The biogeography of Table Mountain, Bonne Bay, Newfoundland.: An investigation of plant community composition and distribution on a serpentine bedrock

• Main Author: Dearden, Philip
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1975
• Subjects: Table Mountain; Newfoundland
• Online Access: https://research.library.mun.ca/10386/; https://research.library.mun.ca/10386/1/Dearden_Philip.pdf

This thesis is a phytogeographical study of Table Mountain, Bonne Bay, Newfoundland (N49°28’ W58°00’). It describes and analyzes the composition and distribution of plant communities on the serpentine bedrock of Table Mountain. Serpentine vegetation is characterized by its discontinuous nature, and stunted and unusual specimens. Research has indicated that four soil properties, low available calcium, and high magnesium, nickel and chromium contents are the dominant limiting factors for plant growth. The thesis postulates that these factors, in conjunction with other environmental variables, may be important in explaining the distribution and composition of plant communities on serpentine. -- The vegetation and soils are rigorously sampled, and the vegetation samples analyzed by a three-dimensional indirect ordination. The axis representing the major gradient of compositional change was found to be highly correlated with the amount of available calcium in the soil. The samples with the most diverse species, tallest specimens and most continuous vegetation cover, also had the greatest amounts of available calcium. This would appear to substantiate the theory that low calcium availability is a major factor in serpentine ecology, and furthermore suggest that it is a major factor in determining community composition and distribution on serpentine. -- The distribution of characteristic species, groups of species and edaphic properties are graphically presented within a two-dimensional ordination. This facilitates identification of phytosociological and edaphic relationships and permits the delimitation of six abstract phytosociological groups within the ordination. These groups are related to specific topographic situations and locations on Table Mountain, and their composition, edaphic characteristics and interrelationship discussed in detail. The serpentine vegetation is felt to be in dynamic equilibrium with the environment, and the sparsely colonized areas are no less of a climax than the continuous cover of the ...