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During the Early Holocene, climate was the major factor causing fires, but whether during the Mesolithic (~11.5–7.4 cal ka BP) people co‐shaped their environment by means of fire remains of debate. Few studies have tackled this question by linking high‐resolution multi‐proxy palaeoecological studies from near Mesolithic occupation sites. An Early Holocene sediment record from the Ammer Valley palaeo‐wetland in south‐west Germany was studied using pollen, micro‐ and macrocharcoal, and plant macroremains. Archaeological evidence from Early and Late Mesolithic sites of Rottenburg‐Siebenlinden allowed us to link this palaeoecological record with Mesolithic land use in the same catchment. Between 11.6 and 10.6 cal kabp,intensive wildfires reinforced the persistence of open and pioneer vegetation. A transition from a river‐dominated landscape towards a wetland with open stagnant waters at 10.6–9.5 cal ka bpmade the region attractive to hunter‐gatherers, providing various plant resources (incl. hazel). From 10.1 cal ka bponwards, Mesolithic communities may have shaped their environment by using fire as a tool to expand open areas, which were important for the implementation of their subsistence strategies. After 9.5 cal ka bp, human control over fires cannot be excluded as Mesolithic occupation phases chronologically coincide with frequent low‐intensity fires and vegetation disturbance.

Supplemental material, sj-docx-2-hol-10.1177_09596836221121766 for Buffering new risks? Environmental, social and economic changes in the Turkana Basin during and after the African Humid Period by Elisabeth Hildebrand, Katherine M Grillo, Kendra L Chritz, Markus L Fischer, Steven T Goldstein, Anneke Janzen, Annett Junginger, Rahab N Kinyanjui, Emmanuel Ndiema, Elizabeth Sawchuk, Amanuel Beyin and Susan K Pfeiffer in The Holocene

Supplemental material, sj-pdf-4-hol-10.1177_09596836221121766 for Buffering new risks? Environmental, social and economic changes in the Turkana Basin during and after the African Humid Period by Elisabeth Hildebrand, Katherine M Grillo, Kendra L Chritz, Markus L Fischer, Steven T Goldstein, Anneke Janzen, Annett Junginger, Rahab N Kinyanjui, Emmanuel Ndiema, Elizabeth Sawchuk, Amanuel Beyin and Susan K Pfeiffer in The Holocene

Supplemental material, sj-docx-1-hol-10.1177_09596836221121766 for Buffering new risks? Environmental, social and economic changes in the Turkana Basin during and after the African Humid Period by Elisabeth Hildebrand, Katherine M Grillo, Kendra L Chritz, Markus L Fischer, Steven T Goldstein, Anneke Janzen, Annett Junginger, Rahab N Kinyanjui, Emmanuel Ndiema, Elizabeth Sawchuk, Amanuel Beyin and Susan K Pfeiffer in The Holocene

Supplemental material, sj-docx-3-hol-10.1177_09596836221121766 for Buffering new risks? Environmental, social and economic changes in the Turkana Basin during and after the African Humid Period by Elisabeth Hildebrand, Katherine M Grillo, Kendra L Chritz, Markus L Fischer, Steven T Goldstein, Anneke Janzen, Annett Junginger, Rahab N Kinyanjui, Emmanuel Ndiema, Elizabeth Sawchuk, Amanuel Beyin and Susan K Pfeiffer in The Holocene

Lithics and cut-marked mammal bones, excavated from the paleo-lake Marathousa 1 (MAR-1) sediments in the Megalopolis Basin, southern Greece, indicate traces of hominin activity occurring along a paleo-shoreline ca. 444,000years (444ka) ago. However, the local environment and climatic conditions promoting hominin activity in the area during the MIS12 glacial remain largely unknown. In order to reconstruct the paleo-environment including paleo-lake levels and governing paleo-climatic factors on a high temporal resolution, we analyzed a 6-meter-long sediment sequence from the archeological site MAR-1 and a Bayesian age model was computed for a better age constrain of the different sedimentary units. A multiproxy approach was applied using ostracods, sponge spicules, diatoms, grain sizes, total organic carbon, total inorganic carbon and conventional X-ray fluorescence analysis. The results from the site represent a protected region surrounded by high mountains under the constant influence of water, either as a shallow partly anoxic water body surrounded by reed belts (>463–457ka

Diatoms, a common siliceous alga, are effective paleoclimate and pollution indicators. They have been used in northern, eastern, and southern Africa as such because of well-documented ecologies of many taxa. In southwestern Africa, however, the country of Angola lacks similar modern assemblage studies. To close this gap, modern diatoms were sampled across four water bodies on the Humpata Plateau in southwestern Angola in the dry season of July 2019, with in-situ measurements of pH, conductivity, and total dissolved solids and laboratory analysis of cations and anions. This research concludes that bedrock determines local hydrochemistry. In addition, this exploratory study finds that diatoms in southwestern Angola can infer relative conductivities and trophic levels, but limited data hinder interpretations of diatom ecological preferences of pH, temperature, alkalinity, ions, and pollution, requiring further analyses. Such research is beneficial for both African diatomists interested in using accurate transfer functions across Africa to reconstruct paleoclimates as well as local communities and hydrologists interested in understanding water chemistry and pollution, given that these studied sites are vital water resources for local communities on the Humpata Plateau.

