Temperature and Food

Figure 1: Graph made by Blake Hummel:  Showing the correlation between an increase in Temperature and the eventual decline in Grizzly Bears.  Refer to Figure 2 to relate an Increase in Temperature with eventual decline in food sources. This figure is based on previous trends found in scientific research with my own estimates of what might occur to the population based on similar situations occurring in other organisms.[2, 5, 8, 9]

Figure 2:  Graph made by Blake Hummel: Correlation between Temperature and eventual decline in food sources of the Grizzly Bear.  This figure is based on previous trends found in scientific research with my own estimates of what might occur to the population based on similar situations occurring in other organisms. [2, 5, 8, 9]

Temperature and Food

With an increase in mean annual temperature, there are typically consequences.  With these increases in temperature, it is causing a decrease in population of two of the primary food sources of the grizzly bear, whitebark pine and army cutworm moth. With these increases in temperature, the bears are most likely being forced to perform an elevation range shift in order to escape these increase in temperatures [7, 11].  These plants and insects are both found at high elevations already, and probably got to where they are by shifting up a mountain seeing as they aren't capable of moving vast distances in order to escape the temperature changes.   With these, it leads me to believe there might be the possibility of an increase in temperature resulting in an increase of fitness of other plants and animals, which in turn could increase other sources of food for a short duration.  This however would lead to an eventual decline with the continually increasing temperature due to plants and animals surpassing their optimal conditions.  Figure 1 below shows my interpretation of how the Grizzly Bear populations might fluctuate over the next century after having looked at the previous trends and impacts such as deforestation, wild fires due to increased temperatures, and so forth.  Then with Figure 2 I show a potential future correlation between the Grizzly Bear's food sources with the increase in temperature.  So with an increase in temperature leading to an initial increase in food and then grizzly bear population and then a fall in populations in succession due to further increases in temperature. [8]

Figure 1 made by myself is portraying the potential future based on the previous century's events for the Grizzly bear population and the estimated increase in global temperature over the next century.  To make this graph, I thought about the impacts of increased temperature on other organisms and used my understanding to show how at first the population might increase from increased performance of some species they prey on.  Then after a certain point, that peak will be met for their prey and begin to deteriorate thereafter.  [2, 5, 8, 9].  For Figure 2, I took that same information regarding the estimated temperature increase and referenced it to the potential sources of food for the Grizzly bear, which I also used in conjunction with making the first figure.  Many species (though not all of course) are estimated to increase in fitness due to slight increases in temperature, however as I mentioned in regards to Figure 1, there is a peak at which these organisms will meet and their population will begin to deteriorate.  [2, 5, 8, 9].  When looking at the two graphs jointly, one can relate the two through the temperature changes and the potential decline in populations in prey and predator.  As with many species, there is potentially a lag in the time it takes for the grizzly bear population to begin to fall after the fall of the prey.  These graphs are rough estimates of what might occur, however the slopes could vary in how fast or slow they occur for either population. 

The increases in temperatures might be too fast for many species to adjust to new ranges, going back to the topic of range shifts [8, 11].  In previous times of drastic climate change, species have typically adjusted to new ranges in order to prevent dying out or suffering a decline in fitness, but with these rapid increase in temperatures, it would be difficult for many to cope with the stresses and shift to new locations in time before they are affected by anything detrimental.  One possible way to help with this could be to physically plant these species in further up niche's where they would thrive for the moment, however this could also be detrimental in that once they are there, it could potentially impact other species already living in the area by a decline in space and nutrients.