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Thesis (Ph.D.)--Murdoch University, 2004. / Thesis submitted to the Division of Science and Engineering. Bibliography: leaves 360-392.

Thesis (M.A.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 37-42). Also available via Humboldt Digital Scholar.

På grund av hårt skogsbruk har den generella skogsstrukturen i Sverige förändrats, vilket har påverkat ljusklimatet i skogsvattendrag. Övergången från gammal skog till yngre produktiv skog i kantzonen längs vattendrag har lett till ett strukturellt skifte mot mer enskiktade krontak som förmodligen lämnar lite utrymmer för ljus att tränga igenom. Ljus är en fundamental faktor som möjliggör många ekologiska processer i skogsvattendrag, vilket gör det till en viktig aspekt att undersöka för att kunna upprätthålla ett hållbart skogsbruk. Denna studie avsåg att undersöka ljusklimatet i skogsvattendrag, med syftet att utreda om det fanns skillnader i förhållande till skogens ålder. Studien utfördes i augusti 2020 i Stockholms län, och innefattade fem vattendrag i medelåldrig skog (40 – 80 år) samt fem i gammal skog (>140 år). Krontakstäckning uppskattades genom hemisfäriska foton tagna med en fish-eye lins vid åtta punkter i varje provlokal, och analyserades med hjälp av en mobilapplikation (GLAMA). En inventering av träd i kantzonerna utfördes enligt point-centered quarter method, och datan användes för att beräkna träddensitet, artrikedom samt absolut densitet för varje påträffad art. Resultaten visade en liten men icke-signifikant skillnad i krontakstäckning mellan ålderskategorierna, med en något högre medelprocent i gammal skog. Både medelåldrig och gammal skog dominerades av gran, och artsammansättningen var lika oavsett ålderskategori. Träddensiteten skilde sig något mellan kategorierna, med indikationer på en högre medeldensitet i gammal skog. Ytterligare studier krävs för att minska osäkerheter samt vidare öka kunskaperna om skogsbrukets effekter för att kunna bevara de akvatiska och terrestra miljöerna i skogsekosystem. / Due to intensive forestry, the general stand structure in Swedish forests has changed, which in turn has affected light availability in forest streams. The transformation from old growth to younger productive forests in the riparian zone has led to a structural shift towards a higher density and single-leveled canopies that limits light penetration. Light is a fundamental factor promoting many ecological processes in forest streams, which makes it an important feature to examine in a sustainable forestry context. This study investigated the light climate in forest streams, with the purpose to look for differences in relation to forest age. The study was conducted in August 2020 in Stockholm County, and consisted of five streams in middle stage forests (40 – 80 years) and five in old growth forests (>140 years). Canopy closure was estimated using hemispherical photos taken with a fish-eye lens at eight sample points within each site and analyzed with a mobile app (GLAMA). An inventory of trees in the riparian zone was carried out according to the point-centered quarter method, and the data were used to measure tree density, species richness and absolute density of each observed species. The results showed small non-significant differences in canopy closure between age categories, with a higher mean percentage in old growth forests. Both middle stage and old growth forests were dominated by spruce, and the species richness was the same regardless of age category. The tree density differed slightly between categories, with a tendency for a higher mean density in old growth forests. Further research is needed to reduce uncertainty and expand on the effects of forestry if we are to sustain the aquatic and terrestrial environments in forest ecosystems.

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One of the human activities impacting biodiversity is the cutting of old-growth forests. In response to the controversy surrounding the cutting of old-growth in the coastal rainforest of BC, the Ministries of the Environment and Forests have produced biodiversity guidelines that are to be applied when manipulating stands in the provincial forest. This study augments these guidelines by investigating the diversity differences between second-growth and old-growth forests in relation to site quality. We demonstrate how standlevel plant diversity differs between 40-year-old and old-growth stands in the Very Wet Coastal Western Hemlock subzone (CWHvm) on Vancouver Island. This information is intended to provide foresters with an understanding of the effects of age, disturbance and site quality on stand-level plant diversity, thereby allowing for informed professional management decisions.

