Hey Bees’ Needs Volunteers and blog followers, my name is Collin Schwantes and I am a recent addition to The Bees’ Needs team. I’m writing this post to tell you about the work I’m doing on the project right now. I’ve just gotten started, so I’ll write again later this summer with some more results. But for now, this is a glimpse of what I’m working on.
You might recall that one of the goals of The Bees’ Needs is to examine how landscape attributes in our communities benefit or discourage native bee and wasp diversity. I have been hired this summer to look into these questions using Geographic Information Systems (GIS) technology. Ultimately, knowing how what we do in our backyards impacts bees and wasps will give us the tools we need to conserve them. The first step is to ask: where are our volunteers seeing the most bee and wasp diversity?
Thanks to all of you, we have an incredibly rich data set that we can use to tackle that question. From my perspective, each of your blocks represents a point on the map where we know something about the bees and wasps living there. Even knowing that no bees or wasps are nesting at your block is important. What we can do next is nearly endless.
I’ve started looking at not only where we find the greatest diversity of nesting bees and wasps, but also at how those “hot spots” for diversity change across the nesting season. For this blog post, I’m going to focus on the greater Boulder area. We know that some bees and wasps build nests early in the year and others later. Using data from each month we can see when and where species start to show up around Boulder. By interpolating between blocks, we can roughly estimate where bees and wasps are found for the entire area surrounding Boulder, even if we don’t have bee blocks there.
Let’s look at this changing map, below. It shows us nesting bee and wasp diversity from June to September in 2013. The red areas are those of greatest diversity, and the blue areas are least diverse. You can see that diversity bounces around quite a bit as different wasps and bees start nesting at different times. June and July appear to be the months with the most diversity across all the bee blocks. In August there appears to be some lingering pockets of high diversity. As I work through subsequent years of your data from the project, it will be interesting to see if these hot spots stay the same, or change.
The heat map you see above has error associated with it simply because we can’t sample all the bees and wasps everywhere. As a result, the estimates of diversity made in the heat map may not perfectly reflect what you have recorded in your block. Fortunately, we can use elements of the urban landscape to try to improve those estimates. If our estimates of where bees can be found are closer to what you report, then we have found a piece of the landscape that predicts bee and wasp presence. We can use maps of streets, parking lots and buildings to figure out where bees probably aren’t. Because the bees and wasps we are interested in can’t eat or nest in blacktop, we can be pretty sure that bees and wasps won’t be found in the middle of a King Soopers parking lot. When we include all of those surfaces in our estimation we can cut out a large chunk of the map.
We will probably find that elements of the urban landscape influence bee and wasp species in complex ways. With some things, like tree cover or conservation areas, increasing the number of species we find in a block and other things, like percent impervious surfaces, decreasing diversity. Some species may do really well in the urban core, while others are only able to exist in small pockets of the city. With the knowledge gained from this work, we will know which parts of the city could use a boost in bee and wasp habitat, and which areas we should be protecting.