Perceptions of the role of Lantana camara on human well-being and rural livelihoods in Vhembe Biosphere Reserve, South Africa
- Authors: Mhlongo, Edward Swazi
- Date: 2021-04
- Subjects: Lantana camara -- South Africa -- Vhembe District Municipality , Introduced organisms -- South Africa -- Vhembe District Municipality , Biological invasions -- South Africa -- Vhembe District Municipality , Plant invasions -- South Africa -- Vhembe District Municipality , Lantana camara -- Control -- South Africa -- Vhembe District Municipality , South Africa -- Rural conditions , Ethnoscience -- South Africa -- Vhembe District Municipality
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177952 , vital:42893
- Description: In the past, social aspects on biological invasions were less documented, this hindered the development of sound and effective management of Invasive Alien Species (IAS). However, there has been a shift in trends with more studies on biological invasions integrating local knowledge together with ecological studies to develop effective management interventions. Invasive Alien Species are widespread throughout Southern Africa and are usually prevalent in the rural areas. Limpopo province consists of large rural areas where people depend on natural resources, wild and exotic species for their livelihoods. Lantana camara is one of the major invaders that is problematic worldwide having detrimental impacts on biodiversity, ecosystem functions, and economies. This study assessed the perceptions of the role of L. camara on the well-being and rural livelihoods of local communities in the Vhembe Biosphere Reserve using household surveys. A total of 300 surveys were administered in six villages. The study further used a two-pronged approach to examine invasion extent and management options. The two-pronged approach included (i) detailed vegetation surveys in 50 household yards within each village, and (ii) focus group to solicit local knowledge of invasion extent and managing L. camara by the rural communities. The results of the study showed that almost all the respondents knew L. camara and could describe it. Most of the respondents were of the view that L. camara had no negative impacts on their livelihoods. Other respondents stated costs associated with L. camara were more than benefits and wanted a reduction in L. camara densities in the area. Most respondents wanted more government intervention to help in managing L. camara, this is because of the perceived future impacts of L. camara. Vegetation survey results showed no significant difference in L. camara abundances and plant heights among the six study villages. The average number of L. camara counted per household yard in all villages was (2.41 ± 0.20) plants, with average plant basal diameter of (0.94 ± 0.02 cm). There were significant differences in canopy width of L. camara among the six study villages. Plant basal diameter was high in Tshakhuma (1.05 ± 0.04 m) and Duthuni (1.00 ± 0.04 m) villages, and low in Ha Mutsha village (0.82 ± 0.03 m). Lantana camara canopy width at household level across all villages averaged 1.34 ± 0.03 m. Canopy cover was high in Tshakhuma village (1.70 ± 0.09 m) and low at Ha Mutsha village (1.03 ± 0.03 m). In all six village focus group discussions, it was noted that mechanical clearing of L. camara was the most used method, but they reported minimum help from the government particularly Working for Water (WfW). The study concludes that L. camara has no substantial adverse impacts to most of the respondents. The study further noted that L. camara is dominant in most household yards ii and that management is taking place however current control options are not enough on their own. Suggestions for further research are to explore more alternative indigenous species present or easily accessible to the community members which may offer the same benefits as IAS. Furthermore, additional research at local level is required for implementing management techniques best suited for the area. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
- Authors: Mhlongo, Edward Swazi
- Date: 2021-04
- Subjects: Lantana camara -- South Africa -- Vhembe District Municipality , Introduced organisms -- South Africa -- Vhembe District Municipality , Biological invasions -- South Africa -- Vhembe District Municipality , Plant invasions -- South Africa -- Vhembe District Municipality , Lantana camara -- Control -- South Africa -- Vhembe District Municipality , South Africa -- Rural conditions , Ethnoscience -- South Africa -- Vhembe District Municipality
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177952 , vital:42893
- Description: In the past, social aspects on biological invasions were less documented, this hindered the development of sound and effective management of Invasive Alien Species (IAS). However, there has been a shift in trends with more studies on biological invasions integrating local knowledge together with ecological studies to develop effective management interventions. Invasive Alien Species are widespread throughout Southern Africa and are usually prevalent in the rural areas. Limpopo province consists of large rural areas where people depend on natural resources, wild and exotic species for their livelihoods. Lantana camara is one of the major invaders that is problematic worldwide having detrimental impacts on biodiversity, ecosystem functions, and economies. This study assessed the perceptions of the role of L. camara on the well-being and rural livelihoods of local communities in the Vhembe Biosphere Reserve using household surveys. A total of 300 surveys were administered in six villages. The study further used a two-pronged approach to examine invasion extent and management options. The two-pronged approach included (i) detailed vegetation surveys in 50 household yards within each village, and (ii) focus group to solicit local knowledge of invasion extent and managing L. camara by the rural communities. The results of the study showed that almost all the respondents