Although the watersheds of the Petite Cascapedia and Bonaventure Rivers, Gaspe Peninsula, have broadly similar geology and land use, their segment-scale river geomorphology is contrasted by subtle differences in valley characteristics that are a legacy of their individual geomorphic histories. These differences have consequences on the distribution of Atlantic salmon habitat such as boulder abundance (for parr rearing and overwintering habitats) and spawning substrate quality. Parr preference for boulder-rich river segments (1--5 km) was observed in the Bonaventure River. In the study systems redd distribution was sensitive to relatively small changes in the fines content of riffle substrate. River segments flowing through moderately narrow semi-alluvial valleys present better overall parr habitat (high boulder abundance) and better spawning substrate quality (percentage of sand) than wider valley sections. These differences are due to additional sources of coarse sediment, higher shear stresses, and lower bank erosion rates in such valleys.

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Thesis (MSc) -- University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The fires, which occurred during January 2000 on the Southern Cape Peninsula, Cape Province, South Africa, focused attention on the importance of sound, informed management of exotic plant invaders in fynbos, especially at the urban interface. The fires also highlighted the relative lack of knowledge about the combined impacts of fire, exotic plants and the exotic-clearing programme on soil seed banks and regeneration. This study examines soil borne seed banks, regeneration, soil chemistry and micro biota in different postfire environments, focusing on three components of exotic plant management: The post-fire effects of standing invasive exotic plants; stacks of slashed exotic plant material which were deliberately burnt and stacks reduced to heat scars by a wildfire. The primary hypothesis addressed is that post-fire vegetation regeneration patterns, seed bank diversity and seed bank abundance are linked to pre-fire vegetation characteristics and, in particular, to the treatment of exotic plant species. It is also hypothesised that soil microbe population sizes are linked to pre-fire vegetation and soil chemical composition. Differences in soil seed banks, soil micro biota and vegetation regeneration patterns occur in different post-fire environments. High volumes of (live or dead) woody exotic biomass negatively impact upon postfire indigenous species diversity and abundance, both above and below-ground. Soil seed banks and above-ground regeneration decline with increasing fire intensity, wildfire burnt stack treatments showing the largest declines followed by wildfire burnt standing exotics, control burnt stacks, wildfire burnt cleared areas and wildfire burnt Mountain Fynbos treatments. Persistent indigenous seed banks are found under some exotic dominated stands. Heat damage, associated with high woody exotic biomass, affects seeds of all species into deep soil layers. Depth of burial is a more important determinant of seed survival during fires than seed size. Soil microbial populations are variably affected by exotic plants, their management and increases in fire intensity. The most drastic microbial population changes are in post-fire treatments of high exotic plant biomass. Soil chemistry affects microbial population sizes as does seasonal climatic changes. In this thesis vegetation, seed bank and microbial responses to various exotic plant management practices are shown and management recommendations are made. Keywords: exotic plants, fire, Fynbos Siome, microbes, post-fire succession, soil seed banks. / AFRIKAANSE OPSOMMING: Die Januarie 2000 vure op die Suid Kaapse Skiereiland het fokus gerig op die belangrikheid van goeie, ingeligte bestuur van uitheemse indringerplante in fynbos, veral naby stedelike gebiede. Die vure het ook 'n relatiewe .gebrek aan kennis aangaande die gekombineerde impakte van vuur, uitheemse plantegroei en indringer plant beheer programme op grond saadbanke en die hergroei van plante na 'n vuur aan die lig gebring. Hierdie projek bestudeer die invloed van vuur op grond saadbanke, hergroei van plante, grond chemie en mikro-organismes. Die klem lê op drie komponente van uitheemse plant bestuur: waar staande uitheemse plante voorkom; waar skoongekapte uitheemse plante in hope gestapel is en gekontraleerd gebrand is en waar soortgelyke hope in 'n onbeplande weghol vuur gebrand is. Die primêre hipotese is dat plant herstelpatrone, saadbank diversiteit en grootte gekoppel is aan veldtoestande voordat daar gebrand is, en veral aan die bestuur van uitheemse plantspesies. Nog 'n sentrale hipotese is dat die grootte van grond mikrobiale populasies gekoppel is aan veld toestande voor die brand en aan grond chemiese samestelling. Hierdie studie dui verskille aan in grond saadbanke, mikro-organismes en plant hergroeipatrone onder verskeie toestande na vuur. Die brand van hoë volumes (lewende of dooie) houtagtige uitheemse plant biomassa benadeel inheemse plant spesie diversiteit en getalle (bo en onder die grond oppervlak). Grond saadbanke neem af met vehogings in vuur intensiteit. Die grootste afnames is in wegholvuur gebrande gestapelde uitheemse plantmateriaal gevolg deur wegholvuur gebrande staande uitheemse plante, opsetlik gebrande hope uitheemse plante, gebrande skoongekapte areas en wegholvuur gebrande Berg Fynbos. Ou inheemse saadbanke is gevind onder sommige areas wat voor die vuur oorheers was deur uitheemse plantegroei. Hitteskade, geassosieer met hoë volumes houtagtige uitheemse biomassa, affekteer sade van alle spesies tot diep in die grond. Saad oorlewing tydens brande is meer geaffekteer deur diepte van begrawing in die grond as deur saad grootte. Grond mikro-organisme populasies is geaffekteer deur uitheemse indringer plante, die bestuur van uitheemse plante en vuur intensiteit. Die grootste veranderinge is waar die biomassa van uitheemse plantegroei baie hoog is. Grond chemiese samestelling en seisoenale veranderinge in weerspatrone affekteer die grootte van mikrobiale bevolkings. In hierdie tesis word verskille in plantegroei, saad store en grond mikrobes, soos geaffekteer deur uitheemse plant beheer programme uitgewys en voorstelle vir toekomstige bestuur gemaak. Sleutelwoorde: Fynbos Bioom, grond saad stoor, mikrobes, plant hergroei, uitheemse plante, vuur.

