| dc.contributor.author | Lazo, M. L. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:29Z | |
| dc.date.issued | 1992 | en_US |
| dc.identifier.other | AAINN80158 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55328 | |
| dc.description | The objectives were to determine the main factors that influence the growth of the seaweed Ascophyllum nodosum stands in southwestern Nova Scotia. A demographic approach was taken. Response variables were assessed at each life-cycle stage. A method to distinguish stages in the life cycle of modules was developed. Experimental studies were conducted to determine the effects of harvesting intensity and season, interference and herbivory on growth, reproduction, vegetative spread and survival. | en_US |
| dc.description | The relationship between size and reproduction determined 4 life cycle stages. These were, class 1, below a minimum critical size needed for reproduction, class 2 and 3 within reproductive size, with class 2 being vegetative and class 3 reproductive, and class 4 the largest modules and almost always reproductive. This class also produced 10 times more eggs than modules in class 3. | en_US |
| dc.description | Harvesting intensity and season did not appear to affect growth in size. The response of all classes (except class 4) was similar in that they all grew on average 10 cm in two years. Growth decreased with life cycle stage, with class 4 experiencing breakage rather than increases in size. As class 1 and 2 were the most numerous classes and of the fastest growth rates, the regrowth rate of a stand depends upon the numbers of modules in classes 1 and 2. | en_US |
| dc.description | Interference influenced vegetative spread, growth in biomass and reproduction but effects were unusual. Low density promoted module natality but modules did not grow in size. High density inhibited vegetative spread but enhanced growth in size. More modules attained reproduction at high than at low densities. High density exerted a negative effect on the formation of class 1 modules but the effect on the other classes was positive or negative. | en_US |
| dc.description | Herbivores consumed 99% of the germlings in one year but did not affect modules. Vegetative spread emerged as a key factor of population growth. The present study suggested that the main factors that influence population growth are the growth rates of the smallest modules, interference and vegetative spread. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1992. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Ecology. | en_US |
| dc.title | Demography of harvested populations of Ascophyllum nodosum. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
