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SUMMARYIn Kenya, lands surrounding wildlife protected areas (PAs), referred to as dispersal areas, have undergone widespread land use changes, but these have been little studied. This study investigated impacts of different land use types on wildlife distribution and composition. Transect data from stratified random sampling based on land use and vegetation type were analysed using correlation and canonical correspondence analysis (CCA). Household density and cultivation intensity were negatively correlated with grass cover and were greatest on small-scale farms and lowest in a dedicated PA. Three patterns of wildlife distribution were identified. Wildlife density in communal grazing and the PA was significantly higher than on other land use types. While most wildlife used pastoral ranches in the wet season, larger herbivores moved to the PA during the dry season. Wildlife density along the grass cover gradient, which was a disturbance gradient, was dome shaped, indicating that wildlife tolerated moderate levels of disturbance. The primary factors influencing wildlife distribution were vegetation type and proximity to water sources in the dry and wet seasons, respectively. The apparent anomaly in the wet season is attributed to wildlife moving from Chyulu, which lacked seasonal ponds, to the lowland Masaai ranches, which had plenty of ponds. In both seasons, cattle density was the most important secondary factor. To mitigate declining wildlife trends, management should ensure a heterogeneity of vegetation types is maintained and wildlife retain access to seasonal water sources.

A botanical inventory and diversity of trees, shrubs (≥5 cm diameter at breast height [dbh]), herbs, climbers and lianas was assessed in plots (154) of 20 × 5 m in Mt. Marsabit forest, northern Kenya. We recorded 52 species of trees and shrubs, twelve species of herbs and six species of climbers and lianas. They belonged to 35 families and 64 genera. Rubiaceae was the richest family with nine species followed by Euphorbiaceae (six), Oleaceae (five), Rutaceae (four), Capparaceae, Labiatae and Leguminosae (three each). The rest of the families were represented by one or two species. Rinorea convallarioides (Bak.f.) Eyles ssp. marsabitensis Grey‐Wilson (Violaceae), an endemic species, and Drypetes gerrardii Hutch. (Euphorbiaceae), were the two most important species, accounting for more than third of the combined importance value. Species diversity indices were 2.735 (Shannon–Wiener), 0.88 (Simpson's) and 0.296 (Evenness). There was a strong evidence of disturbance arising from anthropogenic and wildlife foraging activities. This inventory has affirmed Mt. Marsabit forest as a unique habitat for several endemic, rare, threatened or vulnerable plant species, which should be conserved.

Invasive species in Africa have important impacts on food security and biodiversity conservation. African floodplains in arid areas are critical wildlife habitats in addition to crop production and dry season livestock grazing. The study aimed to understand the patterns of spread of the invader Prosopis juliflora in a typical African floodplain characterised by both multiple dispersers and habitats. Data was collected on faecal seed density, establishment and vegetation composition, and subjected to non-parametric tests and regression analysis. The results showed that both livestock and wildlife species played a critical role in dispersal of Prosopis juliflora, especially yellow baboons (Papio cynocephalus), bush pigs (Potamochoerus larvatus), donkeys and goats. Habitat preference of wildlife dispersers and livestock herding patterns influenced the spatial pattern of invader seed influx. Establishment of Prosopis juliflora was enhanced by ecological disturbance such as in rested crop fields and habitats outside conservation areas as compared to those inside. Establishment was also higher inside the floodplain than outside probably due to higher seasonal soil resources. Lastly, indigenous woody species diversity declined significantly as the density of Prosopis juliflora increased. We conclude that patterns of spread of Prosopis juliflora were related to ecological disturbances, type of disperser and flooplain effect.

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The aim of this study was to establish whether the invasive plant Lantana camara L. alters the soil chemical properties at Ol-Donyo Sabuk National Park. The key objective was to evaluate the soil nutrient composition in areas invaded by L. camara and how these differ from areas without L. camara. Five study sites were selected by purposeful sampling, out of the existing 10 blocks. Soil samples were collected randomly from L. camara invaded areas and similarly from adjacent areas free from L. camara. The soil samples were subjected to determination of the following nutrients and parameters: pH, potassium (K), calcium (Ca) magnesium (Mg), total nitrogen (N), phosphorus (P), total organic carbon (TOC), manganese (Mn), copper (Cu), iron (Fe), zinc (Zn) and sodium (Na). The data obtained was analysed using Two-way ANOVA test to determine difference in nutrients composition in L. camara invaded and non-invaded areas. Three-way ANOVA test was used to gauge the interactions between wet and dry season, invaded and non-invaded areas and study sites. A post-ANOVA test, Tukey’s Honest Significant Difference was done to separate the means. The results from the study indicated L. camara invaded areas had a significant difference in pH, P, N, Mn, Fe and total organic C compared to the patches that had native plants and not invaded by L. camara. High pH also makes P to be more available to plants that is why P was high in the L. camara invaded areas. This study revealed that L. camara remarkably changes the concentration and balance of soil nutrients resulting to a change in chemistry of soil nutrients. This is in a bid to suit its survival to the detriment of the native plant species. This study is hence vital for designing an effective eradication and preventive strategy of L. camara in Ol-Donyo Sabuk National Park and other protected ecological habitats in Kenya.

Two wetlands (Hyena and Nalogomon) in the Nairobi National Park were investigated by comparing plant composition in and around their immediate vicinity. The most common aquatic plant species in the Hyena wetland was Cyperus dives while in the Nalogomon wetland was Typha domingensis. The terrestrial vegetation surrounding Hyena wetland dominated by while that of surrounding Nalogomon wetland was the grass Hyparrhemia rufa. It was also noted that Hyena Dam waters were colonized by aquatic weeds, namely Gunnera perpensa, Enhydra fluctuans and Ludwigia abyssinica, that were absent in Nalogomon wetland waters. This could have been due to eutrophication of the waters of Hyena Dam as it originated from human settlements (city estates) outside the park boundary. DOI: http://dx.doi.org/10.3126/jowe.v6i0.5909 J Wet Eco 2012 (6): 07-15

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