A model of coppice biomass recovery for mallee-form eucalypts

Planting mallee-form eucalypts amongst crops has the potential to remedy environmental degradation caused by land clearing in low rainfall regions, whilst also providing income through carbon-sequestration or periodic coppicing. Management options can be supported by models of biomass and coppice recovery, and this paper presents the first empirical coppice growth model for mallee eucalypts. Uncoppiced and coppiced belt-planted Eucalyptus polybractea, E. loxophleba and E. kochii were harvested and roots excavated to provide estimates of shoot and root biomass for analysis and model development. Allometric models of shoot biomass were appropriate for both uncoppiced and coppiced trees, but models of root/total biomass ratio for coppice depended on site quality and age, and could not be modelled allometrically. Mean root/total biomass proportions for uncoppiced trees were estimated (with standard errors) to be 0.38 (0.009), 0.50 (0.031), and 0.46 (0.021) for E. polybractea, E. loxophleba, and E. kochii respectively and were sensitive to site quality but insensitive to age. The time taken to regain pre-coppice shoot biomass was about half that of full pre-cut root/total biomass ratio recovery, and was affected by coppicing age and site quality. A conceptual model of coppice growth indicated that coppiced stands may produce more total biomass than uncoppiced stands of the same age

Investigation of Spatial Isotope Ratios in Soil and the Effects of Fertilizer on Plant Isotope Ratios

A previous Honors study analyzed diet of thirteen-lined ground squirrels at the Andrews University Airpark by studying δ13C and δ15N isotope values of their fecal pellets (Chacko, 2013). Fecal samples collected within 25m of a cornfield had elevated isotope values. High δ13C values indicate greater consumption of C4 plants, such as corn (Ehleringer et al., 1986); high δ15N values indicate increased consumption of animal matter (DeNiro and Epstein, 1981 ). However, the spatial pattern may be due to variation in the soil, reflecting long-term patterns in the vegetation. Soil samples were taken throughout the airpark and analyzed for δ13C and δ15N. These baseline values were removed from fecal values, but the patterns of the fecal samples still held. Application of fertilizer to vegetation resulted in a significant increase in δ15N. Thus, the δ15N pattern observed in the fecal samples appears to be due to enrichment in corn

Making top-heavy IMFs from canonical IMFs near the galactic centre

We show that dynamical evolution in a strong (Galactic Centre-like) tidal field can create clusters that would appear to have very top-heavy IMFs. The tidal disruption of single star forming events can leave several bound ‘clusters’ spread along 20 pc of the orbit within 1-2 Myr. These surviving (sub)clusters tend to contain an over-abundance of massive stars, with low-mass stars tending to be spread along the whole ‘tidal arm’. Therefore observing a cluster in a strong tidal field with a top-heavy IMF might well not mean the stars formed with a top-heavy IMF

Research Fellows Conference Panel on The Politics of Social Transformation

Also CSST Working Paper #26.http://deepblue.lib.umich.edu/bitstream/2027.42/51157/1/389.pd

Cultural leadership in practice : leadership identity construction in the Australian arts and cultural sector

University of Technology Sydney. Faculty of Arts and Social Sciences.Leadership in the Australian arts and cultural sector has become, in recent decades, a prominent topic of discussion. On one hand, there is increased corporatisation in the arts that promotes leaders with strong business orientations, on the other, questions asked about the role arts leaders play in shaping our cultural and intellectual life. In these debates, we are left wondering what constitutes effective arts and cultural leadership, and how we develop it. While there is substantial research on leadership in arts and cultural organisations, it focuses predominantly on established leaders and often neglects large sections of the industry where leadership is practiced in flexible, often precarious, labour markets. We know little of how arts and cultural leaders are developed in the context of sole traders, casual workers and volunteers who are unlikely to access leadership development through traditional channels discussed in management literature. This research explores the development of leadership identity within the Australian arts and cultural sector examining nine disciplinary based cases that are within, across and outside the more frequently researched organisational context. Interviews were conducted with 41 practitioners in the disciplines of theatre, film, music, advertising, digital design, design and craft, visual arts, festival and event curation, and fashion and blogging. It uses social constructionist theories of leadership, identity and development as a theoretical lens to demonstrate how emerging leaders develop an often-complex relationship with leadership. In the face of identity regulation, or intentional social processes that impact identity construction and reconstruction, some arts and cultural emerging leaders demonstrate resistance to identifying as a leader, even when engaged in leadership practice. Building on critical approaches to leadership and leadership development, this thesis establishes that emerging leaders who engage in communities of practice, or collaborative practice that involves joint enterprise, mutual engagement and shared repertoire, are less likely to be reluctant leaders. Leadership identity development within communities of practice offers a space for positive construction of leadership identity within creative practice, mitigating against identity regulation, broadens leadership understanding and provides alternate strategies to the more individualistically oriented leader development models found in industry and organisational theory. From the case studies, five leadership personas are formulated that demonstrate differing relationships arts and cultural workers have to leadership. This research contributes to theories of critical leadership and leadership development, particularly in the arts and cultural sector, while also offering practical recommendations to enhance industry-based leadership development

