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Analysis of hydrology and erosion in small, paired watersheds in a juniper-sagebrush area of central OregonFisher, Michael, (Michael Patrick), 1966- 22 September 2004 (has links)
Current research indicates that the expansion of
western juniper can inhibit soil water retention, storage
and prolonged releases from watersheds. This phenomenon
is of great importance in eastern Oregon, as western
juniper is encroaching into sagebrush/grass communities
with a correlated reduction in herbaceous ground cover,
resulting in reduced infiltration rates and increased
soil loss. A paired watershed study for the purpose of
monitoring water quality/quantity as affected by western
juniper in the Camp Creek drainage, a tributary to the
Crooked River, was established in 1994.
Monitoring methods consisted of annual and
semiannual measurements of hillslope soil movement,
channel morphology, including total cross-sectional area,
scour and deposition, channel discharge, depth to
groundwater, and precipitation. Channel discharge was
established using a 3,0 H-flume with a pressure
transducer and stilling well and data logger. Changes in channel morphology were determined using 25 permanent,
channel cross-section plots per watershed. Hillslope
erosion processes were determined using 12 transects of 3
sediment stakes per watershed, located within gullies of
subwatersheds.
Data showed the two study areas to be well
correlated with regards to soil movement, both within the
main channels and in the subwatersheds (hillslopes).
Some of the geomorphometric properties are similar (not
statistically different) and differences in other
parameters can be explained. Channel discharge appears
to be significantly different in intensity, frequency,
and duration of flow. These differences in surface
discharge may be explained as further data collection of
subsurface flow analysis in conjunction with sampling of
springs located in each watershed are conducted. / Graduation date: 2005
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Western juniper encroachment into aspen communities in the Northwest Great BasinWall, Travis G. 30 June 1999 (has links)
In the Northwest Great Basin, aspen (Populus tremuloides) communities
uniquely contribute to the biodiversity of a semi-arid, sagebrush-dominated
landscape. In this same region, western juniper (Juniperus occidentalis) is
encroaching into aspen stands. This study determined the timing, extent, and some
of the effects of this expansion.
Aspen stands below 2,133 m elevation were sampled in northwest Nevada,
northeast California, and southeast Oregon for density, canopy cover, age, stand
structure, and recruitment of western juniper and aspen. Soils and tree litter from
both species were collected to analyze the effects of western juniper in areas
previously influenced by aspen. Additionally, two large aspen complexes in
southeast Oregon were intensively aged to determine disturbance (fire) frequencies.
Western juniper encroachment into aspen stands peaked from 1920 to 1939
with 77% of all juniper trees sampled establishing during this period. Five percent
were greater than 100 years and none exceeded 145 years. Three-fourths of aspen
stands sampled have established populations of western juniper. Twenty-three
percent have a dominant canopy of western juniper. Twelve percent of aspen stands
sampled were completely replaced by western juniper. Average density of western
juniper was 1,573 trees per hectare of aspen. Seventy percent of aspen stands
sampled had zero recruitment of new aspen. Within the study area aspen stands
averaged 98 years old. Forty-eight percent of stands were greater than 100 years old.
There was an inverse correlation between aspen canopy cover and western juniper
canopy cover (r��=.80, p=.0001).
Soils influenced by western juniper had a higher C:N ratio and pH; higher
amounts of salts, lime, and sulfate; and lower amounts of magnesium, iron, copper,
and manganese (p<.05). Aspen litter had a lower C:N ratio than western juniper
litter (p<.05).
Prior to 1870, the two major aspen complexes sampled had mean fire return
intervals of 10 and 11 years. However, the most recent disturbance in either
complex was 80 to 90 years ago. This lack of disturbance (fire) coupled with aspen
stand decadence and low recruitment levels leaves aspen communities in the
Northwest Great Basin vulnerable to western juniper encroachment and replacement. / Graduation date: 2000
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Understory vegetation response and nitrogen cycling following cutting of western juniperBates, Jonathan D. 07 June 1996 (has links)
Since the late 1880's western juniper has expanded in range and
increased in density in sagebrush-bunchgrass, riparian, and forested plant
communities of the Pacific Northwest. Succession to western juniper
woodland has been shown to reduce the productivity and diversity of the
understory component, result in concentration of soil nutrients beneath juniper
canopies, and reduces soil moisture storage. This study assessed understory
plant succession, soil nitrogen (N) cycling, litter decomposition, and soil
moisture availability following cutting of a western juniper woodland on Steens
Mountain, Oregon.
