Kevin Mearns

Detecting changes in surface water area of Lake Kyoga sub-basin using remotely sensed imagery in a changing climate

Detection of changes in Earth surface features, for example lakes, is important for understanding the relationships between human and natural phenomena in order to manage better the increasingly scarce natural resources. This work presents a procedure of using modified normalised difference water index (MNDWI) to detect fluctuations of lake surface water area and relate it to a changing climate. The study used radiometrically and geometrically rectified Landsat images for 1986, 1995 and 2010 encompassing the Kyoga Basin lakes of Uganda, in order to investigate the changes in surface water area between the respective years. The standard precipitation index (SPI) and drought severity index (DSI) are applied to show the relationship between variability of surface water area and climate parameters. The present analysis reveals that surface water area fluctuation is linked to rainfall variability. In particular, Lake Kyoga sub-basin lakes experienced an increase in surface water area in 2010 compared to 1986. This work has important implications to water resources management for Lake Kyoga and could be vital to water resource managers across Ugandan lakes.

Assessing the phylogenetic dimension of Australian Acacia species introduced outside their native ranges

Abstract Biological invasion is a long process that starts with humans introducing intentionally (most of the time) species into a new environment to benefit from the ecosystem services that these species provide. Increasing evidence suggests that species providing ecosystem services might be phylogenetically closer than expected, but only a few studies actually demonstrate this. Also, recent studies indicate that naturalized and invasive species are two functionally distinct groups, but evidence that they are also two phylogenetically distinct groups is mixed. Using the set of Australian Acacia species known to have been introduced intentionally by humans to several parts of the world for the ecosystem services they provide, we first tested whether there is a phylogenetic pattern in the subset of introduced species. We found that species moved beyond Australia are phylogenetically more closely related than expected at random, suggesting that the ecosystem services that guide human-mediated introduction of these species into new areas (e.g. famine food, medicines, fuel, fodder, ornament) may be shared between closely related species. We also found that naturalized non-invasive and naturalized invasive species are closely related and both are not a phylogenetically random subset of introduced species based on mean phylogenetic distance, suggesting that naturalization and invasion processes may be phylogenetically mediated. Collectively, our study indicates that phylogeny might play different roles at different stages of the biological invasion process.

Managing stakeholder relations, natural resources and tourism: A case study from Ololosokwan, Tanzania:

This manuscript investigates the complexities and challenges in the management of the Ololosokwan community conservation area in Northern Tanzania. The conservation area is adjacent to the Serengeti National Park, just south of the Tanzanian-Kenyan Border where nomadic Maasai Pastoralists are free to cross international borders in search of grazing for their cattle. The Ololosokwan community is faced with the difficulties of managing a number of conflicting land-uses and community aspirations while striving toward the maintenance of a successful and sustainable community conservation area in collaboration with a private tourism operation. Benefit sharing was found to be an effective way in which to heal negative stakeholder engagements of the past, and active participation in the development of community livelihoods was found to be a more meaningful pursuit in this cause than merely sharing money. Despite opportunities for stakeholders to show that they are willing to work together, existing conflict is likely to continue as stakeholders still mistrust each other and often align themselves with groups that share common interests.

Lake Sibayi variations in response to climate variability in northern KwaZulu-Natal, South Africa

The optimal management of natural resources like lakes requires understanding the relationship with other environmental elements. Remote sensing techniques using multi-temporal and multi-sensor images for change detection purposes are important in this regard. This study used a combination of approaches to detect changes in the lake surface area of Lake Sibayi in relation to changes in past climates. Delineation of the study area is achieved using WR2012 endoreic maps and Landsat satellite images from 1992 to 2016. Using data from eight meteorological stations, past climate of the lake catchment was investigated. Thereafter, a multivariate correlation analysis is conducted to examine the relationship between the changes in the lake surface area and the changes in climatic (precipitation, temperature) variables and water levels. Results suggest that the lake surface area has decreased by 20% since 1992. There are significant changes in temperatures, while the annual rainfall totals declined significantly. The correlation between precipitation in the catchment and annual water level changes is 0.88. Statistically, significant increases in the water level and precipitation were experienced in 1993 and 2001. SPI analysis reveals that the study area is getting drier and the probability of recurrence of moderate dryness is 10%. The rate at which the lake is shrinking is not solely climatic related, as anthropogenic aspects are also responsible. To prevent further shrinkage of Lake Sibayi, it will be necessary to develop aggressive restoration policies and action plans aimed at maintaining inflows in the face of compounding climate change and water demand. Recommendations of the nature of further studies that can increase our understanding are included.

