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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Ecological genetics of two polymorphic enzymes in three species of Megalorchestia (Amphipoda:Talitridae)

McDonald, John H. 16 December 1983 (has links)
Graduation date: 1984
22

The political economy of public-private partnerships : forestry co-management in northwest Saskatchewan

Orb, Jocelyn D 30 April 2008
This thesis examines the political economy of public-private partnerships (PPPs), specifically how power has been shared among the partners involved in the co-management of forestry lands in Northwest Saskatchewan. It uncovers the political agendas of the groups involved, how decisions have been made and costs/benefits been shared, and considers the implications this model of co-management has for the future of forestry in this province. This study reveals a complex partnership in which power is not being shared equally. A private corporation, Mistik Management Ltd., possesses power over production, knowledge and credit. It purports to be working together with stakeholders in the co-management of forestry lands in Northwest Saskatchewan, but in truth Mistik is managing this resource with minimal input from forest users and residents in the region. The company does, however, appear sincere in its consultation process with stakeholders and is trying to improve the level of their engagement in day to day forestry operations. In addition, and despite this deficiency in stakeholder engagement, Mistik is practicing what is arguably the most environmentally sustainable forestry management in the province.
23

Spatial Patterns of Tree Invasion in an Old Field: Implications for Restoration

Buschert, Karen Elizabeth January 2008 (has links)
In north-eastern North America, abandoned agricultural fields typically revert to forest after many decades of spontaneous succession. This process can be influenced in part by nearby available propagule sources and their natural patterns of dispersal. Ecological restoration encompasses understanding this natural process and how it may influence active or passive restoration efforts. This study attempts to determine the spatial and temporal patterns of establishing trees arising in an old field at 10 years post-cultivation and the implications of this process on restoration at rare and other similar sites. The 0.8 ha field is situated at rare, an ecological reserve in Cambridge, Ontario and is bordered by forest or hedgerow on all sides. Using Environmental Monitoring and Assessment Network (EMAN) protocols, vegetation sampling was completed in the field and adjacent forest and hedgerow. A complete tree inventory was undertaken in the field, followed by a sampling of potential seed sources in the forest and hedgerow. ESRI ArcMap, a Geographic Information System (GIS) was utilized for both spatial representation and spatial analysis. Research revealed that the application of geostatistics to ecological data here and elsewhere in the literature has some specific challenges which need to be overcome for analysis of spatial data. Currently, the old field shows early signs of woody plant invasion from the nearby forest. Both trees and shrubs have become established, though not yet dominant. The primary dispersal of these species follows spatial patterns based on method of dispersal (wind, nut, fruit and clonal) and there is a higher degree of clustering of all species closer to the forest edge. Invasive species such as Rhamnus cathartica and Rhamnus frangula have become established in the old field and may influence successional patterns. Implications for restoration include the creation of goals and objectives which incorporate these natural processes into a future management plan. Specific recommendations include: 1) Develop a management strategy for invasive species such as Rhamnus spp. which can detrimentally affect restoration goals; 2) Continue to monitor EMAN plots for the production of time-series data on the same site; 3) Identify sites with good regeneration potential based on spatial patterns identified in this research and collect additional information such as soil conditions, canopy cover, etc.; 4) Extend the current GIS database created for this thesis to become an inventory of natural and cultural features for the reserve. Advanced spatial analysis required a more extensive data set and/or custom programming.
24

Spatial Patterns of Tree Invasion in an Old Field: Implications for Restoration

Buschert, Karen Elizabeth January 2008 (has links)
In north-eastern North America, abandoned agricultural fields typically revert to forest after many decades of spontaneous succession. This process can be influenced in part by nearby available propagule sources and their natural patterns of dispersal. Ecological restoration encompasses understanding this natural process and how it may influence active or passive restoration efforts. This study attempts to determine the spatial and temporal patterns of establishing trees arising in an old field at 10 years post-cultivation and the implications of this process on restoration at rare and other similar sites. The 0.8 ha field is situated at rare, an ecological reserve in Cambridge, Ontario and is bordered by forest or hedgerow on all sides. Using Environmental Monitoring and Assessment Network (EMAN) protocols, vegetation sampling was completed in the field and adjacent forest and hedgerow. A complete tree inventory was undertaken in the field, followed by a sampling of potential seed sources in the forest and hedgerow. ESRI ArcMap, a Geographic Information System (GIS) was utilized for both spatial representation and spatial analysis. Research revealed that the application of geostatistics to ecological data here and elsewhere in the literature has some specific challenges which need to be overcome for analysis of spatial data. Currently, the old field shows early signs of woody plant invasion from the nearby forest. Both trees and shrubs have become established, though not yet dominant. The primary dispersal of these species follows spatial patterns based on method of dispersal (wind, nut, fruit and clonal) and there is a higher degree of clustering of all species closer to the forest edge. Invasive species such as Rhamnus cathartica and Rhamnus frangula have become established in the old field and may influence successional patterns. Implications for restoration include the creation of goals and objectives which incorporate these natural processes into a future management plan. Specific recommendations include: 1) Develop a management strategy for invasive species such as Rhamnus spp. which can detrimentally affect restoration goals; 2) Continue to monitor EMAN plots for the production of time-series data on the same site; 3) Identify sites with good regeneration potential based on spatial patterns identified in this research and collect additional information such as soil conditions, canopy cover, etc.; 4) Extend the current GIS database created for this thesis to become an inventory of natural and cultural features for the reserve. Advanced spatial analysis required a more extensive data set and/or custom programming.
25

