Life Sciences Commons^™

Effects Of Nitrogen Deposition And Empirical Nitrogen Critical Loads For Ecoregions Of The United States, Linda H. Pardo, Mark E. Fenn, Christine L. Goodale, Linda H. Geiser, Charles T. Driscoll, Edith B. Allen, Jill S. Baron, Roland Bobbink, William D. Bowman, Christopher M. Clark, Bridget Emmett, Frank S. Gilliam, Tara L. Greaver, Sharon J. Hall, Erik A. Lilleskov, Lingli Liu, Jason A. Lynch, Knute J. Nadelhoffer, Steven S. Perakis, Molly J. Robin-Abbott, John L. Stoddard, Kathleen C. Weathers, Robin L. Dennis

Frank S. Gilliam

Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge. The objectives of this project were to synthesize …

Synthesis, Linda H. Pardo, Linda H. Geiser, Mark E. Fenn, Charles T. Driscoll, Christine L. Goodale, Edith B. Allen, Jill S. Baron, Roland Bobbink, William D. Bowman, Christopher M. Clark, Bridget Emmett, Frank S. Gilliam, Tara Greaver, Sharon J. Hall, Erik A. Lilleskov, Lingli Liu, Jason A. Lynch, Knute Nadelhoffer, Steven S. Perakis, Molly J. Robin-Abbott, John L. Stoddard, Kathleen C. Weathers

Frank S. Gilliam

Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is dei ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge. The objective of this project was to synthesize …

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Frank S. Gilliam

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …

Effects Of Experimental Nitrogen Additions On Plant Diversity In An Old-Growth Tropical Forest, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Guoyi Zhou, Yunting Fang

Frank S. Gilliam

Response of plant biodiversity to increased availability of nitrogen (N) has been investigated in temperate and boreal forests, which are typically N-limited, but little is known in tropical forests. We examined the effects of artificial N additions on plant diversity (species richness, density and cover) of the understory layer in an N saturated old-growth tropical forest in southern China to test the following hypothesis: N additions decrease plant diversity in N saturated tropical forests primarily from N-mediated changes in soil properties. Experimental additions of N were administered at the following levels from July 2003 to July 2008: no addition (Control); …

Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal

Madhav Nepal

Comparative Sequence Analysis Of Fatty Acid Desaturase 2 (Fad2) Cdna Sequences From The Compositae [Asteraceae], Paul Ames Muller Jr.

Paul Muller

Fatty acid desaturases are enzymes capable of modifying carbon-carbon bonds within fatty acids. All higher plants contain one or more oleic acid desaturases that catalyze insertion of a double bond between carbons 12 and 13 of oleic acid to produce linoleic acid, an unsaturated fatty acid. However, this family of enzymes may vary in specificity and are responsible for a wide spectrum of unsaturated fatty acids found in nature that play important ecological, physiological, and industrial roles. Here, I examine nucleotide sequence evolution and predict structural changes of translated expressed Fatty Acid Desaturase 2 (FAD2) cDNA sequences in the Compositae …

Biodiversity Status In Ethiopia And Challenges, Azamal Husen, V.K. Mishra, Kamal Semwal, Dinesh Kumar

Prof. Azamal Husen

Ethiopia is rich in faunal, floral and microbial diversity. Conservation paradigms, practices and policies have been variably successful. Traditional approaches in conservation have evolved awareness about biodiversity conservation. Climate change poses unknown fear and challenge to biodiversity conservation in the 21st century. There is urgent need of mapping of biodiversity in various environments, inventorization, monitoring of biodiversity, and global data sharing. Conservation of genetic resources will assist in future genetic improvement of crop plants and livestocks. Bioprospecting-value addition to biodiversity will provide economic gain for the country. Necessary measures need to be initiated to safeguard the germplasms against potential threat …