McMurdo Dry Valleys LTER: Transplant Lake Integrated Connectivity Experiment (tLICE) in Taylor Valley, Antarctica, January 2018

The purpose of this experiment, performed as part of the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) program, was to investigate the impact of lake level rise and moat expansion on microbial community diversity and function in the East Lobe of Lake Bonney, located in Taylor Valley, Antarctica. The “tLICE†experiment tested the following MCM5 Hypotheses: H3-Disturbance increases connectivity and accelerates shifts towards homogeneity, and H4-Decreased heterogeneity reduces community resistance and resilience. Lake water from the East Lobe of Lake Bonney was collected at depths representing maximum phytoplankton productivity (5 m, 17 m, 23 m), and transferred to dialysis bags. The bags were then attached to PVC frames and transplanted to new locations within the lake in two experiments: 1) a moat transplant, in which 5 m communities were transplanted to the open water moat; and 2) shallow to deep transplant, in which communities from all three sampling depths were moved 3 m down the water column to mimic approximately one decade of lake level rise. Transplanted samples were incubated under these conditions for two weeks, and then frames were recovered and samples were processed for a number of measurements. This data package includes the following measurements: nutrient concentration, chlorophyll-a content, chlorophyll fluorescence, cell density, amplicon gene sequences (16S and 18S rRNA genes), and physical parameters.

本实验作为麦克默多干谷长期生态研究（McMurdo Dry Valleys Long Term Ecological Research, MCM LTER）计划的一部分开展，旨在探究湖面水位上升与冰间水道扩张对南极洲泰勒谷邦尼湖东支微生物群落多样性与功能的影响。本次“tLICE”实验对两项MCM5假说进行了验证：H3——干扰可提升群落连通性并加速其向同质化状态转变；H4——群落异质性降低会削弱其抗性与恢复力。研究人员从邦尼湖东支采集了对应浮游植物最大生产力深度（5 m、17 m、23 m）的湖水样本，将其转移至透析袋中。随后将透析袋固定于聚氯乙烯（Polyvinyl Chloride, PVC）框架，分两组实验将透析袋移植至湖内新区域：1）冰间水道移植实验：将5 m深度的微生物群落移植至开放水域冰间水道；2）浅至深移植实验：将三个采样深度的微生物群落沿水柱向下迁移3 m，以模拟约十年的湖面水位上升过程。移植样本在上述条件下培养两周后，研究人员回收框架并对样本进行处理以开展多项检测。本数据包包含以下检测指标：营养盐浓度、叶绿素a含量、叶绿素荧光强度、细胞密度、扩增子基因序列（16S and 18S rRNA genes）以及物理参数。