Normalized Difference Vegetation Index (NDVI) dataset from Small Mammal Experiment 2018-2023 (3 sites near Toolik Lake, Alaska)

We conducted a field experiment in which small mammal density was manipulated at three replicate sites were set up in tussock tundra near Toolik Lake, Alaska(AK) (68.6⁰N, 149.5⁰W, 760 meters (m) above sea level). The motivation for collecting this Normalized Difference Vegetation Index (NDVI) dataset was to understand and quantify the impact of the most abundant herbivores, small rodents (voles and lemmings) on dynamics of canopy productivity on tussock tundra vegetation communities in the Arctic.
In July of 2017, at each site we set up an 8 m x 8 m fenced exclosure with a 0.635 centimeter(cm) square mesh to prevent herbivore grazing and increase vegetation cover (Exclosure treatment (EX)) and identified an 8 m x 8 m unfenced control plot marked at each corner with pin flags at each site (Control (CT)). In 2018, at each site we set up a 20 m x 20 m enclosure that was stocked with up to 4 voles from spring snowmelt through September in each year from 2018-2023 (Press treatment (PR)). In 2019, at each site we set up 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 (Pulse treatment (PU)).
Within each treatment at each site, we measured NDVI at 8 distinct locations within each quadrat and subplot during the period of peak leaf out (~July) in each of 2018-2023. In 2022 only, we measured NDVI approximately every 2-3 weeks starting mid-June through mid-August. All NDVI measurements were made with a RapidSCAN CS-45 Handheld Sensor (Holland Scientific, USA).