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Physical Sciences and Mathematics Commons

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Life Sciences

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Connecticut College

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2009

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Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Distribution And Diversity Of Archaeal And Bacterial Ammonia Oxidizers In Salt Marsh Sediments, Nicole S. Moin, Katelyn A. Nelson, Alexander Bush, Anne E. Bernhard Dec 2009

Distribution And Diversity Of Archaeal And Bacterial Ammonia Oxidizers In Salt Marsh Sediments, Nicole S. Moin, Katelyn A. Nelson, Alexander Bush, Anne E. Bernhard

Biology Faculty Publications

Diversity and abundance of ammonia-oxidizing Betaproteobacteria (β-AOB) and archaea (AOA) were investigated in a New England salt marsh at sites dominated by short or tall Spartina alterniflora (SAS and SAT sites, respectively) or Spartina patens (SP site). AOA amoA gene richness was higher than β-AOB amoA richness at SAT and SP, but AOA and β-AOB richness were similar at SAS. β-AOB amoA clone libraries were composed exclusively of Nitrosospira-like amoA genes. AOA amoA genes at SAT and SP were equally distributed between the water column/sediment and soil/sediment clades, while AOA amoA sequences at SAS were primarily affiliated with the …


Seedlings’ Substrate Preferences In A Minnesota Old Growth Thuja-Betula Forest, Stephen C. Rossiter May 2009

Seedlings’ Substrate Preferences In A Minnesota Old Growth Thuja-Betula Forest, Stephen C. Rossiter

Environmental Studies Honors Papers

Northeastern Minnesota’s logging history has altered the forests enough to cause concern about the reproduction of Thuja occidentalis and Betula alleghaniensis. I studied a rare old growth example of an already rare mesic Thuja-Betula forest and asked how well those species were regenerating in that mostly unaltered ecosystem. In managed forests, a lack of suitable substrate is thought to be limiting their seedling establishment so I asked which substrates the seedlings preferred in the old forest. To answer both questions, I measured the seedling densities of all canopy tree species across height classes and substrate types within twenty 100m2 plots. …


Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral Jan 2009

Dispersal And Establishment Both Limit Colonization During Primary Succession On A Glacier Foreland, Chad C. Jones, Roger Del Moral

Botany Faculty Publications

Plant colonization can be limited by lack of seeds or by factors that reduce establishment. The role of seed limitation in community assembly is being increasingly recognized, but in early primary succession, establishment failure is still considered more important. We studied the factors limiting colonization on the foreland of Coleman Glacier, Washington, USA to determine the importance of seed and establishment limitation during primary succession. We also evaluated the effects of seed predation, drought and existing vegetation on establishment. We planted seeds of seven species into plots of four different ages and found evidence that both seed and establishment limitation …