Cutting of western juniper reduced below-ground competition for water
and N, increasing soil moisture storage and N availability for understory
species. Leaf water potentials were less negative, and N concentration and
biomass in understory plants were greater in the cut treatment. Understory
species responded to improved growth conditions with increased cover,
biomass, density, and diversity. In 1993, total understory biomass and
canopy cover were 870% and 300% greater, respectively, in the cut treatment
than the uncut woodland. Understory succession was dominated by plants
present on the site prior to cutting. Results indicated initial that bunchgrass
densities of 2 plants/m2 were sufficient for perennial grasses to dominate
following juniper cutting. Juniper cutting is an effective method for restoring
the understory component in sagebrush rangelands that are currently
dominated by western juniper woodland.
Nitrogen availability was greatest in cut-interspace locations the first
year following treatment and in cut-duff locations in the second year.
Nitrification was lowest in cut-slash and woodland-duff locations, areas
receiving fresh litter inputs and experiencing lower temperatures than
interspace (cut and woodland treatments) and cut-duff locations.
Decomposition of juniper litter was two times faster in the cut treatment,
however the release of litter N occurred earlier in the woodland. Large inputs
of N poor litter from cut juniper slash were hypothesized to have increased
microbial demand for N, resulting in immobilization of litter N. Immobilization
of litter N may be important in conserving N on sites following cutting. / Graduation date: 1997
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The recombinant expression of two pollen allergens using plant-viral and yeast expression systemsMoehnke, Marcie H. Kearney, Christopher Michel, January 2005 (has links)
Thesis (Ph.D.)--Baylor University, 2005. / Includes bibliographical references (p. 145-157).
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Effects of juniper removal by shearing and dozing on seedbed preparation and vegetation establishment in the Lampasas Cut Plain, TexasMannel, Cheryl K. 15 May 2009 (has links)
Woody encroachment upon grasslands is a global trend that is cause for concern. In the Lampasas Cut Plain of Texas, Ashe juniper is the dominant woody invasive species. Grassland restoration is dependent upon proper seedbed preparation and seedling establishment. Shearing and bulldozing are common methods of juniper removal. Three hypotheses were tested in this experiment. The first was that bulldozing and shearing results in similar seedbed preparations. The second was that electrical conductivity (ECa) models soil moisture storage heterogeneity across a landscape. The third hypothesis tested was that bulldozing and shearing result in similar seedling establishment. Eighteen plots were selected and three treatments were applied: 1) shearing, 2) dozing, and 3) control. After clearing with both juniper removal methods, the levels of soil disturbance and vegetation regrowth were measured. Point measures were used to describe soil surface disturbance, and at each point, presence and size of ground cover and surface depressions were recorded. After germination, when the plants were large enough to identify, vegetation was sampled at 20-24 locations in each plot. At each sample location a quadrat was placed on the transect, and total herbaceous, grass, forb, rock, litter, and bare soil cover were recorded in cover classes. All species were identified, seeded species were enumerated, and in the second vegetation sample, dominant species were assigned a cover class. There was considerable variation between plots for all parameters measured. Bulldozing created a greater number of depressions in the soil than shearing. It also had a higher percent of large depressions. There was no difference in ground cover change between treatments except in the case of the largest litter category. ECa was effective in modeling soil moisture storage patterns and had a lower coefficient of variation than manual soil depth measurements. There was no difference between sheared and dozed plots for any of the vegetation establishment parameters, but control plots had lower establishment in most categories. Overall, there was little difference between the two treatments in seedbed preparation and seedling establishment. The cost of shearing was 80% of the cost of dozing, which made it more desirable in this scenario.
