Greenland’s melting sea ice could be the reason there is a lower number of caribou being born and a higher rate of calf mortality, revealed new research on the link between melting sea ice and changes in the time of year plants grow on land.
Penn State University researchers say that ice melt leads to plants growing earlier in the year, which affects the caribou’s feeding pattern. They say that caribou bearing fewer offspring can be directly linked to sea ice melt.
Eric Post, a biologist at Penn State, said his original interest was to find out how closely timed the start of the vegetation green-up and the calving season were, without even thinking about the fact climate change could also affect this relationship.
Post gathered data on Greenland for two decades, observing that the plant-growing season over the years got earlier and earlier. He noticed that this did not lead to the caribou calving season undergoing a similar shift. He explained that when plants are at a young age, their nutrients are extremely beneficial to caribou.
Researcher Jeffrey Kerby explained that as plants are now beginning life earlier in the year, they are older and often have less nutritional value when the caribou need them. He added that the caribou turns up expecting a feast only to find the café has already closed.
Kerby went on to say this is known as a trophic mismatch – when the time that plants are most nutritious differs from the time the animals need their nutrients the most.
Post said that in the broader climate system this shows how sea ice can affect plants and animals. He added that how sea ice melt could affect how species interact deserves greater attention.