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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Les occupations du site Nebessis (BiEr-3) : une approche palethnographique

Vidal, Violette January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
272

Le village iroquoien de Mailhot-Curran, Saint-Anicet

Woods, Audrey 04 1900 (has links)
Ce mémoire porte sur l’étude d’un petit groupe d’Iroquoiens du Saint-Laurent qui habitait la région de Saint-Anicet au cours du Sylvicole supérieur tardif. Nous traitons de l’occupation villageoise de Mailhot-Curran (BgFn-2) et, plus particulièrement, d’une analyse morpho-stylistique de la poterie. En considérant la variabilité culturelle qui caractérise les Iroquoiens du Saint-Laurent, nous replaçons cette communauté à l’intérieur du grand réseau d’interactions auquel participe ce groupe culturel. Notre objectif général est de déterminer l’apparentement stylistique des potières de Mailhot-Curran selon quatre grandes échelles d’interactions sociales, soit locale, régionale, interrégionale et internationale, et de situer le site à l’étude dans le temps. Cette étude permet de proposer que Mailhot-Curran date du XVIe siècle, mais contrairement à l’effervescence ressentie au site Mandeville au cours du même siècle, les potières seraient demeurées assez conservatrices dans la réalisation de leur poterie. De plus, les potières de Mailhot-Curran semblent posséder une identité villageoise relativement forte. Nous avons aussi observé qu’un style régional caractérise les sites de Saint-Anicet. En considérant l’aspect diachronique des sites Mailhot-Curran, Droulers et McDonald, nos résultats supportent l’idée qu’ils forment un ensemble culturel cohérent qui pourrait indiquer une occupation continue de la région par un même groupe. En outre, notre étude démontre que le site Mailhot-Curran appartient à la province occidentale qui inclut les régions de Prescott et de Summerstown en Ontario, les régions de Montréal et de Saint-Anicet au Québec, ainsi que le nord du lac Champlain au sud-est. Par contre, Mailhot-Curran semble se situer plus en périphérie du réseau d’interactions auquel participent les regroupements de Prescott et de Summerstown au nord du lac Saint-François et il parait s’ouvrir sur d’autres régions comme Montréal et le nord du lac Champlain. Par ailleurs, les potières sont ouvertes à certaines influences provenant de la province centrale, leur région voisine à l’est. / This thesis focuses on a small group of St. Lawrence Iroquoians that lived in the Saint-Anicet region in the last centuries of the Late Woodland period. The results concern the village occupation at the Mailhot-Curran site (BgFn-2) and, specifically, a morpho-stylistic analysis of the pottery. Taking St. Lawrence Iroquoian cultural variability into account, we discuss the cultural position of this community within the broad interaction network which involved this cultural group. Our main goal is to determine the potters’ stylistic relationship according to the local, regional, interregional and international interaction scales, and to date the site. This study allows us to date the Mailhot-Curran site to the 16th century but, unlike the effervesce felt at the Mandeville site during the same period, the potters seem to have remained rather conservative in making their pottery. Furthermore, the Mailhot-Curran potters seem to have a relatively strong village identity. We also observe that a regional style characterizes the Saint-Anicet sites. Considering the diachronic character of Mailhot-Curran, Droulers and McDonald, our results support the idea that they form a coherent cultural ensemble which might suggest a continuous regional occupation by that group. Moreover, our study demonstrates that the Mailhot-Curran site belongs to the western province that includes the Prescott and Summerstown regions in Ontario, Montreal and Saint-Anicet in Quebec, and the northern Lake Champlain region to the southeast. On the other hand, Mailhot-Curran seems to lie on the periphery of the interaction network involving the Prescott and Summerstown regions located to the north of Lake St. Francis and seems to open up to other regions like Montreal and northern Lake Champlain. Otherwise, Mailhot-Curran’s potters are open to influences from the neighboring central province to the East.
273

Conservatisme et innovation chez les potières iroquoiennes du site Droulers-Tsiionhiakwatha

