Plant Physiological Responses to Environmental Change in a Marsh-Mangrove Ecotone

Globally, photosynthesis (A) and autotrophic respiration (R) are the two largest physiological processes responsible for CO2 flux. Coastal wetland ecosystems are responsible for some of the highest rates of C sequestration. Marsh grass and mangrove habitats responsible for this service are important in supporting biodiversity and preventing shoreline erosion, yet little is known about how this vegetation will respond physiologically to effects of climate and global change. In the first chapter a warming experiment was used to determine whether a C4 marsh grass (Spartina alterniflora) and a C3 mangrove (Avicennia germinans) acclimate leaf R to seasonal changes in temperature and experimental warming, and whether variation in leaf N (proxy for enzyme concentrations) explains temperature acclimation patterns in both species. In the second chapter a long-term fertilization experiment was conducted to determine whether Avicennia alters parameters of A and R over time in response to nutrient enrichment of nitrogen (N) or phosphorus (P), and whether the response to pulse enrichment of nutrients is temporary or leaves a legacy effect. In chapter 1, Avicennia generally increased respiratory capacity as growth temperatures increased, but Spartina acclimated to warmer temperatures by reducing respiratory capacity. Although temperature acclimation of R differed between Spartina and Avicennia, changes in Nmass explained temperature acclimation patterns in both species. In chapter 2, N addition increased R capacity (Rmass25), CO2 assimilation (Asat), and the maximum rate of Rubisco carboxylation (Vcmax). The effects of N addition on photosynthesis were short-lived, but the effect of N addition on leaf R was consistent over time, indicating a possible legacy effect of R but not A. This thesis provides new insight into temperature controls of leaf R in marsh and mangrove species, which may aid predictions of CO2 fluxes from coastal wetlands. This research also improves our understanding of the short- and potentially long-term impacts of N and P enrichment on mangrove physiology

The sciences in America, circa 1880

For many years American science in the late 19th century was regarded as an intellectual backwater. This view derived from the assumption that the health of American science at the time was equivalent to the condition of pure science, especially pure physics. However, a closer look reveals that there was considerable vitality in American scientific research, especially in the earth and life sciences. This vitality is explainable in part by the natural scientific resources of the American continent but also in part by the energy given science from religious impulses, social reformism, and practicality. Furthermore, contrary to recent assumptions, the federal government was a significant patron of American science. The portrait of American science circa 1880 advanced in this article suggests that the nation's scientific enterprise was characterized by pluralism of institutional support and motive and that such pluralism has historically been the normal mode

Navigating LGBTQ+ and Disabled Intersections Online: Social Support and Identity Construction in the Age of Social Media

There is a lack of research about the lived experiences of self-identified lesbian, gay, bisexual, transgender, queer, and otherwise-identified (LGBTQ+) young adults with disabilities who use the Internet to achieve particular social aims. Using open-ended survey questions, the researcher applied multidimensional and overlapping frameworks of intersectionality, feminist-disability theory, and social work to answer the following: What are the lived experiences of disabled, LGBTQ+ young adults who use social media for social support and identity construction? Using secondary data, fifteen (N=15) cases of LGBTQ+ disabled young adults aged 18 to 31 living in the United States were selected, and data was analyzed using a phenomenological thematic analysis. The research revealed salient themes, such as community/belonging, access to “others like me,” positive identity formation and protective mental health factors to name a few, each of which respectively facilitated or complicated participants’ motives to use social media platforms. Implications of v the research findings for social science scholars and suggestions for future research are discussed

Rich, Penny

Penny Rich is a 70-year old lesbian living in Portland, Maine. She recieved a bachelor\u27s degree in English from the University of Southern Maine. She is known for her involvement in major social events such as Portland Pride and the Women\u27s Coffeehouse, as well as her experiences with gay bar culture throughout the 60\u27s and 70\u27s. She spends her time socializing, exercising, reading, and getting involved in local political and social issues that affect the LGBTQ+ community in Portland, Maine. Citation Please cite as: Querying the Past: LGBTQ Maine Oral History Project Collection, Lesbian, Gay, Bisexual, Transgender, and Queer+ Collection, Jean Byers Sampson Center for Diversity in Maine, University of Southern Maine Libraries. For more information about the Querying the Past: Maine LGBTQ Oral History Project, please contact Dr. Wendy Chapkis.https://digitalcommons.usm.maine.edu/querying_ohproject/1025/thumbnail.jp

Exploring patterns of thermal acclimation of leaf respiration in a marsh-mangrove ecotone