The objective of this thesis was to understand the spatial patterns and processes responsible for canopy and understorey spider (Arachnida: Araneae) diversity at multiple spatial scales in north-temperate hardwood forests. I sampled tree trunks (sticky traps) and foliage (beating) of sugar maple and American beech tree canopies and their understorey saplings in old growth forests near Montreal, Quebec. Results show the composition of canopy and understorey assemblages differed significantly, and so did sugar maple and American beech canopy assemblages. Each stratum was also dominated by different species. The rank-abundance distribution of species from each habitat wsa also verticaly stratified because it fit different distribution models. Different factors likely structure assemblages in both habitats, particularly since the canopy is a less stable environment. Spiders from canopy and understorey foliage were tested in a laboratory for their propensity to balloon. General linear models indicated that small sized web-building spiders of the RTA and Orbicularia clades have the highest propensity to balloon. Small bodied species initiated ballooning regardless of the habitat they were collected in or their developmental stage. My results support the mixed evolutionarily stable strategy theory and indicate the absence of risk-spreading in the dispersal strategy of canopy spiders. My last chapter focused on dispersal capacity and diversity patterns of spiders at multiple spatial scales. Analyses of the species diversity of limited and high dispersal capacity species subsets through nested-multivariate ANOVA, additive diversity partitioning, and species-abundance distribution curves all point towards species-sorting processes as the main driver of local community spider diversity at the tree and stand spatial scales. Mass-effects and patch-dynamic processes drive site and regional scale diversity patterns. This thesis demonstrates that spiders provide good models to test many biological hypotheses. The research chapters of this thesis test hypotheses on the vertical stratification of forest spider diversity, the evolution of local dispersal adaptations, and the importance of dispersal capacity on species diversity patterns through a metacommunity framework.

This thesis addresses the situation of First Nations people in forestry of British Columbia. Aboriginal people in British Columbia have been involved in the forest industry as laborers since the 1850s when the commercial logging operations began in the province, but have been politically and economically marginalized in the industry. The institutional and economic factors not only have restricted aboriginal people to control over forest resources on their traditional lands but have affected their forest management practices. For aboriginal communities, it is a critical issue that protecting old growth forests, with which they are culturally associated, without giving up economic benefit generated from harvesting these forests. In order to suggest possible changes and approaches for shaping native forest management in the existing institutional and economic frameworks, I examined the issues of provincial forestry and analyzed how these issues effect and interact with aboriginal people. It is important but difficult for First Nations to obtain forest tenure because their resource management is related to their land rights. However, the issues of aboriginal people in forestry overlap with those of the province. Thus, perspectives and participation of aboriginal people is critical for the government and the industry. Forestry of British Columbia is in transition and has begun to consider the potential contribution of aboriginal people to sustainable forestry. Therefore, aboriginal people have a significant role to play in the future of forestry.

The dynamics in Fagus-Acer forest have been frequently investigated, a particular interest being the replacement patterns and coexistence of the two dominant species, Fagus grandifolia Ehrh. and Acer saccharum Marsh. This thesis examines whether the community pattern and dynamics in a Fagus-Acer forest at Mont. St. Hilaire, Quebec, are consistent with predictions made by the disturbance hypothesis. This conceptual model explains the mechanisms underlying the coexistence and replacement patterns of the two dominant species. While the hypothesis suggests disturbance frequency and interspecific differences in growth under variable light conditions to be the key factors that determine the dynamics in Fagus-Acer forests, I demonstrate that edaphic factors and regeneration of Fagus by root sprouts can also play a significant role. Based on the findings, I propose an alternative model for the coexistence and replacement patterns in Fagus-Acer forest to better account for the influence of edaphic factors and of Fagus root sprouts.

This thesis addresses the situation of First Nations people in forestry of British Columbia. Aboriginal people in British Columbia have been involved in the forest industry as laborers since the 1850s when the commercial logging operations began in the province, but have been politically and economically marginalized in the industry. The institutional and economic factors not only have restricted aboriginal people to control over forest resources on their traditional lands but have affected their forest management practices. For aboriginal communities, it is a critical issue that protecting old growth forests, with which they are culturally associated, without giving up economic benefit generated from harvesting these forests. In order to suggest possible changes and approaches for shaping native forest management in the existing institutional and economic frameworks, I examined the issues of provincial forestry and analyzed how these issues effect and interact with aboriginal people. It is important but difficult for First Nations to obtain forest tenure because their resource management is related to their land rights. However, the issues of aboriginal people in forestry overlap with those of the province. Thus, perspectives and participation of aboriginal people is critical for the government and the industry. Forestry of British Columbia is in transition and has begun to consider the potential contribution of aboriginal people to sustainable forestry. Therefore, aboriginal people have a significant role to play in the future of forestry. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate