Thursday
Mar082018

How can plant-pollinator network science help with conservation?

Network science is a powerful new tool to visualize and analyze the interconnectedness of things that interact. Think of it as similar to a social network that connects people to each other, or a vast telecommunications network. It turns out that the species we care about interact in networks with other species as well. Uncovering the vast web of interconnections in the natural world can give us new ideas about how to help endangered species and restore native communities.

Last year, we collected data to create plant-pollinator networks that reflect webs of interactions between all the plants and all the pollinators in south Puget Sound prairies. We can use these networks in many ways. One use is uncovering how some plants may be indirectly connected with other plants through shared pollinators. For example, we found that at one site, golden paintbrush was visited by two different pollinator species last year. One of those key pollinator species was seen visiting only one other kind of flower during the whole season.  It was a non-native plant, too! This suggests that the non-native plant is supporting one of the pollinators that visits golden paintbrush. We can use this information to guide our restoration and land management plans - as we gradually get rid of that non-native plant, we will make sure to add other native plants that will also support that pollinator, improving the chances that golden paintbrush flowers will continue to get pollination services.

Another use of networks is to help us imagine and simulate what might happen when some species are removed, or when their numbers are very low in a given year. For example, we used networks to simulate what might happen if there was no bumble bee activity in a year. We saw that the loss of bumble bees would lead to losing some of the plant species we currently care about most (golden and harsh paintbrush) at some sites due to the lack of pollinators foraging at new plants. While we aren’t expecting to lose bumble bees any time soon, this allows us to realize that bumble bees are extremely important for the native paintbrushes. Since the paintbrushes themselves are very important to Taylor’s checkerspot butterfly, we unexpectedly find that caring about butterflies means caring about bees too!

Finally, networks can help us visualize changes in the community that happen during restoration processes. We hope that our restoration efforts indirectly bring back pollinators as we add to the diversity of native plants on these sites, but networks can help us look at the ways in which that is actually happening. We have some hopeful signs - there is definitely greater complexity of networks at sites that are more highly restored! Stay tuned for a whole new year of plant-pollinator networks.