Small mammal mark-recapture data 2018-2023 (3 sites near Utqiagvik, Alaska)

We conducted mark-recapture surveys of small mammals in polygonal tundra at three sites near Utqiagvik Alaska (AK) (71.2906 North (N), 156.7885 West (W), 3 meters (m) above sea level). In 2018, we established a mark-recapture grid at each of three sites (greater than; 500 meter (m) apart) in low polygonal tundra within the Barrow Environmental Observatory (Cake Eater (CE), NOAA (NO), and Shed (SH)). Each grid consisted of 120 trap stations set in a 15 x 8 arrangement with 10 m spacing, and encompassed an area of 1.2 hectares (ha). Mark-recapture surveys were conducted twice during the summer season in late June or early July (shortly after snowmelt) and in late August in 2018 - 2023. In each session, grids were surveyed for four consecutive days with traps checked every eight hours. Due to COVID-19 access and quarantine policies sites were only trapped once (in early August for 3 days) in 2020. In addition, in 2019 one site (NO) was monitored for only 3 consecutive days in both June and August. A single Sherman live trap was set to sign within three meters of each station, baited with a mixture of peanut butter and bird seed, and insulated with nestlets. Waterproof tar paper was pinned over each trap. Captured individuals were identified to species, weighed, sexed, aged, and marked with a PIT tag (9 millimeter (mm), Passive Integrated Transponder, Biomark, Inc, Boise, Idaho) to track recaptures. Upon the first capture of an individual in a survey period, a small hair sample was taken from the rump and a small sample of ear tissue was taken. Fecal samples were collected from the trap. Traps which had captured individuals were removed and replaced with clean traps. This dataset is part of a collaborative project examining herbivore effects on vegetation and nutrient cycling. At each site, one mark-recapture grid was paired with a fenced exclosure (8 m x 8 m) and unfenced control plot (8 m x 8 m) as well as two experimental herbivory treatments. The experimental Press treatment (PR) treatment was an enclosure (20m x 20m) that was stocked with up to 4 voles from spring snowmelt through September in each year from 2018-2023 and the experimental Pulse treatment (PU) was a 20 m x 20 m enclosure that was stocked with up to 4 voles from spring snowmelt through September in 2019 only, after which voles were removed and the fences served to exclude voles from 2020-2023. In addition, over-winter herbivore activity (e.g., surface nests, latrines, runways) was quantified each year in control plots, enclosures, and on each mark-recapture monitoring grid following the ITEX herbivory protocol.

我们在阿拉斯加州乌特恰维克（Utqiagvik）附近的三个多边形苔原站点开展小型哺乳动物标记重捕调查，该区域地理坐标为北纬71.2906°、西经156.7885°，海拔3米。
2018年，我们在巴罗环境观测站（Barrow Environmental Observatory）内的低海拔多边形苔原中，于三个间距大于500米的站点分别布设了标记重捕网格，三个站点依次为Cake Eater（CE）、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA，缩写NO）、Shed（SH）。每个标记重捕网格采用15×8的布局，包含120个捕兽站位，站位间距为10米，覆盖总面积达1.2公顷（ha）。
2018年至2023年的夏季，我们每年开展两次标记重捕调查，分别于6月末或7月初（融雪后不久）与8月末进行，每次调查连续开展4天，每8小时检查一次捕笼。受新冠疫情（COVID-19）通行与隔离政策限制，2020年仅在8月初开展了一次为期3天的调查。2019年，NO站点仅在6月与8月各开展了连续3天的监测。
每个站位3米范围内布设1台谢尔曼（Sherman）活捕笼，诱饵为花生酱与鸟籽的混合物，笼内放置巢材垫料以保温，同时用防水油布固定覆盖每台捕笼。捕获的个体将被鉴定至物种层面，测量体重、记录性别与年龄，并通过被动集成应答器（Passive Integrated Transponder, PIT tag，9毫米，Biomark公司，美国爱达荷州博伊西）进行标记，以实现重捕追踪。在调查周期内首次捕获个体时，研究人员还会从其臀部采集少量毛发样本，取一小块耳组织样本，并从捕笼中收集粪便样本。每次捕获个体后，原捕笼将被移除并更换为清洁捕笼。
本数据集隶属于一项协作研究项目，旨在探究草食动物对植被与养分循环的影响。每个站点的标记重捕网格均搭配了围栏排除样地（8米×8米）、未围栏对照样地（8米×8米），以及两组草食动物操控实验处理。其中，持续压力处理（Press treatment，PR）为20米×20米的围栏区域，2018年至2023年每年春季融雪至9月期间，均放养最多4只田鼠；脉冲处理（Pulse treatment，PU）同样为20米×20米的围栏区域，仅在2019年春季融雪至9月期间放养最多4只田鼠，2020年至2023年则移除田鼠，围栏仅用于排除田鼠。
此外，研究团队参照国际冻土实验（International Tundra Experiment, ITEX）的草食动物调查规程，每年在对照样地、围栏区域及各标记重捕监测网格中量化越冬草食动物活动痕迹（如地表巢穴、粪堆、活动通道等）。