Data and R-scripts for: “Misreading or living in denial? Reindeer overstocking and long-term effects on vegetation: an experimental approach”

Our study assessed ground-lichen responses, measured at plots of ca. one m² in size, to reindeer grazing pressure. Our study area is ca. 14 000 km² in size and is in Finnmark, Northern Norway. The study was initiated in 1998, and the same plots were re-visited in 2005, 2010, 2013, and 2018. This study is part of a long-term monitoring program of the lichen pastures in Norway. The data sets include information about ground-lichen biomass (g per m²), volume (L per m²), cover (%), and height (mm), which were our responses. The key predictors consisted of experimental manipulation, reindeer density (individuals per km²), initial conditions (i.e., the observed values for a given response in 1998), and habitat (Forest- and leeward-heath vs. exposed ridges mountain heaths). The experimental manipulation allowed us to compare plots exposed to grazing and trampling by reindeer and other larger herbivores (control) to fenced (treatment) areas. In addition, we included several spatial and temporal variables acting as potential random effects in our mixed effects models: district, transect, block and year (we provide additional information about the data and the analyses in the published article).

本研究针对挪威北部芬马克（Finnmark）郡约14000平方千米的研究区域，评估了约1平方米样地（plot）内的地表地衣（ground-lichen）对驯鹿放牧压力（reindeer grazing pressure）的响应。本研究于1998年启动，并分别于2005年、2010年、2013年及2018年对同一批样地进行了重访。本研究是挪威地衣牧场长期监测计划的组成部分。本数据集涵盖地表地衣的四类响应变量数据，包括生物量（单位：克每平方米）、体积（单位：升每平方米）、盖度（百分比）以及高度（单位：毫米）。核心预测变量包含实验处理设置、驯鹿种群密度（单位：头每平方千米）、初始条件（即1998年各响应变量的观测值）以及生境类型（林内与背风欧石楠灌丛 vs. 裸露山脊山地欧石楠灌丛）。实验处理设置用于对比暴露于驯鹿及其他大型草食动物放牧与踩踏的对照样地，与围栏保护的处理样地之间的差异。此外，本研究在混合效应模型（mixed effects models）中纳入了多项空间与时间变量作为潜在随机效应，包括区域、样带、区组以及年份（本研究的数据集与分析细节已在已发表论文中详述）。