Life Sciences Commons^™

Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel

Ted K. Raab

Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other potential electron acceptors, described the microbial community, and performed experiments in the laboratory and field to measure net rates of Fe(III) reduction and the relationship of this process to C cycling. In most areas within the basin, aerobic conditions existed …

Evaluation Of Harassment Of Migrating Double-Crested Cormorants To Limit Depredation On Selected Sport Fisheries In Michigan, Brian S. Dorr, Ashley Moerke, Michael Bur, Chuck Bassett, Tony Aderman, Dan Traynor, Russell D. Singleton, Peter H. Butchko, Jimmy D. Taylor

Brian S Dorr

No abstract provided.

Strong Feeding Preference Of An Exotic Generalist Herbivore For An Exotic Forb: A Case Of Invasional Antagonism, Kimberly J. La Pierre, W. Stanley Harpole, Katharine N. Suding

W. Stanley Harpole

Many hypotheses dealing with the success of invasive plant species concern plant–herbivore interactions. The invasional meltdown and enemy inversion hypotheses suggest that non-native herbivores may indirectly facilitate the invasion of a non-native plant species by either favorably changing environmental conditions or reducing competition from native plant species. Our objective was to determine the role of herbivory by the non-native snail Otala lactea in structuring California grassland communities. We conducted two experiments to examine the feeding preferences of O. lactea for eight representative grassland species. Overall, O. lactea preferred Brassica nigra, a non-native forb, over all other species tested. Field monocultures …

Background Fluorescence In Groundwater From A Tropical Karst Island Aquifer, Michelle Hoffman

Michelle Hoffman

Background levels of four fluorescent compounds were monitored biweekly at thirteen sampling sites on Guam, consisting of subtidal and intertidal springs, dissolution fractures, and internal upland contact spring discharge, over a 13-month period from 2006 to 2007. Samples were compared to local precipitation and to seawater samples from four nearby reef flats. The data revealed that the concentrations of optical brighteners were consistently two orders of magnitude greater than either sodium fluorescein or rhodamine WT, while Eosine Y was rarely detected. Background levels in seawater, by comparison, accounted for 25% or more of the fluorescent compounds detected at the thirteen …

Non-Senescence In Neoclassical Growth Theory, Harry D. Saunders

Harry D. Saunders

This presentation describes research showing that non-senescent genotypes can dominate senescent ones under certain evolutionary conditions.

Management Effects On Breeding And Foraging Numbers And Movements Of Double-Crested Cormorants In The Les Cheneaux Islands, Lake Huron, Michigan, Brian S. Dorr, Tony Aderman, Peter H. Butchko

Brian S Dorr

No abstract provided.

What Are Social Insects Telling Us About Aging?, Joel D. Parker

Joel D Parker

Abstract: Research on aging in social insects has progressed much more than has been generally acknowledged. Here I review what I think are the four greatest contributions of social insect work to the field of aging research with the hope of highlighting the truly exciting discoveries being made. These include the reversal of the fecundity / lifespan and size / lifespan trade-offs due to the evolution of sociality, that social environment can reverse the effects of aging, the contribution of social insect work to the overturning of the free radical theory of aging, and the discovery of vitellogenin as an …

Landowner Attitudes Toward Elk Management In The Pine Ridge Region Of North-Western Nebraska, R. Daniel Crank, Scott E. Hygnstrom, Scott R. Groepper Mr., Kit M. Hams

Scott R Groepper

Abstract: Little is known about attitudes of landowners toward elk (Cervus elaphus) on privately-owned land. We mailed questionnaires to agricultural landowners in the Pine Ridge region of northwestern Nebraska in both 1995 and 1997 to determine attitudes toward elk populations and management of elk. Fifty-six percent (n = 214) of respondents in 1995 and 57% (n = 461) in 1997 were in favor of free-ranging elk. Motivation for those in favor of elk was utilitarian (opportunity to view and hunt elk), ecological (return of a native species), and economic (benefi ts from increased tourism and leased land for elk hunting). …

Euthanasia Methods In Field Settings For Wildlife Damage Management, Timothy J. Julien, Stephen M. Vantassel, Scott R. Groepper Mr., Scott E. Hygnstrom

Scott R Groepper

No abstract provided.