The political economy of public-private partnerships : forestry co-management in northwest Saskatchewan

Orb, Jocelyn D 30 April 2008 (has links)
This thesis examines the political economy of public-private partnerships (PPPs), specifically how power has been shared among the partners involved in the co-management of forestry lands in Northwest Saskatchewan. It uncovers the political agendas of the groups involved, how decisions have been made and costs/benefits been shared, and considers the implications this model of co-management has for the future of forestry in this province. This study reveals a complex partnership in which power is not being shared equally. A private corporation, Mistik Management Ltd., possesses power over production, knowledge and credit. It purports to be working together with stakeholders in the co-management of forestry lands in Northwest Saskatchewan, but in truth Mistik is managing this resource with minimal input from forest users and residents in the region. The company does, however, appear sincere in its consultation process with stakeholders and is trying to improve the level of their engagement in day to day forestry operations. In addition, and despite this deficiency in stakeholder engagement, Mistik is practicing what is arguably the most environmentally sustainable forestry management in the province.
26

Ecological Differentiation in a Hybridizing Cryptic Species Complex

TURKO, PATRICK 04 January 2012 (has links)
The hybridizing Daphnia mendotae and D. dentifera (Crustacea: Cladocera) are sympatric throughout much of North America, and are considered a cryptic species complex due to their lack of phylogenetically informative morphological characters. They appear to have no biological mating barriers: hybrids may dominate or coexist with either or both parental species, and are sexually competent, forming both F2 hybrids and back-crosses. Nevertheless, the two species remain distinct. There is observational evidence that separation may be enforced by adaptation to different predation regimes: D. mendotae, with its greater anti-predator morphological plasticity, may out-compete D. dentifera under intense invertebrate predation, while the smaller D. dentifera may be better adapted to avoid predation by visually feeding fish. We tested this idea by examining whether D. mendotae and D. dentifera differ in ecologically relevant life history and morphological traits. We performed a replicated life history experiment involving 6 replicates of 6 clones within each species, and measured time until first reproduction, fecundity, and juvenile and population growth rates. In parallel, we examined whether these species differed in morphological traits predicted to arise from adaptation to different predator types, and tested the ecological relevance of these traits by exposing Daphnia to predation by the invasive cladoceran Bythotrephes longimanus. Finally, we examined the plasticity of life history, morphology, and susceptibility to predation by rearing Daphnia under exposure to Bythotrephes chemical cues for two generations. D. mendotae and D. dentifera differed across almost all measured life history and morphological traits in directions that accord with our hypotheses, strongly suggesting that their species boundaries are maintained by adaptation to different predation regimes. Plastic reaction to Bythotrephes, however, was weak and inconsistent, suggesting that these species either do not detect or respond to this recent invader, or that their responses are manifested in other ways. / Thesis (Master, Biology) -- Queen's University, 2011-12-23 20:31:14.76
27

Ecologically conscious consumer behaviour : a research project conducted in Thessaloniki, Greece

Tilikidou, Irene January 2001 (has links)
No description available.
28

The genetics of cultivar and host specificity of Phytophthora sojae and P. vignae

May, K. Unknown Date (has links)
No description available.
29

Uncertainty analysis in ecological risk assessment modeling

Thongsri, Tepwitoon. January 1900 (has links)
Thesis (Ph. D.)--New Jersey Institute of Technology, 2004. / Adviser: Lisa Axe. Includes bibliographical references.
30

Ecological investigations of euphausiids at high latitudes /

Saunders, Ryan Alexander. January 2007 (has links)
Thesis (Ph.D.) - University of St Andrews, June 2007.

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