Spatial variability in polar soil ecosystems: An integrated study of genes, microbial biodiversity and landform evolution as a baseline for monitoring climate change

Metadata record for data from ASAC Project 2952.
See the link below for public details on this project.

By studying microbial within species adaptation, species distribution, ecosystem composition, structure and biogeochemical rates and functions, and relating these parameters to specific landforms at a range of spatial scales we aim to determine whether: Aspects of the Antarctic environment influence the scales and rates of biogeochemical processes and soil microbial population dynamics. and if so: Whether polar soil ecosystems are more sensitive to anthropogenic climate change than temperate regions.

Project objectives:
Do aspects of the Antarctic environment influence the scales and rates of biogeochemical processes and soil microbial population dynamics?

If so,

Are polar soil ecosystems more sensitive to anthropogenic climate change than temperate regions?

We aim to answer these two questions by studying within species adaptation, species distribution, ecosystem composition, structure and biogeochemical rates and functions. To do this, we will collect samples that relate to specific landforms at a range of spatial scales. We will then test the hypothesis that there are differences between sites (landforms), along gradients, between locations and between regions. This Antarctic data can then be compared to data from a much larger International Polar Year (IPY) latitudinal gradients project involving data from the Arctic (Canada and Norway) and temperate and tropical regions (Australia, Europe and low latitude Canada).

Taken from the 2008-2009 Progress Report:
Progress against objectives:
Soil samples have been collected from several sites in Antarctica and the Arctic in the past several years. These have been catalogued in a Sample Tracking Database developed by the EPiC group at the AAD. We have been concentrating on developing our methodology and devising a soil analysis system describing how each sample is subsampled and designating each subsample for particular chemical or genetic analysis. The method concentrates on making the most of the scarce amount of soil available due to the lack of soil development in most Antarctic coastal regions. We have reviewed the soil subsampling protocols and have sub-sampled the soils from the Robinsons Ridge and Main Powerhouse sites. Soil moisture content has been determined for these two sets of soil samples.

Herring Island, Mitchell Peninsula and Casey MPH (Bailey Peninsula) transects have already been subsampled and 10g samples processed at Macquarie University for the integron project. Duplicate DNA samples have been extracted from the Robinsons and Main Powerhouse soils. One set of DNA extractions is stored at Macquarie University, while the duplicate set is stored at the AAD. DNA extractions have been confirmed as PCR competent, further PCR analysis has confirmed the presence of integrons and gene cassettes in these samples. We have begun to use amplification of a hypervariable region of the 16S rDNA gene followed by high resolution electrophoretic analysis to generate an overview of bacterial diversity along all soil transects. All subsamples have been entered into the Sample Tracking Database.

Taken from the 2009-2010 Progress Report:
Soil samples have been collected that relate to specific landforms at a range of spatial scales from several sites in Antarctica and the Arctic.

Analysis of biogeochemical processes within these soils samples is being conducted. All 450 samples from the Antarctic transects have been analysed using the Mid-range infra red spectrometer, we also have total carbon and water content data for all these samples. The data for water content has been collected for the Norway transects (186 samples). The soil sub samples designated for different physical, chemical or genetic analysis have been distributed.

Duplicate DNA has been extracted for all Antarctic transects (Herring Island, Mitchell Peninsula, Browning Peninsula, Robinsons Ridge and Main Power House - Casey) and two Norwegian transects; Vestpynton Longyearbyen (Norway SV) and Spitsbergan Norway (Norway SS). This represents 2320 extractions in total, and the first steps towards investigating soil microbial population dynamics. All DNA extractions have been confirmed as PCR competent.

Further work towards understanding if aspects of the Antarctic environment influence the scales and rates of biogeochemical processes and soil microbial population dynamics has been conducted through examining the presence of integrons and gene cassettes in the samples Integrons and gene cassettes have been confirmed by sequencing and interrogation of BLAST databases. The focus of these investigations has been the Main Power House (MPH) transect. We have cloned sequences that show homology with gene cassettes from Cape Denison, Antarctica (ornothogenic soil) and with Halifax Bay marine sediment that are hydrocarbon contaminated. We are concentrating on intense cloning and sequencing of samples from MPH. This information will be use to develop quick method to identify Integrons and gene cassettes in the rest of samples. We are also trying to identify the integron found in Antarctic soil samples and driving the capture and expression of adaptive genes. Our laboratory is designing primers to target and amplify the integron and the first gene cassette.

We have begun to use amplification of part of the hypervariable region of the 16S rDNA gene followed by high resolution electophretic analysis to generate an overview of bacterial diversity along all soil transects.

A sub sample of every soil sample collected has been logged in the -80oC soil library at AAD and these samples have been catalogued in the Sample Tracking Database managed by the EPiC group.