Perreault, Christine 04 1900 (has links)
Ce mémoire tente d’établir la position sociale et culturelle de la communauté villageoise du XVᵉ siècle du site Droulers dans l’espace iroquoien du Saint-Laurent. À partir d’une analyse morpho-stylistique de la poterie, et particulièrement les vases décorés au dentelé, ce mémoire examine la variabilité culturelle du site et sa participation au sein de la sphère d’interactions des Iroquoiens du Saint-Laurent. La comparaison des tendances stylistiques de Droulers et des communautés voisines contribue ainsi à cerner la position chronologique ainsi que l’apparentement culturel du site au sein de sa région immédiate et des régions occidentale et centrale. Les caractères stylistiques à la fois conservateurs et progressistes relevés sur le site Droulers lui sont propres et expriment à la fois l’homogénéité du site et une certaine indépendance stylistique au sein de sa région. Sur cette base, nous avons déterminé que l’usage du dentelé n’a pas une valeur chronologique fiable à des fins de sériation dans le cas spécifique de Droulers, mais qu’il peut toutefois servir comme marqueur régional distinctif. Cet attribut ainsi que d’autres tendances régionales significatives nous ont ainsi servi à mieux cerner les similarités stylistiques entre les sites et à déterminer que Droulers s’apparente plus particulièrement aux sites Mandeville et Lanoraie, et dans une moindre mesure au site McIvor. De plus, nous avons pu établir que le site Droulers s’intègre dans un réseau d’interactions complexe, le rapprochant de communautés situées autant à l’Est qu’à l’Ouest le long de la vallée du Saint-Laurent. Finalement, l’ensemble des tendances morpho-stylistiques confirme la position chronologique du site, soit à la fin du XVᵉ siècle, et ce malgré une proportion importante du décor au dentelé, traditionnellement considéré comme une caractéristique des sites plus anciens. / This Masters project attempts to integrate the 15th Century village community of Droulers within our current understanding of the Iroquoian social and cultural sphere in the St. Lawrence Valley. Using a stylistic analysis of pottery rim sherds decorated with the dentate stamp technique, this study attempts to evaluate the cultural variability of the site as well as its place within the St. Lawrence Iroquoian world. The comparison of the stylistic specificities of the Droulers site with those of a variety of other sites is used to position this site within the development of the St. Lawrence Iroquoian sequence, and to map the cultural ties that linked this specific site to the rest of its proximate area and within the western and central provinces of the Saint-Lawrence Iroquoian territory. The simultaneous conservative and progressive characteristics of the pottery produced at the Droulers site are unique to this site, and help us to identify the specificity of the site and to establish its stylistic independence within the region. On the basis of this evidence, we have determined that the use of dentate designs cannot alone serve as a reliable indicator for the purpose of establishing the period of occupation of the site. However, the use of dentate designs can still be used as an indicator of patterns of regional interaction. The use of the dentate design, in conjunction with other significant regional variations, has also helped us better delineate a set of stylistic similarities and to determine that Droulers is most closely linked to the Mandeville and Lanoraie sites, and to a lesser extent to the McIvor site. Furthermore, we have also determined that the Droulers site is part of a complex network of interactions that ties it to communities located further East and West along the St. Lawrence Valley. Finally, the different patterns of stylistic variation, taken together, confirm the chronological position of the site at the end of the 15th Century, despite the high ratio of dentate designs traditionally considered to be characteristic of earlier settlements.
274

Modelling forest landscape dynamics in Glen Affric, northern Scotland

Hope, Joseph C. E. January 2003 (has links)
Consideration of forest management at the landscape scale is essential if commitments to the conservation of biodiversity are to be upheld. The ecosystem management approach, developed largely in North America, has made use of various landscape modelling tools to assist in planning for biodiversity maintenance and ecological restoration. The roles of habitat suitability models, metapopulation models, spatially explicit population models (SEPMs) and forest landscape dynamics models (FLDMs) in the planning process are discussed and a review of forest dynamics models is presented. Potential is identified for developing landscape models in the UK for both landscape restoration projects and semi-natural woodland management. Glen Affric, in northern Scotland contains a large area of native pine and birch woodland and is the subject of a long-term restoration project. A new model, GALDR (Glen Affric Landscape Dynamics Reconstruction) is introduced and is believed to be the first FLDM developed for British woodland. The theory behind the model is described in detail and preliminary results and sensitivity analyses are presented. Furthermore, GALAM (Glen Affric Lichen Abundance Model), a new SEPM for the rare epiphytic lichen Bryoria furcellata is also described. Results of simulations from the linked GALDR and GALAM models are presented which shed light on the role of landscape heterogeneity in determining the dynamics of lichen habitats and populations. It is concluded that, whilst much work will be required to develop a management-oriented decision support system from the GALDR model, the modelling process may aid researchers in the identification of knowledge gaps in ecological theory relevant to management and restoration.
275

Un fjord, une rivière, un lac et des ruisseaux : variabilité culturelle paléohistorique sur le bassin hydrographique de la rivière Saguenay (Québec, Canada)

