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You searched for +publisher:"The Ohio State University" +contributor:("Herms, Daniel A."). Showing records 1 – 2 of 2 total matches.

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The Ohio State University

1. Chorbadjian, Rodrigo A. Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer).

Degree: PhD, Entomology, 2008, The Ohio State University

Phenotypic variation in host quality can affect ecological and evolutionary interactions between plants and herbivores. Effects of phenotypic variation in host quality of woody-plants on performance of leaf feeding insects were investigated in three studies: (1) phenological variation of Scots pine (Pinus sylvestris) needle quality for the European pine sawfly (Neodiprion sertifer) as a test of the "phenological window of host susceptibility hypothesis", (2) effects of fertilization on the expression of defoliation-induced resistance of Austrian pine (P. nigra) to European pine sawfly, and (3) manipulation of growth/defense trade-offs in paper birch (Betula papyrifera) and Austrian pine through application of the plant growth regulator paclobutrazol. Consistent with the predictions of the phenological window hypothesis, larval growth and survival decreased as host-insect synchronicity was modified. Foliar quality declined as current-year shoots and needles elongated, which suggests that larvae tolerate plant defenses only if nutrient concentrations are high relative to chemical defenses. A slow increase in host quality occurred late in the growing season as mature foliage once again became suitable. The survival of an experimentally-generated second generation of larvae manipulated to emerge in September was only 20% on current- or previous-year foliage; however survival was 80% the following spring. This phenological window of host susceptibility appears to constrain the evolution of a second generation. The expression of defoliation-induced responses of Austrian pine to European pine sawfly larvae varied with level of fertilization. In the nutrient-rich environment, previous defoliation improved host quality for European pine sawfly larvae, which may promote insect outbreaks through positive density dependent (Allee) effects on population growth. However in the low nutrient treatment, host quality rapidly decreased following defoliation, which is thought to generate negative density dependent effects on population growth, thus stabilizing population density. Austrian pines tolerated defoliation through compensatory growth responses, an effect that was independent of the fertilization level and that was evident two growing seasons after the defoliation event. Concentration of foliar monoterpenes strongly increased one year after the defoliation treatment across all fertility levels. These results are inconsistent with predictions of the carbon nutrient balance hypothesis, which proposes that physiological constraints prevent defoliation-induced accumulation of carbon-based secondary metabolites in evergreens. These results suggest that in nutrient-poor soils Austrian pines would express rapid induced resistance that would help limit outbreaks and thus defoliation, while compensatory growth responses would enhance competitive ability. Application of the plant growth regulator paclobutrazol slowed the growth of paper birch and Austrian pine with no effect on photosynthesis. Consistent with the predictions of the… Advisors/Committee Members: Herms, Daniel A. (Advisor).

Subjects/Keywords: Entomology; Insect-plant interactions host quality secondary metabolites defense nutrients growth-defense trade-offs induced resistance susceptibility European pine sawfly soil fertility paclobutrazol

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chorbadjian, R. A. (2008). Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer). (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1230736665

Chicago Manual of Style (16th Edition):

Chorbadjian, Rodrigo A. “Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer).” 2008. Doctoral Dissertation, The Ohio State University. Accessed January 21, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1230736665.

MLA Handbook (7th Edition):

Chorbadjian, Rodrigo A. “Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer).” 2008. Web. 21 Jan 2020.

Vancouver:

Chorbadjian RA. Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer). [Internet] [Doctoral dissertation]. The Ohio State University; 2008. [cited 2020 Jan 21]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1230736665.

Council of Science Editors:

Chorbadjian RA. Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer). [Doctoral Dissertation]. The Ohio State University; 2008. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1230736665


The Ohio State University

2. Smith, Annemarie. Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan.

Degree: MS, Environmental Science, 2006, The Ohio State University

Emerald ash borer (EAB) (Agrilus planipennis Fairmare) is an exotic, wood- boring beetle that has killed millions of ash trees (Fraxinus species) in southeastern Michigan. If not contained and eradicated this invasive insect has the potential to devastate ash throughout North America causing substantial economic and ecological consequences. The objectives of this research were to (1) determine if community composition, diversity, and stand structure influence susceptibility of forests to EAB invasion, and (2) determine how EAB-induced ash mortality may influence forest community composition.Plots were established during the summers of 2004 and 2005 in 31 forest stands within the Huron River watershed in southeast Michigan that were categorized as xeric (N = 11), mesic (N = 11) or hydric (N = 9). Overstory, understory and seedling tree species composition were quantified in three replicated plots along a transect within each stand. Each ash tree was closely inspected for signs of EAB colonization and degree of dieback. Stem density, basal area, Shannon diversity (H’), relative dominance of ash, relative density of ash, ash importance value, and percent canopy cover were quantified for each stand.EAB has caused significant mortality in all stands across the study area. Dieback of black ash (F. nigra) was more advanced than that of white (F. americana) and green ash (F. pennsylvanica). Percent mortality, percentage of infested stems, and EAB attack frequency were also higher in black ash than the other two species. This difference could be the result of the insect’s preference, differences in the physiology of phloem tissue, or an edge effect inherent in riparian and marshy sites to which black ash is adapted. There were no relationships between EAB-induced dieback or mortality and species diversity, stand density, stand basal area, ash basal area, ash density, relative dominance of ash or relative density of ash. Distance from the putative epicenter of the invasion was the only variable that was negatively correlated with all measures of EAB impact. This suggests that it is only a matter of time until all stands suffer complete mortality of Fraxinus species.Widespread loss of ash due to the EAB invasion will initiate changes in community composition and structure in all three forest types. Maple (Acer spp.) and elm (Ulmus spp.) were common on xeric and mesic stands and will likely experience an increase in importance as numerous saplings fill canopy gaps. However, as elms saplings grow they will become susceptible to Dutch elm disease (Chryphonectria parasitica), which is common in the study area. Maple and cherry were over represented in the understory of hydric stands where they should increase in importance. Oaks were poorly represented in the understory layers of all stands and will likely decrease in dominance over the long term. Ash species were common in the sapling layer and were the most abundant species in the seedling layer in all stand types. The high density of juvenile ash may prolong the EAB invasion by… Advisors/Committee Members: Herms, Daniel A. (Advisor).

Subjects/Keywords: Environmental Science

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Smith, A. (2006). Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan. (Masters Thesis). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1394801603

Chicago Manual of Style (16th Edition):

Smith, Annemarie. “Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan.” 2006. Masters Thesis, The Ohio State University. Accessed January 21, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1394801603.

MLA Handbook (7th Edition):

Smith, Annemarie. “Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan.” 2006. Web. 21 Jan 2020.

Vancouver:

Smith A. Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan. [Internet] [Masters thesis]. The Ohio State University; 2006. [cited 2020 Jan 21]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1394801603.

Council of Science Editors:

Smith A. Effects of Community Structure on Forest susceptibility and Response to the Emerald Ash Borer Invasion of the Huron River Watershed in Southeast Michigan. [Masters Thesis]. The Ohio State University; 2006. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1394801603

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