Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1981. / Vita. Abstract. Includes bibliographical references (leaves 124-134). Also available via the Internet.

Thesis (Ph.D.)--Pennsylvania State University, 2006. / Mode of access: World Wide Web.

Thesis (M.S.)--Eastern Illinois University, 1994. / Includes bibliographical references (leaves 16-17).

An environmental study using the association concept and the 'ecological groups' within the biogeoclimatic zonal framework was conducted in the Sub-Boreal spruce zone in British Colimbia [sic]. Quantitative information on the vegetation and environment of the zone has, hitherto, been lacking. Seventy seven stands have been studied. From the six upland associations, delimited by the methods of Zurich-Montpellier School using Domin-Krajina scale, soils from seventeen different Soil Great Groups have been distinguished and described. The relation between vegetation and soil morphology are obvious at the zonal and association levels but are less distinct at lower levels. Based on fourteen sample plots, four low moor associations on nine Mesisols, four Fibrisols and one Humisol are also described. Microclimatic data, air and soil temperatures, humidity, precipitation and snow cover have been recorded from five stands that differed in canopy density, ground cover, species composition, in soil conditions and topography. Air and soil temperature patterns show a remarkable similarity. Diurnal temperature fluctuations are most pronounced under Pinetum contortae while such fluctuations are much less under Alnetum tenuifoliae and Piceetum glaucae. Chemical analyses of 280 soil samples include a wide range of both macro- and micronutrients as well as some toxic heavy metals. Analyses involved water soluble and replaceable major cations, total nitrogen and available phosphorus, and water soluble, replaceable, EDTA- and HCl-extractable trace metals. The soils under white spruce-devil's club and river alder-ostrich fern are the richest in both macro- and micronutrients, followed by aspen and black spruce. Seemingly soils of the black spruce sites sampled show a high nutrient content but it looks doubtful if all these are readily available because of impeded drainage and low base saturation. From the study of the sites, nutritional requirements of subalpine fir appear to be high and those of lodgepole pine very low. Neither the chemical characteristics of the low moor organic soils nor the water chemistry seem to show any distinct relationship with the vegetation of these sites. Using multiple regression analyses eight statistically significant environmental gradients have been used in the study. The soil texture gradient is based on the weighted averages of the sum of percentage silt and clay content calculated for the rooting depth. The water gradient has been established on the available water capacity expressed as a percentage of the rooting volume of the soil. Five nutrient gradients have been established. The calcium and magnesium gradients are based on the replaceable content expressed as equivalents per square meter of the soil rooting volume. Nitrogen gradient based on total nitrogen analysis are expressed as grams per square meter of the rooting volume. Gradients based on EDTA-extractable manganese and iron are expressed the same way as nitrogen. The light gradient is based on observations from fiftyeight plots, extended over a period of two years, using a chemical light meter. All gradients are quantified and the correlations of associations along these gradients are shown. Of all the gradients considered in the study, plant communities showed better correlations with soil texture, water and replaceable calcium. Using relative species significance rather than presence, distributional patterns of individual species along these gradients have been illustrated. Predictive equations based on regression analyses using both transformed measured values and their logarithms have been given for a number of plant species. / Science, Faculty of / Botany, Department of / Graduate

