Kentucky Bluegrass Invasion Alters Soil Carbon and Vegetation Structure on Northern Mixed-Grass Prairie of the United States

2017 ◽  
Vol 10 (01) ◽  
pp. 9-16 ◽  
Author(s):  
Matt A. Sanderson ◽  
Holly Johnson ◽  
Mark A. Liebig ◽  
John R. Hendrickson ◽  
Sara E. Duke
Keyword(s):  
Vegetation Structure ◽  
Native Species ◽  
Vegetation Change ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Total Carbon ◽  
Stocking Rate ◽  
Soil C ◽  
Exotic Grasses

Invasive nonnative grasses pose a significant threat to rangelands of the Northern Great Plains. Long-term data from a grazing experiment near Mandan, ND (46°46′11.43″N, 100°54′55.16″W) revealed the invasion of native prairie by Kentucky bluegrass, an exotic grass. We hypothesized that bluegrass invasion altered soil13C and15N levels, tracking the increased abundance of invasive cool-season grass aboveground. In 2014, soil samples were collected to depths of 0 to 7.6 cm and 7.6 to 15.2 cm in pastures grazed similarly since 1916. Samples were analyzed for total carbon (C) and nitrogen (N) and13C and15N isotopes and compared against archived samples from 1991. Vegetation change from native to exotic grasses changed the isotopic composition of soil C. The soil δ13C at the 0- to 7.6-cm depth became more negative between 1991 and 2014. Soil δ13C became less negative with increasing stocking rate at both soil depths. Soil δ15N values at the 0- to 7.6-cm depth decreased between 1991 and 2014. Soil δ15N increased with increasing stocking rate at the 0- to 7.6-cm depth in 2014. Soil C and N concentrations at 0 to 7.6 cm increased by 35% (12 g C kg−1) and 27% (0.9 g N kg−1), respectively, from 1991 to 2014; however, concentrations at the 7.6- to 15.2-cm depth did not change. The shift from native C4to invasive C3grass did not reduce soil C storage in the long-term prairie pastures. The more deleterious effect of invasion, however, may have been the buildup of dead biomass, which alters vegetation structure and may reduce native species’ diversity and abundance.

scholarly journals Intercomparability of X<sub>CO<sub>2</sub></sub> and X<sub>CH<sub>4</sub></sub> from the United States TCCON sites

2017 ◽  
Vol 10 (4) ◽  
pp. 1481-1493 ◽  
Author(s):  
Jacob K. Hedelius ◽  
Harrison Parker ◽  
Debra Wunch ◽  
Coleen M. Roehl ◽  
Camille Viatte ◽  
...  
Keyword(s):  
United States ◽  
Error Analysis ◽  
Confidence Intervals ◽  
The United States ◽  
Total Carbon ◽  
Analytical Error ◽  
Portable Spectrometers ◽  
Absolute Bias

Abstract. The Total Carbon Column Observing Network (TCCON) has become the standard for long-term column-averaged measurements of CO2 and CH4. Here, we use a pair of portable spectrometers to test for intra-network bias among the four currently operating TCCON sites in the United States (US). A previous analytical error analysis has suggested that the maximum 2σ site-to-site relative (absolute) bias of TCCON should be less than 0.2 % (0.8 ppm) in XCO2 and 0.4 % (7 ppb) in XCH4. We find here experimentally that the 95 % confidence intervals for maximum pairwise site-to-site bias among the four US TCCON sites are 0.05–0.14 % for XCO2 and 0.08–0.24 % for XCH4. This is close to the limit of the bias we can detect using this methodology.

Owning Up to Our Responsibilities: Who Owns Lands Important for Biodiversity?

2000 ◽  
Author(s):  
Craig R. Groves ◽  
Alan S. Weakley
Keyword(s):  
Land Use ◽  
San Francisco ◽  
Native Species ◽  
The United States ◽  
Land Ownership ◽  
Nature Preserve ◽  
Residential Communities ◽  
Rock Formations ◽  
Golden Gate Bridge

