Microbial mat development and production variation in relation to physio-chemical variation in 13 ponds that all originated from one greater pond near Bratina Island on the McMurdo Ice Shelf

Microbial mat development and production varies from pond to pond due to the physio-chemical variation amongst the ponds. To study this variation a series of 13 ponds were selected that had originated from one greater pond which had drained due to a tide crack opening up. Cores of microbial mats were collected from all 13 ponds for particulate nutrient and pigment analyses, biomass determination and species composition. Surface water samples from 13 ponds were also collected for phytoplankton, chlorophyll a, particulate nutrients and dissolved nutrient analysis. Photosynthesis and nitrogen fixation experiments were conducted on microbial mats collected from 7 ponds. Conductivity and pH measurements, coupled with gross mat morphology were used to select the most contrasting ponds. Collected samples were experimented on and the photosynthesis and respiration rates were determined by measuring the rate of evolution or consumption of oxygen using oxygen electrodes. Samples for dissolved inorganic carbon uptake were taken and injected into vacuette tubes for analysis. Nitrogen fixation was determined and gas samples from the nitrogen fixation were then collected for analysis by gas chromatography.

由于各池塘间存在理化性质差异，微生物垫（microbial mat）的发育与产出因池塘而异。为探究这种差异，研究人员选取了源自某一主池塘的13个次级池塘，该主池塘因潮汐裂隙张开而发生排水干涸。研究人员从全部13个池塘中采集了微生物垫岩芯样本，用于颗粒态营养盐、色素分析、生物量测定以及物种组成研究。同时还采集了13个池塘的表层水样，用于浮游植物（phytoplankton）、叶绿素a（chlorophyll a）、颗粒态营养盐以及溶解态营养盐的分析检测。针对从7个池塘中采集的微生物垫样本，研究人员开展了光合作用与固氮作用（nitrogen fixation）实验。通过测定电导率（conductivity）、pH值，并结合微生物垫的整体形态特征，研究人员筛选出了差异最为显著的池塘。对采集到的样本开展实验后，研究人员通过氧电极测定氧气的释放或消耗速率，以此确定光合作用与呼吸作用速率。采集用于溶解无机碳摄取量检测的样本，并将其注入真空采血管（vacuette tubes）以待分析。研究人员测定了固氮活性，并收集固氮反应产生的气体样本，通过气相色谱法（gas chromatography）开展分析检测。