The Sigmocheirini, a xystodesmid milliped tribe in the Sierra Nevada Mountains, California, U.S.A. (Polydesmida: Xystodesmidae)

AbstractThe xystodesmid milliped tribe Sigmocheirini occupies a band along the western slope of the Sierra Nevada Mountains and eastern fringe of the San Joaquin Valley from Placer to Kern counties, California. It is comprised of two genera, Sigmocheir Chamberlin, with three species occurring from Placer to Tulare counties, and the monotypic Ochthocelata gen. n., the sole component, O. adynata sp. n., occurring in northern Kern County. The species of Sigmocheir display a distinctive, trimaculate pigmentation pattern with yellow middorsal and paranotal spots; the coloration of O. adynata is unknown. Sigmocheir calaveras Chamberlin is a senior name for S. dohenyi Chamberlin, the spelling of which was subsequently corrected to danehyi and assigned to the new genus, Tuolumnia, a synonym of Sigmocheir. Sigmocheir furcata sp. n. is proposed for forms from the northern generic range. The southernmost species is S. maculifer (Chamberlin), comb. n., transferred from Harpaphe Cook. The Sigmocheirini are related to the sympatric tribe Xystocheirini; relationships within Sigmocheir are hypothesized as maculifer + (calaveras + furcata).

Download Full-text

Causal Reasoning Processes of People Affected by Wildfire: Implications for Agency-Community Interactions and Communication Strategies

Western Journal of Applied Forestry ◽

10.1093/wjaf/19.3.184 ◽

2004 ◽

Vol 19 (3) ◽

pp. 184-194 ◽

Cited By ~ 26

Author(s):

Matthew S. Carroll ◽

Yoshitaka Kumagai ◽

Steven E. Daniels ◽

John C. Bliss ◽

John A. Edwards

Keyword(s):

Sierra Nevada ◽

Attribution Theory ◽

Causal Reasoning ◽

Qualitative Interviews ◽

Western Slope ◽

Community Interactions ◽

Dynamic Interactions ◽

Qualitative Approaches ◽

Wildfire Hazard ◽

Sierra Nevada Mountains

Abstract Fire officials are dismayed when victims of wildfire blame fire fighters and others responsible for fire management for damage resulting from uncontrolled fires. This is in spite of the fact that wildfire damage is a consequence of dynamic interactions among natural factors (wind, temperature, location of wildfire, topography, etc.) and human factors (past land management, promptness of firefighting activities, extent of homeowners' defensible space, etc.). Fire and land managers do not typically understand why and how the victims arrive at such oversimplified, and in some cases inaccurate, conclusions about wildfire causation. Attribution theory in social psychology provides a framework for understanding the mechanisms of these blaming processes. In this study, both quantitative and qualitative approaches were used to explore how people who live in wildfire hazard zones and experienced wildfire, perceive the causes of wildfire damage. In the spring of 1999, a prefire survey was conducted in the western slope of the Sierra Nevada Mountains, an area where numerous wildfires are recorded nearly every year. This was followed by a postfire survey in two communities that actually experienced a fire that season. In addition, qualitative interviews were carried out in these two affected communities. Results suggest that people who experienced wildfire tended to attribute the cause of wildfire damage to factors associated with fire officials and nature and did not attribute fire damage to their own actions (or inactions). The implications of these attributions are discussed as are recommendations for future fire education and communication. West. J. Appl. For. 19(3):184–194.

Download Full-text

Observations of the effects of temperature on atmospheric HNO3, ΣANs, ΣPNs, and NOx: evidence for a temperature-dependent HOx source

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-1867-2008 ◽

2008 ◽

Vol 8 (6) ◽

pp. 1867-1879 ◽

Cited By ~ 31

Author(s):

D. A. Day ◽

P. J. Wooldridge ◽

R. C. Cohen

Keyword(s):

Sierra Nevada ◽

Western Slope ◽

Oxides Of Nitrogen ◽

Temperature Dependent ◽

Alkyl Nitrates ◽

Temperature Trends ◽

Sierra Nevada Mountains ◽

Peroxy Nitrates ◽

Effects Of Temperature ◽

Increasing Temperature

Abstract. We describe observations of atmospheric reactive nitrogen compounds including NO, NO2, total peroxy nitrates, total alkyl nitrates, and HNO3 and their correlation with temperature. The measurements were made at a rural location 1315 m a.s.l. on the western slope of the Sierra Nevada Mountains in California during summer of 2001. The ratio of HNO3 to its source molecule, NO2, and the ratio of HNO3 to all other higher oxides of nitrogen (NOz) both increase with increasing temperature. Analysis of these increases suggests they are due to a steep increase in OH of between a factor of 2 and 3 over the range 18–32°C. Total peroxy nitrates decrease and total alkyl nitrates increase over the same temperature range. The decrease in the total peroxy nitrates is shown to be much less than expected if the rate of thermal decomposition were the sole important factor. This observation is consistent with the increase in OH inferred from the temperature trends in the HNO3/NO2 ratio.