Alternative "More Efficient" Irrigation Systems, David A. Bainbridge

David A Bainbridge

Many traditional irrigation systems work well for ecological restoration projects. These demand responsive systems are very water efficient and robust and have proved themselves in the most extreme desert conditions.

Energy Abundance, Trade And Industry Location, Nicole Andréa Mathys, Reyer Gerlagh

Nicole Andréa Mathys

We study the effect of countries’ energy abundance on trade and sector activity, conditional on sector’s energy intensity, using an unbalanced panel with 14 high-income countries from Europe, America and Asia, 10 broad sectors, and years 1970-1997. We find that (i) countries with large energy endowments have low energy prices, and are thus energy abundant both on micro and macro level. (ii) Energy abundant countries have a high level of energy embodied in exports relative to imports. (iii) Energy intensive sectors export from and (iv) have higher economic activity in energy abundant countries. (v) The trade and location effects increase …

Games Played By Predators And Prey, Amos Bouskila

Amos Bouskila

No abstract provided.

International Law, State Sovereignty And Transboundary Waters, Aguinaldo Alemar

Aguinaldo Alemar

The current status of transboundary water resources is to claim a more proactive posture by the sovereign states, mainly those having large reserves of fresh water shared. This new posture involves actions between the states as a key condition to the success of any enterprise that aims to protect the environment. It intends to prove that other actors - national and international - are already mobilizing themselves to consider water as a "common heritage of mankind" and, as such, water must be considered above the classical concepts of sovereignty and territory, excelling by the humanitarian interest that it arouses. At …

Cliff Swallows, Swallow Bugs, And West Nile Virus:, Larry Clark

Larry Clark

The cliff swallow (Petrochelidon pyrrhonota) could play an important role in the transmission of West Nile virus (WNV) because of its breeding ecology, reservoir competence status, and potentially high natural exposure rates. Cliff swallows nest within colonies and their nests are occupied year-round by swallow bugs (Oeciacus vicarius), hematophagus ectoparasites that feed primarily on cliff swallows. These parasites are likely exposed to WNV while feeding on infectious blood of nesting cliff swallow adults and nestlings and thus, if competent vectors, could contribute to seasonal elevations in WNV transmission. In addition, swallow bugs remain within nests year-round and therefore could provide …

Effects Of Vermicomposting Duration To Macronutrient Elements And Heavy Metals Concentrations In Vermicompost, Noor Zalina Binti Mahmood

Noor Zalina Binti Mahmood

Vermicomposting using Lumbricus rubellus was conducted in two different durations, 10 and 30 weeks in the same plots. Three different of treatments combination were prepared with eight replicates for each treatment namely cow dung : kitchen waste in 30:70 ratio (T1), cow dung : coffee grounds in 30:70 ratio (T2), and cow dung : kitchen waste : coffee grounds in 30:35:35 ratio (T3). Macronutrients elements in the vermicompost from each treatment were measured in the tenth and thirtieth week. Comparatively longer duration of vermicomposting by using Lumbricus rubellus enhanced the quality of vermicompost by the increase of the macronutrient elements …

The Coconut Palm, Cocos Nucifera, Impacts Forest Composition And Soil Characteristics At Palmyra Atoll, Central Pacific, Hillary S. Young, Ted K. Raab, Douglas J. Mccauley, Amy A. Briggs, Rodolfo Dirzo

Ted K. Raab

Cocos nucifera, the coconut palm, has a pantropical distribution and reaches near monodominance in many atolls, low lying islands and coastal regions. This paper examines the ecological correlation between C. nucifera abundance and changes in forest structure, floristic diversity and forest soil characteristics. Cumulatively, these data show that C. nucifera has important impacts on floristic, structural and soil characteristics of forests where it becomes dominant. Given the high proportion of tropical coastal areas in which C. nucifera is now naturalized and abundant, this likely has important implications for coastal forest diversity and structure.