Vegetated coastal ecosystems (saltmarsh, mangroves) make a large contribution to global net primary productivity and C cycling despite covering a small proportion of the earth’s surface. Yet, our understanding of C cycling processes over space and time and in response to temperature remain limited for these ecosystems. At the global scale, respiration is the second largest flux of C (behind photosynthesis), and ~50% of respiration comes from leaves. Respiration is also a key parameter for global models that predict climate-carbon cycle interactions. But respiratory responses to temperature in marsh and mangrove species remain uncertain. Here, we repeatedly measured short-term temperature responses of leaf respiration in a C4 marsh grass species (Spartina alterniflora) and a C3 mangrove species (Avicennia germinans) growing under ambient temperatures and experimental warming at two sites in Florida. We tested whether marsh grasses and mangroves show similar acclimation of leaf respiration to seasonal temperature changes at sites differing in temperature seasonality, and whether acclimation is consistent between plants grown under ambient and warmed conditions

Red Sea Rifting Controls on Groundwater Reservoir Distribution: Constraints from Geophysical, Isotopic, and Remote Sensing Data

Highly productive wells in the Central Eastern Desert of Egypt are tapping groundwater in subsided blocks of Jurassic to Cretaceous sandstone (Taref Formation of the Nubian Sandstone Group) and Oligocene to Miocene sandstone (Nakheil Formation), now occurring beneath the Red Sea coastal plain and within the proximal basement complex. Aquifer development is related to Red Sea rifting: (1) rifting was accommodated by vertical extensional displacement on preexisting NW-SE– to N-S–trending faults forming a complex array of half-grabens and asymmetric horsts; and (2) subsided blocks escaped erosion accompanying the Red Sea–related uplift. Subsided blocks were identifi ed and verifi ed using satellite data, geologic maps, and fi eld and geophysical investigations. Interpretations of very low frequency (VLF) measurements suggest the faults acted as conduits for ascending groundwater from the subsided aquifers. Stable isotopic compositions (δD: –19.3‰ to –53.9‰; δ18O: –2.7‰ to –7.1‰) of groundwater samples from these aquifers are interpreted as mixtures of fossil (up to 70%) and modern (up to 65%) precipitation. Groundwater volumes in subsided blocks are large; within the Central Eastern Desert basement complex alone, they are estimated at 3 × 109 m3 and 10 × 109 m3 for the Nakheil and Taref Formations, respectively. Results highlight the potential for identifying similar rift-related aquifer systems along the Red Sea–Gulf of Suez system, and in rift systems elsewhere. An understanding of the distribution of Red Sea rift–related aquifers and modern recharge contributions to these aquifers could assist in addressing the rising demands for fresh water supplies and water scarcity issues in the regio

Red Sea Rifting Controls on Groundwater Reservoir Distribution: Constraints from Geophysical, Isotopic, and Remote Sensing Data

Highly productive wells in the Central Eastern Desert of Egypt are tapping groundwater in subsided blocks of Jurassic to Cretaceous sandstone (Taref Formation of the Nubian Sandstone Group) and Oligocene to Miocene sandstone (Nakheil Formation), now occurring beneath the Red Sea coastal plain and within the proximal basement complex. Aquifer development is related to Red Sea rifting: (1) rifting was accommodated by vertical extensional displacement on preexisting NW-SE– to N-S–trending faults forming a complex array of half-grabens and asymmetric horsts; and (2) subsided blocks escaped erosion accompanying the Red Sea–related uplift. Subsided blocks were identifi ed and verifi ed using satellite data, geologic maps, and fi eld and geophysical investigations. Interpretations of very low frequency (VLF) measurements suggest the faults acted as conduits for ascending groundwater from the subsided aquifers. Stable isotopic compositions (δD: –19.3‰ to –53.9‰; δ18O: –2.7‰ to –7.1‰) of groundwater samples from these aquifers are interpreted as mixtures of fossil (up to 70%) and modern (up to 65%) precipitation. Groundwater volumes in subsided blocks are large; within the Central Eastern Desert basement complex alone, they are estimated at 3 × 109 m3 and 10 × 109 m3 for the Nakheil and Taref Formations, respectively. Results highlight the potential for identifying similar rift-related aquifer systems along the Red Sea–Gulf of Suez system, and in rift systems elsewhere. An understanding of the distribution of Red Sea rift–related aquifers and modern recharge contributions to these aquifers could assist in addressing the rising demands for fresh water supplies and water scarcity issues in the regio