The Effects of Climate Change on Temperate Rain Forests in Southeastern Alaska

            The article I chose to outline the effects of climate change can be found here: http://www.fs.fed.us/pnw/sciencef/scifi149.pdf

            Research conducted by the US Forest Service at their station in Southern Alaska over the past 13 years has highlighted a number of trends that will most likely continue as our climate continues to change.  These changes will have numerous implications on the way these forests are viewed and managed, as species ranges begin to shift.

            One trend that could have potentially positive effects on the temperate rain forest ecosystems as well as globally is an overall increase in biomass within the unmanaged forests found in Alaska.  In higher elevation areas within the range, there have been up to 8 percent increases in total biomass.  This is no small change; the amount of additional biomass in the Chugach National Forest from the past 13 years annually stores an equivalent amount of carbon to the emissions of 500,000 passenger cars over the same period of time.  While there are most likely multiple causes at play for such a large shift, the most notable is the temperature change that has occurred in these ecosystems over the duration of the study.  The average annual temperatures of Alaska’s temperate rain forests have risen 2.7° over the past 50 years.  Even though a shift of two degrees may not look particularly noteworthy, such a change would extend the growing season in these areas while simultaneously allowing trees to grow for more of the year at higher elevations.

            Another interesting effect that the climate change has brought to the temperate rain forests is a slight shift in biomass between tree species.  Some species have been much more capable than others in terms of adapting to the change in growing seasons, as well as adapting to competition from new species.  The species that has made the most notable living-tree biomass gains during this period is the Western redcedar, as it gained approximately 4.2% additional biomass over the period of study.

Another tree that was expected to thrive with the changing climate conditions was the western hemlock.  One of the most abundant trees in Pacific Northwest temperate rain forests, the stands in Southern Alaska are quickly becoming threatened by the expanding range of dwarf mistletoe.  This species of mistletoe is a parasite that affects many conifer species across North American forests by taking water and nutrients from their hosts.  Using climate envelope analysis, the Forest Service has predicted a growth in dwarf mistletoe habitat over the next 100 by a staggering 375-750%, which would offset any potential western hemlock habitat increases by a large margin.

With change on the horizon, the management of these forests will be important for numerous reasons.  As the climate slowly gets warmer, these temperate rain forests will become more productive in terms of live biomass, making such areas incredibly useful in terms of carbon sequestration.  It will also be important to consider how to slow the spread of dwarf mistletoe, as it has the ability to decrease the abilities of numerous tree species in these forests in terms of growth and vitality.  As our climate warms, it can be expected that temperate rain forests such as these will be counted on to adapt and continue to grow to allow for the additional carbon sequestration that might be lost in tropical zones.

Why Ecosystem Ecology?

            As an overall discipline, ecology is something that has always interested me.  The manner in which we, and all organisms for that matter, interact with our environment is something that will always control the human race’s ability to grow and survive as a species.  In the past, we have been able to use the land to create tools and transition from hunter-gatherer societies to those based on agriculture.  It will be equally as fascinating to see how we attempt to transition our current food systems into something that can be sustained into the future while still providing for our burgeoning population.

            Ecosystem ecology is refreshing in the sense that there are systems in the world that don’t entirely revolve around people.  While we do impact them significantly, humans are just one of millions of species that play a role in all-encompassing food and energy cycles.  Additionally, there are aspects of ecosystems that humans have no control over; weather plays an extremely important role in the livelihood of billions of people worldwide.  The idea that humans as a whole are part of something way bigger than our daily lives is something that I find really intriguing. 

            This being said, humans are in an unfortunate position of power, as we did not take the limited nature of our most heavily utilized resources and their effects on the global carbon cycles into account when forming our societies.  Many people get too wrapped up in their own societal communities and lose touch with nature and all of the wonders that it has to offer.  The proverbial crossroads are inching closer and closer, and it seems safe to say that millions of people wouldn’t even notice if we had passed them years ago.

            I hope to gain numerous things from this class.  First, some hope for the future would be nice; as someone who has taken numerous natural resource classes, I have listened to many doom and gloom lectures and read tons of articles that paint a terrifying picture of our current path as a society and our general unwillingness to change.  Second, I would love to see how natural ecosystems affect humans, as opposed to vice versa.  At this point, I can safely say that we haven’t been the greatest influence on other organisms on the planet, but it would be interesting to see how they have affected us.  Lastly, I want to have a greater understanding of the processes that affect the abiotic features of global ecosystems and how we influence them.