A multi-scale assessment of physiological processes in arctic tundra plants under natural and simulated climate change scenarios

Climate warming is predicted to cause an increase in the growing season by as much as 30% for regions of the arctic tundra. This will have a significant effect on the physiological activity of the vascular plant species and the ecosystem as a whole. The need to understand the possible physiological change within this ecosystem is confounded by the fact that research in this extreme environment has been limited to periods when conditions are most favorable, mid June–mid August. This study attempted to develop the most comprehensive understanding to date of the physiological activity of seven tundra plant species in the Alaskan Arctic under natural and lengthened growing season conditions. Four interrelated lines of research, scaling from cellular signals to ecosystem processes, set the foundation for this study. ^ I established an experiment looking at the physiological response of arctic sedges to soil temperature stress with emphasis on the role of the hormone abscisic acid (ABA). A manipulation was also developed where the growing season was lengthened and soils were warmed in an attempt to determine the maximum physiological capacity of these seven vascular species. Additionally, the physiological capacities of four evergreens were tested in the subnivean environment along with the potential role anthocyanins play in their activity. The measurements were scaled up to determine the physiological role of these evergreens in maintaining ecosystem carbon fluxes. ^ These studies determined that soil temperature differentials significantly affect vascular plant physiology. ABA appears to be a physiological modifier that limits stomatal processes when root temperatures are low. Photosynthetic capacity was limited by internal plant physiological mechanisms in the face of a lengthened growing season. Therefore shifts in ecosystem carbon dynamics are driven by changes in species composition and biomass production on a per/unit area basis. These studies also found that changes in soil temperatures will have a greater effect of physiological processes than would the same magnitude of change in air temperature. The subnivean environment exhibits conditions that are favorable for photosynthetic activity in evergreen species. These measurements when scaled to the ecosystem have a significant role in limiting the system's carbon source capacity. ^

The European Parliament, membership expansions, and organizational change

The European Union (EU) is an extraordinary achievement. From a regional economic organization, it grew into a polity within fifty years. The original EU of six members expanded incrementally to 27 over forty years, and it now comprises a population of almost 500 million people. While the five expansions of the European Economic Community/European Community/European Union (EU) have received considerable scholarly attention, surprisingly little attention has been given to their impacts on "Europe's" only legislative body, currently known as the European Parliament (EP). More specifically, little is known about how waves of new members (from widely diverse parties and national backgrounds) affected—and were affected by—the EP's organizational structure and its internal processes. The purpose of this study therefore is to help fill this gap by describing and explaining how the various EEC/EC/EU expansions or "membership shocks" (1973, 1981, 1986, 1995, and 2004) affected the EP's organizational structure and its internal Rules of Procedure (RoP). The central research question of this dissertation is the following: What were the major structural and procedural effects of the five membership expansions of what eventually became the European Union on the European Parliament? This dissertation answers this question by using concepts and measures drawn from organizational theory. While other studies have applied concepts and hypotheses from organizational theory to legislatures, such an approach has never been used to analyze the EP, which is conceptualized here as a "membership organization." This study, through an analysis of the EP, demonstrates that organization theory can help us fully understand the effects of membership expansions on any membership organization. That is, understanding how this particular organization responded to change can inform not only how others in this class (legislatures) do so, but how this process unfolds in a variety of times and places. The principal findings of this study are as follows: (1) EP staff growth revealed an interesting pattern: Staff did not increase concurrently with EP membership. That is, it turned out that the rate of membership growth exceeded the rate of staff increase, suggesting professionalization of EP staff and their relative empowerment vis-à-vis MEPs; (2) The number of rules and the precision within them increased; (3) the largest number of EP rule changes focused on increasing EP efficiency; and (4) The authority was centralized in the hands of EP leadership, that is, the EP President, the Conference of Presidents and also two major political groups.