Rate of permafrost thaw and associated plant community dynamics in peatlands of northwestern Canada

This dataset was collected to document the changing plant community, and associated environmental factors, as warming climate conditions accelerate permafrost thaw in northern peatland environments. Due to the insulative properties of dry, surface peat layers, discontinuous permafrost is preferentially found in peatlands, termed peat plateaux, where the volumetric expansion of ice-rich permafrost has resulted in a raised, dry ground surface dominated by lichens and, often, stunted black spruce forests. As ground temperatures warm, and the ice-rich permafrost thaws, the ground surface sinks to, or below, the water table, and these peat plateau environments change dramatically from black spruce and lichen-dominated peat plateaux to treeless moss- and sedge-dominated collapse scar environments. Data are from a set of 17 sites distributed along a latitudinal gradient in the Mackenzie Valley of Northwestern Canada. At each site, a transect of five to nine contiguous 1x1m quadrats was sampled..., Please note that these methods have been adapted from those in the accompanying paper. Please see the accompanying paper in the Journal of Ecology for full context. Field Sampling In the summers (late June to early September) of 2007 and 2008 (T1: time 1), 16 sites were selected along a latitudinal gradient in the Mackenzie Valley and a single transect was established at each site, perpendicular to the boundary of a collapse scar feature. Each transect was located on an independent peat plateau and consisted of a series of five to nine contiguous 1- x 1- m vegetation quadrats extending from the peat plateau to the collapse scar proper. The transect length (and, thus, the number of quadrats) depended on the distance needed to span this transition such that the transect extended from one or two quadrats into the peat plateau beyond the ‘collapsing slope’ to a point in the collapse scar where vegetation became more consistent and typical of that found in central portions of the collapse ..., , # Rate of permafrost thaw and associated plant community dynamics in peatlands of northwestern Canada [https://doi.org/10.5061/dryad.g4f4qrfz5](https://doi.org/10.5061/dryad.g4f4qrfz5) ## Description of the data and file structure Detailed data collection and processing methods can be found in the associated paper (Errington et al. in press) and in the Dryad metadata. Further contextual information regarding the broader Mackenzie Valley Permanent Monitoring Plot Network, including site-level and forest mensuration plot data can be found in Errington et al. (2018, 2020). This submission contains 4 .csv files: * “env_transect.csv” contains site/ transect level environmental variables, * “env_quadrat.csv” contains quadrat-level environmental and vegetation summary variables, * “community.csv” contains quadrat-level plant community composition, and * “species.csv” contains species information. Missing data is coded as “na”. Field names and contents are clarified below: ###...本数据集旨在记录气候变暖加速北方泥炭地多年冻土融化过程中，植物群落及其相关环境因子的动态变化。由于地表干燥泥炭层的隔热特性，不连续多年冻土多发育于泥炭地中，这类泥炭地被称为泥炭高原（peat plateau）；富冰多年冻土的体积膨胀使得地表抬升形成干燥地面，其植被以地衣为主，通常伴生矮化的黑云杉林。随着地温升高、富冰多年冻土融化，地表沉降至地下水位或低于地下水位，此类泥炭高原环境会发生显著转变：从以黑云杉和地衣为主的泥炭高原，变为无林、以苔藓和薹草为主的塌陷坑（collapse scar）环境。 本数据集的数据源自加拿大西北部麦肯齐谷沿纬度梯度分布的17个样点。每个样点均设置一条包含5~9个连续1米×1米样方的样带进行采样……请注意，本采样方法改编自随附论文，详细背景请参阅《Journal of Ecology》上发表的随附论文。 ## 野外采样 2007年与2008年夏季（6月末至9月初，记为T1：时间点1），研究团队在麦肯齐谷沿纬度梯度选取了16个样点，每个样点均设置一条垂直于塌陷坑边界的样带。每条样带均设置于独立的泥炭高原上，由5~9个连续1米×1米植被样方组成，样带从泥炭高原延伸至塌陷坑核心区域。样带长度（即样方数量）取决于跨越该生态过渡带所需的距离：样带需从"塌陷坡"外侧的泥炭高原内延伸1~2个样方，直至塌陷坑内部植被更为均匀一致，且与塌陷坑中部典型植被特征相符的位置…… # 加拿大西北部泥炭地多年冻土融化速率与相关植物群落动态 https://doi.org/10.5061/dryad.g4f4qrfz5 ## 数据与文件结构说明 详细的数据采集与处理方法可参阅相关论文（Errington等，即将发表）及Dryad元数据（Dryad metadata）。关于更大范围的麦肯齐谷永久监测样地网络的更多背景信息（包括样点级与森林测树样地数据），可查阅Errington等（2018、2020）的研究成果。 本提交数据集包含4个CSV文件： * "env_transect.csv"：包含样点/样带级环境变量 * "env_quadrat.csv"：包含样方级环境与植被汇总变量 * "community.csv"：包含样方级植物群落组成数据 * "species.csv"：包含物种信息。 缺失数据以"na"标记。各字段的名称与含义详见下文： ###……