Standing watch over San Francisco Bay, Ring Mountain lies just a short stretch north of the Golden Gate Bridge. The mountain rises from the Tiburon Peninsula, lined with exclusive residential communities and one of San Francisco’s most desirable suburbs. The slopes of Ring Mountain are exclusive in another sense as well: Here lives the world’s sole population of the Tiburon mariposa lily (Calochortus tiburonemis). Found in the open grasslands near the summit of the mountain, this attractive flower grows only on an unusual rock type known as serpentine for its slick, scalelike, blue-green appearance. A product of California’s restless geology, these rock formations also support several other rare plant species, including the Tiburon paintbrush (Castilleja affinis ssp. Neglecta) and Tiburon jewelflower (Streptanthus niger). While serpentine occurs elsewhere in California and beyond, the Tiburon mariposa lily does not. The view from atop Ring Mountain, a spectacular vista of water, mountains, and skyscrapers, would fetch top dollar for residential development. Bulldozers may well have overrun this unique piece of real estate if The Nature Conservancy had not purchased and managed it as a nature preserve. In buying the land on Ring Mountain, the Conservancy also bought the earth’s entire population of the Tiburon mariposa lily. This created a weighty responsibility, but it also freed the organization to take any action necessary to ensure the survival of this flower and Ring Mountain’s other rare species. Ownership offers the most direct and absolute way to offer conservation to those plants and animals inhabiting a piece of land. On the other hand, land ownership also conveys rights that allow management of property in ways not nearly so beneficial to our native species. Of the four basic strategies for biodiversity conservation discussed in the previous chapter, three relate directly to land: owning and managing land; regulating land use; and influencing land use through nonregulatory means. If we are to understand not only the current condition of species and ecosystems in the United States but also the opportunities and challenges for their long-term protection, we must also understand how the underlying natural patterns relate to the patterns of land ownership and management that have been laid atop them.

scholarly journals Intercomparability of X<sub>CO<sub>2</sub></sub> and X<sub>CH<sub>4</sub></sub> from the United States TCCON sites

2016 ◽  
Author(s):  
Jacob K. Hedelius ◽  
Harrison Parker ◽  
Debra Wunch ◽  
Coleen M. Roehl ◽  
Camille Viatte ◽  
...  
Keyword(s):  
United States ◽  
Error Analysis ◽  
Confidence Intervals ◽  
The United States ◽  
Total Carbon ◽  
Analytical Error ◽  
Portable Spectrometers ◽  
Absolute Bias

Abstract. The Total Carbon Column Observing Network (TCCON) has become the standard for long-term column-averaged measurements of CO2 and CH4. Here, we use a pair of portable spectrometers to test for intra-network bias among the four currently operating TCCON sites in the United States (U.S.). A previous analytical error analysis has suggested that the maximum 2σ site-to-site relative (absolute) bias of TCCON should be less than 0.2 % (0.8 ppm) in XCO2 and 0.4 % (7 ppb) in XCH4. We find here experimentally that the 95 % confidence intervals for maximum pairwise site-to-site bias among the four U.S. TCCON sites are 0.05–0.14 % for XCO2 and 0.08–0.24 % for XCH4. This is close to the limit of the bias we can detect using this methodology.

Grazing exclosures reveal divergent patterns of change in bunchgrass grasslands of Western Canada

Botany ◽  
2021 ◽  
Vol 99 (1) ◽  
pp. 9-22
Author(s):  
Gary E. Bradfield ◽  
W.F. Preston Cumming ◽  
Reg F. Newman ◽  
Maja Krzic
Keyword(s):  
Vegetation Change ◽  
Structural Changes ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Growing Seasons ◽  
South Central ◽  
Species Cover ◽  
Rough Fescue ◽  
Dominant Grasses

Thirty-six long-term (14–83 years) cattle grazing exclosures and adjacent grazed pastures spanning a climatic gradient from cooler–wetter to warmer–drier growing seasons in south-central British Columbia were compared for temporal vegetation change. Trajectories of temporal vegetation change from non-metric multidimensional scaling were mostly scattered for the grazed areas, but more directed toward the dominant grasses, primarily rough fescue (Festuca campestris) or Kentucky bluegrass (Poa pratensis), for the exclosures. Plant community differences, detected only after 10 years of grazing exclusion, were primarily due to structural shifts in overall species cover related to growth increases of the dominant grasses inside exclosures. Species richness remained unchanged between the first and last sampling dates in both grazed areas and exclosures, with both treatments showing moderate degrees (15%–30%) of turnover in species composition. Shannon diversity declined in both treatments as a result of the structural changes in species cover. The results highlight the value of repeated monitoring of long-term exclosures for assessment of grassland resiliency to grazing. Further studies of the interaction of grazing and climate are needed for a more complete understanding of the ongoing vegetation change.

scholarly journals Long-Term Efficacy of Glyphosate for Smooth Brome Control in Native Prairie