Meta-Analysis Of Fertilization Experiments Indicates Multiple Limiting Nutrients In Northeastern Deciduous Forests, Matthew A. Vadeboncoeur

Matthew A Vadeboncoeur

It is widely accepted that N limits primary production in temperate forests, although colimitation by N and P has also been suggested, and on some soils, Ca and base cations are in short supply. I conducted a meta-analysis to assess the strength of existing experimental evidence for limitation of primary production by N, P, and Ca in hardwood forests of the northeastern United States and southeastern Canada using data from 35 fertilization experiments in deciduous forests on glaciated soils across the region.

There is strong evidence for N limitation (formal meta-analysis weighted mean response ratio = 1.51, p < 0.01; simple mean = 1.42, p < 0.001). Forest productivity also tended to increase with additions of P (simple mean = 1.15, p = 0.05) and Ca (simple mean = 1.36, p < 0.001). Across all treatments, 85% of response ratios were positive. Multiple-element additions had larger effects than single elements, but factorial experiments showed little evidence of synergistic effects between nutrient additions. Production responses correlated positively with the rate of N fertilization, but this effect was reduced at high rates of ambient N deposition.

Dispersal Of Stable Flies (Diptera: Muscidae) From Larval Developmental Sites., David B. Taylor, Roger D. Moon, Jack B. Campbell, Dennis R. Berkebile, Philip J. Scholl, Alberto B. Broce, Jerome A. Hogsette

David B Taylor

Seven mark-recapture studies were conducted over 3 yr to assess dispersal of newly emerging adult stable flies, Stomoxys calcitrans L., from larval development sites in a mixed agricultural environment in northeastern Nebraska. Infested hay debris piles were marked by dusting their surfaces with fluorescent pigments, adults were captured with surrounding grids of Alsynite sticky traps, and specimens were dissected to determine feeding histories and reproductive age. Distances and directions of 3,889 marked specimens indicated males and females dispersed equally and in all directions. Midguts of males and females were equally likely to contain blood-meal remnants. Percentage with blood remnants and …

The Delimitation Of Flammulina Fennae, Soňa Ripková, Karen Hughes, Slavomír Adamčík, Viktor Kučera, Katarína Adamčíková

Karen Hughes

Multivariate morphometric analyses of micromorphological characters measured on 35 specimens of Flammulina fennae and related species show that only a combination of spore dimensions and ixohyphidia characters are suitable for delimitation of this species. In order to confirm species identifications based on micromorphology, ribosomal ITS DNA sequences were obtained and compared with those previously deposited in GenBank, and phylogenetic analyses were performed using an ITS dataset of all known Flammulina species. All six specimens morphologically determined as F. fennae were identified by molecular data. Two of twelve specimens morphologically assigned to F. velutipes had F. elastica sequences. One ITS sequence …

A New Genus To Accommodate Gymnopus Acervatus (Agaricales), Karen Hughes, David A. Mather, Ronald H. Peterson

Karen Hughes

Phylogenies based on ITS and LSU nrDNA sequences show Agaricus (Gymnopus) acervatus as unique within the Gymnopus/Rhodocollybia complex. These phylogenies imply that a separate genus is necessary, and Connopus is proposed. Infraspecific morphological and DNA-based variation within C. acervatus suggests that a western North American clade might be reproductively isolated from the eastern North American/Scandinavian clade and that in this species complex the European and eastern North American clade might be conspecific. A Scandinavian exemplar is selected for bar-coding. Two GenBank sequences with name-phylogenetic placement inconsistencies are identified.