Pre-flood (1995), and post-flood (1996) channel stability surveys were conducted on 22 reaches along Oak Creek, Benton County, Oregon in an effort to note if the flood of February 1996 altered the channel and if the channel stability survey that was being used accurately predicted the channels resistance to change resulting from a flood. The channel stability survey that was used was the method described in the 'Channel Stability Evaluation and Stream Reach Inventory' designed by the USDA Forest Service, Northern Region, in Colorado (Pfankuch, 1978). This was a non-parametric study, based on an opportunity to reoccupy survey locations from a previous study. A model was proposed to describe the 1995 ratings as predictions for change should a flood event occur. This predicted change was compared to the actual change that occurred as a result of the 1996 flood in order to test the surveys ability to accurately predict change. Changes in the survey totals, the 15 channel stability indicator items that compose the survey, and the sediment distribution were evaluated within and between years at the reach, station and stream scale. An increase in the percentage of fine gravel occurred at all scales when post-flood and pre-flood sediment distribution was compared. Except for an increase in fine gravel, the stream remained similar to its pre-flood state. In 1995, the stream's channel stability was rated as 'fair', indicating that a moderate amount of change should take place if a flood occurred. The 1995 predictions for change did not match the actual change observed after the February 1996 flood at the three scales when defined by the survey totals. When independently evaluating the fifteen individual channel stability indicator items, a considerable amount of change was detected at the reach level. Although change occurred in the indicator items at each reach, the stream average for each of the independent indicator items was similar between the two years. This may indicate that, although change occurred at the reach level, the stream maintained its physical diversity after the flood. The survey method was unable to accurately predict changes to Oak Creek incurred by the February 1996 flood when viewed at the entire stream level, yet it may be more applicable at the reach level when viewing specific changes to channel stability indicator items. In general, the Stream Reach Inventory and Channel Stability Evaluation is designed for observational efficiency but does not have sufficient scientific basis or measurement precision to accurately predict the extent or type of channel change. / Graduation date: 1998

Spatial distribution of species and thus the composition of deciduous forests are expected to change in response to global climatic warming. Climate-growth response algorithms in forest simulation models that represent the influence of climate on tree growth are based on the geographic range limits of a species. These models assume that temperature limitations control the latitudinal range boundaries for tree species in the eastern United States, and that water limitations control the western range boundary. This study investigated spatial variation of tree-growth responses to historical variations in climate using tree-ring data for Quercus rubra L. from 71 study sites across latitudinal and longitudinal temperature and precipitation gradients in eastern North America. Correlation analyses were used to identify significant site-specific associations between radial growth indices and 130 climate variables for the common time interval 1930-1980. Geographic information systems (GIS), and Mantel and partial Mantel spatial correlation analyses were used to map, identify, and measure spatial associations between oak sensitivity to climate and regional climate patterns to test the hypothesis that climate controls the spatial distributions of species range limits.Seasonal climate variables exhibited the strongest correlations with radial growth most consistently across the 71 study sites. However, spatial patterns in regional climate were only weakly associated with spatial variation in red oak sensitivity to climate variables. Contrary to expectations, correlations between red oak radial growth indices and temperature variables at northern and southern sites were not significant, failing to support the hypothesis that latitudinal range limits are defined by temperature effects on mature tree growth. High early growing season temperature reduced growth mostly at sites in the southwest region, which concomitantly experienced high inter-annual variability in soil moisture. Increased early growing season site water balance and precipitation was associated with greater radial growth in the western third of red oak's range, partially supporting the hypothesis that the western range limit is defined by limited water availability. These results indicate that climate only partially determines range limit locations; thus model projections may exaggerate forest responses to climate change. / Department of Biology

The purposes of this study were: 1) to review the land use history of Oak Creek watershed since European settlement. And 2) to consider the human-caused impacts and their effects associated with different land uses. The study area was classified into three land use patterns: residential, agricultural, and forested areas. Since the European settlement in the mid 1840's, the Oak Creek watershed has experienced changes of land use simultaneous with the development of the city of Corvallis and its vicinity. Associated with this, different impacts have occurred on riparian areas. By and large, these impacts were inherent to each land use. / Graduation date: 1993

