Spatial modelling of small mammal distributions in relation to parasite transmission in western China

Marston, C 2008, Spatial modelling of small mammal distributions in relation to parasite transmission in western China , PhD thesis, University of Salford.

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Abstract

This research investigates the spatial distributions of small mammal species which act as intermediate host vectors for the parasitic tapeworm Echinococcus multilocularis, which causes a significant burden of human disease in western China. Small mammal distributions are modelled in relation to landscape characteristics derived from multiple Landsat TM, Landsat ETM+ and MODIS satellite-derived datasets. Statistical models are used to identify the landscape variables influencing the small mammal spatial distributions, and to describe the nature of these relationships. They are then used predictively to determine probable small mammal distributions over large areas. Assessment of landscape change in two study areas, over a thirty year period, and its impact on small mammal communities is also modelled. Results indicate that some small mammal distributions are significantly related to the spatial distribution of the degraded grassland habitat, with landscape metrics analysis indicating that these distributions are also positively related to degraded grassland patch size. Small mammal distributions are also shown to be negatively related to single-date vegetation index values, although the strength of these relationships is lower. When modelled against time-series MODIS vegetation index data, small mammal distributions show stronger relationships than when using the single-date Landsat ETM+ imagery. These validated timeseries models are used to predict small mammal distributions to a high level of accuracy. Although successful for locations where both MODIS and small mammal transect datasets are available, these models are not temporally or geographically transferable. Long-term landscape change assessed using Landsat MSS and ETM+ imagery showed that large scale landscape degradation occurred at the Serxu site between 1977 and 2001, increasing the area of degraded grassland, and the probability of small mammal presence. At the Yili site no overall landscape change trends were displayed. Probability maps of small mammal distributions have been produced, allowing the identification of potential Echinococcus multilocularis transmission foci. This has potentially significant applications in aiding the development of future disease control programmes.

Item Type:	Thesis (PhD)
Contributors:	Danson, M (Supervisor) and Armitage, RP (Supervisor)
Schools:	Schools > School of Environment and Life Sciences
Funders:	US National Institutes of Health
Depositing User:	Institutional Repository
Date Deposited:	18 Aug 2021 14:54
Last Modified:	04 Aug 2022 11:21
URI:	https://usir.salford.ac.uk/id/eprint/61625

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