The distribution of terrestrial and hydro-terrestrial algal associations at three contrasting locations in southern Victoria Land, Antarctica

Broady, Paul A.

doi:10.1127/1864-1318/2006/0118-0095

Cited by 37 publications

(31 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Four to twenty-seven AFLs were seen in the ARISA profiles from the Miers Valley soils. Previous studies (for example, Cavacini, 2001;Broady, 2005) and our data show that Chroococcales, Nostocales and Oscillatoriales are present in soil samples. Interestingly, many of the sequences obtained from the clone libraries had low similarity scores to any 16S rDNA database entries, suggesting the presence of as yet uncharacterized cyanobacteria.…”

Section: Discussionmentioning

confidence: 50%

“…Cyanobacteria have been identified in the majority of ice-free habitats on the continent (Broady, 1996(Broady, , 2005Adams et al, 2006). However, it is their presence in Antarctic lakes and ponds that have attracted the most interest and led to detailed research into their taxonomy (morphological and molecular), community structure, biogeographical distribution and physiology (for example, Vincent et al, 1993;Taton et al, 2003Taton et al, , 2006ade los Ríos et al, 2004;Jungblut et al, 2005;Novis and Smissen, 2006).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sources of edaphic cyanobacterial diversity in the Dry Valleys of Eastern Antarctica

et al. 2008

View full text Add to dashboard Cite

Cyanobacteria are major components of Antarctic Dry Valley ecosystems. Their occurrence in lakes and ponds is well documented, however, less is known about their distribution in edaphic environments. There has been considerable debate about the contribution of aquatic organic matter derived largely from cyanobacteria to terrestrial ecosystems. In this study, automated rRNA intergenic spacer analysis (ARISA) and 16S rRNA gene clone libraries were used to investigate cyanobacterial diversity in a range of soil environments within the Miers and Beacon Valleys. These data were used to elucidate the input of aquatic cyanobacteria to soil communities. Thirty-eight samples were collected from a variety of soil environments including dry and moist soils, hypoliths and lake and hydroterrestrial microbial mats. The results from the ARISA and 16S rRNA clone library analysis demonstrated that diverse cyanobacterial communities exist within the mineral soils of the Miers Valley. The soil samples from Beacon Valley were depauparate in cyanobacterial signals. Within Miers Valley, significant portions (29%-58%) of ARISA fragment lengths found in aquatic cyanobacterial mats were also present in soil and hypolith samples, indicating that lacustrine and hydroterrestrial cyanobacteria play a significant role in structuring soil communities. The influence of abiotic variables on the community structure of soil samples was assessed using BEST analysis. The results of BEST analysis of samples from within Miers Valley showed that total percentage of carbon content was the most important variable in explaining differences in cyanobacterial community structure. The BEST analyses indicated that four elements contributed significantly to species compositional differences between valleys. We suggest that the complete absence of lakes or ponds from Beacon Valley is a contributing factor to the low cyanobacterial component of these soils.

show abstract

Section: Discussionmentioning

confidence: 50%

Section: Introductionmentioning

confidence: 99%

Sources of edaphic cyanobacterial diversity in the Dry Valleys of Eastern Antarctica

et al. 2008

View full text Add to dashboard Cite

show abstract

“…(Warren-Rhodes et al 2007), whilst in others, a more diverse range of taxa have been identified (Tracy et al 2010). Polar hypolithons comprise a relatively diverse cyanobacterial assemblage comprising various Oscillatoriales, Aphanocapsa, Aphanothece, Chroococcidiopsis and Gloeocapsa morphotypes (Broady 1981(Broady , 2005Cockell and Stokes 2004). Culture-independent molecular studies have revealed a greater cyanobacterial diversity (Wood et al 2008) than identified by microscopy and have indicated the presence of diverse bacterial phylotypes (Pointing et al 2009;Khan 2009).…”

