The scale dependency of trait-based tree neighborhood models

Questions: We asked: (a) whether the strength of conspecific and heterospecific neighborhood crowding effects on focal tree survival and growth vary with neighborhood radii; and (b) if the relative strength of the effect of neighborhood interactions on tree growth and survival varies with neighborhood scale. Location: Luquillo Forest Dynamics Plot, Puerto Rico. Methods: We used tree survival and growth data and included information on species‐mean trait values related to several leaf traits, maximum height, seed mass and wood density. We incorporated a tree neighborhood modeling approach that uses an area around a focal tree with a specified radius, to describe the interactions between a focal tree and its neighbors. We constructed survival and growth models for each functional trait using a Bayesian approach, and varied the size of the radius from 5 m to 30 m, at 5‐m intervals. Results: The results suggested that the estimated effects of conspecific and heterospecific neighbors on tree performance do not vary based on the size of the neighborhood (5–30 m), suggesting that the effects of conspecific and heterospecific neighbors on the performance of a focal tree likely do not vary substantially beyond a neighborhood radius of 5 m in the Luquillo forest. In contrast, the estimated strength of the functional neighborhood (effect of neighbors based on their functional trait values) on tree performance was dependent on the neighborhood range. Our results also suggested that the effects of trait distances and trait hierarchies on tree survival and growth are acting simultaneously and at the same spatial scales. Conclusion: Findings from this study highlight the importance of spatial scale in community assembly processes, and specifically, call for increased attention when selecting the radius that defines the neighborhood around a focal tree as the selected neighborhood radius influences the community patterns discovered, and affects the conclusions about the drivers that control community assembly

The Journal of BSN Honors Research, Volume 7, Issue 1, Summer 2014

Papers submitted to the University of Kansas School of Nursing in partial fulfillment of the requirements for the Nursing Honors Program.The University of Kansas School of Nursing Bachelor of Science Nursing Honors Progra

ON THE STATUS OF CODACOND IN PHONOLOGY

Onset/coda feature licensing asyrnmetries have been extensively studied in the generative phonological literature. Pre-Optimality Theory analyses of such asymmetries rely on positional licensing or positional rnarkedness statements, ofwhich Ito's (1986,1989) Coda Conditionis the best-known. In OT, a different approach to onsetlcoda asyrnmetries has emerged: onset-specific faithfulness (Padgett 1995; Beckman 1999; Lombardi 1999,2001). In a recent paper, Lombardi (2001) argues that both onset faithfulness and the Coda Condition are required to account for the range of repairs associated with coda/onset asymrnetries in the licensing of place features, arguing that positional faithfulness alone cannot generate epenthesis as a repair strategy. In this paper, I show, through analyses of Tamil and Axininca Carnpa, that the Coda Condition is not required to generate place-driven epenthesis; rather, epenthesis emerges from the interaction of onset faithfulness with other, independently motivated faithfulness and syllable well-formedness constraints

Positional faithfulness

There are a variety of phonological asymmetries exhibited by segments which appear in perceptually or psycholinguistically prominent positions such as roots, root-initial syllables, stressed syllables, and syllable onsets. In such positions, segmental or featural contrasts are often maintained, though they may be neutralized in non-prominent positions. Segments in prominent positions frequently trigger phonological processes such as assimilation, dissimilation and vowel harmony; conversely, they often block or resist the application of these processes. The goal of this dissertation is to develop a theory of positional faithfulness which will both generate and explain the range of positional asymmetries attested in natural language phonology. Chapter 1 introduces the notion of positional privilege, as well as the fundamental aspects of Optimality Theory. Positional faithfulness constraints are introduced and demonstrated in an analysis of onset/coda asymmetries in Catalan voice assimilation. I argue that positional faithfulness provides an explanation for the attested onset/coda asymmetries that is not afforded by licensing alternatives. Faithfulness in root-initial syllables, a position in which prominence derives largely from psycholinguistic (rather than phonetic) properties, is considered in Chapter 2. Particular attention is given to the analysis of vowel harmony in Shona, and to the phonology of consonantal place in Tamil. Chapter 3 is devoted to the domain of stress, showing once again that positional faithfulness constraints unify and explain a wide range of phonological asymmetries associated with the positional prominence. The core of the chapter is an analysis of nasal harmony in Guarani; vowel reduction in Catalan is also examined. In Chapter 4, I turn to positional privilege effects which are sensitive to the distinction between root and affix. Such cases provide further support for positional faithfulness theory. Finally, in Chapter 5, a different type of positional faithfulness effect, that of positional maximization, is examined. I argue that constraints which favor maximal packing of prominent constituents are necessary. Such constraints are crucial in cases of prominence-driven ambisyllabicity, as in Ibibio. Positional MAX constraints also account for the appearance of complex syllable margins in prominent positions, though complex margins may be excluded elsewhere in the language

On the Status of CODACOND in Phonology

Onset/coda feature licensing asyrnmetries have been extensively studied in the generative phonological literature. Pre-Optimality Theory analyses of such asymmetries rely on positional licensing or positional rnarkedness statements, ofwhich Ito's (1986,1989) Coda Conditionis the best-known. In OT, a different approach to onsetlcoda asyrnmetries has emerged: onset-specific faithfulness (Padgett 1995; Beckman 1999; Lombardi 1999,2001). In a recent paper, Lombardi (2001) argues that both onset faithfulness and the Coda Condition are required to account for the range of repairs associated with coda/onset asymrnetries in the licensing of place features, arguing that positional faithfulness alone cannot generate epenthesis as a repair strategy. In this paper, I show, through analyses of Tamil and Axininca Carnpa, that the Coda Condition is not required to generate place-driven epenthesis; rather, epenthesis emerges from the interaction of onset faithfulness with other, independently motivated faithfulness and syllable well-formedness constraints