The Ethiopian rift is known for its diverse landscape, ranging from arid and semi-arid savannahs to high and humid mountainous regions. Lacustrine sediments and paleo-shorelines indicate water availability fluctuated dramatically from deep fresh water lakes, to shallow highly alkaline lakes, to completely desiccated lakes. To investigate the role lakes have played through time as readily available water sources to humans, an enhanced knowledge of the pace, character and magnitude of these changes is essential. Hydro-balance models are used to calculate paleo-precipitation rates and the potential pace of lake level changes. However, previous models did not consider changes in hydrological connectivity during humid periods in the rift system, which may have led to an overestimation of paleo-precipitation rates. Here we present a comprehensive hydro-balance modeling approach that simulates multiple rift lakes from the southern Ethiopian Rift (lakes Abaya, Chamo, and paleo-lake Chew Bahir) simultaneously, considering their temporal hydrological connectivity during high stands of the African Humid Period (AHP, ~15–5 ka). We further used the Surface Energy Balance Algorithm for Land (SEBAL) to calculate the evaporation of paleo-lake Chew Bahir's catchment. We also considered the possibility of an additional rainy season during the AHP as previously suggested by numerous studies. The results suggest that an increase in precipitation of 20–30% throughout the southern Ethiopian Rift is necessary to fill paleo-lake Chew Bahir to its overflow level. Furthermore, it was demonstrated that paleo-lake Chew Bahir was highly dependent on the water supply from the upper lakes Abaya and Chamo and dries out within ~40 years if the hydrological connection is cut off and the precipitation amount decreases to present day conditions. Several of such rapid lake level fluctuations, from a freshwater to a saline lake, might have occurred during the termination of the AHP, when humid conditions were less stable. Fast changes in fresh water availability requires high adaptability for humans living in the area and might have exerted severe environmental stress on humans in a sub-generational timescale.

The aim of this study was to assess the levels and distribution of heavy metals in Lake Chilwa and its catchment, and to understand the associated level of pollution. Water and sediment samples were collected from the lake and main inflowing rivers. A total of 23 surface water samples were sampled and analysed for pH, EC, Cu, Cr, Zn, Cd, Pb, As and Hg. Conductivity and pH were measured on-site with a Hanna portable multi meter, while metals were analysed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The pH was found within the alkaline range (7.87-10.13), while conductivity ranged from 97-390μS/cm. The following metals were detected in the water samples; Zn (6.24–1168.70 μg/L), Cu (BDL–47.83 μg/L), Pb (BDL–49.94 μg/L), Cr (0.22–33.05 μg/L), Ni (0.40–8.20 μg/L) and Cd (BDL–0.53 μg/L). Hg and As were not detected in all sampling locations. Strong positive correlations were observed between Cd and Pb (r = 0.70), Cu and Zn (r = 0.70), while Cd and Ni (r = 0.50), Pb and Ni (r = 0.41) showed mild correlations, suggesting similar sources of input. Sediments were sampled from 2 locations in the lake and the following metals were detected; Zn (66.13 mg/Kg), Pb (7.74 mg/Kg), Ni (35.39 mg/Kg), Cu (20.02 mg/Kg), Cr (54.81 mg/Kg) and As (1.0 mg/Kg). Mercury and arsenic were not detected from both sampling locations. The heavy metal pollution index ranged from 2.24 to 114.45. All points except Kachulu harbour had values far below the critical pollution index value of 100. The values observed were well below the tolerable limits recommended by the World Health Organisation (WHO) standard for potable water, except for Pb at Kachulu Bay (P19) which was above the limit. Concentrations of the metals in the rivers were low upstream and increased downstream. Highest values for most of the elements were observed from the lake. Though levels are low now, the persistent and cumulative properties of these elements would render them unsafe in the near future if proper controls are not enforced.Keywords: Heavy metals, Lake Chilwa, Water pollution, Water quality

The Kenyan and Ethiopian rifts in eastern Africa are known for their diverse landscape, ranging from arid and semi-arid savannahs to high and lush mountainous regions, where anatomically modern humans were present since ∼195 ka BP. Lacustrine sediments and paleo-shorelines indicate water availability fluctuated dramatically during this period from deep fresh water lakes, to shallow highly alkaline lakes, to completely desiccated lakes. To investigate the role lakes have played through time as readily available water sources to humans, an enhanced knowledge of the pace as well as the magnitude of these changes near key paleo-anthropological sites in eastern Africa is essential. Hydro-balance models are used to calculate paleo-precipitation rates and the potential pace of lake level changes. Such models, which were successfully applied to numerous lake basins in Kenya, could prove similarly useful for investigating paleo-lake basins in Ethiopia. However, these models did not consider changes in hydrological connectivity during humid periods, which may have led to an overestimation of paleo-precipitation rates. Here we present a comprehensive hydro-balance modelling approach that simulates multiple rift lakes from the southern Ethiopian Rift (Abaya, Chamo, Chew Bahir) simultaneously, considering their temporal hydrological connectivity. During the high stand at the peak of the African Humid Period (AHP, 15-5-ka), the lakes were hydrologically linked and display cascade-like behavior, flowing southwards from Abaya to Chamo to Chew Bahir and finally spilling over into Lake Turkana. We further used the Surface Energy Balance Algorithm for Land (SEBAL) to calculate the evaporation of Lake Chew Bashir's catchments and used the energy balance to determine possible paleo-evaporation conditions due to shifts in precipitation patterns. The results suggest an increase in the long-term precipitation trend of 20.6% to 28.6% throughout the whole Southern Ethiopian Rift is necessary to fill Lake Chew Bahir to its overflow level. Furthermore, it was demonstrated that Lake Chew Bahir was highly dependent on the water supply from the upper lakes Abaya and Chamo and dries out within ∼30 years if the hydrological connection is cut off and the precipitation amount decreases to present day conditions. Several of such rapid lake level fluctuations, from a freshwater to a saline lake, might have occurred during the termination of the AHP, when humid conditions were less stable due to a change in precessional cycle. Fast changes in fresh water availability requires high adaptability for humans living in the area and might have caused strong migration pressure towards more favorable regions such as the Ethiopian Highlands within single generations or even less.