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Full-Text Articles in Biology

Utilizing Fishermen Knowledge And Expertise: Keys To Success For Collaborative Fisheries Research, Noëlle Yochum, Richard M. Starr, Dean Wendt Dec 2011

Utilizing Fishermen Knowledge And Expertise: Keys To Success For Collaborative Fisheries Research, Noëlle Yochum, Richard M. Starr, Dean Wendt

Biological Sciences

Collaborative fisheries research provides a mechanism for integrating the unique knowledge, experience, and skills of fishermen and scientists. It is a joint intellectual endeavor that begins with the inception of a project and continues until its final stages, with each group having mutual investment in—and ownership of— the project. Collaborative fisheries research promotes communication and trust among fishermen, scientists, and managers and can provide much-needed scientifically valid data for fisheries management. It can enhance federal and state management data collection programs, which span broad sections of coastline, by increasing the ability to detect changes in local metapopulations that may be …


Climate Change, Body Size, And Phenotype Dependent Dispersal, Shannon J. Mccauley, Karen E. Mabry Nov 2011

Climate Change, Body Size, And Phenotype Dependent Dispersal, Shannon J. Mccauley, Karen E. Mabry

Biological Sciences

No abstract provided.


Parasite Infection And Sand Coarseness Increase Sand Crab (Emerita Analoga) Burrowing Time, Gita R. Kolluru, Zachary S. Green, Larisa K. Vredevoe, Matthew R. Kuzma, Sera N. Ramadan, Marc R. Zosky Nov 2011

Parasite Infection And Sand Coarseness Increase Sand Crab (Emerita Analoga) Burrowing Time, Gita R. Kolluru, Zachary S. Green, Larisa K. Vredevoe, Matthew R. Kuzma, Sera N. Ramadan, Marc R. Zosky

Biological Sciences

Parasites with indirect life cycles require trophic transmission from intermediate hosts to definitive (vertebrate) hosts. Transmission may be facilitated if parasite infection alters the behavior of intermediate hosts such that they are more vulnerable to predation. Vulnerability to predation may also be influenced by abiotic factors; however, rarely are the effects of parasites and abiotic factors examined simultaneously. The swash zone of sandy beaches is a particularly harsh environment. Sand crabs (Emerita analoga) burrow rapidly in the swash zone to avoid predators and dislodgment. We examined prevalence and abundance of the acanthocephalan parasite Profilicollis altmani in sand crabs, …


Educational Curriculum Standards & Standardized Educational Tests: Comparing Apples & Oranges?, William D. Stansfield Sep 2011

Educational Curriculum Standards & Standardized Educational Tests: Comparing Apples & Oranges?, William D. Stansfield

Biological Sciences

Mandated biology curriculum standards and standardized tests may vary widely from one state to another, making academic-performance comparisons among the states problematic. This report outlines the effects of the “No Child Left Behind” law and uses California as a test case against which teachers in other states may make comparisons of their own biology curriculum standards and tests. Several sources are cited that offer sample multiple-choice questions that have appeared on previous California standardized tests for sciences/life sciences/biology. These examples, and critique thereof, may help teachers better prepare their own tests to improve student performance in meeting the state's curriculum …


The Proteomic Response Of Sea Squirts (Genus Ciona) To Acute Heat Stress: A Global Perspective On The Thermal Stability Of Proteins, Loredana Serafini, Jay B. Hann, Dietmar Kültz, Lars Tomanek Sep 2011

The Proteomic Response Of Sea Squirts (Genus Ciona) To Acute Heat Stress: A Global Perspective On The Thermal Stability Of Proteins, Loredana Serafini, Jay B. Hann, Dietmar Kültz, Lars Tomanek

