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Full-Text Articles in Life Sciences

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda Dec 2011

Bryoecology In The American Southwest: Patterns Of Biodiversity And Responses To Global Change, John Carroll Brinda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation combines investigation of the large-scale responses of bryophyte species diversity and distribution with small-scale physiological adaptations to global change. These two areas of inquiry are linked because one way to predict plant species responses to global change is to examine their distribution across current ecological gradients produced by factors such as latitude and elevation. By examining these biogeographic patterns one can identify those species that have a narrow tolerance and therefore are most sensitive to change. Selected bryophytes might then be used as indicator species in long-term monitoring programs. Where historical data exist, these can be used to …


Going All The Way: Phylogeography And Trans-Pacific Divergence Genetics Of Nucella Lima, Lisa Cox Aug 2011

Going All The Way: Phylogeography And Trans-Pacific Divergence Genetics Of Nucella Lima, Lisa Cox

All Theses

Fluctuating climate over the last 2 million years (MY) has repeatedly caused latitudinal shifts in species distributions, fueling the hypothesis that the glacial-interglacial dynamics of the Pleistocene could have driven regional genetic differentiation and potentially speciation. For species whose distributions spanned the entire North Pacific, regional extinction of northern populations during cooler glacial periods may have resulted in isolation and genetic differentiation of eastern and western populations. To test this hypothesis, I gathered genetic data from a rocky shore intertidal gastropod, Nucella lima, whose current (i.e. warm interglacial) distribution spans the entire North Pacific. Mitochondrial DNA sequences are genetically structured …


Climate Change And Community Dynamics: A Hierarchical Bayesian Model Of Resource-Driven Changes In A Desert Rodent Community, Glenda M. Yenni May 2011

Climate Change And Community Dynamics: A Hierarchical Bayesian Model Of Resource-Driven Changes In A Desert Rodent Community, Glenda M. Yenni

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Predicting effects of climate change on species persistence often assumes that those species are responding to abiotic effects alone. However, biotic interactions between community members may affect species’ ability to respond to abiotic changes. Latent Gaussian models of resource availability using precipitation and NDVI and accounting for spatial autocorrelation and rodent group-level uncertainty in the process are developed to detect differences in seasons, groups, and the experimental removal of one group. Precipitation and NDVI have overall positive effects on rodent energy use as expected, but meaningful differences were detected. Differences in the importance of seasonality when the dominant group was …


Warming Alters Photosynthetic Rates Of Sub-Boreal Peatland Vegetation, Arvo Aljaste Jan 2011

Warming Alters Photosynthetic Rates Of Sub-Boreal Peatland Vegetation, Arvo Aljaste

Dissertations, Master's Theses and Master's Reports - Open

Boreal peatlands are important in the global carbon cycle. Despite covering only 3% of the global land area, peatlands store approximately one third of all soil carbon. Temperature is one of the major drivers in peatland carbon cycling as it affects both plant production and CO2 fluxes from soils. However, it is relatively unknown how boreal peatland plant photosynthesis is affected by higher temperatures. Therefore, we measured plant photosynthetic rates under two different warming treatments in a poor fen in Northern Michigan. Eighteen plots were established that were divided into three treatments: control, open-top chamber (OTC) warming and infrared …


Biological Reserves Under Climate Change; A Case Study In Brazil's Atlantic Rainforest, Maria Amin Jan 2011

Biological Reserves Under Climate Change; A Case Study In Brazil's Atlantic Rainforest, Maria Amin

Dissertations and Theses

No abstract provided.


Causes And Consequences Of Changes In Algal Community Structure Of Arctic Tundra Ponds From Barrow, Alaska, Mariana Vargas Medrano Jan 2011

Causes And Consequences Of Changes In Algal Community Structure Of Arctic Tundra Ponds From Barrow, Alaska, Mariana Vargas Medrano

Open Access Theses & Dissertations

Algal communities in the Arctic are highly sensitive to environmental change, such as longer growing seasons and changes in ice cover. On the north slope of Alaska, ponds and lakes cover large portions of the total land area. We surveyed the periphytic algal communities in tundra ponds from Barrow, Alaska to assess environmental effects on their populations. Samples were collected in August 2008-10 from two main study areas: the IBP (the International Biological Program), which was also studied in 1970-71 but now is located near to human settlements, and the BEO (Barrow Environmental Observatory), which is within a protected area. …


The Response Of Tall Fescue And Its Fungal Endophyte To Climate Change, Glade Blythe Brosi Jan 2011

The Response Of Tall Fescue And Its Fungal Endophyte To Climate Change, Glade Blythe Brosi

University of Kentucky Master's Theses

Tall fescue is the most common cool-season grass in the eastern USA, with broad economic and ecological importance to the region. Tall fescue is known to associate with a fungal endophyte, Neotyphodium coenophialum, whose presence can decrease biotic and abiotic stress experienced by the plant. This thesis evaluates the response of tall fescue and the fungal endophyte symbiosis to predicted climate change. I participated in two multi-factor climate change projects where I investigated the response of tall fescue tissue chemistry and growth to various climate change factors. Endophyte-infected (E+) tall fescue had decreased alkaloid production under elevated CO2 …