How is the tundra biome responding to global change? We just made a small contribution to a new study in Nature led by Anne Bjorkman and Isla Myers-Smith. They have written an excellent blog post, and you can also read a summary at the BBC News.

Through several years of work, they were able to assemble an extensive dataset for community change and trait dynamics in tundra ecosystems around the globe, over several decades of time. Our contribution was to provide a small amount of data for some high-elevation sites in the Colorado Rocky Mountains. However, most of the study’s data come from higher latitudes.

The first main message coming out of the study is that species’ traits are changing, primarily due to replacement of some species by others. Specifically, warming environments are driving the occurrence of taller plants – an effect strong enough that tundra communities may become 20-60% taller (i.e. much shrubbier) by the end of the century, depending on the anthropogenic emissions scenarios that are realized. This is a huge projected change, and will have broad implications for ecosystem functioning in these regions, including provision of resources for animals, storage of carbon, surface albedo, and so on.

The second main message is that space-for-time substitutions are unlikely to provide as much insight into these dynamics as direct time-series data. The trait-environment relationships estimated across contemporary research sites make very different predictions for future warming than the trait-time relationships that were directly measured. This means that species have lagged responses to climate change, and that long-term monitoring efforts are critical for accurately forecasting future biodiversity dynamics.

It was a pleasure to take a small part in this important work. Studies like this are only possible with the data contributions of a great number of researchers collaborating across national boundaries, and with long-term funding commitments of their respective nations.

You can read the paper at the journal or get a PDF (11MB).