Biological Sciences

Congeners belonging to the genus Ciona have disparate distributions limited by temperature. Ciona intestinalis is more widespread with a cosmopolitan distribution ranging from tropical to sub-arctic zones, while Ciona savignyi is limited to temperate-latitudes of the northern Pacific Ocean. To compare the heat stress response between congeners, we quantified changes in protein expression using proteomics. Animals were exposed to 22 °C, 25 °C, and 28 °C for 6 h, then recovered at a control temperature (13 °C) for 16 h (high heat stress experiment). In a second experiment we exposed animals to lower levels of heat stress at 18 °C, …


Season And Sex Of Host Affect Intensities Of Ectoparasites In Western Fence Lizards (Sceloporus Occidentalis) On The Central Coast Of California, Anthony S. Lumbad, Larisa K. Vredevoe, Emily N. Taylor Sep 2011

Season And Sex Of Host Affect Intensities Of Ectoparasites In Western Fence Lizards (Sceloporus Occidentalis) On The Central Coast Of California, Anthony S. Lumbad, Larisa K. Vredevoe, Emily N. Taylor

Biological Sciences

Seasonal variability in intensities of ectoparasites of western fence lizards (Sceloporus occidentalis) was quantified in spring, summer, and autumn 2008. Lizards were suspended over pans of water in the laboratory to enumerate replete western black-legged ticks (Ixodes pacificus) and mites. Intensity of ectoparasites was greatest in spring. On average, mites comprised the greatest proportion of ectoparasites, followed by larval and nymphal ticks, respectively. Mites were on lizards year-round. Overall intensity of ticks was greatest in spring, but low during summer and autumn. Males were more heavily parasitized by ticks than females in spring, whereas females had …


Addressing Biased Occurrence Data In Predicting Potential Sierra Nevada Red Fox Habitat For Survey Prioritization, Casey Cleve, John D. Perrine, Barbara Holzman, Ellen Hines Aug 2011

Addressing Biased Occurrence Data In Predicting Potential Sierra Nevada Red Fox Habitat For Survey Prioritization, Casey Cleve, John D. Perrine, Barbara Holzman, Ellen Hines

Biological Sciences

The Sierra Nevada red fox Vulpes vulpes necator is listed as a threatened species under the California Endangered Species Act. It originally occurred throughout California’s Cascade and Sierra Nevada mountain regions. Its current distribution is unknown but should be determined in order to guide management actions. We used occurrence data from the only known population, in the Lassen Peak region of northern California, combined with climatic and remotely sensed variables, to predict the species’ potential distribution throughout its historic range. These model predictions can guide future surveys to locate additional fox populations. Moreover, they allow us to compare the relative …


Bridging The Marine-Terrestrial Disconnect To Improve Marine Coastal Zone Science And Management, Benjamin I. Ruttenberg, Elise F. Granek Jul 2011

Bridging The Marine-Terrestrial Disconnect To Improve Marine Coastal Zone Science And Management, Benjamin I. Ruttenberg, Elise F. Granek

Biological Sciences

Coastal zone ecosystems sit between larger terrestrial and marine environments and, therefore, are strongly affected by processes occurring in both systems. Marine coastal zone systems provide a range of benefits to humans, and yet many have been significantly degraded as a result of direct and indirect human impacts. Management efforts have been hampered by disconnects both between management and scientific research and across linked marine–terrestrial systems. Management jurisdictions often start or end at the shoreline, and multiple agencies at different levels of government often have overlapping or conflicting management goals or priorities, or suffer from a lack of knowledge or …


Tissue-Specific Thyroid Hormone Regulation Of Gene Transcripts Encoding Iodothyronine Deiodinases And Thyroid Hormone Receptors In Striped Parrotfish (Scarus Iseri), Kaitlin M. Johnson, Sean C. Lema Jul 2011

Tissue-Specific Thyroid Hormone Regulation Of Gene Transcripts Encoding Iodothyronine Deiodinases And Thyroid Hormone Receptors In Striped Parrotfish (Scarus Iseri), Kaitlin M. Johnson, Sean C. Lema

