Saturday, September 27, 2014

Climate Change Workshop, part 5.

The climate change workshop for teachers, sponsored by Oklahomans for Excellence in Science Education (OESE) and the Oklahoma Climatological Survey continued this afternoon and evening.

The first two presentations were about phenology. Phenology is the seasonal pattern of biological processes: the time of year that trees burst their buds, that animals hibernate or migrate, etc. Phenological data are particularly valuable to a study of global warming because the organisms integrate many physical factors. How do you measure temperature? Average maximum temperature? Average minimum temperature? Threshold temperatures? But you can let the organisms themselves do the measuring. If global warming causes winter to be shorter and warmer, and spring to come earlier, perhaps the best way to measure this is to quantify the budburst date of deciduous trees or the flowering date of herbaceous plants.

The first presenter was Dr. Lara Souza of the University of Oklahoma and the Oklahoma Biological Survey. What happens when species experience global warming? They could either stay where they are and adapt (either through natural selection or acclimatization); go extinct; or migrate to other locations with cooler temperatures.

Consider some examples. Camille Parmesan and associates showed that some British butterflies moved north during the twentieth century. They gathered their data from insect collections, in which the date and location are recorded. Another study, by Lenoir and associates, showed that most but not all species of mountain plant species shifted their distributional range to higher elevations. You can download the Lenoir data from Science (these data are open access, unlike many of the articles in Science) and have students compare the average elevation in the early vs. the late twentieth century for each species, either by making a graph or by doing a simple statistical analysis (paired-t test). The Rocky Mountain BiologicalLaboratory, at about 10,000 feet elevation in the Rockies, also has an excellent data set about the first day in spring at which many species of birds and mammals became active; this data set stretches back to 1974. Some, but not all species, have become active much earlier in the spring in the past forty years. The RMBL website is being reconstructed, but the link should lead you to the data at a later time. Another study, led by Laura Burkle, revisited some nineteenth-century pollination study plots to see how much changes has occurred in phenology. She found that, in many cases, the plants were flowering earlier but the pollinators were arriving at the same time compared to 150 years earlier.

Lara then told us how students can contribute their own data to, or work with data sets made available by, the National Phenological Network. There are also some citizen-science projects being done, including common garden experiments where people in different places plant the same plants, and keep track of their phenological responses. With the example of lilacs, people all over the country have planted not just lilacs but exactly the same breed of lilacs so that they can make direct comparisons of the same breed of plant in very different geographic locations. (There are some limitations. For example, lilacs do not grow well in Oklahoma.) Students can participate in these citizen-science projects and contribute their data to a national database.

The Saturday evening presentation was by me. Now think about this. A group of energetic teachers who have been in a workshop for a day and a half. Should I just give them a scientific seminar? Uh, no. Especially since there is no place else for them to go except to my presentation! There used to be a bar down the highway but it closed. So it behooved me to present a standup comedy routine before getting into the science.

Standup comedy is not something entirely new to me. In June 2012, when I was staying with my sister in La Jolla, I walked past the San Diego Comedy Club, and it was open mike night. Why not? I signed my name on the list and went to get my Darwin hat. It was a pretty big audience, or so I thought. The only problem is that the real audience was only about six people, and everyone else was on the list for performing. Each person did his or her little thing, then left, so when they got to me (number 28) the room was pretty empty. Most of the routines were pretty lame, and most of them for the same reason: they talked only about themselves. I might have been the only comedian to talk about something other than himself. I didn't tell them my real name. I talked to them, instead, about hagfishes. Anyone who knows about hagfishes knows that you can get a lot of truly disgusting comedy material out of them. At the end, the emcee took a vote for best performance. I was one of two nominees. The emcee chose as the winner a third person who was not nominated. If I were a budding young comedian, I would have been bent out of shape, but I have a day job, so whatever. The audience was in the parking lot as I walked to the supermarket, and they said, "Hey, Darwin!" and told me they liked it. I told them I was a professor and I did things like this in my classes.

Then I gave my scientific presentation, which I briefly summarize here. I have nine years of data about budburst times of deciduous trees in Durant, Oklahoma, and the results clearly show that budburst has occurred earlier during the course of those nine years--not consistently every year, but clearly overall. But not in all species.

Then, I wanted to know what might happen in the future. Suppose that Oklahoma gets so warm that winter disappears altogether? Would that mean that the deciduous trees would grow new leaves as soon as they drop their old ones? (They will still drop their leaves, a process controlled by daylength.) That is, can I extrapolate my budburst data? The answer is not always. The answer is yes for sweetgum trees, whose buds are fully formed in the fall, but the answer is no for sycamores and pecans, whose buds require a period of cold temperatures in order to complete their development. This conclusion is based on research I conducted with my student Sonya Ross. Therefore, if global warming occurs so much that winter disappears, the budburst of some tree species will actually be delayed.

I let them go, but they all stayed to hear me perform my Evolution rap (which is on YouTube here) and my cowboy version of Wrangham's cooking hypothesis (which is on YouTube here). I then shared some refreshments with them. For workshop participants, as for students, they learn more when they are having fun--to an extent, anyway.

No comments:

Post a Comment