Author: Robert W. Ling
Publisher:
ISBN:
Category : Acid precipitation (Meteorology)
Languages : en
Pages : 180

Get Book Here

Book Description

Author: Karen Markel Howser
Publisher:
ISBN:
Category : Acid rain
Languages : en
Pages : 80

Get Book Here

Book Description

Author: Robert Peter Cook
Publisher:
ISBN:
Category : Acid pollution of rivers, lakes, etc
Languages : en
Pages : 196

Get Book Here

Book Description

Author: Nicholas Gervais
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
"Declines in amphibian populations have been noted since the late 1980's with many of the causes linked to habitat contamination and destruction by natural and anthropogenic sources. Amphibians with bi-phasic life histories have been thought to be particularly vulnerable to negative environmental conditions but there is much evidence of their resilience and capacity to survive in degraded or contaminated environments. Larval amphibians in small permanent or ephemeral ponds may be particularly vulnerable to altered environmental conditions and may face the greatest pressure to adapt. In Chapter 1, I briefly review the evidence of amphibian declines and how populations may adapt to and overcome assorted negative environmental factors. In Chapter 2, I investigated the phenomenon of adaptation in a particular circumstance. I collected Spotted Salamander (Ambystoma maculatum) egg masses from a population breeding in a naturally acidic pond called Bat Lake, as well as four other populations living in lakes closer to pH neutral. To determine if the salamanders were adapted to their particular breeding lakes, I used common garden experiments in the lab where I raised larvae from each of the lakes in the waters from all the other lakes, as well as their own and compared the survival rates, size at metamorphosis and time to metamorphosis. Bat Lake larvae grew larger and survived longer in their acidic native breeding pond water than in the waters of other lakes suggesting they are adapted to their native pond waters. The larvae from the other lake populations showed similar results and fared better in their native waters than in the Bat Lake water. Based on these results, in Chapter 3, I tested if pH, specifically, was causal. I raised larvae from the five populations in waters of different pH (4.0, 5.5, 7.0), reasoning that if the Bat Lake population was more adapted to the high acidity compared to the other populations, the larvae from Bat Lake should demonstrate higher fitness correlates at lower pH than larvae of other populations. In this experiment, the Bat Lake larvae survived longer and grew larger in the highly acidic water than did larvae from the other populations. My results are consistent with natural selection for tolerance of low pH conditions tolerance among Bat Lake Spotted Salamander larvae and indicate that the salamanders from Bat Lake potentially exhibit signs of local adaption to the highly acidic conditions in which they live. This study was unable, however to prove whether this adaptation was due to evolutionary change, phenotypic plasticity, maternal effects or some other unknown factor. " --

Author: M. A. Peterson
Publisher:
ISBN:
Category : Acid rain
Languages : en
Pages : 62

Get Book Here

Book Description

Author: H.C. Martin
Publisher: Springer Science & Business Media
ISBN: 9400933851
Category : Science
Languages : en
Pages : 2096

Get Book Here

Book Description
Since the beginning of the 1980's, research has continued to clarify and improve our understanding of the problern of the ecological impact of acidic precipitation. From September 15-20, 1985, Canada convened the the Muskoka Symposium on Acidic Precipitation to review progress and help chart the direction of future studies. The Conference was held in central Ontario, Canada, a region of heavy sulphate deposition where aquatic effects are evident. Approximately 700 people attended, over 500 of whom were research scientists. Over 400 papers were presented. Nearly 200 of the papers are included in these proceedings, which tagether give the present state of the art of acid rain research. The Conference focused on atmospheric science and aquatic and terrestrial effects. I have made some general observations on progress in clarifying issues and linkages between these areas of research. Out standing issues which require a great deal more work are identified. These are my views, influenced by personal bias and limited by my expertise. Atmospheric Seiences Three aspects were covered: measurement techniques, the actual measure ments, and source-receptor relationships.

Author: Wade H. Shafer
Publisher: Springer Science & Business Media
ISBN: 1468451979
Category : Science
Languages : en
Pages : 407

Get Book Here

Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 29 (thesis year 1984) a total of 12,637 theses titles from 23 Canadian and 202 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 29 reports theses submitted in 1984, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.

Author: R. Cook
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description

Author: Julie Charbonnier
Publisher:
ISBN:
Category : Environmental engineering
Languages : en
Pages :

Get Book Here

Book Description
Organisms with complex life cycles may experience diverse stressors during their development. Stressors experienced in early life stages may influence the quantity and quality of individuals in later life stages. However, it is unclear if these effects persist later in life and how they may influence population dynamics. This dissertation uses two amphibian species, the Western spadefoot toad (Pelobates cultripes) and the spotted salamander (Ambystoma maculatum) to explore how biotic and abiotic factors experienced in aquatic and terrestrial environments influence phenotype and survival. We use a combination of field mesoscosm studies, laboratory studies and modeling to explore how early life history stressors persist in diverse environmental contexts. In Chapter 1, pond drying and larval density negatively influence multiple aspects of phenotype in the Western spadefoot toad. In Chapter 2, reduced body size due to larval stressors persisted in the first year of life in spotted salamanders in both high and low terrestrial resource environments. Additionally, there was no relationship between size at metamorphosis and post-metamorphic terrestrial survival. In Chapter 3, low terrestrial moisture levels reduced post-metamorphic growth rates by reducing food intake in juvenile spotted salamanders from both high and low larval density treatments. In Chapter 4, we scale up the effects of reduced body size in the Western spadefoot toad to explore how reduced body size due to pond drying may influence population densities using a stage specific matrix model. Reduced body size, by delaying maturity, may reduce adult densities in the Western spadefoot toad. This dissertation suggests that life stages are highly interconnected, as stressors experienced early in life stage may persist through their effects on phenotype in the absence of compensatory mechanisms. Variation in later life stages may also influence phenotype, but may not completely erase effects of early environments. Stressors experienced early in life may also translate to population level consequences, especially when organisms experience multiple stressors across life stages.

Author: David Gordon Chiller
Publisher:
ISBN:
Category : Spotted salamander
Languages : en
Pages : 102

Get Book Here

Book Description