Biological Sciences

In fish as in other vertebrates, the diverse functions of thyroid hormones are mediated at the peripheral tissue level through iodothyronine deiodinase (dio) enzymes and thyroid hormone receptor (tr) proteins. In this study, we examined thyroid hormone regulation of mRNAs encoding the three deiodinases dio1, dio2 and dio3 – as well as three thyroid hormone receptors trαA, trαB and trβ – in initial phase striped parrotfish (Scarus iseri). Parrotfish were treated with dissolved phase T3 (20 nM) or methimazole (3 mM) for 3 days. Treatment with exogenous T3 elevated circulating T3, while the …


A Preliminary Study Of The Vegetation Of Vernal Pools Of Acadia National Park, Maine, U.S.A, Brett Ciccotelli, Tanner B. Harris, Bruce Connery, Nishanta Rajakaruna Jul 2011

A Preliminary Study Of The Vegetation Of Vernal Pools Of Acadia National Park, Maine, U.S.A, Brett Ciccotelli, Tanner B. Harris, Bruce Connery, Nishanta Rajakaruna

Biological Sciences

We conducted a preliminary floristic study of six vernal pools in Acadia National Park on Mount Desert Island, Maine. Plant species were recorded on three sampling dates from April to October, 2008. Sixty-five vascular plant species from 26 families were recorded. Of these, 27 are considered occasional or uncommon in Acadia National Park. Thirteen species are new reports for vernal pools in the northeastern United States. This represents the first published study of the vernal pool flora of Acadia National Park.


Predator-Induced Demographic Shifts In Coral Reef Fish Assemblages, Benjamin I. Ruttenberg, Scott L. Hamilton, Sheila M. Walsh, Mary K. Donovan, Alan Friedlander, Edward Demartini, Enric Sala, Stuart A. Sandin Jun 2011

Predator-Induced Demographic Shifts In Coral Reef Fish Assemblages, Benjamin I. Ruttenberg, Scott L. Hamilton, Sheila M. Walsh, Mary K. Donovan, Alan Friedlander, Edward Demartini, Enric Sala, Stuart A. Sandin

Biological Sciences

In recent years, it has become apparent that human impacts have altered community structure in coastal and marine ecosystems worldwide. Of these, fishing is one of the most pervasive, and a growing body of work suggests that fishing can have strong effects on the ecology of target species, especially top predators. However, the effects of removing top predators on lower trophic groups of prey fishes are less clear, particularly in highly diverse and trophically complex coral reef ecosystems. We examined patterns of abundance, size structure, and age-based demography through surveys and collection-based studies of five fish species from a variety …


Homocysteine: A Potential Molecular Link Between Alzheimer's Disease And Type 2 Diabetes Mellitus, Cyndel Carreau May 2011

Homocysteine: A Potential Molecular Link Between Alzheimer's Disease And Type 2 Diabetes Mellitus, Cyndel Carreau

Biological Sciences

In order to elucidate some of the mechanisms through which Alzheimer’s disease (AD) and Type II Diabetes Mellitus (T2DM) are linked, this study investigated the effects of elevated plasma homocysteine levels – a risk factor for AD – in a rat model of T2DM. Both elevated plasma homocysteine levels and T2DM are associated with cognitive deficits and are recognized as strong risk factors for the development of AD. The present experiment examined the effects of diet-induced hyperhomocysteinemia on the development of cognitive impairments and insulin-resistance, as well as on the insulin signaling cascade, in a diet-induced obese rat model of …


Characterization Of Rna Aptamers To Drosophila Splicing Protein B52”, Benjamin Stern May 2011

Characterization Of Rna Aptamers To Drosophila Splicing Protein B52”, Benjamin Stern

