Spectral Distribution of Light in Florida Spring Ecosystems

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Material Information

Title:
Spectral Distribution of Light in Florida Spring Ecosystems Factors Affecting the Quantity and Quality of Light Available for Primary Producers
Physical Description:
1 online resource (269 p.)
Language:
english
Creator:
Szafraniec, Mary Lucy
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Environmental Engineering Sciences
Committee Chair:
DELFINO,JOSEPH J
Committee Co-Chair:
BROWN,MARK T
Committee Members:
FRAZER,TOM K
COHEN,MATTHEW J
KNIGHT,ROBERT LEE

Subjects

Subjects / Keywords:
attenuation -- light
Environmental Engineering Sciences -- Dissertations, Academic -- UF
Genre:
Environmental Engineering Sciences thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Light availability is a major forcing factor for spring ecosystem productivity and sustainability. It appears that water clarity has decreased in many springs in Florida, which could have had an effect on the quantity and quality of light available for primary producers in springs and spring-runs. Factors controlling the loss of water clarity and light availability are poorly defined in spring systems. To understand the causes of increased light attenuation in these optically complex lotic systems, it is necessary to measure the quantity and the quality of light available to primary producers. Optical water quality determines the underwater light field that provides the basis for habitat suitability, in terms of vegetation abundance, distribution, and survival in springs. Studies were conducted to assess the spectral distribution and potential limitation of wavelength-specific photosynthetically active radiation (PAR) by measuring the percent blue, green and red light available to primary producer communities in springs. Optical properties of the underwater light field were assessed to determine the relative magnitude and contribution of key inherent water clarity driving components. Results revealed a spatial optical gradient in both systems studied. Light attenuation of the blue band was dominated by algal pigment and colored dissolved organic matter absorption, and the green and red light bands were most strongly attenuated by scattering and absorption by particulates. Resulting underwater spectral light field characteristics for each spring system were used to develop and calibrate spectrally explicit, site specific and general spring system, empirical optical models to predict historical water clarity conditions. Optical modeling results indicate that both spring systems studied have not significantly changed since the early 2000s, aside from a few trends where particulate scattering and absorption properties have increased in one system and decreased in the other. The lower portions of each river studied had low levels of blue light available in the benthic zone throughout the time series. Finally, linkages were established among light availability, benthic community composition, distribution, and ecosystem primary productivity. The results from a synoptic field survey of spectral light availability and submerged aquatic vegetation biomass identified a minimum blue light requirement threshold range of 38-45%, below which may not be sufficient to support the growth and production of Sagittaria kurziana, an important primary producer in most spring systems.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Mary Lucy Szafraniec.
Thesis:
Thesis (Ph.D.)--University of Florida, 2014.
Local:
Adviser: DELFINO,JOSEPH J.
Local:
Co-adviser: BROWN,MARK T.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2014
System ID:
UFE0046619:00001