Mount Kenya's Lewis Glacier Status and Microbial Threats | InformativeBD

Josiah Ochieng Kuja , Huxley Mae Makonde , Anne Thairu Muigai , Agnes Omire , Hamadi Iddi Boga, and, Jun Uetake from the different institute of the kenya and usa wrote a review article  about Mount Kenya's Lewis Glacier Status and Microbial Threats, entitled "The status of Lewis Glacier of Mount Kenya and the threat to Novel microbial communities"this review paper published by the International Journal of Microbiology and Micology |IJMM an open access scholarly research journal on microbiology under the affiliation of the International Network for Natural Sciences | INNSpub an open access multidiciplinary research journal publisher.

Abstract

The disappearance of African glaciers is of great concern. Most important is the status of Lewis glacier, the smallest glacier in Africa that is rapidly melting. Lewis glacier is a well-documented tropical glacier that experiences a rapid retreat establishing deglaciated foreland. The steep elevation and lack of accumulation layer for Lewis glacier is a possible factor to the rapid loss of its content. The greatest concern is the microbial communities that are lost through the flowing glacier material. The psychrophilic microbes of the glacier are lost in the supraglacial and subglacial to the glacier melting points. The glacier melt, however, creates a deglaciated terrestrial foreland that is recolonized by bacteria, fungi and vascular plants. Most of the foreland community structures are dynamic and differ from the glacier ecology due to various microbial activities including nutrient cycling and mineralization of the rocks. These geochemical process make the glacier foreland to be a chronological ecosystem with spatial biodiversity. The primary foreland is colonized by the bacteria, that prepare the habitat for the saprophytic and mycorrhizal associations. Most of the plants, especially the Senecio keniophytum form symbiotic association with some of the nitrogen fixing microorganisms. The ecological change from glacier ecosystem to foreland soil totally creates a new ecosystem with spatial biodiversity that need to be fully investigated for informative conclusions. 

Introduction

Glaciers and ice sheets are known to be biotic ecosystems (Hodson et al., 2008; Stibal et al., 2010) characterized with the complex cryoconite aggregates and diverse microbial community structures (De Smet and Van Rompu, 1994; Takeuchi et al., 2001; Simon et al., 2009; Hodson et al., 2010; Langford et al., 2010). Glacier ecosystems are habitable due to the available melt water, debris and aerosol deposits (Stibal and Tranter, 2007; Hodson et al., 2008) as a result of episodic atmospheric processes (Kühnel et al., 2011), external environment activities (Hodson et al., 2008) and the psychrophilic microbial activities on the glacier surfaces (Hodson et al., 2010; Langford et al., 2010; Stibal et al., 2012; Telling et al., 2012).

The diversity of the microbial communities and their activities on the surface snow, ice and glacier surfaces varies due to spatial biogeochemical processes within the cryoconite material (Stibal et al., 2012; Telling et al., 2012). The biology of cryoconite is known to consist of the organic and inorganic substances (Takeuchi et al., 2010). These substances are however, important in the glacier surface energy budget, slope avalanching and melt water runoff redistribution (Kustas et al., 1994; Hock and Holmgren, 2005).

A number of studies have focused on the diversity of microorganisms on the surface glacier and in the cryoconite aggregates of the polar and mid-polar ecosystems. Polar glaciers are known to harbor unique microbial ecosystems with significant contribution to cryoconite aggregation through the production of cohesive extracellular polymeric substances (Langford et al., 2010; Telling et al., 2010; Stibal et al., 2012). However, the information on microbial ecology, the accumulation of organic and regulation of inorganic substances is limited and no attempts have been made to study these processes on the tropical glaciers of Africa. This review addresses the critical ecological status of the surviving African glaciers, especially the fast disappearing Lewis glacier of Mount Kenya. These high altitude ecosystems are the most neglected sites with more research focusing on the low altitude terrestrial ecosystems in Africa. The ecological shift from the glacier area to the foreland soil of Lewis glacier indicates the development of an ecosystem of diverse organisms with the loss of novel psychrophilic microorganisms in the glacier.

The foreland chronosequence is a clear indication of this shift with the chronological occurrence of Lichens, Mosses, herbs and vascular trees along the foreland soil.

Source:The status of Lewis Glacier of Mount Kenya and the threat toNovel microbial communities