Canopy Gap Characteristics of an Oak-Beech-Maple Old-Growth Forest in Northeastern Ohio

Author Institution: School of Natural Resources, The Ohio State UniversityForests are gap-driven systems as openings within the tree canopy directly influence species composition, structure, and regeneration. Most gap studies have occurred in small, mesic, old-growth remnants. This study sought to further the understanding of gap characteristics by examining gaps in one of Ohio's largest old-growth forests, which has wet-mesic site conditions and high species diversity. A modification of the methodology recommended by Runkle (1992) was used to obtain data on gap characteristics. An important portion (17.7%) of this old-growth forest was in gaps. Most of the gaps sampled were large (100-400 m2), and multiple-tree gaps were significantly larger than single-tree gaps. Tip-up and basal shear of a canopy tree were the primary means by which a gap was created (origin type). These findings differ from some other similar gap studies, and the contrasts may be due to the advanced age and particular species composition of this forest, the poor soil drainage conditions, and the large size and stressed condition of the overstory trees

Composition and Structure of Two Old-growth Forest Ecosystem Types of Southeastern Ohio

Author Institution: School of Natural Resources, Ohio Agricultural Research and Development Center, The Ohio State UniversityLess than 1% of the pre-European settlement forest in Ohio currently remains, mostly as small and scattered woodlots. Consequently, few studies have been undertaken to quantify the composition and structure of Ohio’s old-growth forests using a landscape ecosystem perspective. We used an existing multifactor ecosystem classification system developed for the Wayne National Forest in southeastern Ohio to compare the composition and structure of two old-growth forest ecosystem types, located on contrasting north-facing and south-facing middle slopes. No differences in physiography were observed among the stands other than aspect; however, the north-facing old-growth ecosystem type had a greater A horizon thickness and a higher pH than the south-facing old-growth ecosystem type. Mixed-oaks dominate the south-facing ecosystem type, while sugar maple, American beech and northern red oak dominate the north-facing ecosystem type. No differences were detected in stand structural components. Similar trends were observed for the ground-flora layer; specifically, we observed differences in groundflora composition between the two ecosystem types but no differences in total percent cover or species richness. Finally, the composition and structure of coarse woody debris differed between the contrasting ecosystem types. Maple and oak snags and fallen logs dominate the north-facing ecosystem while oak standing snags and fallen stems are typically observed in the south-facing ecosystem. Few differences between the two ecosystem types were detected in coarse woody debris structure, except that snag density tends to be higher in the south-facing old-growth ecosystem and log density and volume tends to be higher in the north-facing ecosystem (P <0.10). Through the use of this ecosystem approach, we can begin to quantify the ecological factors regulating the composition and structure of old-growth communities, improving our ability to effectively manage and restore these rare ecosystems

Relationships between spruce budworm damage and site factors in spruce-fir-dominated ecosystems of Western Upper Michigan

Damage by the spruce budworm, Choristoneura fumiferana (Clemens), on balsam fir, Abies balsamea (L.) Mill., in local ecosystems (site units) of the Ottawa National Forest (western Upper Peninsula of Michigan, U.S.A.) was studied in relation to site factors. A multi-factor ecological approach was used to distinguish 25 spruce-fir-dominated ecosystems on a variety of different sites, ranging from dry-mesic outwash plains to river floodplains and swamps. Spruce budworm damage on balsam fir appears to be more directly related to site factors (specifically soil type and drainage class) than to stand parameters such as relative dominance or living-plus-dead basal area. Damage on balsam fir was greatest on wetland ecosystems with organic soils and on dryland ecosystems with impeded drainage. The heavy damage on these soils is probably a consequence of shallow rooting habit which predisposes the physiologically mature balsam fir to drought injury, lessened vigor, and a lessened ability to withstand defoliation. Black spruce, Picea mariana (Mill.) B.S.P., also exhibited heavy damage on sites where it is not well adapted, i.e. somewhat excessively drained dryland ecosystems. An understanding of the site factors and the ecosystem classification provide the basis for predicting where the greatest damage can be expected.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26584/1/0000125.pd

The Role of Electron Captures in Chandrasekhar Mass Models for Type Ia Supernovae

The Chandrasekhar mass model for Type Ia Supernovae (SNe Ia) has received increasing support from recent comparisons of observations with light curve predictions and modeling of synthetic spectra. It explains SN Ia events via thermonuclear explosions of accreting white dwarfs in binary stellar systems, being caused by central carbon ignition when the white dwarf approaches the Chandrasekhar mass. As the electron gas in white dwarfs is degenerate, characterized by high Fermi energies for the high density regions in the center, electron capture on intermediate mass and Fe-group nuclei plays an important role in explosive burning. Electron capture affects the central electron fraction Y_e, which determines the composition of the ejecta from such explosions. Up to the present, astrophysical tabulations based on shell model matrix elements were only available for light nuclei in the sd-shell. Recently new Shell Model Monte Carlo (SMMC) and large-scale shell model diagonalization calculations have also been performed for pf-shell nuclei. These lead in general to a reduction of electron capture rates in comparison with previous, more phenomenological, approaches. Making use of these new shell model based rates, we present the first results for the composition of Fe-group nuclei produced in the central regions of SNe Ia and possible changes in the constraints on model parameters like ignition densities and burning front speeds.Comment: 26 pages, 8 figures, submitted to Ap