knew L. camara and could describe it. Most of the respondents were of the view that L. camara had no negative impacts on their livelihoods. Other respondents stated costs associated with L. camara were more than benefits and wanted a reduction in L. camara densities in the area. Most respondents wanted more government intervention to help in managing L. camara, this is because of the perceived future impacts of L. camara. Vegetation survey results showed no significant difference in L. camara abundances and plant heights among the six study villages. The average number of L. camara counted per household yard in all villages was (2.41 ± 0.20) plants, with average plant basal diameter of (0.94 ± 0.02 cm). There were significant differences in canopy width of L. camara among the six study villages. Plant basal diameter was high in Tshakhuma (1.05 ± 0.04 m) and Duthuni (1.00 ± 0.04 m) villages, and low in Ha Mutsha village (0.82 ± 0.03 m). Lantana camara canopy width at household level across all villages averaged 1.34 ± 0.03 m. Canopy cover was high in Tshakhuma village (1.70 ± 0.09 m) and low at Ha Mutsha village (1.03 ± 0.03 m). In all six village focus group discussions, it was noted that mechanical clearing of L. camara was the most used method, but they reported minimum help from the government particularly Working for Water (WfW). The study concludes that L. camara has no substantial adverse impacts to most of the respondents. The study further noted that L. camara is dominant in most household yards ii and that management is taking place however current control options are not enough on their own. Suggestions for further research are to explore more alternative indigenous species present or easily accessible to the community members which may offer the same benefits as IAS. Furthermore, additional research at local level is required for implementing management techniques best suited for the area. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2021
- Full Text:
A community–wide trophic structure analysis in intertidal ecosystems on the south coast of South Africa
- Authors: Gusha, Molline Natanah C
- Date: 2018
- Subjects: Food chains (Ecology) , Coastal ecology -- South Africa , Intertidal ecology -- South Africa , Marine animals -- Climatic factors -- South Africa , Marine animals -- Food -- South Africa , Marine animals -- Habitat -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63312 , vital:28392
- Description: Coastal ecosystems are more than microhabitats for marine species. Acting as atmospheric carbon filters, species in coastal environments are directly and/or indirectly associated with transferring organic carbon to species at higher trophic levels. However, the progressing change in global climatic conditions has created the need to assess the consequences of the shifting conditions on both direct and indirect interactions of physical and biological parameters at species and/or community levels. From these perturbations, the effects of biotic homogenization on ecosystem functioning and resilience can also be realised. Herein, I discuss the effects of temperature, nutrients, biotic interactions and habitat characteristics on community dynamics within intertidal rock pool systems on the south coast of South Africa using complementary qualitative and quantitative analytical methods. Seasonality had a significant impact on rock pool species with changes in composition and higher richness in winter than summer. The first two axes of the Canonical Correspondence Analysis (CCA) of the plant and animal communities each explained ~20% of the relationship between physico-chemical parameters and biological variables. The CCA highlighted that seasonal shifts in chlorophyll-a, conductivity, salinity, water depth, surface area and substratum type indirectly influenced species composition. For example, pools with heterogenous substratum comprising a mixture of sand and rock exhibited higher species diversity than homogenously bedded pools. Furthermore, a Bayesian analysis of community structure based on stable isotope ratios was used to assess how trophic pathways of carbon and nitrogen elements reflected community composition and richness. Isotopic biplots showed an increase in food web size, food chain length and the trophic positions of fish and some gastropods in winter compared to summer. There was greater dietary overlap among species in larger pools. In addition, while isotopic nearest neighbour distance and species evenness also showed a positive increase with pool size in summer, the same metrics were almost constant across all pool sizes in winter. These changes in food web packing and species evenness suggest seasonal preferences or migration of species in summer from small pools to larger pools with stable physico-chemical parameters. Furthermore, the presence of fish was seen to promote trophic diversity within some pools. The results from laboratory microcosm grazing experiments demonstrated significant direct and indirect effects of temperature and nutrients within plankton communities. Copepod grazing had an indirect positive influence on phytoplankton biomass and size structure while the interactive effects of temperature and nutrients had contrasting effects on both phytoplankton communities and copepod biomass. Shifts in water chemistry and nutrient treatments were also observed in the presence of copepods. Phosphate addition had a recognisable impact on plankton communities. The presented synthesis of the literature mainly highlighted that positive effects at one trophic level do not always positively cascade into the next trophic level which is evidence of complex interactive biotic, habitat and water chemistry effects within these intertidal ecosystems. Thus, to further understand cascading effects or community structure functioning in general, there may be a need to incorporate and understand species functional traits and how they contribute to trophic diversity, community restructuring and functioning in coastal habitats.
