Generalist herbivores profoundly influence the biomass and species composition of macroalgae assemblages. In subtidal ecosystems of temperate latitudes, large invertebrates are usually the most influential herbivores. I tested the prediction that exclusion of invertebrate herbivores would lead to changes in the biomass and species composition of the macroalgae assemblages that are a prominent feature of the reefs in south-western Australia. The most abundant invertebrate herbivores were sea urchins (Heliocidaris erythrogramma, Phyllacanthus irregularis and Centrostephanus tenuispinus), and these occupied different trophic positions. Heliocidaris was present at virtually all reefs surveyed, and was particularly abundant in the Fremantle region. Analyses of stable isotopes and direct observations of gut contents revealed that it was almost exclusively herbivorous, and that it mainly ate foliose brown algae. In contrast, Phyllacanthus and Centrostephanus were omnivorous; while they consumed large proportions of algae, a substantial proportion of the diet of both species was animal tissue. Because Heliocidaris is a generalist herbivore that occurs at high densities, it could exert a large influence on the macroalgae assemblage. This prediction was tested by a series of press experiments. Contrary to the prediction, Heliocidaris exerted a very minor influence on the biomass, and no detectable influence on the species composition, of attached macroalgae. However, it exerted a major influence on the retention of drift macroalgae and seagrass by trapping and feeding on drift. It exerted a particularly strong influence on retention of the kelp Ecklonia radiata. This kelp was not abundant in the attached algae assemblage (when all plots were pooled it ranked 35th in biomass), but was abundant as drift (ranking 1st). Most of the drift Ecklonia was retained by sea urchins, rather than freely drifting.Herbivorous fish may also influence macroalgae assemblages. To compare the effects of sea urchins versus fish on recruiting and adult macroalgae a 13-month exclusion experiment was conducted. There were no detectable effects of sea urchins (mainly Heliocidaris) on either recruiting or adult macroalgae. There were some patterns in the biomass of recruiting algae consistent with an influence by herbivorous fish; however, these patterns were also consistent with the presence of artefacts (shading and reduced water flow) by fish exclusion devices. I began with the prediction that large invertebrate herbivores were a major influence on the macroalgae assemblages of subtidal reefs in south-western Australia. Overall, there was little evidence to support this prediction: within spatial extents of tens of square metres and over periods of 1-2 years, only minor effects were detected. However, it remains plausible that herbivores exert an influence over long time periods across large spatial extents in south-western Australia. I propose that trophic subsidies support the comparatively high densities of Heliocidaris that exist at some reefs. I further propose that these subsidies mediate the effects of sea urchins on the attached macroalgae assemblage, and that they might play an important role in energy and nutrient cycling in these nearshore ecosystems.

Thesis (M.S.)--Georgia Southern University, 2007. / Title from PDF title page (viewed on Feb. 19, 2008). Electronic version approved: May 2007. Vita. Includes bibliographical references.

Thesis (D. Min.)--New Orleans Baptist Theological Seminary, 2003. / Includes abstract and vita. Includes bibliographical references (leaves 153-158).

Thesis (D. Min.)--New Orleans Baptist Theological Seminary, 2003. / Includes abstract and vita. Includes bibliographical references (leaves 153-158).

In 1955, barely ten years after the end of the most devastating war in Modern German history, a new German military was established in the Federal Republic, the Bundeswehr. In order properly fill the ranks of this new military the government, under the leadership of Konrad Adenauer, believed that it would have to draft men from the West German population into military service. For the government in Bonn conscription was a double-edged sword, it would not only ensure that the Bundeswehr would receive the required number of recruits but it was also believed that conscription would guarantee that the Bundeswehr would be more democratic and therefore in tune with the policies of the new West German state. What this study seeks to explore is what the West German population thought of conscription. It will investigate who was for or against the draft and seek to determine the various socioeconomic factors that contributed to these decisions. Furthermore this study will examine the effect that the public opinion had on federal policy.

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Distributions of larval fishes in the Winfield Pool, Kanawha River, West Virginia, were determined by sampling two sites with bongo and push nets. Cyprinids, clupeids, and <i>Aplodinotus grunniens</i> dominated collections. Main channel densities were a fraction of the densities along the shoreline, indicating the importance of the shoreline as a nursery. Diel trends in abundance were evident for several taxa, but were likely caused by diel changes in gear avoidance and distribution of larvae. Vertical trends in abundance were apparent for several taxa at the deeper and more lentic sampling site (lower pool). <i>Aplodinotus grunniens</i> were generally more abundant near the bottom, especially during daylight. Cyprinids were more abundant near the bottom in mid-June, but displayed no vertical trends on other sampling dates. Clupeids were more abundant at middepth or surface during daylight, while equally dispersed or near the bottom at night. Vertical trends were not evident at the shallower and more lotic site (upper pool) except for <i>Aplodinotus grunniens</i>, which displayed the same preference for the bottom, as at the lower site. / Master of Science

The aim of this thesis is to explain the existence and coexistence of diverse hired labour arrangements in two contrasting localities in rural West Bengal (India). Hired labour arrangements for seasonal migrants are included in the analysis, the methods for which are drawn from a review of the contractual arrangements literature. One study locality, in Bardhaman District, was characterised by double-cropping of paddy facilitated by groundwater irrigation, the other, in Purulia District, by rainfed paddy cultivation. The structure of landownership was skewed - more so in the Bardhaman locality. Daily employment records were kept by ninety-two sampled households over two seasons. In each locality six different indigenous types of hired labour arrangement were identified. Analysis of the rationales for the existence and coexistence of these labour arrangements and of the variation within each type confirmed the embeddedness of the terms and conditions of labour hire (including those for migrant labour) in the land-holding structure, in ideologies of gender and caste, and in party political allegiances. Possibilities for and constraints on hiring out labour in particular arrangements are explained in part by the logic of deployment of household labour to unwaged reproductive and productive work, which is also socially embedded in the same way. The thesis thus sets a new agenda for research. It questions the received wisdom on rural labour exchange in India: i) that villages tend to have just one wage rate for 'casual' labour determined by supply and demand alone, ii) that stylised labour arrangements (eg 'casual' and 'attached') are appropriate occupational classifications for individuals and households, and iii) that rural labour is immobile. If the coexistence of diverse labour arrangements is to be explained, more, careful microstudies are required, so that a typology of socio-economic, political and agro-ecological contexts can be developed.