| dc.contributor.advisor | mallik, azim | |
| dc.contributor.author | bloom, robin g. | |
| dc.date.accessioned | 2017-06-07t20:08:05z | |
| dc.date.available | 2017-06-07t20:08:05z | |
| dc.date.created | 2001 | |
| dc.date.issued | 2002 | |
| dc.identifier.uri | http://knowledgecommons.lakeheadu.ca/handle/2453/3151 | |
| dc.description.abstract | the goal of this thesis was to estimate the relative importance of the mechanisms by
which forest stands of east-central newfoundland are replaced by unproductive dwarf-shrub
communities following wildfire. sheep laurel (kalmia angustifolia l.) is the dominant species
of these heath communities and its proliferation after forest fires may initiate a retrogressive
pathway rather than forest stand replacement.
this problem is addressed in four chapters that evaluate the roles o f differential plant
establishment success (chapters i & ii), availability o f limiting resources (chapter iii) and the
availability o f canopy cover (chapter iv) as factors affecting vegetation dynamics following
catastrophic fire. the main findings of the research are (1) that at least part of the inhibition
pathway is caused by physical limitations on regeneration niches for black spruce and that the
biotic process of competition from kalmia is a less proximate cause o f forest regeneration
failure; (2) plant functional diversity and black spruce productivity are restricted spatially and
physiologically by patterns in fire severity; (3) burned habitats dominated by kalmia have
suppressed species richness and functional diversity irrespective o f low and high concentrations
o f limiting resources; (4) failure o f black spruce to re-colonize these sites and provide cover to
kalmia is associated with measurable reductions in soil microbial activity and herb abundance.
a recurring theme among these chapters is the inconsistency between the pattern o f stand
retrogression observed in eastern newfoundland and general theoretical models of succession as
they have developed in the ecological literature. as a result of these comparisons, this thesis
supports the view that the prevailing models of succession fail to be generalizable across
geographic and environmental gradients. in the eastern boreal forest, the factors of fire severity
and restriction o f regeneration niches for successional species are the critical aspects of
disturbance ecology which are not explicitly accounted for in existing successional models.
until general theories account for forces other than competition that potentially affect
community structure, a unified theory of plant succession will remain elusive. | |
| dc.language.iso | en_us | |
| dc.subject | forest regeneration effect of wildfires on newfoundland and labrador | |
| dc.subject | black spruce effect of wildfires on newfoundland and labrador | |
| dc.subject | sheep laurel and black spruce | |
| dc.title | direct and indirect effects of post-fire conditions on successional pathways and ecological processes in black spruce-kalmia forests | |
| dc.type | thesis | |
| etd.degree.name | master of science | |
| etd.degree.level | master | |
| etd.degree.discipline | biology | |
| etd.degree.grantor | 阿根廷vs墨西哥竞猜
| |
| dc.contributor.committeemember | mackereth, rob | |
| dc.contributor.committeemember | hecnar, stephen | |
| dc.contributor.committeemember | macdonald, alastair d. | |