Biological Sciences

The protein B52 is an essential component of the spliceosome in Drosophila M. and is responsible for processing precursor-mRNA. B52 belongs to a family of proteins named SR proteins which are critical in initiation and commitment of RNA splicing. Analogous to human SRp55, B52 has been shown to be responsible for alternative and constitutive splicing during a multitude of cellular and developmental events. RNA aptamers selected during an in vitro selection and amplification process (SELEX) for B52 were found to have a co-variation in the stem of these aptamers. Using biochemical and structural techniques, I will explore the RNA-protein interaction …


The Role Of Rac1 Signaling In Tissue Polarity And Branching Morphogenesis During Salivary Gland Development, Janice Jin May 2011

The Role Of Rac1 Signaling In Tissue Polarity And Branching Morphogenesis During Salivary Gland Development, Janice Jin

Biological Sciences

Salivary gland development in embryonic mouse occurs through the process of branching morphogenesis and differentiation to ultimately give rise to a fully functional, saliva-secreting adult gland. During branching morphogenesis, epithelial cells establish an apical and basal pole which determines the ultimate direction in which salivary fluid and proteins are secreted. Exactly how salivary tissue polarity is determined on a cellular and glandular level is not fully understood. Rac1, a member of the Rho GTPase family, is an intracellular signal transducer that has been shown in other cell types to regulate cell polarization. Rac1 is also important for the organization of …


Distinct Microbiome In Pouchitis Compared To Healthy Pouches In Ulcerative Colitis And Familial Adenomatous Polyposis, Garrett C. Zella, Elizabeth J. Hait, Tiffany Glavan, Dirk Gevers, Doyle V. Ward, Christopher L. Kitts, Joshua R. Korzenik May 2011

Distinct Microbiome In Pouchitis Compared To Healthy Pouches In Ulcerative Colitis And Familial Adenomatous Polyposis, Garrett C. Zella, Elizabeth J. Hait, Tiffany Glavan, Dirk Gevers, Doyle V. Ward, Christopher L. Kitts, Joshua R. Korzenik

Biological Sciences

Background: Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).

Methods: Nineteen patients were enrolled in thi s cross-sectional study (nine UCP, tl1ree HUC, seven FAP). Patie nts with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal …


Using Portfolio Theory To Assess Tradeoffs Between Return From Natural Capital And Social Equity Across Space, Benjamin S. Halpern, Crow White, Sarah E. Lester, Christopher Costello, Steven D. Gaines May 2011

Using Portfolio Theory To Assess Tradeoffs Between Return From Natural Capital And Social Equity Across Space, Benjamin S. Halpern, Crow White, Sarah E. Lester, Christopher Costello, Steven D. Gaines

Biological Sciences

Spatial variance in returns from natural resources, driven by resource dynamics and regulations, can have strong consequences for equitable delivery of value to individuals and communities. Yet resource management models implicitly weight returns equally across space, even when space is explicitly included in model dynamics and policy. Here we translate financial portfolio theory from the temporal to spatial realm and use it to quantify the inherent tradeoff between resource returns and social equity, defined as a more uniform distribution of resource value across space. We illustrate this approach with a marine case study of the Channel Islands, California, USA. Depending …


The Truth About Models: How Well Do Mechanical Models Mimic The Observed Gender Distributions In Two-Child Families?, William D. Stansfield, Matthew A. Carlton Apr 2011

The Truth About Models: How Well Do Mechanical Models Mimic The Observed Gender Distributions In Two-Child Families?, William D. Stansfield, Matthew A. Carlton

Biological Sciences

We question the use of mechanical models, such as coin flipping, to represent the probabilities of gender distributions in sibship families consisting of two children. Both the assumptions of the models and the reliability of the data should be evaluated. Using models without these critical evaluations may tend to perpetuate myths rather than elucidate biological realities.


Regional Scale Monitoring Of Methane Production By Dairy Farm Ungulates; A Proposal To The National Science Foundation (Nsf) And The National Ecological Observatory Network (Neon, Inc.), Lindsey Anne Peterson Mar 2011

Regional Scale Monitoring Of Methane Production By Dairy Farm Ungulates; A Proposal To The National Science Foundation (Nsf) And The National Ecological Observatory Network (Neon, Inc.), Lindsey Anne Peterson

Biological Sciences

No abstract provided.


