Spatial and temporal analysis of the critical zone in the Western rift valley corridor: towards earth stewardship science in East Africa

Over the coming decades, Africa is expected to experience disturbing effects due to climate change and increased land cover change due to human influences presenting a significant concern for the future well-being of human and biological systems, the latter being the foundation of ecosystem services supplied to humanity. Therefore, unprecedented transdisciplinary cooperation, coordination, and integration amongst researchers, government, and civil society are necessary to increase the resiliency of these systems. This study aims to provide an outline of the Africa Alive Corridors (AAC) as an essential model for the encouragement of sustainable development through Earth Stewardship science. These aims are accompanied by the quantification and forward modelling for land cover change of the Critical Zone over 10 Great Lake Basins across one of the AAC, the Western Rift Valley Corridor (WRVC), in East Africa between the years 2018 and 2060. This approach provides the foundation for implementing improved regional governance, better encouragement of sustainable development beyond the 2030 United Nations Sustainable Development Goals, and education programs, such as the AAC, that promote socio-ecological resilience through Earth Stewardship Science. The AAC archives a portion of East Africa as the WRVC, a corridor along the western branch of the East African Rift System that highlights twenty heritage nodes, primarily great lakes, mountain ranges, national parks, and biological hotspots. These heritage entities are associated with ca. 12-million-years of evolution and transformation of the East African topography and related African Great Lake (AGL) systems. The thesis defines the study area by delineating AGL basins intersected by the WRVC. Across these basins, land cover change analysis provides a platform for an integrated assessment of the projected health of the corridor region. Existing land cover datasets provide the initial conditions of the study area for 2008 and 2013. Land cover between 2008 and 2013 is cross-tabulated using the Land Cover Module in the Terrset software, followed by the iii delineation of sub-models and driver variable identification. The Multi-Layer Perceptron algorithm provides the transition potentials between tree cover, urban area, cropland, wetland, and open area classes. Change quantification and prediction using Markov Chain analysis are then established for 2018, 2030, and 2060. The model successfully simulated future land cover change and concluded that: (1) proximity to existing human activity, proximity to existing tree cover, and population are the primary drivers of change; (2) the dominant land cover of the ten lake basins for 2018 was cropland at ca. 48%, followed by tree cover at ca. 33%; (3) total anthropogenic change over the coming four decades equates to over ca. 52 000 km2 (5 200 000 ha), and particularly (4) an urban area is expected to increase by >130%. This assessment ultimately provides a platform for regional governance development at the basin scale and Earth Stewardship science in East Africa. These changes require transdisciplinary action from researchers to civil society. The AAC provides the foundation for understanding the dynamics of the systems that support life across broader spatial and temporal resolutions in Africa, highlighting the need for future generations to build socio-ecological resilience to anticipate challenges such as biodiversity loss posed by climate change and excessive land cover change.Thesis (DSc) -- Faculty of Science, School of Environmental Sciences, 202

Diversification of shrub frogs (Rhacophoridae, Pseudophilautus) in Sri Lanka - Timing and geographic context

US National Science Foundation (DEB 0345885) to CJS and JH; National Geographic Society (7612-04) to CJS; and Society of Systematic Biologists Graduate Student Award for Research to MM. MM was also supported by a Harvard University Center for the Environment (HUCE) Ziff Environmental Postdoctoral Fellowship. (DEB 0345885 - US National Science Foundation; 7612-04 - National Geographic Society; Society of Systematic Biologists Graduate Student Award for Research; Harvard University Center for the Environment (HUCE) Ziff Environmental Postdoctoral Fellowship)Accepted manuscrip

Assessing human impacts on Lake Tanganyika cichlid fish communities

This thesis assesses the human impacts on rocky shore cichlid fish communities from the biodiversity hotspot Lake Tanganyika, by comparing the diversity of its protected and unprotected areas. Chapters two and three use cichlid community composition data collected from a range of localities in the Tanzanian section of Lake Tanganyika, to investigate whether human impact is negatively affecting their species, functional, and phylogenetic diversity, and to assess whether protected areas are conserving these components of diversity. In terms of species diversity, alpha diversity was higher in protected areas than adjacent unprotected localities, and the pattern of beta and zeta diversity in protected areas indicate a more even community composition. Additionally, benthic feeding herbivores were the most affected trophic group. Functional diversity, which was defined as the shape variation of geometric morphometric landmarks reflecting key traits, was also higher in protected areas than adjacent unprotected localities, as was phylogenetic diversity. Furthermore, functional and phylogenetic diversity were both linked to species richness, possibly due to a lack of variation in species uniqueness. Chapter four investigates the possible reasons for changes in cichlid diversity in unprotected areas using stable isotope and stomach content analysis. Benthic feeding species from the most disturbed locality had significantly higher nitrogen stable isotopes and stomach sediment proportions than a less disturbed locality, which may contribute to the lower species diversity of this trophic group. In conclusion, protection from human disturbance prevents a reduction in the core components of cichlid fish diversity in Lake Tanganyika, and therefore the network of freshwater and terrestrial protected areas should be increased. Moreover, protection of species appears to be an effective conservation strategy for the core components of biodiversity, so species richness could be used as a surrogate for biodiversity assessments in other systems

