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Ecological Analysis of Marine Microfossil Communities: Insight into the Timing, Magnitude, and Drivers of Change
Ecological Analysis of Marine Microfossil Communities: Insight into the Timing, Magnitude, and Drivers of Change
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105146
- ISBN
- 9798293834112
- DDC
- 550
- 서명/저자
- Ecological Analysis of Marine Microfossil Communities: Insight into the Timing, Magnitude, and Drivers of Change
- 발행사항
- [Sl] : University of California, San Diego, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 154 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-03, Section: B.
- 주기사항
- Advisor: Norris, Richard D.
- 학위논문주기
- Thesis (Ph.D.)--University of California, San Diego, 2025.
- 초록/해제
- 요약The Plio-Pleistocene Caribbean basin underwent dynamic changes as the uplift of the Isthmus of Panama separated the Atlantic from the Pacific and global cooling manifested in strengthening glacial-interglacial oscillations. In this thesis I quantify community variability across known paleoenvironmental transitions to identify the dominant scales of ecological change, resolve the hierarchy of environmental controls on community assembly, and assess how tectonic and climatic thresholds shaped marine ecosystems during this critical interval in Earth's history. Utilizing a high-resolution (~3 ky) record of planktonic foraminifera abundances from 5.03-1.38 Ma, I identify compositionally and temporally distinct intervals of relatively persistent community configurations. I resolve the timing and magnitude of these distinct compositional shifts, demonstrating that faunal turnovers associated with the closure of the Central American Seaway (CAS) and the amplification of Northern Hemisphere Glaciation (NHG) occurred in rapid, discrete transitions lasting 100 ky to 330 ky. This tempo contrasts previous interpretations of gradual change derived from coarser-resolution records which I address through down-sampling experiments, demonstrating that coarse resolution sampling may obscure the true tempo of biotic change. Integrating faunal data with published geochemical proxies shows that community structure most strongly correlates with sea level and nutrient-related proxies. These results suggest that nutrient dynamics, mediated by changing ocean circulation and ventilation states, act as the primary driver of changes in Caribbean planktonic foraminifera community composition. Finally, I leverage the 171 glacial and interglacial oscillations archived in our record as natural experiments to assess the predictability of community assembly and the effects of climate cyclicity on community composition. While early Pliocene assemblages showed minimal differentiation between ice states, the onset of Northern Hemisphere Glaciation (~2.71 Ma) and the final closure of the Central American Seaway (~3 Ma) amplified glacial-interglacial contrasts, driving deterministic shifts in community composition. Pleistocene communities stabilized into predictable, low-diversity configurations, revealing a tradeoff between richness and stability.
- 일반주제명
- Geobiology
- 일반주제명
- Paleoecology
- 일반주제명
- Paleoclimate science
- 키워드
- Caribbean
- 키워드
- Panama isthmus
- 키워드
- Global cooling
- 기타저자
- University of California, San Diego Scripps Institution of Oceanography
- 기본자료저록
- Dissertations Abstracts International. 87-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202105146
■006m o d
■007cr#unu||||||||
■020 ▼a9798293834112
■035 ▼a(MiAaPQ)AAI32241238
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a550
■1001 ▼aChristensen, Rials Viselli.
■24510▼aEcological Analysis of Marine Microfossil Communities: Insight into the Timing, Magnitude, and Drivers of Change
■260 ▼a[Sl]▼bUniversity of California, San Diego▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a154 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-03, Section: B.
■500 ▼aAdvisor: Norris, Richard D.
■5021 ▼aThesis (Ph.D.)--University of California, San Diego, 2025.
■520 ▼aThe Plio-Pleistocene Caribbean basin underwent dynamic changes as the uplift of the Isthmus of Panama separated the Atlantic from the Pacific and global cooling manifested in strengthening glacial-interglacial oscillations. In this thesis I quantify community variability across known paleoenvironmental transitions to identify the dominant scales of ecological change, resolve the hierarchy of environmental controls on community assembly, and assess how tectonic and climatic thresholds shaped marine ecosystems during this critical interval in Earth's history. Utilizing a high-resolution (~3 ky) record of planktonic foraminifera abundances from 5.03-1.38 Ma, I identify compositionally and temporally distinct intervals of relatively persistent community configurations. I resolve the timing and magnitude of these distinct compositional shifts, demonstrating that faunal turnovers associated with the closure of the Central American Seaway (CAS) and the amplification of Northern Hemisphere Glaciation (NHG) occurred in rapid, discrete transitions lasting 100 ky to 330 ky. This tempo contrasts previous interpretations of gradual change derived from coarser-resolution records which I address through down-sampling experiments, demonstrating that coarse resolution sampling may obscure the true tempo of biotic change. Integrating faunal data with published geochemical proxies shows that community structure most strongly correlates with sea level and nutrient-related proxies. These results suggest that nutrient dynamics, mediated by changing ocean circulation and ventilation states, act as the primary driver of changes in Caribbean planktonic foraminifera community composition. Finally, I leverage the 171 glacial and interglacial oscillations archived in our record as natural experiments to assess the predictability of community assembly and the effects of climate cyclicity on community composition. While early Pliocene assemblages showed minimal differentiation between ice states, the onset of Northern Hemisphere Glaciation (~2.71 Ma) and the final closure of the Central American Seaway (~3 Ma) amplified glacial-interglacial contrasts, driving deterministic shifts in community composition. Pleistocene communities stabilized into predictable, low-diversity configurations, revealing a tradeoff between richness and stability.
■590 ▼aSchool code: 0033.
■650 4▼aGeobiology
■650 4▼aPaleoecology
■650 4▼aPaleoclimate science
■653 ▼aCaribbean
■653 ▼aCompositional change
■653 ▼aPanama isthmus
■653 ▼aPlanktic foraminifera
■653 ▼aGlobal cooling
■690 ▼a0483
■690 ▼a0426
■690 ▼a0653
■71020▼aUniversity of California, San Diego▼bScripps Institution of Oceanography.
■7730 ▼tDissertations Abstracts International▼g87-03B.
■790 ▼a0033
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359615▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