Analysis of landscape performance assessment by key stakeholders in a transfrontier conservation area

Abstract Stakeholder engagement has become an important aspect of sustainable natural resources management. This study analysed a landscape performance assessment by local and ‘external’ stakeholders in a transfrontier conservation area in Southern Africa. The landscape was divided into three agro-ecological zones and focus group discussions were facilitated for stakeholders to evaluate the landscape based on four ecoagriculture dimensions (production, conservation, livelihoods and institutions). The conservation dimension showed the best performance and the overall score for the landscape was 2.97, implying a fairly good performance. Perceptions and ratings did not significantly differ by age, gender or stakeholder groups. We conclude that despite their low levels of formal education and training, communal farmers can assess the performance of local landscapes in a consistent way. This study provides information about the degree to which the landscape under focus conformed to the main ecoagriculture goals and can guide development planning and extension service provision.

Khanyayo village and Mkhambathi Nature Reserve, South Africa: a pragmatic qualitative investigation into attitudes towards a protected area

ABSTRACT Protected areas are often surrounded by impoverished communities. Biodiversity must be conserved while enabling community members’ livelihoods. Benefit-sharing has been promoted as a means of fostering positive relationships between protected areas and local people, but views differ regarding which benefits have positive results; and which are most valued by communities themselves. This research investigates the attitudes of Khanyayo village towards Mkhambathi Nature Reserve on the Wild Coast of South Africa. A pragmatic, multi-method comparative qualitative approach was followed. Participants were local community members and key staff at Mkhambathi, who work with the community. Individual interviews, focus group interviews and an adapted nominal grouping technique were used, which aided triangulation. Results indicated a range of significant benefits and losses. Tangibles included access to natural resources, employment, infrastructure and training. More intangibles emerged though, such as enjoyment of reserve, involvement in the reserve, communication and environmental education. Losses predominantly related to prohibited or restricted access to natural resources. The comparison between the two participant groups yielded interesting insights. Knowing which benefits are most important to the community and aligning the perceptions of the people and the park staff could improve the relationship as well as enhance successful benefit-sharing.

Ethnobotany at a local scale: diversity of knowledge of medicinal plants and assessment of plant cultural importance in the Polokwane local municipality, South Africa

Abstract Unravelling the pattern of traditional plant usages in a society is necessary to inform interventions for biodiversity conservation. In the present study, we documented traditional knowledge of plant usages and analysed the pattern of culturally important plants along a phylogeny of South Africa’s medicinal plants. Data were collected through interviews, field visits and group discussions, and cultural importance was assessed using two metrics: use value (UVs) and quality use value of species (QUVs). K statistic was used to assess how UVs and QUVs values are distributed on a phylogeny. Overall, 50 medicinal plant species in 35 botanical families were reported. Fabaceae and Celastraceae contain more medicinal species than any other family, perhaps because of a wider distribution in the study area. Although there was no evidence that knowledge of medicinal uses varies significantly according to informant status, sex, ethnic group and age category, or residence time of the informant in the study area, traditional healers show a wider range of medicinal knowledge than any other informants. Culturally important plants are not significantly clustered on the phylogeny, suggesting a priori a limited value of phylogeny in identifying culturally valuable plants. However, this potential limitation could be driven by the local focus of the present study. We call for further investigations at a broader scale to establish potential phylogenetic signals in plant cultural importance.