Wednesday, January 14, 2015

Canadian National Parks Malaise Program

The Canadian National Parks (CNP) Malaise Program, a collaboration between Parks Canada and the Biodiversity Institute of Ontario (BIO), represents a first step toward the acquisition of detailed temporal and spatial information on terrestrial arthropod communities across Canada. The program addresses the current lack of a systematic approach for tracking shifts in the species composition of terrestrial communities in response to environmental disturbance or global climate change.

It is no secret that here at BIO we work a lot with Malaise traps and one of the reasons is the fact that assessments of terrestrial environments are lacking a standard protocol to derive biotic indices. This is very different from e.g. water quality assessments which are routinely based on surveys of freshwater invertebrate species composition. Terrestrial assessments often rely on a handful of indicator taxa which are very often vertebrates and plants. The problem is that most species in terrestrial ecosystems and others for that matter are invertebrates.

The Canadian National Parks Malaise program started in 2012 and by the end of 2014 it covered pretty much all of Canada (see map above). Not long ago the team at BIO finished analyzing the year 2013 which in total means that 227 weekly samples with some 280 000 specimens were analyzed. About 240 000 of those provided a DNA Barcode with sufficient length to allow for a BIN assignment. Some 17 500 BINs were found for the year 2013 with 14 sites. Numbers that are pretty impressive and even more so when the previous year is added to the picture. Just have a look at the BIN/species accumulation curve on the right. The colleagues here have generated reports for each participating park and I highly recommend checking those out. Each reports starts with an overview and summary of the total results before looking into the details of the particular site.

The comparisons between the sites are pretty impressive, too. I particularly like one figure, a chord diagram of species overlap between all National Parks probed in the years 2012 and 2013. It looks beautiful and perhaps confusing at first but there is a lot of information in it. The width of each wedge is proportional to the number of BINs captured in a given park. The width of the internal humps reflect the number of unique BINs within each park. Arcs connecting the parks reflect the proportion of shared species between the parks. The parks have been arranged according to geography and neighborhood.

Species overlap can also be documented over time at a given location. The last figure shows overlap between weekly (A) and bi-weekly (B) samples over the collection period in 2013. The node size is proportional to the number of BINs per sample while the width of arcs reflects the number of species shared between each sample. 

The images might be a bit small when embedded in the text but you should be able to click on them to enlarge them to a reasonable size. If that doesn't work for some reason I'll recommend the original reports

My blog post can only be a teaser for these very data rich reports. Personally I find these comprehensive studies very fascinating and going back to the original intent of this project - this is definitely a way to provide standardized and systematic assessments of terrestrial environments. It is already far more detailed than any report one could get even from a comprehensive survey of a freshwater environment and it is done using a lot of human workforce and traditional sequencing. After all we are still assembling the DNA Barcode library for Canada's life. Just imagine what will happen when we are done and start to introduce metabarcoding...

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