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Document Type:Latin Dissertation
Language of Document:English
Record Number:53332
Doc. No:TL23286
Call number:‭3395609‬
Main Entry:George Gatere Ndiritu
Title & Author:Ecology of protosteloid and myxomycete amoebae and their relation to land use regimes in the Aberdare region, Central KenyaGeorge Gatere Ndiritu
College:University of Arkansas
Date:2009
Degree:Ph.D.
student score:2009
Page No:255
Abstract:A strong relationship exists between the environment and the life history strategies of organisms. Organisms have evolved and adapted to changing demographics and environmental gradients, and this is evident in the diverse sizes of their bodies and the unique distribution patterns they display in nature. How these organisms survive and interact with their niches are some of the major unresolved questions in ecology. Most of what is known about biodiversity is derived from natural ecosystems, with very negligible work from anthropogenic ecosystems, particularly from the northern hemisphere and Central America. Anthropogenic biomes occupy more than 75% of the Earth's ice-free land surface and incorporate nearly 90% of the terrestrial net primary productivity, while natural biomes occupy less than 25% and provide about 11% of the terrestrial net primary productivity. The best known aspects of anthropogenic ecosystems relate to macroscopic organisms, with a little known about micro algae, diatoms, bacteria and almost nothing is known on other eukaryotic microorganisms. As part of a global effort to increase our knowledge of the spatial distribution and ecology of eukaryotic microorganisms, this project described in this dissertation attempts: first to provide a general overview on the knowledge of protosteloid (protostelids) and myxomycete amoebae in Africa, and thereafter a detailed characterization of these organisms in Kenya. Approximately 294 myxomycetes are known to occur in Africa, which corresponds to only about 33% of the myxomycetes (ca. 880 species) known worldwide. No myxomycete records exist for 27 of the 58 countries and territories in Africa. For protostelids, records exist only in the five countries of Algeria, Egypt, Uganda, Tanzania, Malawi, Kenya and South Africa. Rapid assessments of the two groups of species in a variety of habitats in Kenya found a number of species to be widespread and abundant, and these results were comparable with findings reported from other several parts of the world. Species assemblages differed among microhabitats, with both richness and abundances being greatest on aerial litter microhabitats, moderate on ground litter and low on both aerial and ground bark microhabitats. In a number of cases, strong relationships existed between species assemblages and land use/cover, elevation, and pH, although this varied across the four microhabitats and ecological climatic regions. In-depth investigation of these factors revealed that both protosteloid and myxomycete amoebae showed a number of obvious similarities and differences at different levels of community organization in response to environmental gradients. It was apparent that spatial species variation and the distribution patterns observed were a product of environmental factors at the local (or microhabitat) level and disturbance regimes at the land use/cover level, and dispersal rate effects at the regional level. The strong relationship found between species assemblages and environmental gradients was an indication that fruiting amoebae and perhaps other non fruiting naked amoebae as well, are good indicators of environmental conditions.
Subject:Biological sciences; Land use; Protostelids; Myxomycete amoebae; Slime molds; Ecology; Microbiology; 0329:Ecology; 0410:Microbiology
Added Entry:University of Arkansas