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Effects of juniper removal by shearing and dozing on seedbed preparation and vegetation establishment in the Lampasas Cut Plain, TexasMannel, Cheryl K. 15 May 2009 (has links)
Woody encroachment upon grasslands is a global trend that is cause for concern. In the Lampasas Cut Plain of Texas, Ashe juniper is the dominant woody invasive species. Grassland restoration is dependent upon proper seedbed preparation and seedling establishment. Shearing and bulldozing are common methods of juniper removal. Three hypotheses were tested in this experiment. The first was that bulldozing and shearing results in similar seedbed preparations. The second was that electrical conductivity (ECa) models soil moisture storage heterogeneity across a landscape. The third hypothesis tested was that bulldozing and shearing result in similar seedling establishment. Eighteen plots were selected and three treatments were applied: 1) shearing, 2) dozing, and 3) control. After clearing with both juniper removal methods, the levels of soil disturbance and vegetation regrowth were measured. Point measures were used to describe soil surface disturbance, and at each point, presence and size of ground cover and surface depressions were recorded. After germination, when the plants were large enough to identify, vegetation was sampled at 20-24 locations in each plot. At each sample location a quadrat was placed on the transect, and total herbaceous, grass, forb, rock, litter, and bare soil cover were recorded in cover classes. All species were identified, seeded species were enumerated, and in the second vegetation sample, dominant species were assigned a cover class. There was considerable variation between plots for all parameters measured. Bulldozing created a greater number of depressions in the soil than shearing. It also had a higher percent of large depressions. There was no difference in ground cover change between treatments except in the case of the largest litter category. ECa was effective in modeling soil moisture storage patterns and had a lower coefficient of variation than manual soil depth measurements. There was no difference between sheared and dozed plots for any of the vegetation establishment parameters, but control plots had lower establishment in most categories. Overall, there was little difference between the two treatments in seedbed preparation and seedling establishment. The cost of shearing was 80% of the cost of dozing, which made it more desirable in this scenario.
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Porovnání a zhodnocení výsadeb řízkovanců jalovce obecného (Juniperus communis) z let 1981-1985, původem z PR Mšály / Comparison and evaluation explantates plantings of juniper (Juniperus communis), originally from PR Mšály (1981-1985)BUBLÍK, Martin January 2018 (has links)
Common juniper (Juniperus communis) is a tree or a shrub. This species is original in the Czech Republic which was very widespread in the landscape. It is from the lowland to the mountain range, which means that it is completely unmistakable for the soil species. It is classified as a critically endangered species in the Czech Republic, due to changes in landscape management. The aim of this work was mapping and surveying the situation on the mentioned localities, where the research was carried out in 2004-2005 and in 2015. At the Na Mšálech locality there were found 135 individuals. Based on the data found, the overall health condition was greatly aggravated by the populations under study, specifically at the Paris site.
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Vegetation Community Responses to Juniper Slash/Burn and Broadcast Burn on A Semi-Desert Tobosa GrasslandJanuary 2015 (has links)
abstract: ABSTRACT
Modern management techniques to maintain rangelands and deter encroachment of juniper into grassland habitats currently includes fire prescription. Additionally, a large body of research has indicated that fire has multiple benefits to grasslands resulting in increased diversity of flora and fauna. In the semi-arid grassland of the Agua Fria National Monument, fire treatments may be able to provide similar advantages. This study considers two methods of fire prescription on the Agua Fria National Monument within central Arizona: 1) Juniper thinning with pile burning; 2) Broadcast burning.
The Agua Fria National Monument upland ecosystem has limited research focusing on semi-arid grassland and juniper stand’s response to implemented treatments over time. The four year monitoring duration of this study aids in assessing the outcome of treatments and reaching the objectives of the management plan.
Vegetation in 981 quadrats was measured for species richness, cover, densities, height, and biomass during the fire prescription period from 2009 through 2013. The study was divided into two treatment types: 1) Juniper cutting and pile burn; 2) Broadcast burn areas in open grasslands.