2017 ◽  
Vol 10 (4) ◽  
pp. 350-355 ◽  
Author(s):  
Jessica I. Slopek ◽  
Eric G. Lamb
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Control Method ◽  
Kentucky Bluegrass ◽  
Control Measures ◽  
Effective Control ◽  
Smooth Brome ◽  
Native Prairie ◽  
And Function

Effective control measures are required for the invasive forage grass smooth brome in native prairie to maintain native prairie diversity and function. The objective of this study was to assess the long-term effectiveness of glyphosate as a control method for smooth brome and to evaluate the subsequent recovery of native prairie species at Kernen Prairie near Saskatoon, SK, Canada. In 1999 and 2000, a total of forty 6- to 8-m-diameter patches of smooth brome were spot sprayed with glyphosate; community composition in each patch was monitored for 17 yr. Following glyphosate application, the abundance of smooth brome decreased, and recovery of native species richness and the abundance of important native species, including plains rough fescue, was observed. In the long term however, the elimination of smooth brome created empty niche space ultimately occupied by other invasive species, particularly Kentucky bluegrass. The spot application of glyphosate is thus an effective control method for reducing smooth brome in native prairie; however, maintaining desirable native species composition in this system posttreatment depends on other factors, including the presence of additional invasive species that may move in after the elimination of smooth brome.

Speech-Language Pathology in the Peace Corps: Necessity and Sustainability

2012 ◽  
Vol 2 (1) ◽  
pp. 11-18
Author(s):  
Melissa A. Pierce
Keyword(s):  
United States ◽  
Special Education ◽  
Peace Corps ◽  
People With Disabilities ◽  
Communication Disorders ◽  
The United States ◽  
Speech Language Pathology ◽  
Speech Language Pathologists ◽  
Language Pathology

In countries other than the United States, the study and practice of speech-language pathology is little known or nonexistent. Recognition of professionals in the field is minimal. Speech-language pathologists in countries where speech-language pathology is a widely recognized and respected profession often seek to share their expertise in places where little support is available for individuals with communication disorders. The Peace Corps offers a unique, long-term volunteer opportunity to people with a variety of backgrounds, including speech-language pathologists. Though Peace Corps programs do not specifically focus on speech-language pathology, many are easily adapted to the profession because they support populations of people with disabilities. This article describes how the needs of local children with communication disorders are readily addressed by a Special Education Peace Corps volunteer.

Multidisciplinary Evidence to Treat Bilingual Individuals with Aphasia

2008 ◽  
Vol 15 (3) ◽  
pp. 66-72 ◽  
Author(s):  
José G. Centeno
Keyword(s):  
Stroke Rehabilitation ◽  
Culturally Diverse ◽  
Treatment Strategies ◽  
The United States ◽  
Intervention Strategies ◽  
Steady Increase ◽  
Clinical Procedures ◽  
Bilingual Speakers ◽  
Aphasic Clients

Abstract The steady increase in linguistic and cultural diversity in the country, including the number of bilingual speakers, has been predicted to continue. Minorities are expected to be the majority by 2042. Strokes, the third leading cause of death and the leading cause of long-term disability in the U.S., are quite prevalent in racial and ethnic minorities, so population estimates underscore the imperative need to develop valid clinical procedures to serve the predicted increase in linguistically and culturally diverse bilingual adults with aphasia in post-stroke rehabilitation. Bilingualism is a complex phenomenon that interconnects culture, cognition, and language; thus, as aphasia is a social phenomenon, treatment of bilingual aphasic persons would benefit from conceptual frameworks that exploit the culture-cognition-language interaction in ways that maximize both linguistic and communicative improvement leading to social re-adaptation. This paper discusses a multidisciplinary evidence-based approach to develop ecologically-valid treatment strategies for bilingual aphasic individuals. Content aims to spark practitioners' interest to explore conceptually broad intervention strategies beyond strictly linguistic domains that would facilitate linguistic gains, communicative interactions, and social functioning. This paper largely emphasizes Spanish-English individuals in the United States. Practitioners, however, are advised to adapt the proposed principles to the unique backgrounds of other bilingual aphasic clients.

