## 4 Discussion
### Non-Timber Harvest Influences  
_CR_ can be influenced by water temperature [29,55]. [PERSON] _et al._[29] found a strong positive correlation between _CR_ and temperature, concluding that with a 5 \({}^{\circ}\)C warming in global temperature, increased _CR_ would lead to a near doubling of global stream carbon emissions to the atmosphere. Unlike the findings of [PERSON] _et al._[29], no particularly strong correlation between daily averages of water temperature and rates of _CR_ at our study site was found, although this may be due to the very different climatic and stream morphological conditions; our study area is characterized by a humid subtropical climate, while the study by [PERSON] _et al._[29] was conducted in a cold tundra region. Central Louisiana has a mild winter and the temperature of Turkey Creek is mostly between 15 and 25 \({}^{\circ}\)C throughout the year. The effect of temperature on our observed rates of _CR_ cannot be separated from seasonal physical and chemical variations (e.g., leaf emergence, nutrient fluctuations) as [PERSON] _et al._[29] were able to do by having simultaneous data from both a cold stream and a stream influenced by geothermal heat.  
In addition to the possible temperature effects, _CR_ has been shown to be influenced by dissolved organic carbon, and organic carbon bound up in the benthic stream sediment [55]. In a study investigating sediment respiration in the Hubbard Brook Experimental Forest, [PERSON] [55] found that both water temperature and water column dissolved organic carbon played roles in determining rates of respiration, though neither was as influential as the type of organic carbon in the bentnos.  
[PERSON] [55] found that forested streams generally acquire their organic matter from woody debris and other terrestrial inputs that lead to a higher fiber content and a slower breakdown than in systems that receive most of their organic carbon from autochthonous production, such as lakes and estuaries. Our results agree with his findings, as there appeared to be high quantities of woody debris in the stream channel of Turkey Creek (field observations), although rates of _CR_ were relatively low (\(\leq\)2 g O\({}_{2}\) m\({}^{-2}\) day\({}^{-1}\) for 81% of the time at N1 and 87% of the time at N2 _CR_).  
Other studies have found that seasonal effects play a role in determining rates of _GPP_ and _CR_[56, 57]. In a Danish river metabolism study conducted by [PERSON] _et al_. [56], productivity varied seasonally much in the same way that our results showed; annually, the authors reported minimum rates of primary productivity in the winter, with the maximum occurring in early summer. Their study also found fall and spring to be \"transitional periods\" between the highest productivity, in the summer, and the lowest, in the winter. A study by [PERSON] [57] found that seasonal effects could account for as much as 50% of metabolic variation. Mean rates of _CR_ and _GPP_ in Turkey Creek peaked in the spring and summer, respectively. This range of months, from March through August, has a greater photoperiod than September through February in the northern hemisphere. Another factor possibly acting alone or in conjunction with daylight hours would be water temperature, although the correlation between daily-averaged water temperature and metabolic rates was not seen in Turkey Creek.