High arctic spring weeks earlier than a decade ago
Spring is arriving in the high Arctic weeks earlier than it did a decade ago, according to new research. The Danish-American team's findings came about thanks to phenology, the study of the timing of spring events such as plants flowering, birds laying eggs or insects emerging. Similar studies carried out at lower latitudes have already revealed that Spring is getting earlier and earlier. For example, it has advanced by an average of five days per decade for European plants and animals. However, until now, there has been little research into the effects of climate change on phenological events in the high Arctic. This is despite the fact that temperatures in the Arctic are currently increasing at twice the global average. The latest study looked at changes in the flowering dates for six plant species, emergence dates for 12 arthropod species and the egg laying dates of three bird species for the period 1996-2005 at a site in north-eastern Greenland. The study is published in the journal Current Biology. The researchers found 'extremely rapid climate induced advancement' in the species studied. The average time of advancement was 14.5 days per decade, while some species had advanced by over 30 days. There was a lot of variation in levels of response to the warming, both within and between species. 'Our study confirms what many people already think, that the seasons are changing and it is not just one or two warm years but a strong trend seen over a decade,' commented Dr Toke Høye of the National Environmental Research Institute at the University of Aarhus in Denmark. 'We were particularly surprised to see that the trends were so strong when considering that the entire summer is very short in the high Arctic - with just three to four months from snowmelt to freeze up at our Zackenberg study site.' While phenological changes at lower latitudes are related to temperature, in the far north it is snow cover that is the decisive factor, as variation in phenology was found to be closely linked to the timing of snowmelt. The results have serious implications for the species living in the Arctic. 'The strong responses and the large variability within species and taxa illustrate how easily biological interactions may be disrupted by abiotic forcing, and how dramatic responses to climatic changes can be for Arctic ecosystems,' the researchers warn. 'Indeed, such dramatic phenological changes may weaken or even disrupt ... interactions among species that are crucial to successful reproduction in this highly seasonal environment.'