The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach Mar 2011

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997). As far as we know, no previous data have been compiled regarding hormones and condition index of guppies. In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River. Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator. The condition …


Exposure To Ultraviolet Radiation Causes Proteomic Changes In Embryos Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Joseph P. Campanale, Lars Tomanek, Nikki L. Adams Feb 2011

Exposure To Ultraviolet Radiation Causes Proteomic Changes In Embryos Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Joseph P. Campanale, Lars Tomanek, Nikki L. Adams

Biological Sciences

We performed experiments to determine how environmentally relevant ultraviolet radiation (UVR) affects protein expression during early development in the sea urchin, Strongylocentrotus purpuratus. To model the protein-mediated cell cycle response to UV-irradiation, six batches of embryos were exposed to UVR, monitored for both delays in the first mitotic division and changes in the proteome at two specific developmental time points. Embryos were exposed to or protected from artificial UVR (11.5 W/m2) for 25 or 60 min. These levels of UVR are within the range we have measured in coastal waters between 0.5 and 2 m. Embryos treated with …


Acquired Traits Revisited, William D. Stansfield Feb 2011

Acquired Traits Revisited, William D. Stansfield

Biological Sciences

Most biology texts villify Lamarck's concept of “inheritance of acquired characters” and leave the impression that all acquired characters are never transmitted to offspring. However, recent research indicates that this is not true! Some “acquired” traits are inherited. I profile some of these striking cases and their importance for evolution and for understanding a broader epigenetic context for heredity and ontogeny (the emerging field of “evo-devo”). Further, I discuss how such cases, even considered as exceptions, contribute to understanding the nature of science, both the role of general rules in biology and the occurrence of conceptual change, or paradigm shifts.


Observed And Modeled Bio-Optical, Bioluminescent, And Physical Properties During A Coastal Upwelling Event In Monterey Bay, California, Igor Shulman, Mark A. Moline, Bradley Penta, Stephanie Anderson, Matthew Oliver, Steven H.D. Haddock Jan 2011

Observed And Modeled Bio-Optical, Bioluminescent, And Physical Properties During A Coastal Upwelling Event In Monterey Bay, California, Igor Shulman, Mark A. Moline, Bradley Penta, Stephanie Anderson, Matthew Oliver, Steven H.D. Haddock

Biological Sciences

During spring and summer time, coastal upwelling influences circulation and ecosystem dynamics of the Monterey Bay, California, which is recognized as a National Marine Sanctuary. Observations of physical, bio‐optical properties (including bioluminescence) together with results from dynamical biochemical and bioluminescence models are used to interpret the development of the upwelling event during August 2003 in Monterey Bay, California. Observations and the biochemical model show the development of a phytoplankton bloom in the southern portion of Monterey Bay. Model results show an increase of nutrients in the southern portion of the bay, where nutrient‐rich water masses are brought in by the …


The Control Of Marine Biofouling On Xerogel Surfaces With Nanometer-Scale Topography, Nikhil Gunari, Lenora H. Brewer, Stephanie M. Bennett, Anastasiya Sokolova, Nadine D. Kraut, John A. Finlay, Anne E. Meyer, Gilbert C. Walker, Dean E. Wendt, Maureen E. Callow, James A. Callow, Frank V. Bright, Michael R. Detty Jan 2011

The Control Of Marine Biofouling On Xerogel Surfaces With Nanometer-Scale Topography, Nikhil Gunari, Lenora H. Brewer, Stephanie M. Bennett, Anastasiya Sokolova, Nadine D. Kraut, John A. Finlay, Anne E. Meyer, Gilbert C. Walker, Dean E. Wendt, Maureen E. Callow, James A. Callow, Frank V. Bright, Michael R. Detty