A study was carried out to ascertain the biogeochemical role of understory vegetation in three representative sites characteristic of the Mountain Hemlock Biogeoclimatic Zone. The three sites were selected to represent a typical topographic sequence of plant associations and were classified as members of the Vaccinio (membranacei) -Tsugetum mertensianae, Abieto (amabilis) - Tsugetum mertensianae and Streptopo (rosei) - Abietetum amabilis plant associations (xeric, mesic, and hygric site types, respectively). The overstory layer was found to be typical of old growth, high elevation forests of southwestern coastal British Columbia. Overstory biomass on the three sites was estimated to be 60.88, 55.68, and 34.05 kg•m⁻² for the hygric, mesic, and xeric site types, respectively. Understory aboveground biomass was found to be less than one percent of the aboveground overstory biomass. Average values for the three sites were: 44.1, 66.1, and 399.3 g•m⁻² for the hygric, mesic, and xeric site types, respectively. Understory aboveground production (UAP) was found to represent a greater proportion of overstory aboveground production, as indicated by the mean annual increment (MAI), than the biomass figures might suggest. UAP values of 25.95, 14.19, and 63.12 g•m⁻²•yr⁻¹ for the hygric, mesic, and xeric site types, respectively, were equivalent to 11.28 percent, 6.06 percent, and 48.55 percent of the estimated aboveground overstory production. Only a small percentage of the total aboveground nutrient standing crop was found in the understory. This is in agreement with comparable published values for old growth forest ecosystems. However, the understory was found to cycle a much greater proportion of its total standing crop annually compared to overstory. Approximately 80 percent of the macronutrients present in the understory standing crop are found in the understory annual production on the Streptopo - Abietetum amabilis site (hygric site type). Estimates of 17.6, 8.3, and 20.6 g•m⁻²•yr⁻¹ of understory aboveground litterfall (exclusive of the moss layer) were obtained for the hygric, mesic, and xeric sites, respectively. These values are substantially less than for overstory litterfall, but the biomass of different litterfall components (e.g. understory or overstory) was shown to be a poor indicator of the proportional contribution of the components to the quantity of nutrients in aboveground litterfall. Understory was shown to return a significant proportion of the litterfall nutrients on a yearly basis, the bulk of which was returned as a single pulse during the first autumn snowfall. Understory vegetation above the moss layer was shown to have a significant effect on the quantity of nutrients present in throughfall precipitation reaching the ground. The effect was seasonal in nature with PO₄-P, N0₃-N, and NH₄-N being removed in the spring and Ca, Mg, and K being added to overstory throughfall in the autumn. It was concluded that modifications of water chemistry previously attributed to the forest floor may in some cases reflect unmeasured influences of understory vegetation. The understory aboveground nutrient cycles follow two basic patterns. The first pattern, a conservative cycle, is exemplified by nitrogen and phosphorus and has the following characteristics: (1) removal of nitrogen and phosphorus from overstory throughfall by the non-bryophyte understory, (2) estimated annual nitrogen and phosphorus uptake up bryophyte production in excess of the remaining throughfall nitrogen and phosphorus content and (3) a large proportion of the annual requirement was accounted for by internal redistribution within the understory plants. The second cycling pattern, an open cycle, is characteristic of calcium and magnesium and displays characteristics opposite to those of the "conservative cycle". The potassium, manganese, zinc, and copper cycles are intermediate between the "conservative" and "open" nutrient cycles. The results are discussed with respect to a proposed model of ecosystem function and it is hypothesized that understory plays a major role in maintaining ecosystem stability by promoting nutrient cycling. / Forestry, Faculty of / Graduate

Thesis (Ph. D.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 246-256). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 152-159).

Thesis (M.S.)--Oregon State University, 1995. / Typescript (photocopy). Includes bibliographical references (leaves 120-130). Also available on the World Wide Web.

published_or_final_version / Botany / Doctoral / Doctor of Philosophy

I identified the seasonal ranges and migration routes for Rocky mountain elk (Cervus elaphus nelsoni) that summered on the White Mountains Apache Reservation (reservation). I described elk distributions, movements, diets, and behaviors related to habitats in the White Mountains, Arizona from October 1983 to July 1986. I identified neonatal elk hiding habitats and how long they were used. Adult and neonatal elk were captured and radio collared. I determined movements and habitat use from direct observations of marked elk relocated by radio-telemetry. Yearly home ranges in this population were large; 638.9 ± 465.2 (SE) km² and 385.7 ± 313.1 km² for males and females, respectively. Distances elk moved/day were greater in summer (7.5 ± 0.3 km) and fall (6.5 ± 0.4) than in winter (3.2 ± 0.2 km). In summer, males selected spruce (Picea spp.) forests and associated clear cuts while females selected mixed-conifer types. In winter, males selected juniper (Juniperus spp.) and cleared sites. Females selected junipers and cleared sites, but also selected meadows and mixed-confer sites. Daily and seasonal elk activity patterns were similar to those reported elsewhere. Seasonal segregation of male and female elk groups occurred and was most related to elevational (and associated habitat) differences. Females moved to higher elevations, following snowmelt, earlier than males in spring, but males moved to higher elevations than females by summer. In fall, males and females used habitats at mid-elevations. Females were more frequently seen in forested types than males which were often observed in small forest openings. Habitat differences in winter were mostly spatial rather than structural. Spring elk diets were dominated by grasses (57.8%), summer diets by forbs (65.6%), fall diets by grasses (35.2%) and forbs (37.9%), and winter diets by evergreen oaks (Quercus spp.) (41.0%). Diets were similar between sexes in all seasons. Neonatal elk hid until 16 days old. Calves <10 days old moved less than calves ≥10 days old. Calf hiding sites were in mid-elevational ponderosa (Pinus ponderosa) on gentle southwest slopes. Hiding cover 0.36 m to 1.70 m tall was the most important component of calf hiding sites.