Gully erosion as a mechanism for wetland formation: an examination of two contrasting landscapes
- Pulley, Simon, Ellery, William F N, Lagesse, Juliette V, Schlegel, P Philippa, McNamara, Shaun J
- Authors: Pulley, Simon , Ellery, William F N , Lagesse, Juliette V , Schlegel, P Philippa , McNamara, Shaun J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144410 , vital:38343 , DOI: 10.1002/ldr.2972
- Description: Wetlands occupy broad, gently sloping valleys characterised by net deposition. Consequently, gully incision is viewed as an agent of wetland destruction. However, little attention has been given to the role of gullies in natural wetland formation. This paper determines if gully cutting and filling cycles have led to wetland formation in both an extant eroding wetland and a semi‐arid environment that once supported wetlands. At both sites, the valley fill was investigated to identify infilled gullies, and a 14C date was obtained from the gully fill.
- Full Text:
- Date Issued: 2018
- Authors: Pulley, Simon , Ellery, William F N , Lagesse, Juliette V , Schlegel, P Philippa , McNamara, Shaun J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144410 , vital:38343 , DOI: 10.1002/ldr.2972
- Description: Wetlands occupy broad, gently sloping valleys characterised by net deposition. Consequently, gully incision is viewed as an agent of wetland destruction. However, little attention has been given to the role of gullies in natural wetland formation. This paper determines if gully cutting and filling cycles have led to wetland formation in both an extant eroding wetland and a semi‐arid environment that once supported wetlands. At both sites, the valley fill was investigated to identify infilled gullies, and a 14C date was obtained from the gully fill.
- Full Text:
- Date Issued: 2018
Orí (Head) as an xxpression of Yorùbá aesthetic philosophy:
- Ajíbóyè, Olusegun, Fọlárànmí, Stephen, Umoru-Ọkẹ, Nanashaitu
- Authors: Ajíbóyè, Olusegun , Fọlárànmí, Stephen , Umoru-Ọkẹ, Nanashaitu
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146145 , vital:38499 , DOI https://doi.org/10.2478/mjss-2018-0115
- Description: Aesthetics was never a subject or a separate philosophy in the traditional philosophies of black Africa. This is however not a justification to conclude that it is nonexistent. Indeed, aesthetics is a day to day affair among Africans. There are criteria for aesthetic judgment among African societies which vary from one society to the other. The Yorùbá of Southwestern Nigeria are not different. This study sets out to examine how the Yorùbá make their aesthetic judgments and demonstrate their aesthetic philosophy in decorating their orí, which means head among the Yorùbá. The head receives special aesthetic attention because of its spiritual and biological importance. It is an expression of the practicalities of Yorùbá aesthetic values. Literature and field work has been of paramount aid to this study. The study uses photographs, works of art and visual illustrations to show the various ways the head is adorned and cared for among the Yoruba. It relied on Yoruba art and language as a tool of investigating the concept of ori and aesthetics. Yorùbá aesthetic values are practically demonstrable and deeply located in the Yorùbá societal, moral and ethical idealisms. It concludes that the spiritual importance of orí or its aesthetics has a connection which has been demonstratively established by the Yorùbá as epressed in the images and illustrations used in this paper.
- Full Text:
- Date Issued: 2018
- Authors: Ajíbóyè, Olusegun , Fọlárànmí, Stephen , Umoru-Ọkẹ, Nanashaitu
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146145 , vital:38499 , DOI https://doi.org/10.2478/mjss-2018-0115
- Description: Aesthetics was never a subject or a separate philosophy in the traditional philosophies of black Africa. This is however not a justification to conclude that it is nonexistent. Indeed, aesthetics is a day to day affair among Africans. There are criteria for aesthetic judgment among African societies which vary from one society to the other. The Yorùbá of Southwestern Nigeria are not different. This study sets out to examine how the Yorùbá make their aesthetic judgments and demonstrate their aesthetic philosophy in decorating their orí, which means head among the Yorùbá. The head receives special aesthetic attention because of its spiritual and biological importance. It is an expression of the practicalities of Yorùbá aesthetic values. Literature and field work has been of paramount aid to this study. The study uses photographs, works of art and visual illustrations to show the various ways the head is adorned and cared for among the Yoruba. It relied on Yoruba art and language as a tool of investigating the concept of ori and aesthetics. Yorùbá aesthetic values are practically demonstrable and deeply located in the Yorùbá societal, moral and ethical idealisms. It concludes that the spiritual importance of orí or its aesthetics has a connection which has been demonstratively established by the Yorùbá as epressed in the images and illustrations used in this paper.