Download Full-text

On the effect of upwind emission controls on ozone in Sequoia National Park

10.5194/acp-2017-1006 ◽

2017 ◽

Author(s):

Claire E. Buysse ◽

Jessica A. Munyan ◽

Clara A. Bailey ◽

Alexander Kotsakis ◽

Jessica A. Sagona ◽

...

Keyword(s):

Sierra Nevada ◽

Regulatory Focus ◽

National Park ◽

Western Slope ◽

Sequoia National Park ◽

Time Period ◽

Sierra Nevada Mountains ◽

Emission Controls ◽

The U.S ◽

Do So

Abstract. Sequoia National Park (SNP) experiences the worst ozone (O3) pollution of any national park in the U.S. SNP is located on the western slope of the Sierra Nevada Mountains, downwind of the San Joaquin Valley (SJV), which is home to numerous cities ranked among the most O3-polluted in the U.S. Here, we investigate the influence of emission controls in the directly upwind SJV city of Visalia on O3 concentrations in SNP over a 12-yr time period (2001–2012). We show that export of nitrogen oxides (NOx) from the SJV plays a larger role in driving high O3 in SNP than does transport of O3. As a result, O3 in SNP has been more responsive to NOx emission reductions as a function of increasing downwind distance from the SJV. We report O3 trends by various concentration metrics, but do so separately for when environmental conditions are conducive to plant O3 uptake and for when high O3 is most common, which are time periods that occur at different times of day and year. We find that precursor emission controls have been less effective at reducing O3 concentrations in SNP in springtime, which is when plant O3 uptake in Sierra Nevada forests has been previously measured to be greatest. We discuss the implications of regulatory focus on high O3 days in SJV cities on O3 concentration trends and impacts in SNP.

Download Full-text

On the effect of upwind emission controls on ozone in Sequoia National Park

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-17061-2018 ◽

2018 ◽

Vol 18 (23) ◽

pp. 17061-17076 ◽

Cited By ~ 3

Author(s):

Claire E. Buysse ◽

Jessica A. Munyan ◽

Clara A. Bailey ◽

Alexander Kotsakis ◽

Jessica A. Sagona ◽

...

Keyword(s):

Sierra Nevada ◽

Regulatory Focus ◽

National Park ◽

Western Slope ◽

Ecosystem Impacts ◽

Sequoia National Park ◽

Time Period ◽

Sierra Nevada Mountains ◽

The Us ◽

Emission Controls

Abstract. Ozone (O3) air pollution in Sequoia National Park (SNP) is among the worst of any national park in the US. SNP is located on the western slope of the Sierra Nevada Mountains downwind of the San Joaquin Valley (SJV), which is home to numerous cities ranked in the top 10 most O3-polluted in the US. Here, we investigate the influence of emission controls in the SJV on O3 concentrations in SNP over a 12-year time period (2001–2012). We show that the export of nitrogen oxides (NOx) from the SJV has played a larger role in driving high O3 in SNP than transport of O3. As a result, O3 in SNP has been more responsive to NOx emission reductions than in the upwind SJV city of Visalia, and O3 concentrations have declined faster at a higher-elevation monitoring station in SNP than at a low-elevation site nearer to the SJV. We report O3 trends by various concentration metrics but do so separately for when environmental conditions are conducive to plant O3 uptake and for when high O3 is most common, which are time periods that occur at different times of day and year. We find that precursor emission controls have been less effective at reducing O3 concentrations in SNP in springtime, which is when plant O3 uptake in Sierra Nevada forests has been previously measured to be greatest. We discuss the implications of regulatory focus on high O3 days in SJV cities for O3 concentration trends and ecosystem impacts in SNP.

