Browsing by Author "Meliyo, Joel, L."

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The effect of soil physical properties and soil microclimate on rodent burrows’ abundance and their characteristics in Western Usambara Mountains, Tanzania
(ournal of Agriculture and Ecology Research International, 2014-12-16) Meliyo, Joel, L.; Brabers, Leon; Massawe, Boniface H. J.; Msanya, B. M.; Kimaro, D. N.; Mulungu, L. S.; Kihupi, N. I.; Deckers, Jozef, A.; Gulinck, Hubert; Leirs, Herwig
The present study was carried out between September 2009 and June 2013 in Western Usambara Mountains plague focus with the aim of establishing the influence of selected soil physical properties and soil microclimate on rodent burrows’ abundance, portal orientation and use. Two landscapes with high and medium plague frequencies in Lokome and Lukozi villages were studied. In the two landscapes data were collected from 117 and 200 observation sites respectively, using 100 m x 200 m quadrats. At each quadrat crossing, a sample quadrat of 20 m x 20 m was demarcated for scanning rodent burrows whereby burrows encountered were counted and their portal orientation and burrow use described. Within each sample quadrat, selected soil physical properties including thickness of the soil genetic horizons and soil dry consistence were determined. Soil samples were collected from each horizon for laboratory texture analysis. Temperature (surface and subsurface to a depth 10 cm) and relative humidity at a depth of 10 and 30 cm were collected using infrared, thermo-couple thermometers and i-Buttons. Descriptive statistics, ANOVA and logistic regression were used to analyse the data by R-software. There were significant (P=.0001) differences between the two landscapes regarding topsoil depth, infrared temperature, relative humidity and rodent burrows’ abundance. In the high plague frequency landscape there was a significant influence (P=.05) of topsoil horizon thickness on rodent burrows’ abundance and use. Results also indicate that soil temperature to a depth of 10 cm was significantly (P=.05) correlated with rodent burrow use. Likewise, in the medium plague frequency landscape, soil physical properties and soil microclimate significantly (P=.0001) discouraged rodent burrowing. It was concluded that soil physical and soil microclimate encouraged and discouraged burrowing in the high and the medium plague frequency landscapes, respectively. The landscape with high rodent burrows’ abundance corresponded with high plague frequency records.
Landform and surface attributes for prediction of rodent burrows in the Western Usambara Mountains, Tanzania
(Tanzania Journal of Health Research, 2014-07) Meliyo, Joel, L.; Massawe, Boniface H. J.; Msanya, B. M.; Kimaro, D. N.; Hieronimo, Proches; Mulungu, Loth S.; Kihupi, N. I.; Deckers, Jozef, A.; Gulinck, Hubert; Leirs, Herwig
Previous studies suggest that rodent burrows, a proxy for rodent population are important for predicting plague risk areas. However, studies that link landform, surface attributes and rodent burrows in the Western Usambara Mountains in Tanzania are scanty. Therefore, this study was conducted in plague endemic area of the Western Usambara Mountains in northern, Tanzania, to explore the relationship between rodent burrows, and landform and surface attributes. The study was carried out in three areas corresponding to high (Lokome), medium (Lukozi) and low (Mwangoi) frequency of reported plague cases. Data were collected from 117, 200 and 170 observation sites for Lokome, Lukozi and Mwangoi, respectively using 100 m x 200 m quadrats. Remote sensing and field surveys were used to collect data on landform and surface attributes. Rodent burrows were surveyed and quantified by counting the number of burrows in 20m x 20m grids demarcated on the main 100m x 200m quadrats. The collected data were analysed in R software using boosted regression trees (BRT) technique. Rodent burrows were found at an elevation of above 1600m in the high and medium plague frequency landscapes. No burrows were found in the low plague frequency landscape situated below 1500m. BRT analysis shows a significant relationship between landform characteristics and rodent burrows in both high and medium plague frequency landscapes. Overall, elevation and hillshade are the most important determinants of rodent burrow distribution in the studied landscapes. It is concluded that in high altitudes, specific landform attributes (hill-shade, slope, elevation) and vegetation cover- favour rodent burrowing.
Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania
(Tanzania Journal of Health Research, 2014-07) Meliyo, Joel, L.; Kimaro, D. N.; Msanya, B. M.; Mulungu, L. S.; Hieronimo, Proches; Kihupi, N. I.; Gulinck, Hubert; Deckers, Jozef, A.
Small mammals particularly rodents, are considered the primary natural hosts of plague. Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this study was to investigate the relationship between on the one hand landforms and associated soil properties, and on the other hand small mammals and fleas in West Usambara Mountains in Tanzania, a plague endemic area. Standard field survey methods coupled with Geographical Information System (GIS) technique were used to examine landform and soils characteristics. Soil samples were analysed in the laboratory for physico-chemical properties. Small mammals were trapped on pre-established landform positions and identified to genus/species level. Fleas were removed from the trapped small mammals and counted. Exploration of landform and soil data was done using ArcGIS Toolbox functions and descriptive statistical analysis. The relationships between landforms, soils, small mammals and fleas were established by generalised linear regression model (GLM) operated in R statistics software. Results show that landforms and soils influence the abundance of small mammals and fleas and their spatial distribution. The abundance of small mammals and fleas increased with increase in elevation. Small mammal species richness also increases with elevation. A landform-soil model shows that available phosphorus, slope aspect and elevation were statistically significant predictors explaining richness and abundance of small mammals. Fleas’ abundance and spatial distribution were influenced by hill-shade, available phosphorus and base saturation. The study suggests that landforms and soils have a strong influence on the richness and evenness of small mammals and their fleas’ abundance hence could be used to explain plague dynamics in the area.