Langevin, Érik 06 1900 (has links)
En archéologie, l’identification des identités culturelles spécifiques pose souvent problème. Cependant, lorsqu’on en arrive à la fin de la Paléohistoire et plus particulièrement au cours de la Protohistoire, les vestiges archéologiques trouvent alors des alliées sous la forme de sources littéraires et iconographiques qui documentent tant bien que mal la géographie humaine de l’époque. Sur le bassin hydrographique de la rivière Saguenay, quelques-unes de ces mentions révèlent que se trouvaient au cours de la Protohistoire un certain nombre de groupes distincts parmi lesquels des Iroquoiens du Saint-Laurent, des Montagnais de Tadoussac, des Kakouchacks et autres groupes du Nord. Les vestiges archéologiques des 393 sites archéologiques qui comptent au moins une composante de la Protohistoire ou de la Paléohistoire récente sur le bassin hydrographique de la rivière Saguenay ont été mis à contribution afin de déterminer si ce qui est mentionné où illustré dans les documents historiques est vérifiable du point de vue archéologique. Que ce soit les vestiges céramiques, lithiques, ostéologiques ou autres, ceux-ci ont en effet révélé certaines tendances qui ne peuvent s’expliquer que par des trames culturelles spécifiques. Après avoir constaté la présence de cette mosaïque culturelle au cours de la Protohistoire, le défi était de déterminer depuis quand celle-ci s’était mise en place et surtout d’en identifier les causes. Si l’environnement très variable qui caractérise le bassin hydrographique de la rivière Saguenay (incluant le lac Saint-Jean) a certes joué un rôle, d’autres événements ou comportements ont assurément contribué à diversifier les populations. Parmi ceux-ci, il y a la provenance des populations qui fréquentaient la rivière et ses affluents, les axes de circulations qu’ils empruntaient dans le cadre de leur cycle saisonnier, de même que le contexte des échanges qui se pratiquaient à l’échelle pan-bassin hydrographique. Tous ces aspects ont assurément joué un rôle dans la détermination de ce qu’était une population des basses terres du lac Saint-Jean versus une population du Bas-Saguenay. / In archaeology, determining specific cultural identities is often problematic. However, towards the end of the Paleohistoric period, and especially during the Protohistoric period, archaeological assemblages are more often than not supported by written and pictorial sources that more or less accurately depict the human geography of the period. Along the Saguenay River watershed, some of these sources reveal that, during the Protohistoric period, a number of distinctive groups frequented the area, including St. Lawrence Iroquoians, Tadoussac Montagnais (Innu), Kakouchacks, and other northern groups. The archaeological assemblages of the 393 archaeological sites along the Saguenay River watershed with at least one Protohistoric or late Paleohistoric component were analyzed in an effort to determine if what is written or illustrated in historic texts can be confirmed from an archaeological standpoint. Be they ceramic, lithic, osteological, or other, the latter have revealed a number of trends that can only be interpreted as specific cultural fabrics. The presence of this Protohistoric cultural mosaic raised several challenges as to the timeline of this dynamic and, particularly, how it came about. While the widely changing Saguenay River watershed environment (including Lake St. Jean) surely played a part, other events, or behaviours, undoubtedly contributed to the diversity of those populations; such as the origins of the populations that navigated the river and its tributaries, the routes they followed through their seasonal cycles, and the context in which exchanges were made along the entire watershed. All these factors unquestionably played a part in characterizing, say, Lake St. Jean lowland groups from lower Saguenay groups.
276

L’identité chez les Iroquoiens du Saint-Laurent : analyse du mobilier céramique du site McDonald, Saint-Anicet

