Monthly Archives: May 2014


Grades are in, just this week! Summer has officially arrived for the academic.

It's arrived in Minnesota, as well -- we've got beautiful weather, sunny days, warm temperatures. I've been trying to get caught up on weeding and planting things in the garden, since I traveled a lot this month and the days of frost were pretty recent here. Today in the garden I noticed a bee, but only one. It's not surprising that it seems like there are fewer bees than usual out and about. Bee population collapses have been getting a lot more news: the population numbers aren't good, but we still love all the fruits and vegetables that bees help to pollinate.

We're still not sure exactly why bee numbers have declined so much, but it seems to be a complex interaction between parasitic mites that have invaded bee colonies and agricultural chemicals we use to suppress other insects.

What can you do? Look up information about what plants you can grow that help bee populations. In Minnesota, check out the U of MN's Bee Lab pages! Avoid certain types of pesticides and fungicides. Talk to your Lowe's or Home Depot about not selling plants and flowers treated with neonicotinoids, a pesticide that comes up through a plant and weakens bees who collect the pollen, or buy from a smaller distributor who doesn't use neo-nics.

On the math side, there's a lot of differential equations to model bee colonies and their populations! There are quantitative models of honey bee population dynamics and mathematical model of bee colony collapse disorder. There's an online simulation you can run. You can tweak the models yourself if you know enough math, and one honors thesis I found did just that.

So on the docket, coming soon, are some worksheets or activities that explore bee populations at a few different mathematical levels. As always, I want students to have entry points into this interesting problem from a wide range of mathematical starting points!

Average change: nitrates again

Spring still keeps happening slowly in Minnesota, and snow is still melting up north. Iowa and other big agricultural states to our south have experienced all their snow melt, though, and are beginning the farming season.

Here's a worksheet that's pretty well inappropriate to the academic year -- no one is doing rate of change right now in calculus or precalculus! But it's written, so I may as well share. Again, it's about nitrate and nitrite runoff into the Raccoon River in Iowa. Spring is a good time to fertilize soil, but the runoff that's happening during the first snow melt is actually all from fertilizer applied last summer.

Average Change: Nitrates in the Raccoon River

The semester is coming to a close. Just a few more weeks of class and it's over. I'm working, as slowly as the spring, on some new worksheets about White Bear Lake water levels and about bee ecology. I learned today that Michelle Obama keeps bees near the White House garden. They're fascinating creatures!

More later... just a few final exams to go 🙂