The amount of snowfall, its accumulation and timing of melt contribute to determining the nutrient status of soil and plants in the High Arctic. In addition, timing of snowmelt determines the phenology of plant development during the summer, and thereby the timing of forage availability for residential and migrating herbivores. Recent research suggests that High Arctic vascular plants have a fixed growing season length, and that the timing of senescence is dependent, at least in part, on the date of snowmelt. An earlier snowmelt could therefore potentially lead to an earlier ending of nutrient-rich green summer growth, and an earlier timing of brown, senescing, nutrient-poor vascular plant vegetation, which has much lower value as forage.
Our group recorded near-ground remotely-sensed (NRS) data from Adventdalen in Svalbard (2015-2018), and has gathered vascular plant phenology data during this period. Of particular interest is the relative contribution of vascular plants and mosses to the NRS signals, as well as the role of soil and plant moisture content and nutrients. We are developing the link between hand-collected data and NRS data at the plot-level, so that we can scale-up to the landscape level. This will enable us to interpret satellite-obtained remotely sensed data that covers larger, more inaccessible geographical areas. Ultimately, we will then be able to describe the role of snowmelt date, as well as summer growing conditions, on the timing and amount of vascular and bryophyte growth, and its knock-on effects for the herbivore populations.