Lévesque, Geneviève 04 1900 (has links)
Ce mémoire porte sur la variabilité stylistique présente dans l’assemblage céramique du site McDonald, dans la région de Saint-Anicet, et a pour principal objectif de déterminer comment s’exprime cette variabilité à travers les différents niveaux identitaires auxquels appartiennent les Iroquoiens du Saint-Laurent, soit la famille linguistique iroquoienne, la sphère d’interaction des Iroquoiens du Saint-Laurent, les provinces culturelles, les villages, les clans et les maisonnées. Cette étude abordera également la distribution spatiale des vases retrouvés sur le site à l’aide d’un travail de remontage effectué à l’échelle du site. Cette méthode permettra également d’aborder le mode d’occupation du site McDonald, notamment par l’étude de la relation existant entre le contenu des habitations et celui présent dans chacun des dépotoirs. Une fois ce travail effectué, l’étude de la variabilité stylistique sera abordée par une étude comparative des unités décoratives observées sur les différents registres de décoration des vases à l’intérieur d’un site, c’est-à-dire entre les différentes maisons-longues qui le composent, mais également avec d’autres sites iroquoiens de la vallée du Saint-Laurent. Une étude simultanée des résultats de ces comparaisons intra et intersites aura pour objectif d’identifier la variabilité présente dans les différents niveaux identitaires auxquels appartiennent les habitants du site McDonald et plus précisément la maisonnée, le clan, le village et la province iroquoienne. / This thesis is focused on the stylistic variability observed within the ceramic assemblage of the McDonald site, locatedSt-Anicet cluster, and how this variability can be observed at different levels of St. Lawrence Iroquoian identity. These levels of identity are the Iroquoian linguistic family, the St. Lawrence Iroquoian interaction sphere, the village cluster, the village, the clan and the household. The study includes a spatial distribution of the ceramic on the site through an observation of the pottery refits. This also helps to understand the settlement pattern by looking at, for example, the connections between the longhouses and the middens. The stylistic variability between longhouses and with other St. Lawrence Iroquoian sites will be studied by a comparative analysis of all the decorative techniques on the ceramic vessels. The objective of a comparison between longhouses is to identify the variability within the site and to determine the cultural identity of each household. Finally, a comparison with other St. Lawrence Iroquoian sites will be used to determine the position of the McDonald site within the St. Lawrence Iroquoian interaction sphere.
277

L’industrie osseuse des Iroquoiens du site Mailhot-Curran (BgFn-2) : une étude des déchets de fabrication

Boisvert, Marie-Ève 11 1900 (has links)
Bien que l’os soit une matière première ayant joué un rôle essentiel au sein des activités quotidiennes des Iroquoiens du Saint-Laurent, il existe à ce jour très peu d’analyses systématiques de l’outillage en os et des débris de fabrication retrouvés en Iroquoianie. Afin de pallier ces lacunes, ce mémoire de maitrise porte sur l’analyse des vestiges en os ouvragés récupérés sur le site villageois Mailhot-Curran (BgFn-2), occupé durant le Sylvicole supérieur tardif par une communauté iroquoienne du Saint-Laurent. Plus précisément, l’étude consiste à analyser l’industrie osseuse en portant une attention particulière aux déchets de fabrication. Cet examen attentif a pour principal objectif de documenter les modes de gestion et de sélection de la matière première ainsi que d’améliorer la compréhension des techniques préhistoriques employées pour la fabrication des objets en os. Au moyen d’analyses technologiques, zooarchéologiques et tracéologiques, il sera possible de classifier les déchets de fabrication, de documenter leur origine technologique et, ultimement, de reconstituer un certain nombre de chaines opératoires. Une étude détaillée de la distribution spatiale des artéfacts permettra également de mieux comprendre l’organisation des activités dans l’espace villageois. Ce mémoire a aussi pour objectif de fournir des balises méthodologiques et empiriques relatives à l’étude des déchets de fabrications en os, afin de démontrer la pertinence de considérer ces derniers dans la compréhension des systèmes socioéconomiques et culturels. / The St. Lawrence Iroquoians were very talented producers of bone tools of all kinds but little is known about the ancient technologies involved in the manufacture of these objects. The relevance of this study arises from the fact that there are significant methodological and theoretical gaps in the analysis of the bone objects produced by St. Lawrence Iroquoians. The aim of this thesis is to provide some answers to those specific gaps of information. This research involves various analyses which are characteristic of technological approaches, and zooarchaeological and use-wear methods. These particular methods will allow me to examine and understand more accurately the past technologies associated with St. Lawrence Iroquoians bone tool industries. Through the analysis and classification of the by-products, debris, blanks, rough-outs and finished objects, I hope to provide a method for understanding the sequence underlying the production of bone tools (procurement, selection, treatment, debitage, shaping, finishing, etc.) and to evaluate the investment made in the procurement and selection of the raw materials. A spatial distribution analysis is carried out to better understand the context for the planning and manufacture of bone tools within the village space. The main purposes of this study are to present methodological guidelines regarding the classification of bone refuse and by-products; to reveal morphological and technological characteristics of these archeological remains through macrosopic and microscopic obsevations, and to provide an empirical model adapted to the analysis of the chaines opératoires leading to distinct categories of bone refuse.
278

Analyse techno-économique des chaînes opératoires lithiques du Témiscouata (Québec), durant le Sylvicole et la période de Contact

