Monday, April 21, 2014

Chinese Tallow and Climate Change Effects on Lithobates sphenocephalus

            As we have seen, wetlands are incredibly delicate ecosystems that require constant maintenance and strict preservation guidelines to ensure its survival.  The Chinese tallow (Triadica sebifera) is an invasive tree species, notorious for taking over and replacing native wetland vegetation.  The leaf litter produced by this invasive species has been noted to decrease survival rates of native amphibians.  Anuran breeding cycles are highly directed by weather conditions.  Given that the invasive species is native to China; its leaf fall can be drastically affected by the varying climate, as well as the recent rising climate change. This study, done by Daniel Saenz, Erin Fucik, and Matthew Kwiatkowski, aimed to compare the effects of climate change on the leaf fall of the Chinese tallow, and in turn, determine the how the timing of said leaf fall alters the survival ability of Anuran populations.
                To conduct the study, the authors used pools to create five different levels of tallow leaf litter decomposition (20 pools each for 100 total pools) to simulate the differential timing of leaf fall.  The southern leopard frog (Lithobates sphenocephalus) was chosen as the subject due to its wide distribution across Texas, their area of focus.  L. sphenocephalus larvae were placed in the pools and their physiological conditions and survival rates were recorded.  The characteristics of the water such as pH, salinity levels, etc. were also recorded for each level of decomposition to see the chemical composition of the water played a factor. 
                The results showed that the pools with more decomposed leaf litter (levels 1,2 and 3) had a much higher tadpole survival rate than levels 4 and 5 that had leaf litter with little decomposition.  It was found that these two pools also had the lowest dissolved oxygen levels and the highest salinity levels.  The pH levels in all of the treatments were within the normal range of a wetland habitat in the area. 

                The authors of this study clearly demonstrated that climate change has a profound effect on Anuran species.  The delayed shedding of leaves due to the global temperature increase affects the breeding success of these species.  The leaves do not have enough time to decompose before it is time for the frogs to breed.  This results in a lower availability of oxygen for larvae to exploit, as well as higher saline levels which these larvae have yet to adapt to tolerate.  Apart from climate change, this study is a prime example of how devastating invasive species can be to native populations.  The native species have not been given a gradual introduction to which they can adapt, rather the introduced species abruptly take over the habitat, not giving the native species enough time to cope with and adapt to the changes.  This study comparing invasive species and climate change to native species gives the general public insight into how our daily lives have an impact on all living things.  Carelessly introducing species has the potential to wipe out a common species that we see on a daily basis.  Those species that cannot outcompete with the invading species will ultimately diminish.  With regards to climate change, even the slightest increase (which we may not deem significant) can, unbeknownst to us, drastically impact other species.  Every decision we make has a consequence.  


-Article published in Web of Science

1 comment:

Allison Welch said...

Very interesting article. It's fascinating (and troubling) that frogs can be harmed by an invasive plant interacting with climate change. I wonder if this complex interaction could have been predicted ahead of time?