- Full Text:
- Authors: Gusha, Molline Natanah C
- Date: 2018
- Subjects: Food chains (Ecology) , Coastal ecology -- South Africa , Intertidal ecology -- South Africa , Marine animals -- Climatic factors -- South Africa , Marine animals -- Food -- South Africa , Marine animals -- Habitat -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63312 , vital:28392
- Description: Coastal ecosystems are more than microhabitats for marine species. Acting as atmospheric carbon filters, species in coastal environments are directly and/or indirectly associated with transferring organic carbon to species at higher trophic levels. However, the progressing change in global climatic conditions has created the need to assess the consequences of the shifting conditions on both direct and indirect interactions of physical and biological parameters at species and/or community levels. From these perturbations, the effects of biotic homogenization on ecosystem functioning and resilience can also be realised. Herein, I discuss the effects of temperature, nutrients, biotic interactions and habitat characteristics on community dynamics within intertidal rock pool systems on the south coast of South Africa using complementary qualitative and quantitative analytical methods. Seasonality had a significant impact on rock pool species with changes in composition and higher richness in winter than summer. The first two axes of the Canonical Correspondence Analysis (CCA) of the plant and animal communities each explained ~20% of the relationship between physico-chemical parameters and biological variables. The CCA highlighted that seasonal shifts in chlorophyll-a, conductivity, salinity, water depth, surface area and substratum type indirectly influenced species composition. For example, pools with heterogenous substratum comprising a mixture of sand and rock exhibited higher species diversity than homogenously bedded pools. Furthermore, a Bayesian analysis of community structure based on stable isotope ratios was used to assess how trophic pathways of carbon and nitrogen elements reflected community composition and richness. Isotopic biplots showed an increase in food web size, food chain length and the trophic positions of fish and some gastropods in winter compared to summer. There was greater dietary overlap among species in larger pools. In addition, while isotopic nearest neighbour distance and species evenness also showed a positive increase with pool size in summer, the same metrics were almost constant across all pool sizes in winter. These changes in food web packing and species evenness suggest seasonal preferences or migration of species in summer from small pools to larger pools with stable physico-chemical parameters. Furthermore, the presence of fish was seen to promote trophic diversity within some pools. The results from laboratory microcosm grazing experiments demonstrated significant direct and indirect effects of temperature and nutrients within plankton communities. Copepod grazing had an indirect positive influence on phytoplankton biomass and size structure while the interactive effects of temperature and nutrients had contrasting effects on both phytoplankton communities and copepod biomass. Shifts in water chemistry and nutrient treatments were also observed in the presence of copepods. Phosphate addition had a recognisable impact on plankton communities. The presented synthesis of the literature mainly highlighted that positive effects at one trophic level do not always positively cascade into the next trophic level which is evidence of complex interactive biotic, habitat and water chemistry effects within these intertidal ecosystems. Thus, to further understand cascading effects or community structure functioning in general, there may be a need to incorporate and understand species functional traits and how they contribute to trophic diversity, community restructuring and functioning in coastal habitats.
- Full Text:
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