Arctic sea ice decline has the potential to influence dynamics of terrestrial ecosystems, which may then play a direct role in the reproductive success of herbivore populations, reports research published in Nature Communications.
It has been suggested that loss of sea ice due to increased atmospheric CO2 concentrations has repercussions on terrestrial ecosystems. Jeffrey Kerby and Eric Post used data on air temperature and sea ice extent in West Greenland over a period of 11 years. They then used data collected daily in the spring and summer over the same period on plant emergence timing and caribou reproductive biology in order to note any possible links between sea ice extent and the dynamics of terrestrial ecosystems. The authors use plant emergence timing as an approximate measure of when plants are most nutritious. Eating young, nutritious plants increases the chances of offspring survival, and therefore matching timing of spring plant growth and caribou reproduction is essential for this caribou population. The authors find, however, a temporal mismatch between caribou reproduction and plant emergence timing, with plants emerging in 2011 on average 16 days earlier than 2002, while caribou continue to reproduce at the usual time of the year. This leads to an increased early mortality and lower production of caribou calves.
The reported advance in the timing of plant emergence, and by extension reduced caribou reproductive performance, is more closely linked to the recent decline of sea ice than to other measured environmental factors. The study therefore highlights additional indirect impacts of sea ice decline on Arctic ecosystems, and its importance for the dynamics and conservation of terrestrial species, including emblematic species such as the caribou.