Eid, Patrick 01 1900 (has links)
Cette thèse porte sur l’analyse technologique d’assemblages lithiques provenant du Témiscouata dans le Bas-Saint-Laurent (Québec, Canada) et datés entre le Sylvicole moyen tardif (500 à 1000 apr. J.-C.) et la période de Contact (XVIe et XVIIe siècles apr. J.-C.). Cette région, située dans l’extrémité septentrionale de la haute vallée de la rivière Saint-Jean, possède une importante source de matière première lithique, le chert Touladi, qui a été fortement exploitée à la préhistoire et même durant la période historique par les Premières Nations. Les chaînes opératoires lithiques de cinq sites archéologiques du Témiscouata ont été analysées via l’approche technologique afin d’en reconstituer les schèmes techno-économiques et leur implication dans les modes de vie des chasseurs-cueilleurs nomades de la région. Les industries lithiques du Témiscouata montrent l’existence de trois chaînes opératoires : la taille de pièces bifaciales, le débitage de nucléus et l’utilisation de pièces esquillées. Quant à l’outillage, il est constitué par des pièces bifaciales et des outils simples sur éclats (outils ad hoc, grattoirs et pièces esquillées). La production des outils sur éclats a été faite sur des supports issus de ces trois chaînes opératoires, mais c’est le processus bifacial qui est cependant à l’origine de la majorité d’entre eux et c’est pourquoi il occupait une place centrale dans ces industries. Les pièces bifaciales combinaient ainsi les rôles d’outils et de « nucléus » fournissant l’essentiel des supports. Les artefacts en chert local ont permis de mieux comprendre comment les technologies étaient organisées pour les besoins à une échelle locale, mais également territoriale alors que les groupes profitaient des carrières de chert Touladi pour se préparer à leurs besoins futurs, anticipés ou non. Quant aux pièces en matériaux exogènes, même si elles comptent pour une part minime des assemblages lithiques, elles ont permis d’entrevoir les stratégies économiques adoptées préalablement à l’occupation du Témiscouata, dans des contextes de rareté en matières premières lithiques de bonne qualité. Les schèmes techno-économiques mis en œuvre par les communautés de chasseurs-cueilleurs du Témiscouata ont constitué des éléments importants de leur stratégie d’adaptation en leur fournissant l’outillage nécessaire selon les multiples contextes rencontrés au cours de leur cycle annuel de nomadisme. Ils traduisent ainsi des choix révélateurs de leurs modes de vie, de leurs modalités d’occupation des sites et de leur réalité socio-économique. / This thesis presents data and analyses on chipped stone tool techno-economic patterns of nomadic hunters-gatherers at a quarry source area in the Témiscouata region (Québec, Canada) during the latter part of the Middle Woodland (500-1000 AD), the Late Woodland (1000-1550 AD) and also the early historic period (XVIe-XVIIe centuries AD). Located in the hinterland of the Bas-Saint-Laurent region, in the upper St. John river drainage, the Témiscouata region is rich in natural resources, perhaps among the most important is an important chert outcrop. The Touladi chert is present in two main quarries and is also found in pebble form scattered in the vicinity of the surrounding lakes and rivers. We applied a technological analysis, from the technological approach in the French tradition, to five lithic collections with the objective of reconstructing the chaînes opératoires and their economic management patterns (techno-economy). The most prominent artifacts found are of course the countless flakes which have been derived from three different chaînes opératoires: the bifacial process, the multidirectional (ad hoc) core reduction, and the use of pièces esquillées. The production of bifacial tools is the most important process in the Témiscouata lithic industries and is the one which produced most of the flakes found on the prehistoric settlements. The tool assemblage is first characterized by the bifacial tools which are primarily manufactured from tabular blocks of chert. As for the flake tools, they are mostly represented by informal (ad hoc) tools (retouched and used flakes), endscrapers and pièces esquillées. Techno-economic patterns of Touladi chert use have demonstrated that most of the flake tools were made on flake blanks derived from the bifacial process, mostly from the early and middle stages of this chaîne opératoire. The bifacial process was also segmented in time and space so that blanks and preforms could be carried throughout the territory to be used as “cores”. The two other production sequences are quite secondary based on the small amount of tools manufactured and they are far less mobile than the bifacial process. Stone tools that are made of exotic materials, even if they represent a small part of the archaeological record, reveal the patterns that prevailed while hunters-gatherers were outside the quarries zone. The technological analysis provides empirical evidence that hunter-gatherers of the Témiscouata region adopted flexible and simple, yet efficient, techno-economical strategies. These management schemes, which use the bifacial chaîne opératoire as the central element of tool manufacturing, are well adapted to their way of life based on a generalist, seasonal and flexible subsistence economy.
279

Pollination ecology of Trachymene incisa (Apiaceae): Understanding generalised plant-pollinator systems