Traumatic Brain Injury: A Trauma Surgeon's Perspective

2012 ◽  
Vol 22 (3) ◽  
pp. 82-89
Author(s):  
Oscar D. Guillamondegui
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Multidisciplinary Approach ◽  
Trauma Team ◽  
The United States ◽  
Long Term Outcomes ◽  
Term Care ◽  
Injured Brain ◽  
The Moment

Traumatic brain injury (TBI) is a serious epidemic in the United States. It affects patients of all ages, race, and socioeconomic status (SES). The current care of these patients typically manifests after sequelae have been identified after discharge from the hospital, long after the inciting event. The purpose of this article is to introduce the concept of identification and management of the TBI patient from the moment of injury through long-term care as a multidisciplinary approach. By promoting an awareness of the issues that develop around the acutely injured brain and linking them to long-term outcomes, the trauma team can initiate care early to alter the effect on the patient, family, and community. Hopefully, by describing the care afforded at a trauma center and by a multidisciplinary team, we can bring a better understanding to the armamentarium of methods utilized to treat the difficult population of TBI patients.

Mafias on the Move

2011 ◽  
Author(s):  
Federico Varese
Keyword(s):  
United States ◽  
New York ◽  
Organized Crime ◽  
The United States ◽  
The West ◽  
Market Expansion ◽  
The North ◽  
Economic Transformations ◽  
At Will

Organized crime is spreading like a global virus as mobs take advantage of open borders to establish local franchises at will. That at least is the fear, inspired by stories of Russian mobsters in New York, Chinese triads in London, and Italian mafias throughout the West. As this book explains, the truth is more complicated. The author has spent years researching mafia groups in Italy, Russia, the United States, and China, and argues that mafiosi often find themselves abroad against their will, rather than through a strategic plan to colonize new territories. Once there, they do not always succeed in establishing themselves. The book spells out the conditions that lead to their long-term success, namely sudden market expansion that is neither exploited by local rivals nor blocked by authorities. Ultimately the inability of the state to govern economic transformations gives mafias their opportunity. In a series of matched comparisons, the book charts the attempts of the Calabrese 'Ndrangheta to move to the north of Italy, and shows how the Sicilian mafia expanded to early twentieth-century New York, but failed around the same time to find a niche in Argentina. The book explains why the Russian mafia failed to penetrate Rome but succeeded in Hungary. A pioneering chapter on China examines the challenges that triads from Taiwan and Hong Kong find in branching out to the mainland. This book is both a compelling read and a sober assessment of the risks posed by globalization and immigration for the spread of mafias.

Russian-Japanese Relations: Long-Term Development Factors

2020 ◽  
Vol 13 (3) ◽  
pp. 68-85
Author(s):  
D. V. Streltsov
Keyword(s):  
Security Policy ◽  
The United States ◽  
Peace Treaty ◽  
Strategic Decisions ◽  
Chinese Market ◽  
External Energy ◽  
Economic Relations ◽  
Bilateral Relations ◽  
Personal Diplomacy

The article analyzes long-term external and internal factors determining the course of development of Russian-Japanese relations in 2019-2020. On the one hand, the anti-Russian component in Tokyo's foreign policy is shaped by its membership in the Security Treaty with the United States and its solidarity with the sanctions policy of the Group of Seven towards Russia. On the other hand, Japan and Russia are both interested interest in political cooperation in creating multilateral dialog mechanisms of international security in East Asia, resolving the nuclear issue on the Korean Peninsula, and easing tensions around territorial disputes in the East China and South China seas. Among the economic factors, the author focuses on the significant place of Russia in the context of Japan's task of diversifying sources of external energy supplies, as well as on Russia's desire to avoid unilateral dependence on the Chinese market while reorienting the system of foreign economic relations from the West to the East. Personal diplomacy of political leaders plays a significant role in relations between Russia and Japan, and, above all, close personal relationships and frequent meetings between Prime Minister Abe and President Putin, which make it possible to partially compensate the unfavorable image of the partner country in the public opinion of both Russia and Japan. Against the background of a deadlock in the Peace Treaty talks which emerged in 2019, the search for a way out of the diplomatic impasse is on the agenda. In the author's opinion, it would be appropriate at the first stage to proceed to the conclusion of a basic agreement on the basis bilateral relations, which would be "untied" from the Peace Treaty. In addition, Russia could stop criticizing Japan for its security policy and show greater understanding of the Japanese initiative in the field of quality infrastructure. In turn, Japan could take a number of strategic decisions on cooperation with Russia and announce them in the Prime Minister's keynote speech. In addition, Tokyo could stop positioning the issue of the peace Treaty as the main issue in relations with Russia, which would allow our countries to "untie" bilateral relations from the problem of border demarcation and focus on their positive agenda.

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