreaks over the entire RGNF on average every 24 years. These synchronous periods of outbreaks coincided with periods of increased moisture as indicated by an independently reconstructed summer Palmer Drought Severity Index, while relatively few trees recorded outbreaks during dry periods. The reconstruction on the RGNF does not support the hypothesis that human land use has significantly altered outbreak patterns. Tree response to outbreaks in the RGNF was different from prior studies as reductions in the growth were typically detectable only when growth was compared to that of nonhost tree species.

JF - School of Renewable Natural Resources PB - University of Arizona CY - Tucson VL - Master of Science ER - TY - THES T1 - New perspectives on settlement patterns: Sedentism and mobility in a social landscape T2 - Anthropology Y1 - 1997 A1 - Mark Varien KW - colorado AB - Reconstructing the economic organization of ancient societies and unraveling the development of political complexity requires an understanding of sedentism and mobility. Southwestern archaeology has increasingly focused on sedentism and mobility using a conceptual framework derived from hunter-gatherer research, which emphasizes seasonal movement and the ecological factors that influenced mobility. While producing many valuable studies, this framework is inadequate for a full understanding of population movement. This dissertation addresses this problem by expanding the temporal and spatial scales examined and by viewing mobility as a socially negotiated activity. Residential mobility in the Mesa Verde region is examined by focusing on two social scales--households and communities--and three analytic scales--sites, localities, and regions. Household residential mobility is evaluated by determining the occupation span of residential sites; occupation span is measured by determining the total accumulation of cooking pot sherds and calibrating an annual accumulation rate per household. Community sedentism within a locality is examined through an analysis of structure and site abandonment, and the length of time that individual communities occupied their locality is measured by determining how continuously timbers were harvested. Finally, community mobility within the region is assessed using tree-ring dates and settlement pattern data. These data on household and community movement are interpreted in social terms by reconstructing the changing social landscape in which mobility occurred. Geographic information systems analysis is used to examine how the rugged terrain of the Mesa Verde region affected population movement and to analyze the catchments surrounding individual communities. Residential mobility is an essential part of the mode of production whereby individuals, households, and larger factions gained access to land and labor, the two most important resources for agricultural production. Thus, residential movement is an example of human agency, which occurred in the context of a social structure that developed historically. Land tenure, residence rules, and marriage rules are aspects of the structure that are particularly relevant to understanding population movement. This dissertation examines how the structure both enabled and constrained the practice of residential mobility, and how the practice of residential mobility both reproduced and transformed the structure. JF - Anthropology PB - Arizona State University VL - Phd UR - http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=739774541&sid=19&Fmt=2&clientId=43922&RQT=309&VName=PQD ER - TY - BOOK T1 - Tree-Ring Dates from Colorado W Durango Area Y1 - 1975 A1 - Dean, Jeffrey S. KW - Archaeology KW - colorado KW - date KW - dendrochronology KW - durango KW - tree ring PB - University of Arizona CY - Tucson ER - TY - BOOK T1 - Tree-Ring Dates from Colorado V Mesa Verde Area Y1 - 1974 A1 - Robinson, William J. A1 - Harrill, Bruce G. KW - colorado KW - date KW - dendrochronology KW - mesa verde KW - southwest KW - tree ring PB - University of Arizona CY - Tucson ER - TY - JOUR T1 - Boating Down the Colorado JF - University of Arizona Monthly Y1 - 1907 A1 - Douglass, A.E. KW - boat KW - boating KW - colorado KW - Douglass KW - university of arizona VL - 8 IS - No. 1 ER -