Davila, Yvonne Caroline January 2006 (has links)
Doctor of Philosophy (PhD) / A renewed focus on generalised pollinator systems has inspired a conceptual framework which highlights that spatial and temporal interactions among plants and their assemblage of pollinators can vary across the individual, population, regional and species levels. Pollination is clearly a dynamic interaction, varying in the number and interdependence of participants and the strength of the outcome of the interaction. Therefore, the role of variation in pollination is fundamental for understanding ecological dynamics of plant populations and is a major factor in the evolution and maintenance of generalised and specialised pollination systems. My study centred on these basic concepts by addressing the following questions: (1) How variable are pollinators in a generalised pollination system? To what degree do insect visitation rates and assemblage composition vary spatially among populations and temporally among flowering seasons? (2) How does variation in pollinators affect plant reproductive success? I chose to do this using a model system, Trachymene incisa subsp. incisa (Apiaceae), which is a widespread Australian herbaceous species with simple white flowers grouped into umbels that attract a high diversity of insect visitors. The Apiaceae are considered to be highly generalist in terms of pollination, due to their simple and uniform floral display and easily accessible floral rewards. Three populations of T. incisa located between 70 km and 210 km apart were studied over 2-3 years. The few studies investigating spatial and temporal variation simultaneously over geographic and yearly/seasonal scales indicate that there is a trend for more spatial than temporal variation in pollinators of generalist-pollinated plants. My study showed both spatial and temporal variation in assemblage composition among all populations and variation in insect visitation rates, in the form of a significant population by year interaction. However, removing ants from the analyses to restrict the assemblage to flying insects and the most likely pollinators, resulted in a significant difference in overall visitation rate between years but no difference in assemblage composition between the Myall Lakes and Tomago populations. These results indicate more temporal than spatial variation in the flying insect visitor assemblage of T. incisa. Foraging behaviour provides another source of variation in plant-pollinator interactions. Trachymene incisa exhibits umbels that function as either male or female at any one time and offer different floral rewards in each phase. For successful pollination, pollinators must visit both male and female umbels during a foraging trip. Insects showed both preferences and non-preferences for umbel phases in natural patches where the gender ratio was male biased. In contrast, insects showed no bias in visitation during a foraging trip or in time spent foraging on male and female umbels in experimental arrays where the gender ratio was equal. Pollinator assemblages consisting of a mixture of different pollinator types coupled with temporal variation in the assemblages of populations among years maintains generalisation at the population/local level. In addition, spatial variation in assemblages among populations maintains generalisation at the species level. Fire alters pollination in T. incisa by shifting the flowering season and reducing the abundance of flying insects. Therefore, fire plays an important role in maintaining spatial and temporal variation in this fire-prone system. Although insect pollinators are important in determining the mating opportunities of 90% of flowering plant species worldwide, few studies have looked at the effects of variation in pollinator assemblages on plant reproductive success and mating. In T. incisa, high insect visitation rates do not guarantee high plant reproductive success, indicating that the quality of visit is more important than the rate of visitation. This is shown by comparing the Agnes Banks and Myall Lakes populations in 2003: Agnes Banks received the highest visitation rate from an assemblage dominated by ants but produced the lowest reproductive output, and Myall Lakes received the lowest visitation rate by an assemblage dominated by a native bee and produced the highest seedling emergence. Interestingly, populations with different assemblage composition can produce similar percentage seed set per umbel. However, similar percentage seed set did not result in similar percentage seedling emergence. Differences among years in reproductive output (total seed production) were due to differences in umbel production (reproductive effort) and proportion of umbels with seeds, and not seed set per umbel. Trachymene incisa is self-compatible and suffers weak to intermediate levels of inbreeding depression through early stages of the life cycle when seeds are self-pollinated and biparentally inbred. Floral phenology, in the form of synchronous protandry, plays an important role in avoiding self-pollination within umbels and reducing the chance of geitonogamous pollination between umbels on the same plant. Although pollinators can increase the rate of inbreeding in T. incisa by foraging on both male and female phase umbels on the same plant or closely related plants, most consecutive insect movements were between plants not located adjacent to each other. This indicates that inbreeding is mostly avoided and that T. incisa is a predominantly outcrossing species, although further genetic analyses are required to confirm this hypothesis. A new conceptual understanding has emerged from the key empirical results in the study of this model generalised pollination system. The large differences among populations and between years indicate that populations are not equally serviced by pollinators and are not equally generalist. Insect visitation rates varied significantly throughout the day, highlighting that sampling of pollinators at one time will result in an inaccurate estimate and usually underestimate the degree of generalisation. The visitor assemblage is not equivalent to the pollinator assemblage, although non-pollinating floral visitors are likely to influence the overall effectiveness of the pollinator assemblage. Given the high degree of variation in both the number of pollinator species and number of pollinator types, I have constructed a model which includes the degree of ecological and functional specialisation of a plant species on pollinators and the variation encountered across different levels of plant organisation. This model describes the ecological or current state of plant species and their pollinators, as well as presenting the patterns of generalisation across a range of populations, which is critical for understanding the evolution and maintenance of the system. In-depth examination of pollination systems is required in order to understand the range of strategies utilised by plants and their pollinators, and I advocate a complete floral visitor assemblage approach to future studies in pollination ecology. In particular, future studies should focus on the role of introduced pollinators in altering generalised plant-pollinator systems and the contribution of non-pollinating floral visitors to pollinator assemblage effectiveness. Comparative studies involving plants with highly conserved floral displays, such as those in the genus Trachymene and in the Apiaceae, will be useful for investigating the dynamics of generalised pollination systems across a range of widespread and restricted species.
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Quantifying stand structural complexity in woodland and dry Sclerophyll Forest, South-Eastern Australia