ASAC项目2952的数据集元数据记录。请点击下方链接查看该项目的公开详情。

本研究通过分析微生物种内适应性、物种分布、生态系统组成、结构及生物地球化学速率与功能，并将这些参数与不同空间尺度下的特定地貌相关联，旨在探究两大问题：其一，南极环境的相关特征是否会影响生物地球化学过程的规模与速率，以及土壤微生物种群动态；其二，若上述结论成立，极地土壤生态系统是否比温带区域对人为气候变化更为敏感。

项目目标：
南极环境的相关特征是否会影响生物地球化学过程的规模与速率，以及土壤微生物种群动态？

若该结论成立，
极地土壤生态系统是否比温带区域对人为气候变化更为敏感？

本研究将通过分析微生物种内适应性、物种分布、生态系统组成、结构及生物地球化学速率与功能，来解答上述两个问题。为此，我们将采集不同空间尺度下与特定地貌相关的土壤样本。随后我们将验证以下假说：不同样地（地貌）间、梯度上、不同地点间以及不同区域间均存在差异。后续可将本项目获取的南极数据与一项更大规模的国际极地年（International Polar Year, IPY）纬度梯度项目的数据进行对比，该项目涵盖北极（加拿大与挪威）、温带及热带区域（澳大利亚、欧洲以及低纬度加拿大）的相关数据。

以下内容摘自2008-2009年度进展报告：
目标推进进展：
过去数年间，我们已从南极与北极的多个样地采集了土壤样本。这些样本已被录入由澳大利亚南极局（Australian Antarctic Division, AAD）EPiC团队开发的样本追踪数据库（Sample Tracking Database）中。我们一直致力于优化实验方法，搭建土壤分析体系，明确每份样本的分样流程，并为每份分样指定对应的化学或遗传学分析方向。鉴于南极多数沿海区域土壤发育程度较低，本方法旨在最大化利用稀缺的土壤样本资源。我们已审核土壤分样规程，并完成了罗宾逊岭（Robinsons Ridge）与主发电站（Main Powerhouse）样地的土壤分样工作。已测定上述两组土壤样本的含水量。

赫林岛（Herring Island）、米切尔半岛（Mitchell Peninsula）以及凯西主发电站（Casey MPH，即贝利半岛Bailey Peninsula）样带均已完成分样，其10克样本已在麦考瑞大学（Macquarie University）完成整合子（integron）相关项目的处理。我们已从罗宾逊岭与主发电站的土壤样本中提取了重复DNA样本：一组DNA提取物留存于麦考瑞大学，另一组重复样本则留存于澳大利亚南极局（AAD）。经验证，所有DNA提取物均可用于聚合酶链式反应（PCR）；后续PCR分析进一步证实，这些样本中存在整合子与基因盒（gene cassette）。我们已开始通过扩增16S rDNA基因的高变区，并结合高分辨率电泳分析，以获取所有土壤样带的细菌多样性概况。所有分样均已录入样本追踪数据库。

以下内容摘自2009-2010年度进展报告：
我们已从南极与北极的多个样地采集了不同空间尺度下与特定地貌相关的土壤样本。

目前正对这些土壤样本中的生物地球化学过程开展分析。南极样带的全部450份样本已通过中红外光谱仪完成分析，我们还获取了所有这些样本的总碳含量与含水量数据。挪威样带的186份样本已完成含水量数据采集。已分配指定用于不同物理、化学或遗传学分析的土壤分样。

我们已完成所有南极样带（赫林岛、米切尔半岛、勃朗宁半岛、罗宾逊岭以及凯西主发电站样带）以及两条挪威样带（挪威SV的维斯皮顿·隆伊尔比恩Vestpynton Longyearbyen、挪威SS的斯匹次卑尔根Spitsbergan）的重复DNA提取工作，总计完成2320次提取，这是探究土壤微生物种群动态的初步步骤。所有DNA提取物均已验证可用于PCR实验。

为进一步探究南极环境特征是否会影响生物地球化学过程的规模与速率以及土壤微生物种群动态，我们对样本中的整合子与基因盒进行了检测：通过测序与BLAST数据库比对，已证实二者的存在。本次研究的重点为凯西主发电站（MPH）样带。我们已克隆得到与南极丹尼森角（Cape Denison）的鸟成土（ornithogenic soil）中的基因盒以及受碳氢化合物污染的哈利法克斯湾海洋沉积物中的基因盒具有同源性的序列。目前我们正聚焦于凯西主发电站样带样本的大规模克隆与测序工作。该信息将用于开发一种快速鉴定其余样本中整合子与基因盒的方法。我们还尝试鉴定南极土壤样本中发现的整合子，并探索适应性基因的捕获与表达机制。本实验室正设计靶向并扩增整合子与首个基因盒的引物。

我们已开始通过扩增16S rDNA基因的部分高变区，并结合高分辨率电泳分析，以获取所有土壤样带的细菌多样性概况。

所有采集到的土壤样本的分样均已存入澳大利亚南极局（AAD）的-80℃土壤样本库，并被录入由EPiC团队管理的样本追踪数据库。