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Morphological Variation In Codium Fragile In The Northwest Atlantic, Lucy Elizabeth Pleticha

Master's Theses and Capstones

Codium fragile (Suringar) Hariot, an invasive Asiatic green alga, has colonized areas of the NW Atlantic within the past fifty years. The plant has a dichotomously branched cylindrical thallus made of tangled filaments surrounded by a dense covering of swollen filament tips, or utricles, terminating in pointed mucrons. This study's goal was to investigate morphological differences in NW Atlantic C. fragile populations to determine which subspecies are present. In the summer of 2008, I surveyed 24 sites from the Canadian Maritimes to Long Island Sound and evaluated size variation in utricles. Morphological investigations revealed a two-fold difference in utricle and …

Photosynthetic And Oxidative Stress In The Green Alga Dunaliella Tertiolecta: The Effects Of Uv-B And Uv-A Radiation, Priya Sampath Wiley

Doctoral Dissertations

The penetration of ultraviolet-B (UV-B; 290-320 nm) into the biosphere has increased in response to decreased stratospheric ozone. As a consequence, significant attempts have been made to elucidate the effects of UV-B radiation on primary producers such as phytoplankton and plants. Considerably less effort has been devoted to describing the role played by ultraviolet-A (UV-A; 320-400 nm) radiation, which is not attenuated by stratospheric ozone. The present work details the independent and combined effects of UV-B and UV-A radiation on photosynthetic and oxidative stress responses using the unicellular green alga Dunaliella tertiolecta as a model organism. A UV-B spectral profile …

An Assessment Of The Biodiversity And Bioremediation Potential Of Distromatic Ulva Spp (Chlorophyta) In The Great Bay Estuarine System Of New Hampshire And Maine, Usa, Laurie Carol Hofmann

Master's Theses and Capstones

Eutrophication of coastal ecosystems is a global problem, and algae have become an important resource for bioremediation. The goals of this study were (1) to assess the biodiversity of Ulva spp. in the Great Bay Estuarine System (GBES) of New Hampshire and Maine, and (2) to assess which Ulva populations are most appropriate for bioremediation by determining if environmental nutrient history and/or taxonomie differences affect ammonium uptake. Molecular analysis of the internal transcribed spacer nrDNA regions of Ulva spp. revealed four distinct distromatic taxa: Ulva lactuca Linnaeus, Ulva rigida C. Agardh, Ulva compressa Linnaeus, and U. pertusa Kjellman. The latter …

Extrapolating Hyperspectral Anthocyanin Indices To Multispectral Satellite Sensors---Applications To Fall Foliage In New England, Erica Lindgren

Master's Theses and Capstones

Anthocyanin, thought to be a universal indicator of plant stress, is a red pigment found in many plant species and can seen in New England autumns. Detecting its presence is useful for ecosystem analysis and monitoring changes during autumn senescence. Currently fall foliage is subjectively measured; creation of a satellite-based anthocyanin index will provide an objective measurement and enhance understanding of the distribution of plant stress and senescence over large areas. Anthocyanin indices were tested hyperspectrally in a laboratory setting, then indices were simulated for Hyperion, MERIS, MODIS, and Landsat TM/ETM+ to see which most accurately represents changes in anthocyanin …

An Assessment Of Stress In Acer Saccharum As A Possible Response To Climate Change, Martha Carlson

Master's Theses and Capstones

Climate change is projected to extirpate Acer saccharum throughout its range in the United States. The current investigation evaluates the potential of spectral indices of foliar reflectance, measures of leaf area and bud quality, and historic trends in sap sugar and wood increments for detecting stress in sugar maple.

Thirty trees were examined in 10 plots on 5 sugar bushes in or near the Bearcamp Valley, New Hampshire, over the course of the 2008 growing season. The study found water stress in 100% of trees; reduced chlorophyll content in 60%; early abscission of leaves in 80%; reduced growing season in …