Enset‐based agricultural systems in Ethiopia: A systematic review of production trends, agronomy, processing and the wider food security applications of a neglected banana relative

Enset (Ensete ventricosum (Welw.) Cheesman) is the major starch staple of the Ethiopian Highlands, where its unique attributes enhance the food security of approximately 20 million people and have earned it the title “The Tree Against Hunger”. Yet enset‐based agriculture is virtually unknown outside of its narrow zone of cultivation, despite growing wild across much of East and Southern Africa. Here, we review historical production data to show that the area of land under enset production in Ethiopia has reportedly increased 46% in two decades, whilst yield increased 12‐fold over the same period, making enset the second most produced crop species in Ethiopia—though we critically evaluate potential issues with these data. Furthermore, we address a major challenge in the development and wider cultivation of enset, by reviewing and synthesizing the complex and fragmented agronomic and ethnobotanic knowledge associated with this species; including farming systems, processing methods, products, medicinal uses and cultural importance. Finally, we provide a framework to improve the quality, consistency and comparability of data collected across culturally diverse enset‐based agricultural systems to enhanced sustainable use of this neglected starch staple. In conclusion, we discuss the challenges and opportunities for enset cultivation beyond its restricted distribution, and the regional food security potential it could afford smallholders elsewhere in Southern and East Africa

Protostellar discs formed from turbulent cores

We investigate the collapse and fragmentation of low-mass, trans-sonically turbulent prestellar cores, using SPH simulations. The initial conditions are slightly supercritical Bonnor-Ebert spheres, all with the same density profile, the same mass (M_O=6.1 Msun) and the same radius (R_O=17,000 AU), but having different initial turbulent velocity fields. Four hundred turbulent velocity fields have been generated, all scaled so that the mean Mach number is M=1. Then a subset of these, having a range of net angular momenta, j, has been evolved. The evolution of these turbulent cores is not strongly correlated with j. Instead it is moderated by the formation of filamentary structures due to converging turbulent flows. A high fraction (~ 82%) of the protostars forming from turbulent cores are attended by protostellar accretion discs, but only a very small fraction (~16%) of these discs is sufficiently cool and extended to develop non-linear gravitational instabilities and fragment.Comment: 10 pages, 8 figures, submitte

Evaporation of Compact Young Clusters near the Galactic Center

We investigate the dynamical evolution of compact young clusters (CYCs) near the Galactic center (GC) using Fokker-Planck models. CYCs are very young (< 5 Myr), compact (< 1 pc), and only a few tens of pc away from the GC, while they appear to be as massive as the smallest Galactic globular clusters (~10^4 Msun). A survey of cluster lifetimes for various initial mass functions, cluster masses, and galactocentric radii is presented. Short relaxation times due to the compactness of CYCs, and the strong tidal fields near the GC make clusters evaporate fairly quickly. Depending on cluster parameters, mass segregation may occur on a time scale shorter than the lifetimes of most massive stars, which accelerates the cluster's dynamical evolution even more. When the difference between the upper and lower mass boundaries of the initial mass function is large enough, strongly selective ejection of lighter stars makes massive stars dominate even in the outer regions of the cluster, so the dynamical evolution of those clusters is weakly dependent on the lower mass boundary. The mass bins for Fokker-Planck simulations were carefully chosen to properly account for a relatively small number of the most massive stars. We find that clusters with a mass <~ 2x10^4 Msun evaporate in <~ 10 Myr. A simple calculation based on the total masses in observed CYCs and the lifetimes obtained here indicates that the massive CYCs comprise only a fraction of the star formation rate (SFR) in the inner bulge estimated from Lyman continuum photons and far-IR observations.Comment: 20 pages in two-column format, accepted for publication in Ap

Establishing a Center to Support Faculty Research

This is the author's accepted manuscript. The original publication is available at http://dx.doi.org/10.1007/s10755-005-8347-z.This article describes the establishment in fall 2002 of a School of Education Research Center designed to support faculty in increasing productivity and quality in research. Details are provided about center goals, services, staffing, space, resources, and logistics during the first year of operation. In addition, data are shared about faculty usage of the Center, the level of faculty satisfaction with center services in the first year, and initial increases in faculty productivity. The article concludes with plans for continued data collection to monitor the impact of the Center, a discussion of lessons learned at this point in the Center's development, and possibilities for the evolution of the Center