Native Annual Plant Response to Fire: an Examination of Invaded, 3 to 29 Year Old Burned Creosote Bush Scrub from the Western Colorado Desert

Creosote bush scrub vegetation typically contains high diversity of native annual plants relative to shrubs, cacti, perennial herbaceous species, or other plant life forms. This vegetation type is also very susceptible to exotic, invasive annual plants, which promote fire by changing fuel properties. The impact of fire on most perennial species is severe but the impact on native annual plants is not well understood. We measured annual species composition in five sites that each contained paired burned and unburned stands in the western Colorado Desert, California. The burned stands at each site ranged in time since fire from 3 to 29 years ago. Annual plant cover, species richness, and soil chemical and physical properties were compared in the paired burned and unburned reference stands. Differences between paired stands at the time of each fire are assumed negligible since shrub cover across fuel breaks did not differ prior to each fire based on aerial photographs. Fires elevated soil pH but otherwise had little effect on other soil properties. In recently burned stands, invasive annual grass abundance increased while native annual plant cover and species richness decreased. However, in older burned stands, annual plant composition did not always differ between paired stands because invasive annual plant abundance was very high in both stands. Thus, while fires can have long-lasting negative impacts to perennial components of creosote bush scrub, invasive species can displace native annual plants regardless of whether or not a site burns, although fire disturbance appears to accelerate invasive plant dominance

Zonal Wind Calculations from Mars Global Surveyor Accelerometer and Rate Data

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76565/1/AIAA-28588-795.pd

Can Resource-Use Traits Predict Native vs. Exotic Plant Success in Carbon Amended Soils?

Productivity in desert ecosystems is primarily limited by water followed by nitrogen availability. In the deserts of southern California, nitrogen additions have increased invasive annual plant abundance. Similar findings from other ecosystems have led to a general acceptance that invasive plants, especially annual grasses, are nitrophilous. Consequently, reductions of soil nitrogen via carbon amendments have been conducted by many researchers in a variety of ecosystems in order to disproportionately lower invasive species abundance, but with mixed success. Recent studies suggest that resource-use traits may predict the efficacy of such resource manipulations; however, this theory remains largely untested. We report findings from a carbon amendment experiment that utilized two levels of sucrose additions that were aimed at achieving soil carbon to nitrogen ratios of 50:1 and 100:1 in labile sources. Carbon amendments were applied once each year, for three years, corresponding with the first large precipitation event of each wet season. Plant functional traits measured on the three invasive and 11 native herbaceous species that were most common at the study site showed that exotic and native species did not differ in traits associated with nitrogen use. In fact, plant abundance measures such as density, cover, and biomass showed that carbon amendments were capable of decreasing both native and invasive species. We found that early-germinating species were the most impacted by decreased soil nitrogen resulting from amendments. Because invasive annuals typically germinate earlier and exhibit a rapid phenology compared to most natives, these species are expected to be more competitive than native annuals yet more susceptible to early-season carbon amendments. However, desert annual communities can exhibit high interannual variability in species composition and abundance. Therefore, the relative abundance of native and invasive species at the time of application is critical to the success of carbon amendments at our study site. For land management purposes, carbon amendments remain relatively impractical and may only be useful at small scales or in conjunction with other invasive species removal techniques

Transplant Critical Care: Is There A Need for Sub-specialized Units? — A Perspective

The critical care involved in solid-organ transplantation (SOT) is complex. Pre-, intra- and post-transplant care can significantly impact both – patients’ ability to undergo SOT and their peri-operative morbidity and mortality. Much of the care necessary for medical optimization of end-stage organ failure (ESOF) patients to qualify and then successfully undergo SOT, and the management of peri-operative and/or long-term complications thereafter occurs in an intensive care unit (ICU) setting. The current literature specific to critical care in abdominal SOT patients was reviewed. This paper provides a contemporary perspective on the potential multifactorial advantages of sub-specialized transplant critical care units in providing efficient, comprehensive, and collaborative multidisciplinary care

The Changing California Coast: The Effect of a Variable Water Budget on Coastal Vegetation Succession

The land-ocean interface along the central coast of California is one of the most diverse biogeographic regions of the state. This area is composed of a species-rich mosaic of coastal grassland, shrubland, and forest vegetation types. An acceleration of conifer encroachment into shrublands and shrub encroachment into grasslands along the coast has been recently documented. These vegetation changes are believed to be driven primarily by fire suppression and changing grazing patterns. Climatic variables such as precipitation, fog, cloud cover, temperature, slope, and elevation also play an important role in vegetation succession. Our study area is located along the central California coast, which is characterized by a precipitation gradient from the relatively wetter and cooler north to the drier and warmer south. Some studies indicate changing fog patterns along this coast, which may greatly impact vegetation. A decrease in water availability could slow succession processes. The primary objective of this project is to determine if vegetation succession rates are changing for the study area and to identify climate and ecosystem variables which contribute to succession, specifically the transition among grassland, shrubland, and forest. To identify vegetation types and rates of succession, we classified two Landsat TM 5 scenes from 1985 to 2010 with a resulting overall accuracy of 82.4%. Vegetation succession was correlated to changes in maximum and minimum temperatures, precipitation, and elevation for each sub-region of the study area. Fog frequency was then compared between the northern and southern regions of the study area for determining the spatial relation between fog frequency and the percent of vegetation change

A statistical approach for detecting genomic aberrations in heterogeneous tumor samples from single nucleotide polymorphism genotyping data

We describe a statistical method for the characterization of genomic aberrations in single nucleotide polymorphism microarray data acquired from cancer genomes. Our approach allows us to model the joint effect of polyploidy, normal DNA contamination and intra-tumour heterogeneity within a single unified Bayesian framework. We demonstrate the efficacy of our method on numerous datasets including laboratory generated mixtures of normal-cancer cell lines and real primary tumours

The powers in PowerPoint: Embedded authorities, documentary tastes, and institutional (second) orders in corporate Korea

Microsoft PowerPoint is both the bane and banality of contemporary South Korean office work. Corporate workers spend countless hours refining and crafting plans, proposals, and reports in PowerPoint that often lead to conflicts with coworkers and overtime work. This article theorizes the excessive attention to documents in modern office contexts. Where scholars have been under the impression that institutional documents align with institutional purposes, I describe a context in which making documents for individual purposes and making them for work exist under a basic tension. Based on fieldwork in corporate Korea between 2013 and 2015, I describe how Korean office workers calibrate documents to the tastes of superiors who populate the managerial chain. These practices leave little trace of real "work" on paper, but they are productive for navigating complex internal labor markets and demonstrating a higher order value of attention toward others. These findings suggest that institutional and individual authorities are not competing projects inside organizations but become entangled in increasingly complex participatory encounters, even as they are channeled through a seemingly simple software like PowerPoint. [documents, expertise, authority, technology, South Korea

Work-Unit Absenteeism: Effects of Satisfaction, Commitment, Labor Market Conditions, and Time

Prior research is limited in explaining absenteeism at the unit level and over time. We developed and tested a model of unit-level absenteeism using five waves of data collected over six years from 115 work units in a large state agency. Unit-level job satisfaction, organizational commitment, and local unemployment were modeled as time-varying predictors of absenteeism. Shared satisfaction and commitment interacted in predicting absenteeism but were not related to the rate of change in absenteeism over time. Unit-level satisfaction and commitment were more strongly related to absenteeism when units were located in areas with plentiful job alternatives

2017 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1004/thumbnail.jp