Biological Sciences

Mixtures of n-octadecyltrimethoxysilane (C18, 1-5 mole-%), n-octyltriethoxysilane (C8) and tetraethoxysilane (TEOS) gave xerogel surfaces of varying topography. The 1:49:50 C18/C8/TEOS xerogel formed 100-400-nm-wide, 2-7-nm deep pores by AFM while coatings with ≥3% C18 were free of such features. Segregation of the coating into alkane-rich and alkane-deficient regions in the 1:49:50 C18/C8/TEOS xerogel was observed by IR microscopy. Immersion in ASW for 48 h gave no statistical difference in surface energy for the 1:49:50 C18/C8/TEOS xerogel and a significant increase for the 50:50 C8/TEOS xerogel. Settlement of barnacle cyprids and removal of juvenile barnacles, settlement of zoospores of the …


Environmental Proteomics: Changes In The Proteome Of Marine Organisms In Response To Environmental Stress, Pollutants, Infection, Symbiosis, And Development, Lars Tomanek Jan 2011

Environmental Proteomics: Changes In The Proteome Of Marine Organisms In Response To Environmental Stress, Pollutants, Infection, Symbiosis, And Development, Lars Tomanek

Biological Sciences

Environmental proteomics, the study of changes in the abundance of proteins and their post-translational modifications, has become a powerful tool for generating hypotheses regarding how the environment affects the biology of marine organisms. Proteomics discovers hitherto unknown cellulareffects of environmental stressors such as changes in thermal, osmotic, and anaerobic conditions. Proteomic analyses have advanced the characterization of the biological effects of pollutants and identified comprehensive and pollutant-specific sets of biomarkers, especially those highlighting post-translational modifications. Proteomic analyses of infected organisms have highlighted the broader changes occurring during immune responses and how the same pathways are attenuated during the maintenance of …


Physical Habitat And Social Conditions Across A Coral Reef Shape Spatial Patterns Of Intraspecific Behavioral Variation In A Demersal Fish, Meagan N. Schrandt, Kristin M. Hardy, Kaitlin M. Johnson, Sean C. Lema Jan 2011

Physical Habitat And Social Conditions Across A Coral Reef Shape Spatial Patterns Of Intraspecific Behavioral Variation In A Demersal Fish, Meagan N. Schrandt, Kristin M. Hardy, Kaitlin M. Johnson, Sean C. Lema

Biological Sciences

As coral reef ecosystems decline in health worldwide, reef-associated fishes are being impacted by changes to their coral reef habitats. While previous studies have shown coral reef structure to affect the demography of reef fishes, changes in reef conditions may also impact the behavior of reef fishes as they cope with altered habitats. In this study, we examined spatial patterns of intraspecific behavioral variation in the bicolor damselfish (Stegastes partitus) across the fringing reefs of Curaçao (Caribbean Sea), and explored how this behavioral variation associated with physical and social conditions on the reef. Principal components analysis (PCA) condensed …


The Deadly Effects Of ‘‘Nonlethal’’ Predators, Shannon J. Mccauley, Locke Rowe, Marie-Josee Fortin Jan 2011

The Deadly Effects Of ‘‘Nonlethal’’ Predators, Shannon J. Mccauley, Locke Rowe, Marie-Josee Fortin

Biological Sciences

Nonconsumptive predator effects are widespread and include plasticity as well as general stress responses. Caged predators are often used to estimate nonconsumptive effects, and numerous studies have focused on the larval stages of animals with complex life cycles. However, few of these studies test whether nonconsumptive predator effects, including stress responses, are exclusively sublethal. Nor have they assessed whether these effects extend beyond the larval stage, affecting success during stressful life-history transitions such as metamorphosis. We conducted experiments with larvae of a dragonfly (Leucorrhinia intacta) that exhibits predator-induced plasticity to assess whether the mere presence of predators affects …


Snp-Based Mapping Of Crossover Recombination In Caenorhabditis Elegans, Grace C. Bazan, Kenneth J. Hillers Jan 2011

Snp-Based Mapping Of Crossover Recombination In Caenorhabditis Elegans, Grace C. Bazan, Kenneth J. Hillers

Biological Sciences

Caenorhabditis elegans is an important experimental organism for the study of recombination during meiosis. Here, we provide methods for the use of single-nucleotide polymorph isms (SNPs) for the study of crossing over in C. elegans.