CONSERVATION LIMNOGEOLOGY AND BENTHIC HABITAT MAPPING IN CENTRAL LAKE TANGANYIKA (TANZANIA)

Small scale protected zones are valuable for helping the health and productivity of fisheries at Lake Tanganyika (East Africa). Spatial placement of protected areas relies on accurate maps of benthic habitats, consisting of detailed bathymetry data and information on lake-floor substrates. This information is unknown for most of Lake Tanganyika. Fish diversity is known to correlate with rocky substrates in ≤ 30 m water depth, which provide spawning grounds for littoral and pelagic species. These benthic habitats form important targets for protected areas, if they can be precisely located. At the NMVA, echosounding defined the position of the 30-m isobath and side-scan sonar successfully discriminated among crystalline basement, CaCO3-cemented sandstones, mixed sediment, and shell bed substrates. Total area encompassed from the shoreline to 30 m water depth is ~21 km2 and the distance to the 30-m isobath varies with proximity to deltas and rift-related faults. Total benthic area defined by crystalline basement is ~1.6 km2, whereas the total area of CaCO3-cemented sandstone is 0.2 km2. Crystalline basement was present in all water depths (0-30 m), whereas CaCO3-cemented sandstones were usually encountered in water ≤ 5 m deep. Spatial organization of rocky substrates is chiefly controlled by basin structure and lake level history

Blue harvest: inland fisheries as an ecosystem service

Global food production has increased greatly in recent years and rural livelihoods are much improved in many regions. Yet, despite this clear progress rural poverty and food insecurity remain deeply entrenched in many areas, especially in South Asia and sub-Saharan Africa. In response the international community has renewed calls for increased commitment to meeting the needs of the world's poor. This report, commissioned as a contribution to the 10th Conference of the Parties to the Convention on Biological Diversity taking place in Nagoya, Japan, not only underlines the value of freshwater fisheries but provides guidance on how the ecosystem approach can be applied in order to sustain future harvests.Inland fisheries, Nutrition, Food security, Sustainability, Ecosystems

Transboundary diagnostic analysis of the Lake Victoria basin

This is a report of a Regional Transboundary Diagnostic Analysis (RTDA) for the Lake Victoria Basin which covers Burundi, Kenya, Rwanda, Tanzania and Uganda. It was commissioned by the EAC Secretariat as part of LVEMP II project preparation and conducted between June and December 2006. The RTDA is based on a review of National TDAs conducted between Feb - June 2005 by each of the five riparian countries through a consultative and participatory approach. Additional information was obtained from other sources, including LVEMP I, East African Community (EAC) documents,national policy and legislation documents and reports of other programs, projects and interventions in the Basin. Workshops were held to validate information collected and build consensus among stakeholders. A causal chain analysis of the transboundary Major Perceived Problems and Issues (MPPls) using a modification of the Global International Waters Assessment (GIWA) methodology was undertaken during the study period. Attempt was made to employ pair wise ranking approach for prioritizing and ranking MPPls

A Review on Ecosystem Services and their Threats in the Conservation of Nyando Wetland, Kisumu County, Kenya

Wetlands are vital ecosystems as they are essential to human health, wellbeing, ecological integrityand national development as well as in the attainment of the Sustainable Development Goals.However, despite their contributions to human wellbeing, they have been destroyed and degradedover years. The aim of this paper is to review literature on the ecosystem services in Nyandowetland ecosystem and how they have been helpful to the well-being of its residents and also todetermine the threats to the Nyando ecosystem services. A total of 88 documents were reviewedout of 20,400 documents from the Google engine search. It is concluded in this paper thatecosystem services in the Nyando wetland contribute significantly to the sustenance of thelivelihood of the local communities and that the over dependency on the Nyando wetland by thelocal communities has resulted to over-exploitation of its resources leading to the degradation ofthe ecosystem. It is recommended that since the Nyando ecosystem is of high value to thecommunities living there, sustainable utilization of its resources is important for its sustenance andalso in the reduction of the degradation of its resources. Keywords: Wetlands; ecosystem services; livelihoods; sustainability; conservation &nbsp