[Partial abstract]: This study presents the first detailed geochemical and morphological characterisation of gold grains from the southern Seward Peninsula, Alaska, a region with significant historical and on-going placer gold mining. Quantitative Au, Ag, Hg, and Cu data are presented for gold grains from eleven sites. Additionally, quantitative Te, W, As, and Sb trace element data are presented for gold grains from ten of the eleven sites. Although it is acknowledged that quantitative trace element analysis of gold grains is a relatively new endeavour, the limited trace element data obtained in this study suggest that trace element analysis could be useful for characterising gold sources on the southern Seward Peninsula. Major and minor element geochemical profiling is sufficient at differentiating between sites from regional provenance systems but insufficient at differentiating between sites within a single system. Differentiating among sites within a single system will likely require microchemical analysis of mineral inclusions and analysis of trace element signatures.

No description available.

Une partie de la region de Paspebiac a ete recouverte par deux glaces contemporaines, lors du dernier stade glaciaire du Wisconsinien. Une premiere s'est ecoulee du nord-nord-ouest, a recouvert la partie ouest de la region a l'etude et a erige une grande moraine laterale nord-sud a sa marge orientale; il n'a pu etre determine si cette glace etait l'inlandsis laurentidien ou une calotte gaspesienne. Une seconde glace progressant vers le nord-ouest a englace le sud-est du territoire et a construit une moraine terminale ouest-est, perpendiculaire et jointive a la premiere moraine. Un lac proglaciaire s'est forme a l'encoignure des deux glaces et a recouvert une partie d'un plateau demeure deglace au nord-est. Lors du dernier rechauffement climatique, le front de la glace du sud a regresse le premier, avant que la mer de Goldthwait noit les basses terres jusqu'a 46 metres vers 12 200 BP. Alors seulement, l'autre glace decouvre a son tour le territoire a l'etude. L'emersion est rapide, et certains elements laissent croire que les terres sont de nouveau transgressees depuis quelques millenaires.

This thesis proposes to evaluate the impact of factors such as trade, circumscribed resources, and growing militarism upon the development of social complexity in LBA Argolis, and to what extent these factors may be invoked as triggering mechanisms--or prime movers--in the rise of palatial society in the Argive plain towards the end of the 15th century B.C., during the LH III A-B period. / It is argued that the most plausible model for the rise of palatial society in LBA Argolis is one which acknowledges the interrelations and processes of feedback between these factors, of which trade and militarism may have been original motivating factors. / Finally, it is suggested that the need to organize resource procurement and distribution were instrumental in the emergence of the Mycenaean palatial centers of LBA Argolis.

No description available.