Martin Andrew C, Assmann Jakob J, Bradshaw Richard H W, Kuoppamaa Mari, Kuosmanen Niina I, Normand Signe, Speed James D M, Macias-Fauria Marc
School of Geography and Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK.
Department of Biology, Ny Munkegade 114-116, 8000, Aarhus, Denmark.
Environ Evid. 2022 Apr 4;11(1):13. doi: 10.1186/s13750-022-00267-x.
The Arctic tundra is subject to the greatest climate change-induced temperature rises of any biome. Both terrestrial and freshwater biota are responding to recent climate warming through variability in their distribution, abundance, and richness. However, uncertainty arises within models of future change when considering processes that operate over centennial timescales. A systematic evidence synthesis of centennial-scale variability in biodiversity does not currently exist for the Arctic biome. Here, we sought to address the primary research question: what evidence exists for temporal variability in Arctic terrestrial and freshwater biodiversity throughout the Holocene (11,650 years before present (yBP)-0yBP)?
Consultation with stakeholders informed key definitions, scoping and the appropriateness of the research question. The research question was structured using a PECO framework-Arctic biota (P), a timestamped year in the Holocene (E), another year in the Holocene (C), and the dimensions of biodiversity that have been measured (O)-to inform the search strategy. Search strings were benchmarked against a test list of 100 known sources to ensure a specific and comprehensive return of literature. Searches will occur across 13 bibliographic databases. The eligibility criteria specify that sources must: (a) use 'proxy' methods to measure biodiversity; (b) fall within the spatial extent of the contemporary Arctic tundra biome; and (c) consist of a time-series that overlaps with 11,650yBP to 0yBP (1950AD). Information coded from studies will include proxy-specific information to account for both temporal uncertainty (i.e., the characteristics of age-depth models and dating methods) and taxonomic uncertainty (i.e., the samples and processes used for taxonomic identification). We will assess temporal uncertainty within each source by determining the quality of dating methods and measures; this information will be used to harmonise dates onto the IntCal20 calibration curve and determine the available temporal resolution and extent of evidence through space. Key outputs of this systematic map will be: (1) a graph database containing the spatial-temporal properties of each study dataset with taxonomic harmonisation; and (2) a geographical map of the evidence base.
北极冻原是所有生物群落中受气候变化导致气温上升影响最大的地区。陆地和淡水生物区系都通过其分布、丰度和丰富度的变化对近期的气候变暖做出反应。然而，在考虑百年时间尺度上运行的过程时，未来变化模型中会出现不确定性。目前尚不存在关于北极生物群落生物多样性百年尺度变化的系统证据综合。在此，我们试图解决主要研究问题：在全新世（距今11,650年至公元0年）期间，北极陆地和淡水生物多样性随时间变化的证据有哪些？
与利益相关者的磋商为关键定义、范围界定和研究问题的适当性提供了信息。研究问题使用PECO框架构建——北极生物区系（P）、全新世中的一个带时间戳的年份（E）、全新世中的另一个年份（C）以及已测量的生物多样性维度（O）——以指导搜索策略。搜索词以100个已知来源的测试列表为基准，以确保文献的特定且全面的检索。搜索将在13个书目数据库中进行。纳入标准规定来源必须：（a）使用“替代”方法测量生物多样性；（b）属于当代北极冻原生态系统的空间范围；（c）由一个与距今11,650年至公元0年（公元1950年）重叠的时间序列组成。从研究中编码的信息将包括特定于替代指标的信息，以考虑时间不确定性（即年龄 - 深度模型和测年方法的特征）和分类学不确定性（即用于分类鉴定的样本和过程）。我们将通过确定测年方法和测量的质量来评估每个来源内的时间不确定性；此信息将用于将日期校准到IntCal20校准曲线上，并通过空间确定可用的时间分辨率和证据范围。本系统地图的关键输出将是：（1）一个包含每个研究数据集时空属性并进行分类协调的图形数据库；（2）证据库的地理地图。
