Relative cover of vegetation from a small mammal experiment from summer 2018-2023 near Toolik Lake Alaska

We conducted a manipulative experiment to quantify the impact of small mammal herbivores on the plant community of the tundra at three sites near Toolik Lake, Alaska. At each site we set up grazing fences in July of 2018 to simulate different levels of small mammal herbivore (vole and lemming) activity. Each site had 3 treatment plots and a control plot: 1) Exclosure treatments (EX) were 8 meter (m) x 8m square mesh fences 2) control plots (CT) were 8m x 8m unfenced plots marked with pin flags at corners 3) press treatments (PR) were 20m x 20m square mesh fences stocked with 4 tundra voles (Microtus oeconomus) every summer except for 2024 and 4) pulse treatments (PU) where we stocked the fence with 4 voles in 2018 and then removed and excluded voles from 2019 onward. At each site in each plot we collected relative abundance of plant species and ground cover in 8 1 square meter (m2) plots once each year (except in 2020).本研究于阿拉斯加州图利克湖（Toolik Lake）附近的3个苔原样地开展控制性野外实验，以量化小型哺乳类植食动物（田鼠与旅鼠，vole and lemming）对植物群落的影响。研究于2018年7月在每个样地搭建放牧围栏，以模拟不同强度的小型哺乳类植食动物活动水平。每个样地设置3个处理样地与1个对照样地，具体如下： 1. 围栏排除处理（Exclosure treatments，EX）：采用8米×8米的方形网围栏； 2. 对照样地（Control plots，CT）：设置8米×8米的未围栏样地，四角以标杆旗标记； 3. 持续放牧处理（Press treatments，PR）：搭建20米×20米的方形网围栏，除2024年外，每年夏季向围栏内投放4只苔原田鼠（Microtus oeconomus）； 4. 脉冲式放牧处理（Pulse treatments，PU）：2018年向围栏内投放4只田鼠，自2019年起移除并排除田鼠种群。 每年（2020年除外），研究人员在每个样地的8个1平方米（m²）小样方内采集植物物种相对多度与地表覆盖度数据。