Hurricane Katrina made landfall in 2005 damaging 1.2 billion cubic meters of timber including 48 million cubic meters of hardwood. An economically efficient method of artificial oak regeneration is necessary in many areas to restore this high value resource. Bareroot, conventional containerized, and EKOgrown® seedlings of Quercus shumardii and Q. texana were planted on two sites in south Mississippi. Growth and survival were evaluated for two years. Survival was assessed monthly and at the end of each growing season. Height and groundline diameter were assessed initially after planting and the end of each growing season. After two growing seasons, Q. Nuttallii exhibited superior performance generally when compared to Q. Shumardii. Conventional containerized had poor survival and initial growth likely caused by freeze damage in the nursery. EKOgrown® seedlings performed better than other planting stocks, however, high seedling cost makes them less cost-effective than bareroot seedlings which exhibited acceptable performance overall.

Bare-root Nuttall oak, Shumard oak, and swamp chestnut oak seedlings were planted on former agricultural fields in Mississippi to evaluate growth and survival following treatment by different combinations of mechanical site preparation and pre-emergent Oust XP® applications. Mechanical treatments included: (1) controls, (2) subsoiling treatment, (3) bedding treatment, and (4) combination plowing. Pre-emergent Oust XP® treatments included: (1) one-year Oust XP® applications and (2) two-year Oust XP® applications. Evaluations and measurements were performed over the course of three years. Results within this dissertation should be considered in the context of high quality former agricultural sites with silt loam soils. Seedling height and GLD increased each growing season. Height and GLD of seedlings were greater in bedded and combination plowed areas compared to control and subsoiled areas. Height and GLD were not different by Oust XP® application. However, seedling survival in two-year Oust XP® application areas was reduced compared to one-year Oust XP® application areas. Nuttall oak seedlings planted in bedded and combination plowed areas exhibited greater stem biomass compared to those planted in control or subsoiled areas. Seedlings planted in two-year Oust XP® areas exhibited greater stem and root biomass compared to those planted in areas receiving the one-year treatment. Better growth and biomass production in bedded and combination plowed areas would promote their use for site preparation on similar sites. While survival was lower in two-year Oust XP® treatment areas compared to one-year treatment areas, the difference would not warrant change in management strategy. Additionally, woody biomass was much greater in two-year Oust XP® areas. Thus, if cost is not prohibitive, treatment with two years of Oust XP® is recommended. The objective of the mixed species study was to establish baseline growth and survival data for mixed Nuttall oak and green ash plantations on former agricultural areas. Height and GLD for both species increased each growing season. Third-year survival was excellent at 96.0 percent. In conclusion, the mixture performed satisfactorily. Growth and survival were excellent, which indicates this mixture would be useful in afforesting similar former agriculture sites.

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Many existing Piedmont hardwood stands are composed of trees that are largely under 45 cm in diameter and contain a desirable oak component, as well as large amounts of undesirable red maple and sourwood. In stands under even-aged silviculture, season of harvest can be used as an effective management tool to favor different species compositions. If oak or other hardwood production is the management objective a dormant season harvest will result in increased sprout vigor of all oak as well as non-oak species. If pine conversion is the objective then a growing season harvest will reduce the vigor of all hardwood species and allow for easier competition control. The higher densities of all classes of regenerants on better sites indicates control will be more difficult. / Master of Science

Emory oak (Quercus Emoryi) is a dominant tree species in San Rafael Valley in southeastern Arizona. However, basic information about the effects of coppice thinning on the growth and yield of this species is lacking. Thus, objectives of the study were to measure the effects of coppice thinning on Emory oak survivor growth, ingrowth, and mortality, which are the basic components of a growth budget. This study determined gross growth, net growth, and yield estimates. In addition, this study evaluated the mean annual growth (MAG) values in relation to the biological rotation age of Emory oak in southeastern Arizona. Coppice thinning treatments were applied to sprouts of different ages. Height and diameter at root collar measurements were taken immediately after thinning and again 5 years later. Sprouts were classified into 5 age groups, 4 stump diameters, and 3 level of coppice thinnings and an unthinned control. The interactions of these treatments and their effect on growth and yield were analyzed. Stump diameters did not significantly affect the growth components, growth estimates, or yield estimates. The number of residual sprouts significantly affected the growth components, growth estimates, and yield estimates. Survivor growth, gross growth, net growth, and yield were lowest for 1 residual sprout, except for net growth of 8-year-old sprouts. There were no significant differences in net growth between the different coppice thinning treatments. At age 8-year-old sprouts, the mean annual growth of individual sprouts increased as the number of residual sprouts per stump reduced. Based on this relationship, it is recommended that 1 residual sprout be left when thinning sprouts. Age of sprouts significantly affected growth. There was an increase in the mortality of the control sprouts in the 6th year. Based on those results, it is recommended that thinning be conducted in the 5th year of the sprout's growth. Proper timing of thinning can reduce the rotation age of Emory oak sprouts, if the rotation is based on achievement of a specified diameter. To draw firm conclusions about the effects of thinning on shortening the rotation age, the study measurement needs to be continued into the future.