- Full Text:
- Date Issued: 2018
Plant–herbivore–parasitoid interactions in an experimental freshwater tritrophic system: higher trophic levels modify competitive interactions between invasive macrophytes
- Martin, Grant D, Coetzee, Julie A, Compton, Stephen
- Authors: Martin, Grant D , Coetzee, Julie A , Compton, Stephen
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/103892 , vital:32321 , https://doi.org/10.1007/s10750-017-3417-7
- Description: Natural enemies are known to modify competitive hierarchies among terrestrial plants. Here we examine whether the same applies to freshwater systems. Lagarosiphon major (Hydrocharitaceae) is a submerged aquatic macrophyte, indigenous to South Africa. Outside its native range, it outcompetes with indigenous submerged species and degrades aquatic habitats. Hydrellia lagarosiphon (Diptera: Ephydridae) is the most abundant and ubiquitous herbivore associated with L. major in South Africa and is a potential biological control agent elsewhere. Chaenusa anervata (Hymenoptera: Braconidae: Alysiinae) is its main parasitoid. We generated an experimental system involving one, two or three trophic levels to monitor variation in the competitive ability of L. major relative to that of Myriophyllum spicatum (Haloragaceae), a second submerged macrophyte that can also be invasive. Using inverse linear models to monitor competition, we found that herbivory by H. lagarosiphon greatly reduced the competitive ability of L. major. Addition of the wasp at typical field densities halved the impact of herbivory and re-established the competitive advantage of L. major. Our results demonstrate how multitrophic interactions modify relative competitive abilities among aquatic plants, emphasize the significance of higher tropic levels in these systems and illustrate how parasitoids can reduce the effectiveness of insects released as biocontrol agents.
- Full Text:
- Date Issued: 2018
- Authors: Martin, Grant D , Coetzee, Julie A , Compton, Stephen
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/103892 , vital:32321 , https://doi.org/10.1007/s10750-017-3417-7
- Description: Natural enemies are known to modify competitive hierarchies among terrestrial plants. Here we examine whether the same applies to freshwater systems. Lagarosiphon major (Hydrocharitaceae) is a submerged aquatic macrophyte, indigenous to South Africa. Outside its native range, it outcompetes with indigenous submerged species and degrades aquatic habitats. Hydrellia lagarosiphon (Diptera: Ephydridae) is the most abundant and ubiquitous herbivore associated with L. major in South Africa and is a potential biological control agent elsewhere. Chaenusa anervata (Hymenoptera: Braconidae: Alysiinae) is its main parasitoid. We generated an experimental system involving one, two or three trophic levels to monitor variation in the competitive ability of L. major relative to that of Myriophyllum spicatum (Haloragaceae), a second submerged macrophyte that can also be invasive. Using inverse linear models to monitor competition, we found that herbivory by H. lagarosiphon greatly reduced the competitive ability of L. major. Addition of the wasp at typical field densities halved the impact of herbivory and re-established the competitive advantage of L. major. Our results demonstrate how multitrophic interactions modify relative competitive abilities among aquatic plants, emphasize the significance of higher tropic levels in these systems and illustrate how parasitoids can reduce the effectiveness of insects released as biocontrol agents.
- Full Text:
- Date Issued: 2018
Pro-Environmental behaviour in student residences at Rhodes University, South Africa:
- Thondhlana, Gladman, Hlatshwayo, Thina N
- Authors: Thondhlana, Gladman , Hlatshwayo, Thina N
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144288 , vital:38328 , https://doi.org/10.3390/su10082746
- Description: Human behaviour is at the centre of most environmental problems; hence, the promotion of pro-environmental behaviour is considered to be a pathway towards sustainability. Despite the availability of insights gained from pro-environmental behaviour studies, mainly from household and workplace settings, a key question remains—can these insights be applied in university residence settings? Within university campuses, student residences are a major entity in sustainability debates because they are major consumers of resources including paper, water and energy with severe repercussions for university budgets and the environment. Using a questionnaire survey, this study explores reported pro-environmental behaviour and its determinants at Rhodes University, South Africa. Data were analysed using descriptive and inferential statistics where relevant. The findings show a high level of heterogeneity in reported pro-environmental behaviour, attributed to a suite of internal and external factors. Internal dispositional factors seemed to constrain students from acting pro-environmentally. This study highlights the need to encourage environmental behaviour in university residence settings by supporting the antecedents of and getting rid of barriers to pro-environmental actions.
- Full Text:
- Date Issued: 2018
- Authors: Thondhlana, Gladman , Hlatshwayo, Thina N
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144288 , vital:38328 , https://doi.org/10.3390/su10082746
- Description: Human behaviour is at the centre of most environmental problems; hence, the promotion of pro-environmental behaviour is considered to be a pathway towards sustainability. Despite the availability of insights gained from pro-environmental behaviour studies, mainly from household and workplace settings, a key question remains—can these insights be applied in university residence settings? Within university campuses, student residences are a major entity in sustainability debates because they are major consumers of resources including paper, water and energy with severe repercussions for university budgets and the environment. Using a questionnaire survey, this study explores reported pro-environmental behaviour and its determinants at Rhodes University, South Africa. Data were analysed using descriptive and inferential statistics where relevant. The findings show a high level of heterogeneity in reported pro-environmental behaviour, attributed to a suite of internal and external factors. Internal dispositional factors seemed to constrain students from acting pro-environmentally. This study highlights the need to encourage environmental behaviour in university residence settings by supporting the antecedents of and getting rid of barriers to pro-environmental actions.
- Full Text:
- Date Issued: 2018
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