Download Full-text

Observations of the effects of temperature on atmospheric HNO3, ∑ANs, ∑PNs, and NOx: evidence for a temperature dependent HOx source

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-11091-2007 ◽

2007 ◽

Vol 7 (4) ◽

pp. 11091-11121 ◽

Cited By ~ 4

Author(s):

D. A. Day ◽

P. J. Wooldridge ◽

R. C. Cohen

Keyword(s):

Sierra Nevada ◽

Western Slope ◽

Oxides Of Nitrogen ◽

Temperature Dependent ◽

Alkyl Nitrates ◽

Temperature Trends ◽

Sierra Nevada Mountains ◽

Peroxy Nitrates ◽

Effects Of Temperature ◽

Increasing Temperature

Abstract. We describe observations of atmospheric reactive nitrogen compounds including NO, NO2, total peroxy nitrates, total alkyl nitrates, and HNO3 and their correlation with temperature. The measurements were made at a rural location 1315 m a.s.l. on the western slope of the Sierra Nevada Mountains in California during summer of 2001. The ratio of HNO3 to its source molecule, NO2, and the ratio of HNO3 to all other higher oxides of nitrogen (NOz) all increase with increasing temperature. Analysis of these increases suggests they are due to a steep increase in OH of between a factor of 2 and 3 over the range 18–32°C. Total peroxy nitrates decrease and total alkyl nitrates increase over the same temperature range. The decrease in the total peroxy nitrates is shown to be much less than expected if the rate of thermal decomposition were the sole important factor and to be consistent with the increase in OH inferred from the temperature trends in the HNO3/NO2 ratio.

Download Full-text

Searching for Information in 133 Years of California Snowfall Observations

Journal of Hydrometeorology ◽

10.1175/jhm-d-11-040.1 ◽

2012 ◽

Vol 13 (3) ◽

pp. 895-912 ◽

Cited By ~ 9

Author(s):

John R. Christy

Keyword(s):

Time Series ◽

Sierra Nevada ◽

Basic Data ◽

Western Slope ◽

Heavy Snowfall ◽

Sierra Nevada Mountains ◽

Linear Trends

Abstract Monthly snowfall totals from over 500 stations in California, some of which date back to 1878, are examined. Most data were accessed through the NOAA archive, but several thousand station months of data were separately keyed in from image files of original documents. Over 26 000 of these entries were new relative to the NOAA archive, generally providing data prior to 1920. The stations were then subdivided into 18 regions for the construction of representative time series of each area. There were problems with the basic data—the most difficult with which to deal was the increasing presence of “zero” totals that should have been recorded as “missing.” This and other issues reduce the confidence that the regional time series are representative of true variations and trends, especially for regions with few systematically reporting stations. Interpreting linear trends on time series with infrequent large anomalies of one sign (i.e., heavy snowfall years) and unresolved data issues should be done with caution. For those regions characterized by consistent monitoring and with the most robust statistical reproducibility, no statistically significant trends in their periods of record (up to 133 years) nor in the most recent 50 years are found. This result encompasses the main snowfall region of the western slope of the Sierra Nevada Mountains.

Download Full-text

Transportation and the Environment

California History ◽

10.1525/ch.2017.94.3.37 ◽

2017 ◽

Vol 94 (3) ◽

pp. 37-61

Author(s):

Douglas R. Littlefield

Keyword(s):

Nineteenth Century ◽

San Francisco ◽

Sierra Nevada ◽

Mississippi River ◽

San Joaquin Valley ◽

Eastern United States ◽

Major Health ◽

San Joaquin River ◽

Natural Wetlands ◽

Prevailing View

Some histories of California describe nineteenth-century efforts to reclaim the extensive swamplands and shallow lakes in the southern part of California's San Joaquin Valley – then the largest natural wetlands habitat west of the Mississippi River – as a herculean venture to tame a boggy wilderness and turn the region into an agricultural paradise. Yet an 1850s proposition for draining those marshes and lakes primarily was a scheme to improve the state's transportation. Swampland reclamation was a secondary goal. Transport around the time of statehood in 1850 was severely lacking in California. Only a handful of steamboats plied a few of the state's larger rivers, and compared to the eastern United States, roads and railroads were nearly non-existent. Few of these modes of transportation reached into the isolated San Joaquin Valley. As a result, in 1857 the California legislature granted an exclusive franchise to the Tulare Canal and Land Company (sometimes known as the Montgomery franchise, after two of the firm's founders). The company's purpose was to connect navigable canals from the southern San Joaquin Valley to the San Joaquin River, which entered from the Sierra Nevada about half way up the valley. That stream, in turn, joined with San Francisco Bay, and thus the canals would open the entire San Joaquin Valley to world-wide commerce. In exchange for building the canals, the Montgomery franchise could collect tolls for twenty years and sell half the drained swamplands (the other half was to be sold by the state). Land sales were contingent upon the Montgomery franchise reclaiming the marshes. Wetlands in the mid-nineteenth century were not viewed as they are today as fragile wildlife habitats but instead as impediments to advancing American ideals and homesteads across the continent. Moreover, marshy areas were seen as major health menaces, with the prevailing view being that swampy regions’ air carried infectious diseases.

Download Full-text