Global climate change is predicted to alter the weather patterns around the world, as climatic zones shift, forest carbon sequestration projects (e.g. the UK woodland carbon code) need to take into account the specific requirements of planted species. In the UK, oaks are an important charismatic group of trees favoured in recent planting programmes. The English oak (Quercus robur L.), has poor water conservation, but is a major component of natural forests in lowland UK. On the other hand, Holm oak (Quercus ilex L.) is a Mediterranean oak that has high water conservation and can also tolerate cold despite being restricted by minimum temperatures. At local scales, there may be advantages of planting either evergreen or deciduous oak species for forestry and climate mitigation. Alternatively, a comparative assessment of non native versus native productivity, may give clues to the invasiveness potential of Holm oak and its ability to out compete the deciduous oak along an urban to upland gradient. This thesis documents a series of field based experiments intended to analyse differences in carbon sequestration potential and photosynthetic efficiency between these two species and in relation to their environment within the Southwest UK. 520 one year saplings were planted, half in pots and half in nursery field beds situated on Dart- moor, the east Devon Dartmoor fringe, Totnes, and Plymouth city centre. Originally two sites were chosen for their relative ‘urban’ qualities, two at ‘rural’ localities, one upland and a control site with access to a polytunnel for comparisons with well-watered and non nutrient limited trees. However, data analyses showed that sapling characteristics were site specific with the five sites falling along an urban, rural to upland gradient. The field experiments included monthly height and diameters (ground level diameter or DAG), monthly assimilation rates and analy- sis of chlorophyll fluorescence to aid interpretation of photosystem II functioning and sapling ‘vitality’. Further laboratory experiments analysed specific leaf area (SLA), mass based leaf Nitrogen (Nleaf ) and carbon (Cleaf), with differences between sun and shade leaves included, to aid comparisons between species and sites. The final experiment was a destructive harvest and this was used to find total biomass estimates and carbon allocation to different root shoot fractions. In order to quantify differences between saplings and adult trees a smaller experiment was con- ducted in the canopy using experienced climbers and leaf level productivity analysed. Intrinsic water use (iWUE), stomatal conductance (Gs), means net assimilation rates (An) and chloro- phyll fluorescence parameters; Variable fluorescence over maximum fluorescence (Fv/Fm) and performance index (PI) were measured and relative carbon assimilation rates and productivity assessed and compared between species at one urban , rural and upland site. Results showed that Q. ilex allocated relatively more carbon to branches and leaves as a sapling which in turn increased growth rate and whole tree assimilation rates to larger values than the deciduous oak despite Q. robur being able to increase maximum assimilation rates in response to increasing temperatures. This gives Q. ilex the advantage and overall biomass was higher at all sites than Q. robur apart from the upland site where there were no differences in biomass accumulation between species. However, despite no significant difference in biomass at this site Q. robur had greater survival and photosystem II functioning. In mature trees Q. ilex was under stress and Nleaf and carbon sequestration potential were higher in the deciduous species at the urban site. In contrast, Q. robur was under stress at the upland site at Castle Drogo where thin and nutrient poor soils have made it more vulnerable to drought stress. Here, mature Q. ilex showed reduced photosynthetic efficiency in relation to cold and drought, but was able to recover when milder temperatures occurred. The results were site specific, with a reduction in both SLA and relative allocation to the leaf weight fraction (LWF) in Q.robur the only common urban related effect seen. The potential for Q. ilex to perform well at sapling stage is due to its morphological plasticity and drought tolerance. This species may become more prevalent within the Southwest as local climates continue to push it northwards from its natural Mediterranean range. In contrast, if Q. robur continues to suffer from defoliation and fungal attack and this may leave it more vulnerable to competition throughout less fertile and drier areas of its natural range.

No description available.