McElhinny, Chris, chris.mcelhinny@anu.edu.au January 2005 (has links)
In this thesis I present and test a methodology for developing a stand scale index of structural complexity. If properly designed such an index can act as a summary variable for a larger set of stand structural attributes, providing a means of ranking stands in terms of their structural complexity, and by association, their biodiversity and vegetation condition. This type of index can also facilitate the use of alternative policy instruments for biodiversity conservation, such as mitigation banking, auctions and offsets, that rely on a common currency – the index value – that can be compared or traded between sites. My intention was to establish a clear and documentable methodology for developing a stand scale index of structural complexity, and to test this methodology using data from real stands.¶ As a starting point, I reviewed the literature concerning forest and woodland structure and found there was no clear definition of stand structural complexity, or definitive suite of structural attributes for characterising it. To address this issue, I defined stand structural complexity as a combined measure of the number of different structural attributes present in a stand, and the relative abundance of each of these attributes. This was analogous to approaches that have quantified diversity in terms of the abundance and richness of elements. It was also concluded from the review, that stand structural complexity should be viewed as a relative, rather than absolute concept, because the potential levels of different structural attributes are bound within certain limits determined by the inherent characteristics of the site in question, and the biota of the particular community will have evolved to reflect this range of variation. This implied that vegetation communities with naturally simple structures should have the potential to achieve high scores on an index of structural complexity.¶ I proposed the following five-stage methodology for developing an index of stand structural complexity: 1. Establish a comprehensive suite of stand structural attributes as a starting point for developing the index, by reviewing studies in which there is an established relationship between elements of biodiversity and structural attributes. 2. Develop a measurement system for quantifying the different attributes included in the comprehensive suite. 3. Use this measurement system to collect data from a representative set of stands across the range of vegetation condition (highly modified to unmodified) and developmental stages (regrowth to oldgrowth) occurring in the vegetation communities in which the index is intended to operate. 4. Identify a core set of structural attributes from an analysis of these data. 5. Combine the core attributes in a simple additive index, in which attributes are scored relative to their observed levels in each vegetation community.¶ Stage one of this methodology was addressed by reviewing a representative sample of the literature concerning fauna habitat relationships in temperate Australian forests and woodlands. This review identified fifty-five studies in south-east and south-west Australia, in which the presence or abundance of different fauna were significantly (p&lt0.05) associated with vegetation structural attributes. The majority of these studies concerned bird, arboreal mammal, and ground mammal habitat requirements, with relatively fewer studies addressing the habitat requirements of reptiles, invertebrates, bats or amphibians. Thirty four key structural attributes were identified from these fifty-five studies, by grouping similar attributes, and then representing each group with a single generic attribute. This set, in combination with structural attributes identified in the earlier review, provided the basis for developing an operational set of stand level attributes for the collection of data from study sites.¶ To address stages two and three of the methodology, data were collected from one woodland community –Yellow Box-Red Gum (E. melliodora-E. Blakelyi ) – and two dry sclerophyll forest communities – Broadleaved Peppermint-Brittle Gum (E. dives-E. mannifera ), Scribbly Gum-Red Stringybark (E. rossii E. macrorhyncha ) – in a 15,000 km2 study area in the South eastern Highlands Bioregion of Australia. A representative set of 48 sites was established within this study area, by identifying 24 strata, on the basis of the three vegetation communities, two catchments, two levels of rainfall and two levels of condition, and then locating two sites (replicates) within each stratum. At each site, three plots were systematically established, to provide an unbiased estimate of stand level means for 75 different structural attributes.