Section: Introductionmentioning

confidence: 99%

Distribution and abiotic influences on hypolithic microbial communities in an Antarctic Dry Valley

et al. 2010

View full text Add to dashboard Cite

The Miers Valley within the McMurdo DryValleys of Antarctica supports abundant quartz and marble substrates for hypolithons-microbial colonists on the underside of these translucent rocks. Three physically distinct hypolithic community types have been identified: cyanobacteria dominated (Type I), fungus dominated (Type II) or moss dominated (Type III). The distribution of the three types was mapped across much of the *75 km 2 area of the upper Miers Valley and correlated this with the measurements of selected micro-environmental variables. Type I hypolithons were most common and occurred at all altitudes up to 824 m, whilst Type II and Type III hypolithons were less abundant and restricted to lower altitudes on the valley floor (\415 m and \257 m, respectively). Whilst all colonized quartz effectively filtered incident UVB irradiance, transmittance levels for UVA and PAR varied markedly and were significant in determining hypolith type. Notably, the Type I hypolithons occurred under rocks with a significantly lower transmittance of photosynthetically active radiation than Type II and III hypolithons. Altitude and aspect were also significant factors determining hypolith type, and a role for altitude-related abiotic variables in determining the distribution of Type I, II and III hypolithons is proposed.

show abstract

“…These sub-surface communities account for the majority of standing biomass in desert systems (Pointing and Belnap 2012) including polar deserts (Cary et al 2010;Wierzchos et al 2012). These lithic communities are dominated by cyanobacteria and lichens, but also support a diverse range of archaea, bacteria, chlorophytes and fungi (Friedmann 1982;De La Torre et al 2003;Broady 2005;De Los Rı´os et al 2007;Wood et al 2008;Pointing et al 2009;Cowan et al 2010;Rao et al 2011;Cowan et al 2012;DeLosR´ıos et al 2014;Richter et al 2014;Yung et al 2014). Metazoan life is comparatively sparse, with limited direct evidence for grazing on microbial communities (Wall and Virginia 1999).…”

Section: Introductionmentioning

confidence: 99%

Genetic signatures indicate widespread antibiotic resistance and phage infection in microbial communities of the McMurdo Dry Valleys, East Antarctica

et al. 2015

View full text Add to dashboard Cite

The McMurdo Dry Valleys of Antarctica support extensive yet cryptic microbial communities but little evidence for 'top-down' herbivory control. A question therefore arises as to how standing microbial biomass is regulated. Here, we present results from a survey of soil and rock microbial community metagenomes using the GeoChip microarray that demonstrate antibiotic resistance and phage infection are widespread. We interrogated a range of dry valley locations from maritime to extreme inland sites. Antibiotic resistance genes were identified in three categories: beta-lactamases, tetracycline and vanomycin plus a range of transporter genes. Frequency of recovery generally reflected microbial diversity, with greatest abundance among Halobacteria, Proteobacteria and the photosynthetic bacteria (Chlorobi, Chloroflexi and Cyanobacteria). However, no clear differences between locations and soil/rock communities were apparent. Phage signals were also recovered from all locations in soil and rock communities. The Leviviridae, Myoviridae, Podoviridae and Siphoviridae were ubiquitous . The Corticoviridae occurred only in moisturesufficient hyporheic soils, the Microviridae occurred only in maritime and hyporheic sites and an unidentified group within the order Caudovirales occurred only at dry inland sites. We postulate that widespread antibiotic resistance indicates potential inter-specific interaction and that phage signals indicate possible 'bottom-up' trophic regulation in the dry valleys.

show abstract

The distribution of terrestrial and hydro-terrestrial algal associations at three contrasting locations in southern Victoria Land, Antarctica

Cited by 37 publications

References 0 publications

Sources of edaphic cyanobacterial diversity in the Dry Valleys of Eastern Antarctica

Sources of edaphic cyanobacterial diversity in the Dry Valleys of Eastern Antarctica

Distribution and abiotic influences on hypolithic microbial communities in an Antarctic Dry Valley

Genetic signatures indicate widespread antibiotic resistance and phage infection in microbial communities of the McMurdo Dry Valleys, East Antarctica

Contact Info

Product

Resources

About