Search results for "Glacier foreland"
showing 3 items of 3 documents
Abundance of narG , nirS , nirK , and nosZ Genes of Denitrifying Bacteria during Primary Successions of a Glacier Foreland
2006
ABSTRACT Quantitative PCR of denitrification genes encoding the nitrate, nitrite, and nitrous oxide reductases was used to study denitrifiers across a glacier foreland. Environmental samples collected at different distances from a receding glacier contained amounts of 16S rRNA target molecules ranging from 4.9 × 10 5 to 8.9 × 10 5 copies per nanogram of DNA but smaller amounts of narG , nirK , and nosZ target molecules. Thus, numbers of narG , nirK , nirS , and nosZ copies per nanogram of DNA ranged from 2.1 × 10 3 to 2.6 × 10 4 , 7.4 × 10 2 to 1.4 × 10 3 , 2.5 × 10 2 to 6.4 × 10 3 , and 1.2 × 10 3 to 5.5 × 10 3 , respectively. The densities of 16S rRNA genes per gram of soil increased with…
Glacier drainage and sandur formation at Kötlujökull, South Iceland
1985
Abstract Over a number of years research on a stretch of the southeastern glacier margin of Kotlujokull in South Iceland, 8 km in length, has focused on correlating the manner of glacier drainage with the genesis of sandar, exemplified by the recent evolution of the glacier foreland. The research has yielded the following results. During an initial period, beginning prior to 1945 and ending between 1966 and 1975, a belt of moraines about 1 km wide was destroyed in stages, except for a few remnants, by 11 outbreaks of subglacial meltwater at different times and locations along the glacier front. These outbursts were associated with the genesis of “ordinary”; sandar, which are referred to her…
Microbial succession of nitrate-reducing bacteria in the rhizosphere of Poa alpina across a glacier foreland in the Central Alps
2006
International audience; Changes in community structure and activity of the dissimilatory nitrate-reducing community were investigated across a glacier foreland in the Central Alps to gain insight into the successional pattern of this functional group and the driving environmental factors. Bulk soil and rhizosphere soil of Poa alpina was sampled in five replicates in August during the flowering stage and in September after the first snowfalls along a gradient from 25 to 129 years after deglaciation and at a reference site outside the glacier foreland (> 2000 years deglaciated). In a laboratory-based assay, nitrate reductase activity was determined colorimetrically after 24 h of anaerobic inc…