RECONSTRUCTED HYDROLOGICAL CHANGES DURING THE LITTLE ICE AGE, LAKE SOLAI WETLANDS, KENYA
A two meter long core of organic-rich clays capped by a 68 cm peat was extracted from a freshwater Typha wetland (~0.3 km2). A suite of biological proxies (pollen, non-pollen palynomorphs, macrofossils, microscopic charcoal and diatoms) was examined in order to reconstruct the hydrological history. The biostratigraphy is divided into 3 distinct zones and records changes in the wetland hydrology and increasing anthropogenic impact of pastoralism and agriculture. Zone 3 (182-70 cm) is characterized by saline, shallow water conditions. In Zone 2 (70-40 cm) the proxies indicate drier and possibly erosive conditions; abundant charcoal suggests fire also becomes a significant driver on the landscape. Zone 1 (40-0 cm) is marked by overall wetter conditions, the development of the wetland, and possibly periods of higher lake level. The top 20 cm of sediments reflect eutrophication likely caused by agriculture and pastoral activities. The inception of the peat dates to 880 +/- 40 BP which is consistent with data from throughout East Africa indicating wetter conditions at the start of the Little Ice Age.