Ecological Strategies In California Chaparral: Interacting Effects Of Soils, Climate, And Fire On Specific Leaf Area, Brian Anacker, Nishanta Rajakaruna, David D. Ackerly, Susan Harrison, Jon Keeley, Michael Vasey Jan 2011

Ecological Strategies In California Chaparral: Interacting Effects Of Soils, Climate, And Fire On Specific Leaf Area, Brian Anacker, Nishanta Rajakaruna, David D. Ackerly, Susan Harrison, Jon Keeley, Michael Vasey

Biological Sciences

Background: High values of specific leaf area (SLA) are generally associated with high maximal growth rates in resource-rich conditions, such as mesic climates and fertile soils. However, fire may complicate this relationship since its frequency varies with both climate and soil fertility, and fire frequency selects for regeneration strategies (resprouting versus seeding) that are not independent of resource-acquisition strategies. Shared ancestry is also expected to affect the distribution of resource-use and regeneration traits.

Aims: We examined climate, soil, and fire as drivers of community-level variation in a key functional trait, SLA, in chaparral in California.

Methods: We quantified the phylogenetic, …


Lichens Of The Callahan Mine, A Copper- And Zinc-Enriched Superfund Site In Brooksville, Maine, U.S.A., Nishanta Rajakaruna, Tanner B. Harris, Stephen R. Clayden, Alison C. Dibble, Fred C. Olday Jan 2011

Lichens Of The Callahan Mine, A Copper- And Zinc-Enriched Superfund Site In Brooksville, Maine, U.S.A., Nishanta Rajakaruna, Tanner B. Harris, Stephen R. Clayden, Alison C. Dibble, Fred C. Olday

Biological Sciences

Metal-enriched habitats often harbor physiologically distinct biotas able to tolerate and accumulate toxic metals. Plants and lichens that accumulate metals have served as effective indicators of ecosystem pollution. Whereas the diversity of metal-tolerant lichens has been well documented globally, the literature of metal-tolerant lichen communities for eastern North America is limited. We examined the lichen flora of the Callahan Mine, a Cu-, Pb-, and Zn-enriched superfund site in Brooksville, Hancock County, Maine, U.S.A. Through collections along transects across metal-contaminated areas of the mine, we documented 76 species of lichens and related fungi. Fifty species were saxicolous, 26 were terricolous. Forty-three …


Escape From Competition: Neighbors Reduce Centaurea Stoebe Performance At Home But Not Away, Ragan Callaway, Lauren Waller, Alecu Diaconu, Robert Pal, Alexandra Collins, Heinz Mueller-Schaerer, John Maron Jan 2011

Escape From Competition: Neighbors Reduce Centaurea Stoebe Performance At Home But Not Away, Ragan Callaway, Lauren Waller, Alecu Diaconu, Robert Pal, Alexandra Collins, Heinz Mueller-Schaerer, John Maron

Biological Sciences

The greater abundance of some exotic plants in their nonnative ranges might be explained in part by biogeographic differences in the strength of competition, but these competitive effects have not been experimentally examined in the field. We compared the effects of neighbors on the growth and reproduction of spotted knapweed (Centaurea stoebe) in Europe, where it is native, and in Montana, where it is invasive. There were strong negative competitive effects of neighboring vegetation on C. stoebe growth and reproduction in Europe. In contrast, identical experiments in Montana resulted in insignificant impacts on C. stoebe. Although the mechanisms that produce …