Ecological forestry at National Wildlife Refuges: experiences from

ABSTRACT Although land management over much of the history of the U.S. Fish and Wildlife Service&apos;s National Wildlife Refuge System (NWRS) has emphasized single-species management, recent policy has encouraged land managers to focus on broader ecosystem restoration goals. One framework for forest ecosystem management that is becoming more popular in the NWRS and other federal and state resource agencies has been termed &quot;ecological forestry&quot;-an approach to forest ecosystem management where the focus is on incorporating an understanding of the outcomes of natural disturbances and stand development processes into designing silvicultural practices. This approach stresses understanding the effects of natural disturbances on biological legacies, structural and compositional heterogeneity, and the recovery periods between disturbance events (including how this recovery period influences stand complexity). Recently, resource managers and ecologists from Seney National Wildlife Refuge, The Ohio State University, and Central Michigan University have partnered to examine how these guiding principles can be integrated into NWRS forest ecosystem management. Specifically, we are partnering to develop management strategies to help: 1) restore the once extensive mixed-pine forest ecosystems of eastern Upper Michigan; 2) mitigate the effects of the beech-bark disease complex on American beech (Fagus grandifolia Ehrh.), a foundation species in northern hardwood forests of eastern North America; and 3) promote more natural forest patterns for wildlife species of young jack pine (Pinus banksiana Lamb.) forest ecosystems, including the federally endangered Kirtland&apos;s warbler (Dendroica kirtlandii). These efforts are ongoing and will continue to be monitored over time. However, initial collaborations suggest that the NWRS provides an excellent crucible to study the application of ecological forestry principles and develop novel ways to manage forest ecosystems

The behaviour of political parties and MPs in the parliaments of the Weimar Republic

Copyright @ 2012 The Authors. This is the author's accepted manuscript. The final published article is available from the link below.Analysing the roll-call votes of the MPs of the Weimar Republic we find: (1) that party competition in the Weimar parliaments can be structured along two dimensions: an economic left–right and a pro-/anti-democratic. Remarkably, this is stable throughout the entire lifespan of the Republic and not just in the later years and despite the varying content of votes across the lifespan of the Republic, and (2) that nearly all parties were troubled by intra-party divisions, though, in particular, the national socialists and communists became homogeneous in the final years of the Republic.Zukunftskolleg, University of Konstan

Aggregation and Representation in the European Parliament Party Groups

While members of the European Parliament are elected in national constituencies, their votes are determined by the aggregation of MEPs in multinational party groups. The uncoordinated aggregation of national party programmes in multinational EP party groups challenges theories of representation based on national parties and parliaments. This article provides a theoretical means of understanding representation by linking the aggregation of dozens of national party programmes in different EP party groups to the aggregation of groups to produce the parliamentary majority needed to enact policies. Drawing on an original data source of national party programmes, the EU Profiler, the article shows that the EP majorities created by aggregating MEP votes in party groups are best explained by cartel theories. These give priority to strengthening the EP’s collective capacity to enact policies rather than voting in accord with the programmes they were nationally elected to represent

Modelling the dynamics of support for a right-wing populist party: the case of UKIP

ABSTRACT: Similar to a number of other right-wing populist parties in Europe, Great Britain's United Kingdom Independence Party (UKIP) has experienced increased public support in recent years. Using aggregate data from monthly national surveys conducted between April 2004 and April 2014, time series analyses demonstrate that the dynamics of UKIP support were influenced by a combination of spatial and valence issues. A spatial issue, Euroscepticism, was fundamental, with UKIP support moving in dynamic equilibrium with changing public attitudes towards EU membership. In addition, widespread anti-immigration sentiment and dissatisfaction with the performance of the Conservative–Liberal Democrat coalition government combined with the “oxygen of publicity” to propel UKIP's surge. The political context after the 2010 general election helped as well by enabling UKIP to benefit from valence considerations. Many voters continued to doubt the competence of the major opposition party, Labour, while the Liberal Democrats were part of the government and, hence, unavailable as a protest vehicle. Since many of the forces driving UKIP support are beyond its control, the party's prospects are highly uncertain

Direct Activation of STING in the Tumor Microenvironment Leads to Potent and Systemic Tumor Regression and Immunity

SummarySpontaneous tumor-initiated T cell priming is dependent on IFN-β production by tumor-resident dendritic cells. On the basis of recent observations indicating that IFN-β expression was dependent upon activation of the host STING pathway, we hypothesized that direct engagement of STING through intratumoral (IT) administration of specific agonists would result in effective anti-tumor therapy. After proof-of-principle studies using the mouse STING agonist DMXAA showed a potent therapeutic effect, we generated synthetic cyclic dinucleotide (CDN) derivatives that activated all human STING alleles as well as murine STING. IT injection of STING agonists induced profound regression of established tumors in mice and generated substantial systemic immune responses capable of rejecting distant metastases and providing long-lived immunologic memory. Synthetic CDNs have high translational potential as a cancer therapeutic