¶ I applied a three-stage analysis to identify a core set of attributes from these data. The first stage – a preliminary analysis – indicated that the 48 study sites represented a broad range of condition, and that the two dry sclerophyll communities could be treated as a single community, which was structurally distinct from the woodland community. In the second stage of the analysis, thirteen core attributes were dentified using the criteria that a core attribute should:¶ 1. Be either, evenly or approximately normally distributed amongst study sites; 2. Distinguish between woodland and dry sclerophyll communities; 3. Function as a surrogate for other attributes; 4. Be efficient to measure in the field. The core attributes were: Vegetation cover &lt0.5m Vegetation cover 0.5-6.0m; Perennial species richness; Lifeform richness; Stand basal area of live trees; Quadratic mean diameter of live stems; ln(number of regenerating stems per ha+1); ln(number of hollow bearing trees per ha+1);ln(number of dead trees per ha+1);sqrt(number of live stems per ha &gt40cm dbh); sqrt(total log length per ha); sqrt(total largelog length per ha); Litter dry weight per ha. This analysis also demonstrated that the thirteen core attributes could be modelled as continuous variables, and that these variables were indicative of the scale at which the different attributes operated.¶ In the third and final stage of the analysis, Principal Components Analysis was used to test for redundancy amongst the core attributes. Although this analysis highlighted six groupings, within which attributes were correlated to some degree, these relationships were not considered sufficiently robust to justify reducing the number of core attributes.¶ The thirteen core attributes were combined in a simple additive index, in which, each attribute accounted for 10 points in a total index value of 130. Attributes were rescaled as a score from 0-10, using equations that modelled attribute score as a function of the raw attribute data. This maintained a high correlation (r > 0.97, p< 0.0001) between attribute scores and the original attribute data. Sensitivity analysis indicated that the index was not sensitive to attribute weightings, and on this basis attributes carried equal weight. In this form my index was straightforward to apply, and approximately normally distributed amongst study sites.¶ I demonstrated the practical application of the index in a user-friendly spreadsheet, designed to allow landowners and managers to assess the condition of their vegetation, and to identify management options. This spreadsheet calculated an index score from field data, and then used this score to rank the site relative to a set of reference sites. This added a regional context to the operation of the index, and is a potentially useful tool for identifying sites of high conservation value, or for identifying sites where management actions have maintained vegetation quality. The spreadsheet also incorporated the option of calculating an index score using a subset of attributes, and provided a measure of the uncertainty associated with this score.¶ I compared the proposed index with five prominent indices used to quantify vegetation condition or habitat value in temperate Australian ecosystems. These were: Newsome and Catling’s (1979) Habitat Complexity Score, Watson et al.’s (2001) Habitat Complexity Score, the Site Condition Score component of the Habitat Hectares Index of Parkes et al. (2003), the Vegetation Condition Score component of the Biodiversity Benefits Index of Oliver and Parkes (2003), and the Vegetation Condition Score component of the BioMetric Assessment Tool of Gibbons et al. (2004). I found that my index differentiated between study sites better than each of these indices. However, resource and time constraints precluded the use of a new and independent data set for this testing, so that the superior performance of my index must be interpreted cautiously.¶ As a group, the five indices I tested contained attributes describing compositional diversity, coarse woody debris, regeneration, large trees and hollow trees – these were attributes that I also identified as core ones. However, unlike these indices, I quantified weeds indirectly through their effect on indigenous plant diversity, I included the contribution of non-indigenous species to vegetation cover and did not apply a discount to this contribution, I limited the direct assessment of regeneration to long-lived overstorey species, I used stand basal area as a surrogate for canopy cover, I quantified litter in terms of biomass (dry weight) rather than cover, and I included the additional attributes of quadratic mean diameter and the number of dead trees.¶ I also concluded that Parkes et al. (2003), Oliver and Parkes (2003), and Gibbons et al. (2004), misapplied the concept of benchmarking, by characterising attributes in terms of a benchmark range or average level. This ignored processes that underpin variation at the stand level, such as the increased development of some attributes at particular successional stages, and the fact that attributes can respond differently to disturbance agents. It also produced indices that were not particularly sensitive to the differences in attribute levels occurring between stands. I suggested that a more appropriate application of benchmarking would be at the overarching level of stand structural complexity, using a metric such as the index developed in this thesis. These benchmarks could reflect observed levels of structural complexity in unmodified natural stands at different successional stages, or thresholds for structural complexity at which a wide range of biota are present, and would define useful goals for guiding on-ground management.

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