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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of a conservation education and interpretation guidebook for the Thorne Bay and Craig Ranger Districts, Tongass National Forest /

Atkinson, Nelli R. January 2005 (has links) (PDF)
Thesis (M.S.)--University of Wisconsin--Stevens Point, 2005. / Includes bibliographical references (p. 159-162).
2

Lichen biomonitoring in southeast Alaska and western Oregon

Derr, Chiska C. 09 December 1994 (has links)
Lichen sensitivity to air quality has been recognized in Europe for over 125 years: recently Federal agencies in this country have begun using lichens as air quality bioindicators. This study presents the results of three different approaches to air quality biomonitoring using lichens: (1) a lichen community analysis, (2) an elemental analysis of lichen tissue content, and (3) the growth of removable lichen transplants. The lichen community and elemental tissue content analyses were part of an air quality baseline on the Tongass National Forest in southeast Alaska. The lichen transplant experiment compared the growth of three different lichen species and evaluated and refined a transplant technique in western Oregon. Lichen communities were sampled on 50 Pinus contorta peatlands in southeast Alaska. These peatlands make good air quality biomonitoring sites because: (1) the trees are slow growing and provide stable substrates for lichen colonization; (2) many branches are at eye level, making the canopy epiphytes easily observable; (3) the scattered, open distribution of the trees allows for good air circulation on the sites; and (4) precipitation, light conditions, and relative humidity are high, which stimulate lichen growth. A total of 100 lichen species were encountered during whole-plot ocular surveys of each plot. Multivariate ordination revealed what appears to be a successional gradient represented by high cover of Bryoria species at older sites and high cover of Platismatia norvegica, P. glauca, Hypogymnia enteromorpha sens. lat. and H. inactiva at younger sites. A second pattern revealed by ordination analysis appears to be a climatic gradient with high Alectoria sarmentosa cover on moister, warmer sites, and high cover of Bryoria species on drier, colder sites. The first two gradients contained 35% and 21%, respectively, of the information in the analytical data set (cumulative r��=56%). Elemental tissue content of Alectoria sarmentosa was determined from 43 of the peatland plots in southeast Alaska. The range of values for 16 elements are reported and compared to other regional studies; the ranges of values for most elements were within normal background levels. Quality assurance techniques are described for separation of laboratory and field noise from elemental content signal. Principal components analysis was used to create three synthetic gradients of plot-level elemental content. The first three principal components captured 55% of the correlation structure among elements. Iron (r=-0.91), aluminum (r=-0.80) and chromium (r=-0.71) are all highly correlated with the first gradient. This gradient could represent sites enriched by elements from dirt; aluminum and iron silicates are both persistent and abundant components of weathered rock and soil. Potassium (r=-0.82), phosphorous (r=-0.63), zinc (r=-0.60), manganese (r=-0.58), magnesium (r=-0.51) and nickel (r=0.54) are correlated with the second gradient. Many of these elements are supplemented by salt water aerosols (Nieboer et al. 1978; Rhoades 1988). Lead (r=0.70) and cadmium (r=0.59) were correlated with the third axis. This gradients could represent enrichment from fossil fuel combustion. Recommendations for standardizing future regional studies of lichen elemental content are made. Removable lichen transplants were constructed using live thalli of known weight, a 5 cm length of nylon monofilament, silicone glue, and reusable attachment mechanisms. Transplants were returned to several sites in Western Oregon and were weighed every several months for 13 months. Reference standards for each species were used to correct for changes in lichen water content due to changes in lab humidity. Despite apparent vigor, Alectoria proved unsuitable for repeated weighings because of biomass loss due to fragmentation (average of 9% biomass loss). Growth of Evernia and Lobaria transplants differed both between species and between sites. Average growth over the 13 months for Evernia in the foothills and valley was 40% and 30% respectively; for Lobaria it was 16% and 15%. Differences in growth between species could be due to different: (1) growth rates; (2) sensitivities to air quality; (3) sensitivities to microhabitat; and (4) sensitivities to transplant trauma. Differences in growth between valley and foothill sites could be due to differences in: (1) micro- or macrohabitat conditions; and (2) air quality. / Graduation date: 1995
3

Storm Response and Water Balance of Temperate Rainforest Karst Watersheds: Tongass National Forest, Alaska

Kovarik, Johanna 01 May 2007 (has links)
The Tongass National Forest in southeast Alaska contains 2,176 square kilometers of karst. As part of the evolving Tongass Land Management Plan, research into the function of karst systems is crucial in understanding how forest management affects not only karst areas but also surrounding ecosystems. Dye trace and water balance results in two watersheds on the north end of Prince of Wales Island demonstrate the difficulty in containing the effects of management, as water can enter karst catchments from unknown sources at different flow regimes. A dye trace was conducted in Windgate and Canyon Block watersheds. Two sinking streams were traced to one resurgence spring in Canyon Block, and four sinking streams were traced to one resurgence spring in Windgate. Water balance data calculated for the entire study period and individual storm events suggests that Windgate has been sufficiently delineated. Data from the study period and storm event water balance calculations for Canyon Block suggest that at high flow discharge is pirated into Canyon Block from another system. High resolution monitoring in each catchment show that there is no significant delay between the increase in discharge and the arrival of direct runoff, as evidenced by the quick decrease in specific conductance. This could result in a quick transmission of sediment and contaminants through the karst system into downstream salmon habitat.

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