Heating up and keeping cool
I’m just returning from a lovely vacation in Maine, where the air was cool and the crowds few and far between. It may not always be that way.
It’s no secret that over the next several decades, the average temperature in the United States (and in many parts of the world) is going to increase. That means warmer summers, both in the hot parts of the country and in the more northerly regions where people typically go in the summer to cool off. As the summer weather get warmer, more people may head north on vacation, or they may go further north than before. We can expect animals to try to compensate for warmer weather, too.
The first week of August I was in Minneapolis for the annual meeting of the Ecological Society of America, and I spent Thursday sitting in on two symposiums: “Warming Consumers and their Prey: General Principles and Applications for How Temperature Affects Trophic Interactions” in the morning and “Rapid Climate Change and Species Range Shifts: Observations, Predictions, and Management” in the afternoon.
The morning session was about how warming climate may influence interactions between plants and animals and between animal predators and animal prey. It is not an easy topic, as the relationships among species are complex, and scientists are only starting to understand how warming will affect single species directly (that is, if they don’t interact with other species). One speaker pointed out that while some species might normally adapt to warming or move to cooler areas, having other species around might prevent that adaptation or movement. For example, if you overheat easily and your plant food does not move northward as the climate warms, you cannot very easily move northward to adjust to the changing climate. Another speaker showed that we should think about maximum summer temperatures and minimum winter temperatures, rather than average annual temperature (as is typically done); plants and animals are likely to experience the greatest impact of climate change when they experience unusually hot or unusually cold conditions.
The afternoon session was equally interesting. One speaker talked about how over the past few decades, the ranges of plants and animals studied all over the world are moving towards the poles (north in the northern hemisphere, south in the southern hemisphere), up mountains, and down into deeper water (for aquatic organisms). Another talked about using information from botanical gardens and commercial plant nurseries to understand where some plant species can live and reproduce, even if they’re not native to that area to begin with; this is useful information for predicting how plants might change their ranges in the future.
Regional climate models for East Africa do not suggest that the area is going to get much warmer in the next decades. However, the climate will get more variable, with wetter wet seasons and more frequent droughts. That’s one of the reasons we want to run Snapshot Serengeti for many years. By collecting data over a decade or more, we’re likely to catch at least one drought year and at least one very wet rainy season. If the Serengeti’s future holds more of these extreme climate years, the data from Snapshot Serengeti will help us determine what will happen to the various animals that live there — and in other parts of Africa.
Wetter seasons and drought probably won’t effect the grass much, that stuff is tenacious. It does go dormant in a drought, but comes back as soon as it gets some moisture. Are you expecting this to change migration patterns?
Yes, it may very well. The wildebeest don’t come out onto the short grass plains until they green up after the dry season, for example.