Meeting Abstract
P2.66 Tuesday, Jan. 5 Differences in the thermal tolerances of isopods, from a temperate and tropical region, will buffer temperate isopods from the impacts of climate change BORCHERT, JD*; SHELDON, KS; TEWKSBURY, JJ; Indiana State University; University of Washington; University of Washington jborchert@gmail.com
Organisms in tropic and temperate regions experience very different climatic regimes. This is particularly true in regards to the amount of seasonal temperature variation each of these regions experience, with tropical systems seeing mild levels of annual variation while temperate regions experience a large range of annual variation in temperature. As global warming continues to increase both of these regions are expected to see increased temperatures. However, temperate regions are expected to see a disproportionate increase in warming relative to the tropics. We hypothesized that temperate organisms are more capable of tolerating climate change, despite this greater increase in rising temperatures, since they are adapted to a wider range of temperatures than tropical species. To examine this we found the thermal optima and thermal maxima of an isopod, Oniscus asellus, in both the temperate climate of Seattle and the tropical climate of Ecuador. To find the thermal optimum we found the temperature at which isopods were fastest at righting themselves after being flipped over onto their back. The thermal maximum was defined as the temperature where the isopods were no longer capable of righting themselves. For each region we then compared the difference between the thermal optimum and maximum for the isopods and looked at whether the expected increase in global warming for each region was within this temperature range. We found that the temperate species has a substantially larger difference between its thermal optimum and maximum than the tropical species whose thermal optimum is very close to its thermal maximum. Based on this evidence we believe that the temperate isopod is much more capable of withstanding its expected temperature increase.
