No description available.

No description available.

The cover of the ericaceous shrub Kalmia angustifolia L. (sheep's laurel or lamb's kill) expands rapidly on many clear-cut sites through central Newfoundland and northern Quebec. Previous laboratory and greenhouse studies on the effect of Kalmia on black spruce (Picea mariana (Mill.) B.S.P.) germinants and seedlings have demonstrated that extracts of Kalmia leaves and soil can reduce the germination rate and early root and shoot growth of black spruce. Observations in the field have suggested that Kalmia leaves and soil can reduce the germination rate and early rot and shoot growth of black spruce. Observations in the field have suggested that Kalmia reduces the growth of planted spruce seedlings. The experiments presented in this thesis were designed to determine the importance of Kalmia in controlling spruce growth and nutrition, and to document how the importance of Kalmia varies from site to site. Spruce seedlings growing in close proximity to Kalmia were found to be shorter and had lower foliar concentrations of N and P, and the roots of these seedlings had lower rates of mycorrhization and a more frequent occurrence of the pseudo-mycorrhizal/pathogenic fungus Phialocephala dimorphospora Kendrick. Results suggest that Kalmia impedes the N nutrition of spruce seedlings through the reduction of N mineralization rates and N availability. The results of path analysis further suggest that Kalmia had a direct effect on both spruce foliar N concentration and spruce growth. These findings do not demonstrate, though they are consistent with the suggestion, that Kalmia can affect spruce through allelopathic processes. Although we could not demonstrate that the reduction of rates of mycorrhization were due to indirect effects of Kalmia on spruce nutrition, we demonstrated that improving spruce nutrition in close proximity to Kalmia increased, though not significantly, the occurrence of mycorrhizae on spruce roots. Mycorrhizal symbiosis was shown to play a key role in t

No description available.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Restricted until October 2003. Bibliography: leaves 147-151.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1965. / Bibliography: leaves 69-79.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1951. / Bibliography: leaves 141-145.

The availability of ectomycorrhizal fungi (ECMF) to conifer seedlings above the present treeline is likely related to the presence of alternate ECMF host plants, including Betula glandulosa, Arctostaphylos alpina, and Salix herbacea. The ECMF inoculum potential of soils from above treeline that either supported (host) or lacked (non-host) an alternate host plant was assessed by growing Picea mariana as ECMF bait seedlings in field-collected soils under controlled conditions. Seedlings became colonized when grown in both host and non-host soils, but ECMF percent colonization, richness, and diversity were higher for those grown in host soils. The ECMF community in Arctostaphylos host soils was most similar to the community in forest soils. Seedling growth varied among the different soil types, but was mainly influenced by percent ECMF colonization and soil nutrients. Alternate ECMF host plants will likely act as important sources of fungal inoculum, potentially improving conifer seedling establishment and growth.

The Owl-Flintstone range in southeastern Manitoba is among the most at risk in the province. Through a series of transects and plots established throughout the study area, this study characterized calving habitat at a fine scale, examined the use of caribou calving areas by large mammals and examined if a calving habitat model correctly identified high quality calving habitat. Parturient females utilized black spruce dominated islands and peninsulas on lakes as well as islands and peninsulas in bogs. Bear utilized both predicted low and high quality sites. Black spruce and lichen cover were significantly greater within known calving sites compared to predicted low quality habitat. Forbs, herbs and downed woody debris values were significantly lower within known calving sites compared to predicted high quality sites. The calving habitat model correctly identified both high quality and low quality calving habitat in the Owl-Flintstone range, however parameters could be refined.

Mémoire (M.Ress.Renouv.)-- Université du Québec à Chicoutimi, 1994. / Résumé disponible sur Internet. CaQCU Document électronique également accessible en format PDF. CaQCU