Results of this study provide consistent examples of vegetative change and community movement towards positive response. Percent composition of overall vegetation is 5 – 30% with >50% of litter, bare ground and rock cover. Juniper sites have immediate consequences from tree thinning activities that may be beneficial to wildlife, particularly as connective corridors pronghorn antelope. Grass height was significantly reduced as well as forb density. Forbs that are highly responsive to environmental factors indicate an increase after the second year. Analysis results from grasslands indicated that cactus and unpalatable shrubs are reduced by fire but a return to pre-burn conditions occur by the third year after fire disturbance. Percent cover of perennial grasses has shown a slow increase. Wright’s buckwheat, a palatable shrub, has increased in density and height, indicating fire adaptations in the species. Species richness was reduced in the first year but increase in density continues into the third year after burn. / Dissertation/Thesis / Masters Thesis Applied Biological Sciences 2015
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Semi-arid Grasslands Vegetative Community Response to Prescribed Broadcast Burns and Juniper Thinning and Pile Burning in Central ArizonaJanuary 2014 (has links)
abstract: Grassland habitat restoration activities are occurring within the semi-arid grasslands of the Agua Fria National Monument located 65 km north of Phoenix, AZ. The goal of these restoration activities is to reduce woody species encroachment, remove lignified plant materials and recycle nutrients within the ecosystem thus improving range conditions for both wildlife species and livestock. Broadcast burning, juniper thinning and slash pile burns are the principle tools used to accomplish resource objectives. Line cover, belt transect, densities, heights and biomass of vegetation data were collected to determine the response of the vegetative community to habitat restoration activities. Principal Component Analysis (PCA) was used to reduce data analysis to the more influential factors. Regression analysis was conducted for statistically significant response variables. Quadratic regression analysis found low predictive values. In broadcast burn treatment units, all important factors as identified by PCA had low predictive factors but significantly differed (R2 <0.01, p<0.05) between unburned and the years post treatment. Regression analysis found significant, albeit weak, relationships between time since treatment and independent variables. In pile burn treatment units, data reduction by PCA was not possible in a biologically meaningful way due to the high variability within treatment units. This suggests the effect of juniper encroachment on grassland vegetation persists long after junipers have been cut and burned. This study concluded that broadcast burning of the central Arizona grasslands does significantly alter many components of the vegetative community. Fuels treatments generally initially reduced both perennial woody species and grasses in number and height for two year post fire. However, palatable shrubs, in particular shrubby buckwheat, were not significantly different in broadcast burn treatment areas. The vegetative community characteristics of juniper encroached woodlands of central Arizona are unaffected by the removal and burning of junipers aside from the removal of hiding cover for predators for multiple years. It is recommended that habitat restoration activities continue provided the needs of wildlife are considered, especially pronghorn, with the incorporation of state and transition models specific to each of the respective ecological site descriptions and with the consideration of the effects of fire to pronghorn fawning habitat. / Dissertation/Thesis / M.S. Applied Biological Sciences 2014
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Performance evaluation of a network infrastructure monitored with SNMP polls and traps / Utvärdering av prestanda för en nätverksinfrastruktur övervakad med SNMP polls och trapsEk, Christian, Norling, Edvin January 2011 (has links)
The result of this bachelor thesis is a comparison between three different network devices on how many resources that is used on them when utilizing SNMPv1 and SNMPv2c polls and traps. The devices tested are an old Cisco router, a modern Juniper gateway and a Linux server. The experiments conducted prove that SNMP does not utilize the network devices resources to a point that it becomes an issue for the performance. These tests are done to ensure that SNMP do not use up to many resources on the infrastructure which would decrease the functionality and performance of the network. This study shows whether or not SNMP monitoring is a problem for the enterprise network / Resultatet utav detta kandidatexamensarbete är en jämförelse mellan tre olika nätverksenheter och hur mycket prestanda som utnyttjas när SNMPv1 och SNMPv2c poll och trap används på enheterna. Enheterna som testerna utförs på är en gammal Cisco router, en modern Juniper gateway och en Linux server. Testerna visar att SNMP inte använder såpass mycket utav enheternas resurser att det påverkar prestandan på dessa enheter. Dessa tester görs för att försäkra oss om att SNMP inte tar upp så mycket prestanda på näverksenheterna att funktionaliteten och prestandan minskar. Detta kandidatexamensarbete visar huruvida SNMP övervakning är ett problem för nätverksenheter eller inte.
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