1,782,738 research outputs found
Vivian Williams Utley collection
No full textThis collection contains original wood block prints, etchings, and copies of articles by Vivian Williams Utley
Oral History Interview with Vivian Castleberry, March 29, 2012
No full textInterview with Vivian Castleberry,a journalist in Dallas, Texas. The interview includes biographical information about her life growing up, her educational background, family life raising her children, and her international peace work. She also discusses her career at The Dallas Times Herald and the field of journalism
Vivian-Felde/Diatom_diversity_Vydrino_Lake_Baikal: Public release
No full textTitle
Long-term trends in diatom diversity and palaeoproductivity: a 16 000-year multidecadal study from Lake Baikal, southern Siberia.
Authors
Anson W. Mackay, Vivian A. Felde, David W. Morley, Natalia Piotrowska, Patrick Rioual, Alistair W. R. Seddon, and George E. A. Swann
Corresponding author
Anson W. Mackay ([email protected])
Description
This repo contains R code and data to calculate diatom diversity and investigate the diversity – palaeoproductivity relationship on the Vydrino shoulder of Lake Baikal during the Late Glacial and Holocene.
The diatom and metadata can be downloaded from NOAA https://doi.org/10.25921/q6v1-5q02.
See
Anson W. Mackay, Vivian A. Felde, David W. Morley, Natalia Piotrowska, Patrick Rioual, Alistair W. R. Seddon, and George E. A. Swann 2022. Long-term trends in diatom diversity and palaeoproductivity: a 16 000-year multidecadal study from Lake Baikal, southern Siberia. Clim. Past, 18, 1-18, https://doi.org/10.5194/cp-2020-70.
Abstract
Biological diversity is inextricably linked to community stability and ecosystem functioning, but our understanding of these relationships in freshwater ecosystems is largely based on short-term observational, experimental, and modelling approaches. Using a multidecadal diatom record for the past ca. 16 000 years from Lake Baikal, we investigate how diversity and palaeoproductivity have responded to climate change during periods of both rapid climate fluctuation and relative climate stability. We show dynamic changes in diatom communities during the past 16 000 years, with decadal shifts in species dominance punctuating millennial-scale seasonal trends. We describe for the first time in Lake Baikal a gradual shift from spring to autumnal diatom communities that started during the Younger Dryas and peaked during the Late Holocene, which likely represents orbitally driven ecosystem responses to long-term changes in seasonality. Using a multivariate classification tree, we show that trends in planktonic and tychoplanktonic diatoms broadly reflect both long-term climatic changes associated with the demise of Northern Hemisphere ice sheets and abrupt climatic changes associated with, for example, the Younger Dryas stadial. Indeed, diatom communities are most different before and after the boundary between the Early and Middle Holocene periods of ca. 8.2 cal kyr BP, associated with the presence and demise of Northern Hemisphere ice sheets respectively. Diatom richness and diversity, estimated using Hill's species numbers, are also shown to be very responsive to periods characterized by abrupt climate change, and using knowledge of diatom autecologies in Lake Baikal, diversity trends are interpreted in 30
terms of resource availability. Using diatom biovolume accumulation rates (BVARs; μm^3 cm^-2 yr^-1), we show that spring diatom crops dominate palaeoproductivity for nearly all of our record, apart from a short period during the Late Holocene, when autumnal productivity dominated between 1.8–1.4 cal kyr BP. Palaeoproductivity was especially unstable during the Younger Dryas, reaching peak rates of 18.3 x 10^3 μm^3 cm^-2 yr^-1 at ca. 12.3 cal kyr BP. Generalized additive models (GAMs), which explore productivity–diversity relationships (PDRs) during pre-defined climate periods, reveal complex relationships. The strongest statistical evidence for GAMs were found during the Younger Dryas, the Early Holocene, and the Late Holocene, i.e. periods of rapid climate change. We account for these differences in terms of climate-mediated resource availability, and the ability of endemic diatom species in Lake Baikal to adapt to extreme forms of living in this unique ecosystem. Our analyses offer insight into how productivity–diversity relationships may develop in the future under a warming climate
Vivian Jones
No full textAbstract prepared by Jordin Arnead-Wilson In this interview the narrative of Vivian Jones, a vibrant and colorful personality, unfolds through her recounted experiences at the SAGE Center, reflecting a life rich in travel, friendships, and resilience. From her disco-era clubbing adventures to her deep connections with friends and family, Vivian\u27s zest for life shines through. Her journey through the five boroughs of New York City, marked by simultaneous hardships and beloved experiences, underscores her unwavering spirit. Vivian\u27s passion for astrology, fashion, and storytelling binds her to her queer community, while her album of memories serves as a testament to a life well-lived and loved. Through her tales of travel, queer love, and friendship, Vivian embodies the importance of cherishing relationships and embracing life\u27s adventures. Her enduring positivity and warmth remind us of the enduring power of human connection
Dr. Vivian Wilson Henderson, February 1969
No full textDr. Vivian Wilson Henderson, president of Clark College
President Vivian Wilson Henderson, circa 1965
No full textDr. Vivian Wilson Henderson speaking at an unidentified event
Vivian Walker, 2013
No full textVivian Walker shares her experiences growing up in Memphis during the Civil Rights era
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