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Title: Birch regeneration in heathland vegetation
Author: Gong, Wooi Khoon
ISNI:       0000 0001 3503 6562
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1976
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During its life-history, Calluna undergoes morphological changes which are important with respect to its interactions with other species. Four main phases, with distinctive characteristics can be recognized. Birch regeneration in heathland vegetation appears to be affected by these phases and the corresponding changes in vegetation and environment. This study aimed to test this hypothesis and to determine the factors responsible. Various experiments conducted in the field confirm that birch entry into Calluna heathlands is affected by the growth phases, being easier in recently burnt, pioneer and degenerate areas than in vigorous building and mature areas. The evidence includes the higher density of birch and the better performance of birch seedlings in the first three of these types of area. The close correspondence in age of birch with age of 'associated' Calluna suggests that birch and Calluna enter at the same time when a gap occurs in the canopy. All the factors considered are of some importance. The density of birch is dependent on the seed inoculum, and entry of seed to the ground level may be affected by the Calluna canopy. The seedbeds found in pioneer and degenerate Calluna are more favourable than those typical of building and mature Calluna because there is less interference from vegetation and the nutrient status is higher in the former. The microclimatic conditions characteristic of pioneer (and degenerate) Calluna are more favourable than those typical of building (and mature) plants. The most important factors are temperature and soil moisture for seed germination and light for seedling performance. Under the conditions of several experiments, no evidence was found for the production of a factor toxic to birch. Absence of grazing by domestic animals may contribute to the success of birch in the areas considered. The implications in the management of upland heaths in Scotland, and Dinnet Muir in particular, are discussed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available